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Long-Term Dentoskeletal Changes with the Bionator, Herbst, Twin Block, and MARA Functional Appliances
Abstract
To determine if the long-term dentoskeletal changes in patients treated with tooth-borne functional appliances were comparable to each other and to matched controls.
The experimental sample consisted of 80 consecutively treated patients who were equally divided into Bionator, Herbst, Twin Block, and mandibular anterior repositioning appliance (MARA) groups. The control group comprised 21 children with untreated skeletal Class II malocclusions. Lateral cephalograms were taken for the treated group at T1 (initial records), T2 (completion of functional therapy), and T3 (completion of fixed appliance therapy). A repeated measure analysis of variance (ANOVA) was used to assess the differences between and within groups. If ANOVA results were significant, Tukey-Kramer tests were used to determine where the significant differences occurred.
(1) Temporary restriction of maxillary growth was found in the MARA group (T2-T1). (2) SNB increased more with the Twin Block and Herbst groups when compared with the Bionator and MARA groups. (3) The occlusal plane significantly changed in the Herbst and Twin Block groups. (4) The Twin Block group expressed better control of the vertical dimension. (5) The overbite, overjet, and Wits appraisal decreased significantly with all of the appliances. (6) The Twin Block group had significant flaring of the lower incisors at the end of treatment. (7) Over the long-term, there were no significant soft tissue changes among treated and untreated subjects.
No significant dentoskeletal differences were observed long-term, among the various treatment groups and matched controls.
... One reason for this could be that the patients experienced a larger degree of posterior rotation of the mandible. This rotation would decrease the SNB angle and increase the lower anterior face height, which was observed in the present study; the increase in total anterior face height and lower anterior face height are common findings after functional appliance therapy, as previously described [42,43]. As presented in the results, in the FAG, a mean overjet reduction of about 7 mm was seen, which corrected the increased overjet and left all subjects with an overjet smaller than 3 mm. ...
... A retroclination of the upper central incisors and a proclination of the lower central incisors in the FAG was also observed. Both results are in accordance with earlier studies [43,44]. ...
... With this growth adaptation, the patients in the FAG nearly caught up with the controls, only lacking less than 2 mm mandibular length. Similar trends were noted by Siara-Olds et al. [43] and Baccetti et al. [18]. These changes indicate that patients treated with removable functional appliances experience more growth of the mandible compared to a treated control group [48]. ...
Background: The aim was to assess three-dimensionally mandibular and maxillary changes in growing Class II patients treated with removable functional appliances followed by fixed appliances. Methods: Twenty-four Class II patients (age range: 9 to 14, mean: 12.1 ± 1.1 years) treated with removable functional appliances followed by fixed appliances (functional appliance group—FAG) were retrospectively selected and compared to an age-matched control group (CG) treated with fixed appliances only. To be included in the study, pre- and post-treatment CBCT scans had to be available. The CBCTs were used to analyze, in 3D, the changes following treatment and growth. Results: Before treatment, overjet (FAG: 9 mm ± 2.8 (mean ± standard deviation); CG: 4 mm ± 1.7), ANB (FAG: 5.7° ± 2.0; CG: 3.2° ± 1.4), and effective mandibular length (FAG: 113.0 mm ± 4.1; CG: 116.6 mm ± 5.9) were statistically significantly different between the two groups. After treatment, overjet (FAG: −6.8 mm ± 2.8; CG: −1.8 mm ± 1.8) and effective mandibular length (FAG: 6.3 mm ± 2.6; CG: 3.9 mm ± 2.6) statistically significantly changed. There was a significant difference in the treatment effect between the FAG and the CG in overjet, ANB, and effective mandibular length. Conclusions: The results indicate that functional appliances are effective in correcting Class II malocclusions. The growth modification in the FAG resulted in an increase in mandibular length. Yet, the final length of the mandible in the FAG was smaller when compared to the CG.
... In the TG longitudinal evaluation (Table 3), upper lip retrusion (E line-Ls) was found at Stage I, change that remained unchanged at Stages II and III. Similar (Pancherz et al., 1994) and different (Siara-Olds et al., 2010) findings have been reported by previous investigations. Concerning the RVL, the upper lip showed no significant changes between T1, T2 ...
... In the TG longitudinal evaluation (Table 3), the lower lip showed no changes in relation to E line between T1, T2 and T3, in agreement with a previous investigation (Siara-Olds et al., 2010). However, there was retrusion between T1 and T4, corroborating another previous investigation (Pancherz et al., 1994). ...
... This fact may explain the lack of difference in nasolabial angle in the present investigation, since there was no difference in upper lip position between the groups at Stage I in relation to the RVL. In the TG longitudinal evaluation, the nasolabial angle remained unchanged between T1 and T4, in agreement with a previous investigation (Siara-Olds et al., 2010). ...
The present investigation aimed to evaluate, by cephalometric analysis, the soft tissue profile changes in adolescents with Class II Division 1 malocclusion, treated with Herbst appliance (Stage I) and fixed appliances (Stage II), followed-up for an average of 4 years (Stage III). The adolescents were divided into two groups: treated group (TG) - 33 adolescents with Class II malocclusions (17 boys and 16 girls) consecutively treated with Herbst appliance and fixed appliances; control group (CG) - 28 adolescents (13 boys and 15 girls) with untreated Class II malocclusions. Lateral cephalograms were obtained immediately before (T1) and after (T2) Herbst treatment, after fixed appliances (T3), and on average, 4 years after orthodontic treatment. Intergroup comparison was evaluated by t or Mann-Whitney tests. The TG was evaluated by analysis of variance followed by Tukey test or Friedman test followed by Dunn’s test. Compared to the CG, the TG showed significant favorable changes at Stage I: decrease in facial convexity, upper lip retrusion, lower lip protrusion, improvement of soft tissue pogonion and increase in mentolabial angle. The total posttreatment period (T2-T4) of the TG showed: increase in H line-Prn, and upper and lower lips retrusion, while the others variables remained stable. This study suggests that Herbst therapy improved features of soft tissue facial profile, which were maintained after fixed appliances and for an average of 4 years posttreatment, although the convex facial characteristic has prevailed.
... Class II malocclusion is one of the most prevalent orthodontic problems, with mandibular retrognathism presenting in most of the cases [16][17][18][19]. For Class II treatment, a variety of appliances have been used over the years in order to enhance mandibular growth by posturing the mandible in a forward position [16,20]. ...
... In a systematic review by Cozza et al., it is reported that in two-thirds of the included studies, clinically significant supplementary mandibular elongation was achieved, with Herbst appliance and Twin Block being the most efficient devices [16]. The Herbst and the Twin Block appliances have also been reported as the most effective functional appliances by several studies [18,21,23]. Santamaría-Villegas et al. found significant increase in mandibular length concluding in the effectiveness of functional appliances in mandibular advancement, in agreement with previous studies [18,20,25,26]. ...
... The Herbst and the Twin Block appliances have also been reported as the most effective functional appliances by several studies [18,21,23]. Santamaría-Villegas et al. found significant increase in mandibular length concluding in the effectiveness of functional appliances in mandibular advancement, in agreement with previous studies [18,20,25,26]. ...
The treatment of Class II malocclusion due to mandibular retrognathia is one of the most common challenges met in orthodontic practice. When it comes to a growing patient, functional appliances are the optimal way to achieve growth modification by enhancing mandibular growth. Clear aligners have been part of the orthodontic treatment for several decades but until recently they were only used to correct mild malocclusions. In 2017, Align Technology introduced the Invisalign with Mandibular Advancement Feature (IMAF) which replicates the action of functional appliances. As this device is new to clinical practice, there is limited literature on its clinical efficiency. This case report describes the orthodontic management of a 12-year-old male patient having skeletal Class II malocclusion due to mandibular retrognathia. As the patient was experiencing active growth, the IMAF appliance was chosen for his treatment. The IMAF appliance appears to be successful in the treatment of Class II malocclusion with mandibular retrognathism in a growing patient. As with all functional appliances, the correction of the malocclusion is a result of both skeletal and dental effects and the IMAF presents the advantage of producing less proclination of the lower incisors compared to other functional appliances.
... In our study, U1-RL1 showed a significant increase, which was in accordance with the findings of Oztoprak et al., [9] Henriques et al., [19] McNamara et al., [17] and Schaefer et al. [16] The extrusion of maxillary central incisors may be due to the fact that the distal force applied by the appliance is more toward the occlusal than the center of resistance of the entire maxillary arch, and the resultant torque has a clockwise direction and causes backward and downward movement of the maxillary incisors. [9] Overbite showed a significant reduction in our study, which was in line with the findings of Hanandeh and El-Bialy, [8] Henriques et al., [19] Franchi et al., [14] and Siara-Olds et al. [28] The reason may be the intrusion and protrusion of mandibular incisors or even extrusion of mandibular molars. In addition, these changes may be related to load application by the appliance, causing forward movement of the mandible along the lingual inclination of the maxillary incisors. ...
... In addition, these changes may be related to load application by the appliance, causing forward movement of the mandible along the lingual inclination of the maxillary incisors. [9,26,28] This was in agreement with another study on Class II/1 malocclusion of patients in the postpubertal growth period, in which SUS2 was successful in advancing the mandible as well as increasing the facial height, inhibiting the maxilla's forward growth, decreasing the nasolabial and interincisal angles, proclining the incisors, and causing a clockwise rotation of the OP. [29] During T0-T2, significant changes were noted in Co-Gn, B-RL2, B-RL1, Ar-Pog, ANB, SNB, SN/MP, SN/OP, Pog-NB, A-RL2, Co-A, PNS-RL1, Jarabak ratio, and S-Ar/Ar-Go skeletal indices. ...
... [9,21] Change in A-RL2 and Co-A skeletal indices may be due to the change in the position of point A in the sagittal plane due to the great change in the longitudinal axis of the maxillary incisors in this phase. [28] Difference in PNS-RL1 might be partially explained by the small sample size and measurement errors. ...
Background:
Since there is no comparison between the effects of Sabbagh Universal Spring 2 (SUS2) appliance on Class II division 1 (div 1) versus Class II division 2 (div 2) patients, this preliminary study was conducted to comparatively assess, for the first time, the effects of SUS2 on 34 cephalometric indices in Class II/1 versus Class II/2 patients.
Materials and methods:
This before-after clinical trial was conducted on 75 observations of 25 patients with Class II malocclusion, of whom 12 (9 females and 3 males) had Class II div 1 and 13 (11 females and 2 males) had Class II div 2 malocclusion diagnosed by clinical examination and cephalometric assessment. The growth level of all patients had to be CS3 according to the cervical vertebral maturation index. Lateral cephalographs were obtained before treatment (T0) and the patients underwent fixed orthodontic treatment. Lateral cephalographs were taken again (T1) and the patients received SUS2 functional appliance for 6 months. A final lateral cephalograph (T2) was then obtained. Thirty-four dentoskeletal indices were measured on lateral cephalographs, and changes in indices over time were determined and compared using repeated-measures analysis of variance, post hoc test, and t-test (α =0.05).
Results:
Within-group comparisons showed significant changes over time in SNB, sella nasion (SN)/occlusal plane, ANB, articular (Ar)-pogonion (Pog), L1-NB, condylion (Co)-gnathion, S-Ar/Ar-G, B-RL1, L1/nasion-point B (NB), U6-RL2, incisor mandibular plane angle, overjet, overbite, U1-RL1, and L1-RL2 (P < 0.05). The two groups were significantly different in terms of changes occurred to overjet, interincisal angle, U1/RL1, L1-NB, U1-NA, U1/NA, the Jarabak ratio, A-RL1, U1/SN, Pog-NB, and Co-A (P < 0.05).
Conclusion:
The SUS2 showed therapeutic efficacy for both Class II div 1 and 2 patients although it more commonly caused dentoalveolar rather than skeletal changes. Our study showed no considerable difference between the two groups after using this appliance, and the difference in the Jarabak ratio indicated better long-term growth pattern of div 2 patients and its conformity with camouflage treatments (mild or moderate Class II).
... Cochrane risk of bias assessment method was applied to evaluate the quality of the available studies (Table 1). [8] researched to ascertain if the long-term dento-skeletal alterations in patients receiving tooth-borne functional equipment could be compared to matched controls and each other. Children with untreated class II skeletal malocclusion (twenty-one children) constituted the control group. ...
... The Twin block group revealed the most decrease in upper incisor proclamation, followed by the Bionator group, while the Bass appliance group showed the least. Other Twin block investigations obtained similar results [5,8,17]. ...
... A wide range of functional appliances have been introduced to stimulate mandibular growth and correct the bite by forward positioning of the mandible in children who are in the growth and development stage. [4][5][6] One of the representative appliances, the ...
... 3. Existence of bone islands, osteomas, periapical cysts, root resorption in the tooth movement area. 4. Concurrent systemic diseases, metabolic syndromes or other special needs. ...
Introduction
Class II treatment with mandibular retrusion often involves the Herbst appliance due to its efficiency and low requirement of cooperation. Despite its advantages, it causes side effects concerning the occlusal plane and pogonion in terms of clockwise rotation that hinder the desired mandibular advancement for hyperdivergent patients. In this study, we will use a newly designed Herbst appliance, and a protocol that is accompanied by TADs for vertical control to avoid maxillary clockwise rotation. We hypothesise that the effect of the Herbst appliance with the vertical control approach will be beneficial for maintaining or even decreasing the skeletal divergence in hyperdivergent class II patients compared with conventional Herbst treatment.
Methods and analysis
This study is a randomised, parallel, prospective controlled trial that will study the efficacy of Herbst with or without vertical control in children with hyperdivergent skeletal class II malocclusion. A total of 44 patients will be enrolled and randomised in a ratio of 1:1 to either Herbst treatment or Herbst treatment with vertical control. Participants will be recruited at the Shanghai Stomatological Hospital, Shanghai, China. The primary endpoint is the change in the angle indicating the occlusal plane and Sella-Nasion plane from baseline (T0) to the primary endpoint (T2) on cephalometric measurements by lateral X-ray examination. Important secondary outcomes include the root length of the anterior teeth, and the assessment score of the Visual Analogue Scale Questionnaire, etc. Safety endpoints will also be evaluated.
Ethics and dissemination
This study has been approved by the ethics committee of the Shanghai Stomatological Hospital (Approval No. (2021) 012). Before enrolment, a qualified clinical research assistant will obtain written informed consent from both the participants and their guardians after full explanation of this study. The results will be presented at national or international conferences and published in peer-reviewed journals.
Trial registration number
ChiCTR2100049860, Chinese Clinical Trial Registry
... Most previous studies on treatment with a functional appliance followed by a fixed appliance have investigated cases without extractions [15,16]. However, extractions are very common during fixed appliance treatment in Asian populations due to the amount of crowding and protrusion of the facial profile [2,17]. ...
... In the two-phase group, the lower incisors were significantly proclined during T1-T2, resulting in an increase in the L1/APog distance of 3.10 mm and in L1/MnPl of 5.98 • . Such changes may be attributable to the mesially directed force of the functional appliance on the mandibular dentition [16]. In the T2-T3 phase, the lower incisors retracted, leading to a reduction in the L1/APog distance of 3.55 mm and in L1/MnPl of 9.69 • . ...
Objectives:
Fixed appliance treatment with premolar extraction is often required after functional appliance treatment to relieve crowding and improve facial aesthetics in the Asian population. This study compared the treatment efficacy of two approaches for treating Class II division 1 malocclusion: functional appliance followed by fixed appliance treatment with extraction (two-phase) and fixed appliance treatment with extraction (one-phase).
Methods:
Growing skeletal Class II patients with an overjet of ≥6 mm treated with two- or one-phase orthodontics were included. The two groups consisted of 29 patients (mean age = 12.55) and 30 patients (mean age = 12.72), respectively. Pre- and post-treatment cephalograms were analysed and skeletal, dental, and soft tissue characteristics were compared using independent t-tests. Treatment changes were compared within and between groups using paired and independent t-tests, respectively. Stepwise discriminant analysis was performed to identify the variables that best predicted pre-treatment group allocations.
Results:
At baseline, there were no significant between-group differences in age, gender, cervical vertebral maturation, or overjet. The two-phase group had greater Class II skeletal discrepancies (ANB angle and Wits appraisal). During treatment, the two-phase group showed greater improvements in intermaxillary relationship and facial convexity compared with the one-phase group (p < 0.01). Following treatment, the two-phase group had a greater L1/APog distance (p < 0.05). Facial convexity and Wits appraisal were identified as parameters significantly influencing the clinicians' decision to use a one- or two-phase approach.
Conclusions:
In patients requiring premolar extraction, two-phase (vs. one-phase) treatment produced greater improvements in the intermaxillary relationship and facial convexity.
... 20 The efficacy of the MARA on mandibular growth has been evaluated in numerous studies, but contradictory results have been reported. [21][22][23][24] Some studies found significant mandibular dimensional changes with MARA, 21,23,25 whereas others found no significant differences between MARA and untreated control subjects with Class II malocclusion. 21,24,26 Although the advantages, effectiveness, and dentoalveolar and skeletal changes of fixed functional appliances are well defined through scientific research, there is still a lack in the literature regarding the effects of Forsus and MARA. ...
... [21][22][23][24] Some studies found significant mandibular dimensional changes with MARA, 21,23,25 whereas others found no significant differences between MARA and untreated control subjects with Class II malocclusion. 21,24,26 Although the advantages, effectiveness, and dentoalveolar and skeletal changes of fixed functional appliances are well defined through scientific research, there is still a lack in the literature regarding the effects of Forsus and MARA. Therefore, this study aimed to compare the skeletal, dentoalveolar, and soft-tissue effects of the Forsus FRD and the MARA for Class II malocclusion correction. ...
Introduction:
Fixed functional appliances have been used to treat Class II malocclusion by a huge number of professionals. This retrospective study aimed to analyze the effects of the Forsus fatigue-resistant device and compare the findings with a well-matched group treated with the mandibular anterior repositioning appliance (MARA).
Methods:
The Forsus group was composed of 14 patients at an initial mean age of 12.4 ± 1.3 years, treated with the Forsus fatigue-resistant device followed by a fixed orthodontic appliance. The MARA group comprised 18 patients at an initial mean age of 12.1 ± 1.3 years, treated with MARA followed by fixed orthodontic appliances. The untreated control group consisted of 14 patients matched with the other groups. Posttreatment changes were calculated as T1 - T2. Intergroup comparisons regarding treatment changes were performed using repeated-measures analysis of variance followed by Tukey's test.
Results:
During treatment, the Forsus group showed a statistically significant decrease in maxillary protrusion and maxillomandibular sagittal discrepancy in the control group. The MARA group showed significantly greater retrusion of maxillary incisors than the Forsus and the control group. Overjet decreased significantly more in the treated groups in relation to the control group. Molar relationship improved significantly more in both treated groups, and both showed more correction than the untreated control group.
Conclusions:
The Forsus and MARA associated with fixed appliances effectively corrected the Class II malocclusion, mostly using dentoalveolar changes and maxillary growth restriction.
... The effects of the MARA on mandibular growth were previously evaluated in several studies; nonetheless, the findings are inconsistent. 13,14 Some studies reported significant changes in the mandibular dimensions, whereas others demonstrated no significant differences compared with a control group. [14][15][16] It is speculated that the discrepancy between these studies could be explained by the difference in the statistical analysis used and differences in the level of significance chosen by the authors. ...
... 13,14 Some studies reported significant changes in the mandibular dimensions, whereas others demonstrated no significant differences compared with a control group. [14][15][16] It is speculated that the discrepancy between these studies could be explained by the difference in the statistical analysis used and differences in the level of significance chosen by the authors. 15 Patient compliance is essential in deciding on a removable or fixed functional appliance. ...
Introduction
The objective of this study was to compare the cephalometric changes in Class II Division 1 malocclusion patients treated with the Twin-block (TB) and the mandibular anterior repositioning appliance (MARA).
Methods
This retrospective study was performed with 132 lateral cephalograms of patients with Class II malocclusion divided into 3 groups: a TB group comprised 21 patients with mean initial and final ages of 10.59 and 11.97 years, respectively, treated for a mean period of 1.38 years; a MARA group comprised 21 patients with mean initial and final ages of 11.98 and 13.20 years, respectively, treated for a mean period of 1.22 years; and a control group included 24 subjects with untreated Class II malocclusion with mean initial and final ages of 10.55 and 12.01 years, respectively, observed for a mean period of 1.46 years. Cephalometric intergroup comparisons regarding the treatment changes (T2 − T1) were performed with the analysis of covariance, followed by Tukey tests.
Results
Both appliances demonstrated significant restriction of the maxilla and improvement of the maxillomandibular relationship. The MARA produced a significantly greater amount of labial tipping and protrusion of the mandibular incisors than the other groups. The TB showed significant extrusion of the mandibular incisors and molars compared with MARA and control, respectively. Both treated groups reduced the overjet and overbite. The MARA presented a significantly greater reduction in the molar relationship than the other groups.
Conclusions
The appliances showed a headgear effect on the maxilla and effectively changed Class II cephalometric parameters through a combination of skeletal and dentoalveolar effects. TB showed a greater increase in LAFH. MARA promoted greater labial tipping and protrusion of the mandibular incisors.
... 14,15 These findings corroborate with other types of functional appliances, which present significant differences during the orthopedic phase compared with untreated controls, but most of these differences disappeared in the long term. 16 Evaluation of long-term stability presents remarkable clinical relevance because they bring more certainty to a specific treatment, especially regarding its prognosis. Although some studies focused on the long-term effects of some fixed functional appliances, no study has reported this evaluation for the CBJ. ...
... Significant labial tipping and protrusion of the mandibular incisors are commonly observed during the fixed functional appliance phase. 13,16 These effects remain or even increase as a result of the associated comprehensive treatment with fixed appliances. 6,38 In accordance, our results with the CBJ, followed by fixed appliances, showed slight labial tipping and protrusion during treatment that remained stable in the follow-up stage, as previously demonstrated 25 (Table II; Fig 5). ...
Introduction
This study aimed to assess the long-term stability of Class II malocclusion treatment with the Cantilever Bite Jumper (CBJ) after 13 years of follow-up.
Methods
The treatment group comprised 10 Class II Division 1 malocclusion patients treated with the CBJ, followed by fixed appliances, analyzed at 3 stages: pretreatment (aged 11.56-14.32 years), posttreatment (aged 16.34-19.58 years), and long-term posttreatment (aged 29.04-32.33 years). The control group included 15 subjects with normal occlusion. Intragroup treatment changes comparison was performed with repeated measures and analysis of variance followed by Tukey tests. Intergroup comparisons regarding the long-term posttreatment changes were performed with t tests.
Results
No statistically significant relapse was observed during the follow-up period. Morever, the treated group presented a significantly smaller increase in lower anterior facial height and greater retrusion of the lower lip than the control group in the posttreatment period.
Conclusions
Treatment with the CBJ, followed by fixed appliances, is a stable alternative for Class II Division 1 malocclusion correction. The dentoskeletal and soft-tissue changes obtained during treatment remained stable in the long-term posttreatment follow-up.
... For the second phase of the treatment (T2-T1 period), the changes obtained by the Herbst appliance therapy remained unchanged despite a slight reduction. In agreement with previous follow-up studies (3,32,33), the stable treatment effects after the Herbst therapy may be explained by the reports that the main treatment effect occurs due to condyle remodelling rather than a change in temporary condyle position (4). Besides, the condyle can no longer return to its original size and shape after Herbst removal (3), whereas normal growth-related maturity continues after treatment (3,32,33). ...
... In agreement with previous follow-up studies (3,32,33), the stable treatment effects after the Herbst therapy may be explained by the reports that the main treatment effect occurs due to condyle remodelling rather than a change in temporary condyle position (4). Besides, the condyle can no longer return to its original size and shape after Herbst removal (3), whereas normal growth-related maturity continues after treatment (3,32,33). ...
Objectives
This controlled study aimed to evaluate the effects of Herbst therapy on the trabecular structure of the condyle and angulus mandible using fractal dimension analysis (FD-A) accompanied by skeletal cephalometric changes.
Material and method
The panoramic and cephalometric radiographs of 30 patients with skeletal Class II malocclusion treated with the Herbst appliance (C II-H group, mean age: 15.23 ± 1.08), 30 patients with skeletal Class II malocclusion that received fixed orthodontic treatment (C II-C group, mean age: 15.73 ± 1.38), and 30 patients with skeletal Class I malocclusion (C I-C group, mean age: 15.90 ± 1.30) were selected. FD-A was performed on the superoposterior region (C-SP) and centre of the condyles (C-C) and the mandibular angulus (Ang) on the panoramic radiographs taken at the pretreatment (T0), intermediate stage of treatment (T1), and posttreatment (T2) timepoints just like cephalometric analysis.
Results
Herbst therapy provided a statistically significant increase in SNB, ANS-Me, Na-Me, S-Go, Co-Gn and a decrease in ANB and overjet (P < 0.05). All skeletal changes remained stable during the fixed appliance treatment after Herbst. The FD values in C-C increased (P < 0.05), and C-SP values decreased (P < 0.05) during Herbst therapy, while after removal of the Herbst appliance, no significant change was observed despite an increase in C-SP. The Ang value did not change during Herbst treatment, but then increased significantly (P < 0.05). There was no significant change in the FD values of the C I-C and C II-C groups at any stage of treatment. The C-C and C-SP changes at T1–T0 period, C-SP and Ang changes at T2–T1 period, and C-C, C-SP, and Ang values at T2–T0 period were found higher in C II-H group compared with the C II-C group significantly (P < 0.05).
Conclusion
Herbst therapy changed the trabecular structure of the condyles in different directions at the superoposterior and central regions of the condyles, while the structural complexity of the angulus mandible, which did not change during the Herbst treatment, increased during the fixed orthodontic treatment after Herbst.
... Como 2⁄3 dos pacientes classe II apresentam o retrognatismo mandibular, vários protocolos de tratamento ortopédico visando avançar a mandíbula têm sido descritos na literatura 2-3 . Dentre esses protocolos, destacam-se os aparelhos de avanço mandibular removíveis, como o bionator e o Frankel, e os aparelhos protratores fi xos, como o Herbst, APM, Forsus, Twin Force, Power Scope entre outros [4][5][6] . ...
... Para se mensurar os efeitos de cada modalidade de tratamento, alterações na relação molar e no trespasse horizontal são normalmente mencionadas, assim como alterações cefalométricas esqueléticas e dentoalveolares [4][5][6][7][8][9][10] . Os efeitos esqueléticos induzidos por aparelhos de avanço mandibular mais citados são alterações no comprimento mandibular (Co-Gn +/-2,2 mm) em pacientes classe II tratados comparados a grupos-controle não tratados. ...
RESUMO
A má-oclusão esquelética de classe II apresenta como principal
fator etiológico o retrognatismo mandibular. O perfi l facial convexo
característico dessa má-oclusão associado às alterações oclusais,
trespasse horizontal aumentado e excesso de vestibularização
dos incisivos superiores pode contribuir para uma importante
demanda por tratamento desses pacientes. Vários protocolos de
tratamento ortopédico são descritos na literatura para o tratamento
de pacientes em crescimento, embora esses aparelhos ortopédicos
visem à correção das relações esqueléticas, os maiores efeitos são
os dentoalveolares, como a inclinação para palatino dos incisivos
superiores e inclinação para vestibular dos incisivos inferiores.
Essas alterações podem infl uenciar o perfi l facial dos pacientes
tratados, uma vez que os tecidos moles estão apoiados nos dentes e
esqueleto. Alterações de tecido mole contribuem para a diminuição
da convexidade do perfi l e apesar dessas alterações serem suaves
e variáveis, parece que os pacientes e leigos tendem a apresentar
uma percepção diferente dos ortodontistas em relação a esses
efeitos. Os pacientes se enxergam de frente, e pouco impacto na face
decorrente da má-oclusão de classe II é observado na visão frontal,
o que poderia explicar esse julgamento menos crítico dos perfi s
de pessoas tratadas. Nesse sentido, os ortodontistas deveriam
entender a visão dos pacientes durante o planejamento dos casos,
procurando atender suas expectativas. Em casos de pacientes
classe II sem queixa facial e quando a desarmonia é tratável
ortodonticamente, deve-se sempre priorizar a correção oclusal
aceitando os limites da nossa abordagem de tratamento na face.
... ___________________________________________________________ Revista UNINGÁ, Maringá -PR, n.29, p. 131-144, jul./set. 2011133 2000HAGGLUND;SEGERDAL, 2010;KINZINGER et al., 2002;SIARA-OLDS et al., 2010). ...
O tratamento da Classe II esquelética em pacientes após opico de crescimento puberal apresenta grandes dificuldadesprincipalmente no que diz respeito ao uso limitado dos aparelhosortopédicos e às limitações compensatórias inerentes ao tratamentoortodôntico convencional. Um correto diagnóstico com a identificaçãodos componentes esqueléticos e dentoalveolares responsáveis pela máoclusão associado à queixa e expectativa do paciente é essencial para queuma correção não-cirúrgica satisfatória seja alcançada. Assim sendo, esteartigo apresenta o tratamento não-cirúrgico de uma Classe II esqueléticaem uma paciente que se apresentava na fase pós-pico de crescimento pormeio de um aparelho ortopédico funcional fixo (Herbst-CBJ).
... Há redução da sobremordida, pois a mandíbula migra para frente e ocorre inclinações linguais dos incisivos superiores e foram atribuídas devido a pressão do arco labial (Siara-Olds et al., 2010). ...
Os aparelhos Twin Block e Bionator são aparelhos ortopédicos funcionais indicados para maloclusões de classe II. O passo mais importante para a confecção destes aparelhos é o registro da mordida em cera onde o paciente deve ser instruído a morder com a mandíbula mais à frente. A fase ideal para realizar o tratamento com os estes aparelhos é durante ou um pouco após o início do pico puberal. Como resultado do uso destes aparelhos é possível observar clinicamente resultados ortodônticos como retração e verticalização dos incisivos superiores e vestibularização dos dentes inferiores melhorando o overjet e melhora do overbite que ocorre durante a ativação destes, desgastando na oclusal do acrílico para ajudar o nivelamento da curva de spee. Houve controvérsia entre os resultados ortopédicos em relação ao crescimento mandibular, e sobre a restrição do crescimento maxilar.
... The lower incisors showed significant flaring (L1 to A-pog line) that may occur due to taking support from the lower six anterior teeth by covering them with thermoplastic material connected with the lower guiding surface that engaged to the upper advancement bar during mandibular advancement, so the resulted forces cause labial tipping of lower incisors. This outcome agreed with those of Cremonini et al. 18 who demonstrated F22 Young new appliance caused flaring of lower incisors and Siara et al. 19 reported the twin block group had significant flaring of the lower incisors at the end of treatment. ...
... The Twin block group expressed better vertical dimension control but had significant flaring of the lower incisors. 5 In this case, powerscope used for correction of class II malocclusion by utilizing remaining growth. Powerscope facilitate the forward and downward displacement of the mandible. ...
... Among tooth-borne functional appliances such as Bionator, Herbst, Twin Block appliance, and mandibular anterior repositioning (MARA) modalities; Twin Block showed better control of vertical dimension. 8 The plan of Twin Block treatment was to expect more horizontal than vertical growth; however, as shown in Table 1, the SN-MP angle increased 0.6 + between initial and 1 st stage treatment, which meant the mandible had been growing more vertically than horizontally. According to Ricketts analysis, facial axis angles are used to evaluate growth, and in this patient, the facial angle was less than 90 during each treatment phase. ...
... 25 Lower facial height also increased with twin block therapy, 16,17,19 but Nicole et al demonstrated good vertical control on mandibular plane angle with twin block appliance therapy as compared to Herbst, Bionator and MARA appliances. 26 Another study showed that after twin block treatment, there is significant increase in posterior facial height, total anterior facial height and lower anterior facial height by 3.4 mm,5.5 mm,4.4 mm respectively. Clinically significant rotation of mandible in clockwise direction resulting in decrease in overbite and increase in facial height which is beneficial in class II division 1 patients having deep bite and reduced lower anterior facial height. ...
Twin block appliance, a functional appliance used to correct skeletal malocclusions in growing patients. Ever since it was introduced by Clark, It has gained popularity for treating both class II and Class III malocclusions. In this article we will briefly discuss about role of twin block appliance in class II and Class III malocclusion treatment.
... Facial convexity and facial depth were evaluated at the skeletal level after patients had worn the functional mandibular appliances. Despite the fact that these appliances have a minimal effect on the upper jaw 19 , different studies 2,6,9,10,20 show a restriction of maxillary growth when orthodontic appliances such as Twin-block, Herbst or SBJA are worn. However, Gazzani et al. 11 , who also studied the effect exerted by SBJA, observed an advancement of point A at all the cervical stages analysed (CVS1-CVS4). ...
Aim:
To evaluate the effects produced by functional orthodontic appliances at dental and skeletal level in relation to the level of skeletal maturation in class II patients Study design: Longitudinal and observational study Patients selected for the study had been wearing Sander Bite Jumping Appliance (SBJA) for at least 12 months; they were first diagnosed (T1) with skeletal class II according to Ricketts' cephalometric analysis, and had had lateral cephalograms taken before and after orthopaedic treatment (T2). Variables studied at T1 and T2 were: facial convexity, inclination of the upper and lower incisors, and facial depth. Results were compared between T1 and T2 for each variable and in relation to cervical maturation stage (CVS) according to the Lamparski analysis. Statistical analysis was performed using Shapiro-Wilk, t-student, Analysis of Variance (ANOVA) and multiple comparison tests, taking as statistically significant a p-value <0.05.
Results:
A final sample of 235 patients was obtained. Statistically significant differences were found in the inclination of the mandibular incisors between T1 and T2 and among the different cervical stages when the functional appliances were placed in CVS1 (p = 0.000), CVS2 (p = 0.04) or CVS5 (p = 0.048). For the remaining variables, significant differences were also found between T1 and T2, but these differences were similar in all cervical stages.
Conclusions:
A significant proclination of the mandibular incisors was found when the functional appliance was placed during CVS1, CVS2, or CVS5. Time of placement of the functional appliances was not statistically significant for the remaining variables studied.
... Disorders of the balance between the tongue, cheeks and lips can affect the balance of the dental arch and surrounding soft tissues. Bionators can improve lip pressure against anterior teeth, guide the tongue to occupy the floor of the mouth and make contact with the palate, improve incisor contact relations, change the position of the mandible and improve the jaw relationship [3], [19], [20]. ...
Background: Class II malocclusion is a common condition. The most common clinical presentation is a mandibular deficiency. Treatment with functional devices is an option that can be used for the treatment of malocclusion. In an era of evolving treatments, Bionator is still widely used in clinical practice. Objective: The purpose of this systematic review was to analyze the effectiveness of the treatment of class II malocclusion with the Bionator device in the growth and development phase. Methods: Data collection was carried out by searching literature on article search sites, namely Pubmed, Cochrane, Wiley, Google Scholar and Science Direct which were published from 2011 to 2021. The search was carried out from March to April 2021. Data search was carried out systematically using the bionator keyword. malocclusion class II, orofacial muscles, growth and development. Results: After eliminating published articles, the title and abstract of each article in the analysis amounted to 132 articles, 106 articles were excluded. The full text articles from the exclusion results were re-analyzed and 16 articles were excluded. The text of the article is complete and meets the eligibility of as many as 10 articles. Conclusion: From all the studies reviewed, the Bionator device can improve class II malocclusion in children.
... Several varieties of functional appliances, removable appliances (activator, bionator, twin-block , frankel regulator) or fixed appliances (herbst appliance, mandibular advancement repositioning splint, mandibular protraction appliance, eureka spring, jasper jumper, churro jumper, mandibular anterior repositioning appliance), have been used for many years in the treatment of Class II Division 1 malocclusions to improve skeletal imbalances. [4][5][6] TBs are simple removable bite blocks with occlusal inclined planes which act as a functional appliance, designed for full-time wear. It was invented by Dr. William J. Clark in 1977, and since then, it has been a very popular functional appliance in the correction of malocclusion in growing patients. ...
... Facial convexity and facial depth were evaluated at the skeletal level after patients had worn the functional mandibular appliances. Despite the fact that these appliances have a minimal effect on the upper jaw 19 , different studies 2,6,9,10,20 show a restriction of maxillary growth when orthodontic appliances such as Twin-block, Herbst or SBJA are worn. However, Gazzani et al 11 , who also studied the effect exerted by SBJA, observed an advancement of point A at all the cervical stages analysed (CVS1-CVS4). ...
Aim: To evaluate the effects produced by functional orthodontic appliances at dental and skeletal level in relation to the level of skeletal maturation in class II patients.
Study design: Longitudinal and observational study.
Patients selected for the study had been wearing Sander Bite Jumping Appliance (SBJA) for at least 12 months; they were first diagnosed (T1) with skeletal class II according to Ricketts’ cephalometric analysis, and had had lateral cephalograms taken before and after orthopaedic treatment (T2). Variables studied at T1 and T2 were: facial convexity, inclination of the upper and lower incisors, and facial depth. Results were compared between T1 and T2 for each variable and in relation to cervical maturation stage (CVS) according to the Lamparski analysis. Statistical analysis was performed using Shapiro–Wilk, t-student, Analysis of Variance (ANOVA) and multiple comparison tests, taking as statistically significant a p-value <0.05.
Results: A final sample of 235 patients was obtained. Statistically significant differences were found in the inclination of the mandibular incisors between T1 and T2 and among the different cervical stages when the functional appliances were placed in CVS1 (p = 0.000), CVS2 (p = 0.04) or CVS5 (p = 0.048). For the remaining variables, significant differences were also found between T1 and T2, but these differences were similar in all cervical stages.
Conclusions: A significant proclination of the mandibular incisors was found when the functional appliance was placed during CVS1, CVS2, or CVS5. Time of placement of the functional appliances was not statistically significant for the remaining variables studied.
... The Twin block group expressed better vertical dimension control but had significant flaring of the lower incisors. 5 In this case, powerscope used for correction of class II malocclusion by utilizing remaining growth. Powerscope facilitate the forward and downward displacement of the mandible. ...
This case report demonstrates the efficacy of fixed functional Class II corrector Powerscope™ in the correction of Class II division 2 malocclusion. A patient having Class II division 2 malocclusion with retruded mandible was treated using Preadjusted-Edgewise MBT 0.022” prescription and fixed functional class II corrector appliance Powerscope™. Pre, mid, post- treatment and one year post-treatment follow up photographs, orthopantomograms and lateral cephalograms were taken. Cephalometric analysis was done. 8 months of fixed functional Class II corrector appliance PowerscopeTM wear obtained stable and successful results with improvement in facial profile, skeletal jaw relationship, and mild increase in IMPA. One year follow up record shows stable results achieved by fixed functional Class II corrector appliance PowerscopeTM
... The jaw epidemic is therefore a recent phenomenon and temporal and geographic correlation strongly suggests that it can be traced to changes in environmental factors due to agriculture and industrialization, but exactly what those factors are and how they operate remain uncertain. Indeed, environmental influences on skeletal growth are largely ignored by the orthodontic profession, which often accepts jaw skeletal development as genetic in nature, although the teeth themselves are recognized as subject to environmental influences (Proffit 1978, Tulloch et al. 1998, 2004, Dolce et al. 2007, Siara-Olds et al. 2010, Ehsani et al. 2015. ...
Contemporary humans are living very different lives from those of their ancestors, and some of the changes have had serious consequences for health. Multiple chronic "diseases of civilization," such as cardiovascular problems, cancers, ADHD, and dementias are prevalent, increasing morbidity rates. Stress, including the disruption of traditional sleep patterns by modern lifestyles, plays a prominent role in the etiology of these diseases, including obstructive sleep apnea. Surprisingly, jaw shrinkage since the agricultural revolution, leading to an epidemic of crooked teeth, a lack of adequate space for the last molars (wisdom teeth), and constricted airways, is a major cause of sleep-related stress. Despite claims that the cause of this jaw epidemic is somehow genetic, the speed with which human jaws have changed, especially in the last few centuries, is much too fast to be evolutionary. Correlation in time and space strongly suggests the symptoms are phenotypic responses to a vast natural experiment-rapid and dramatic modifications of human physical and cultural environments. The agricultural and industrial revolutions have produced smaller jaws and less-toned muscles of the face and oropharynx, which contribute to the serious health problems mentioned above. The mechanism of change, research and clinical trials suggest, lies in orofacial posture, the way people now hold their jaws when not voluntarily moving them in speaking or eating and especially when sleeping. The critical resting oral posture has been disrupted in societies no longer hunting and gathering. Virtually all aspects of how modern people function and rest are radically different from those of our ancestors. We also briefly discuss treatment of jaw symptoms and possible clinical cures for individuals, as well as changes in society that might lead to better care and, ultimately, prevention.
... e headgear effect of Herbst appliance is well documented in the literature in various studies such as Pancherz and Anehus-Pancherz, [19] Valant and Sinclair, [20] and Wieslander [21] Similarly, Siara-Olds et al., [22] in their retrospective study, showed that MARA appliance showed a significant headgear effect. Al-Jewair et al. [23] compared skeletal and dentoalveolar effects of MARA and AdvanSync appliances . ...
Objectives
AdvanSync2 (Ormco, Glendora, California, USA) is a molar-to-molar fixed Class II corrector, based on the philosophy of Herbst which allows the bonding of the both upper and lower arches simultaneously along with fixed functional therapy. The purpose of this study was to cephalometrically compare the skeletal and dentoalveolar effects of AdvanSync2 in the correction of Class II malocclusions in circumpubertal and post-pubertal patients.
Materials and Methods
Forty-eight samples were selected and divided into two groups based on their CVMI staging, Group A, i.e., at CVMI Stages 2 and 3 (18 girls and six boys) and Group B, i.e., CVMI Stages 4, 5, and 6 (19 girls and five boys). Cephalograms taken at pre- and post-AdvanSync2 stages were compared and analyzed.
Results
The results showed that there was a significant increase in mandibular length in both groups. Both the groups also showed sagittal maxillary restriction, maxillary molar distalization, and retroclination of maxillary incisors. On comparison between Group A and Group B, there was no statistically significant differences in terms of maxillary position, size of maxilla, as well as upper and lower incisor inclinations in Group A except for improvement of mandibular position (SNB; P ≤ 0.01) and greater amount of chin growth (B -Pg; P ≤ 0.01) with respect to Group B.
Conclusion
AdvanSync2 can be used as an effective fixed functional appliance in post-pubertal group for sagittal mandibular correction in skeletal Class II patients.
... The overjet decreased by 4.1 mm. In addition, and although did not achieve significance, the mandibular incisors proclined 7.1 o over controls, a finding that is in agreement with the results of Baccetti et al. [24] for the Herbst appliance, Siara-Olds et al. [25] for the MARA, and Franchi et al. [2] for the FFRD, in addition to other previous studies [26,27]. However, this proclination relapsed later during retention (T2-T3) leading to a net difference of 5.2 o , which may indicate re-crowding of the mandibular incisors. ...
Objectives
To assess the long-term effects of the Forsus Fatigue Resistant Device (FFRD) for the correction of Class II division 1 malocclusion during pre-peak, peak, and post-peak growth periods.
Materials and methods
This retrospective study was conducted on 60 patients that received FFRD with concurrent full-fixed orthodontic appliances during pre-peak (n = 18), peak (n = 21) and post-peak (n = 21) maturational stages. The FFRD groups were compared with 60 untreated Class II control subjects obtained from the University of Michigan growth study and matched by skeletal age, sex, and observation periods. Lateral cephalograms were obtained at three time-points: [T1] pre-treatment; [T2] end of comprehensive orthodontic treatment; and [T3] retention (average of 3 years in retention). Nineteen linear and angular measurements were recorded. Short-term (T1- T2) and long-term (T1-T3) treatment changes were analyzed using paired Wilcoxon Signed Rank tests.
Results
In the pre-peak group, FFRD caused temporary restraint of maxillary growth and an increase in mandibular length at T1-T2 compared to controls. No significant differences were found at T2-T3 time points. The net changes (T1-T3) included a restraining effect on the maxilla and dentoalveolar compensation. In the peak group, maxillary restraint effect was seen at T1-T2, but this effect relapsed at T2-T3 time points. Similar to the pre-peak group, the net results (T1-T3) included maxillary headgear effect and dentoalveolar compensation. In the post-peak group, the net effects (T1-T3) of treatment included only dentoalveolar compensation.
Conclusions
Overall, Class II malocclusion correction with FFRD is stable at three years post-treatment and is mainly achieved by maxillary restraint and dentoalveolar compensation at the pre-peak and peak stages and dentoalveolar compensation during the post-peak stage.
... 18 Hareketli ve sabit fonksiyonel apareylerin etkinliklerinin değerlendirildiği bir sistemik derlemede en iyi sonuçların Herbst apareyi ile alındığı bildirilmiştir. 19 Herbst apareyi ile büyüme gelişim atılımından sonra bile kondiler büyüme stimülasyonu elde edilebileceği belirtilmiştir. 20 Mandibuler Protraction Appliance Filho 21 tarafından geliştirilen aparey kullanım kolaylığı, düşük maliyet, kırılmaya direnç ve hasta konforu gibi avantajlara sahiptir. ...
... Previous studies [3,5,12] on Cr-MARA design showed similar results. The finding is also in agreement with the annualized short-term mandibular growth enhancement ranges reported in the literature for other fixed Class II corrector appliances (3.0 mm to 6.2 mm) before subtracting normal growth [5,[12][13][14][15]. ...
Objective
To compare the skeletal and dentoalveolar changes in Angle Class II malocclusion subjects treated with the banded Mandibular Anterior Repositioning Appliance (Ba-MARA) and crowned MARA (Cr-MARA).
Materials and methods
This retrospective cohort study included 40 consecutively treated pubertal adolescents with Class II division 1 malocclusion who received full-fixed orthodontic appliances with a phase of orthopedic treatment using Ba-MARA (n = 20) or Cr-MARA (n = 20). The samples were compared with 20 untreated Class II controls obtained from the Michigan Growth Study. Lateral cephalograms were obtained pre-treatment (T1), post-MARA removal (T2), and post-full-fixed orthodontic treatment (T3).
Results
After MARA removal (T2-T1), the total mandibular length increased only in the Cr-MARA group compared to controls (Co-Gn = 5.4 mm; post-hoc P = 0.042). Overall dentoskeletal changes were less significant during the T3-T2 timepoint. After full-fixed orthodontic treatment (T3-T1), and after controlling for normal growth, both Ba- and Cr-MARA groups increased the total mandibular length by 3.1 mm and 3.8 mm respectively. Overjet decreased by 2.2 mm in Ba-MARA and 2.9 mm in Cr-MARA. The mandibular molars erupted and moved mesially in both treatment groups. The mandibular incisors proclined significantly in the Cr-MARA group in comparison to controls (IMPA = 7.1o, post-hoc P = 0.002).
Conclusions
Both MARA designs were effective in correcting the malocclusion by a combination of small skeletal and dental changes. Although significant differences in dentoskeletal outcomes were observed between the MARA groups and the controls, the differences between the two MARA designs were small and did not achieve statistical/clinical significance.
Fixed functional appliances for the management of class II discrepancies have a long history in clinical orthodontics. The Herbst appliance is an established fixed functional appliance in common use throughout the world. However, in recent years a number of alternative designs have been described. This chapter will review the history of fixed functional appliances and describe some of the more recent innovations in the field, including the Eureka spring, Twin Force, Forsus, Modified Crossbow, MARA and Magnoglide appliances. The clinical applications for using these appliances will be discussed and clinical examples presented throughout.
Background
The present study investigated the skeletal and dental effect in class II division I growing patients due to mandibular deficiency treated with the hybrid aesthetic functional (HAF) appliance.
Methods
A sample of 16 growing patients (5 boys and 11 girls; mean age: 9.50 years, standard deviation: 1.15) with class II division I malocclusion were treated using the HAF appliance for an average period of 10±3 months. For each patient, a cephalometric radiograph was taken before and after treatment, and digital analysis was applied using the WebCeph program. The statistical analysis was performed to evaluate dental and skeletal changes associated with the HAF appliance and determine if there were any statistically significant variations in anatomical measurements between the start and completion of the treatment.
Results
The data showed a significant increase in SNB angle (P=0.002), leading to a significant decrease in ANB angle (P=0.001). The mandibular length significantly increased (P=0.008), the lower incisors were flared significantly (P=0.028), and the lower molars were extruded significantly (P≤0.001). Also, this study revealed a significant decrease in Wits appraisal (P≤0.001), overjet (P≤0.001), and overbite (P=0.041). Additionally, a significant increase in lower anterior facial height (P≤0.001), total facial height (P=0.001), and posterior facial height (P=0.037) were observed.
Conclusion
The HAF appliance showed that it could be used to correct class II division 1 skeletal discrepancy by mandibular advancement. The HAF appliance increased all facial heights significantly.
Aim
This current study evaluated and compared the skeletal changes in the head of the condyle, glenoid fossa, and articular space between the twin block appliance and PowerScope™ a fixed functional appliance.
Materials and methods
This study was a pilot, randomized, single-blinded, assessing the skeletal changes in the components of the temporomandibular joint (TMJ) using cone-beam computed tomography (CBCT). The study was conducted in 20 subjects in the age range of 11–14 years with class II division 1 malocclusion. These subjects were distributed randomly between two groups with an allocation ratio of 1:1 (group I—twin block and group I—PowerScope™). Follow-ups of both groups were done till desirable skeletal correction was attained (clinical edge-to-edge incisor relation).
Results
Condylar parameters such as position, height, and length were evaluated bilaterally in the CBCT scans. After using both devices, there was an increase in all condylar qualities; however, the twin block appliance showed a more noticeable difference, which has been determined to be statistically significant. In the twin block group, there was an average decrease of 0.56 mm in the anterior articular space and an increase of 1.2 and 2.64 mm in the middle and posterior articular spaces, respectively. In the PowerScope™ group, there was an average decrease of 0.23 mm in the anterior articular space and an increase of 2.55 and 1.85 mm in the middle and posterior articular spaces, respectively. In the case of the twin block device, the change in glenoid fossa angle was observed to be 6.1 mm on both sides and a mean difference of 1.25 mm on the right-side and 1.75 mm on the left-side was observed in the case of PowerScope™. The difference was established to be significant with a p < 0.05 in all cases.
Conclusion
Condylar attributes increased after the application of both devices but the difference was more pronounced in the case of twin block appliances. The difference in articular space (middle and posterior) between the twin block group and PowerScope™ group, was not significant statistically. In the present study, the remodeling in the glenoid fossa was greater in the twin block group compared to the PowerScope™ group.
How to cite this article
Halapanavar B, MN P, Deshmukh S, et al. Comparison of Skeletal Changes in the Temporomandibular Joint between the Twin Block Appliance and Fixed Functional Appliance: A Longitudinal Follow-up Study. Int J Clin Pediatr Dent 2024;17(1):7–14.
La Organización Mundial de la Salud (OMS) destaca que la maloclusión ocupa la tercera posición en las prioridades de los problemas odontológicos de Salud Pública Global, debido a su amplia prevalencia, lo que la califica como una cuestión relevante en salud pública. La mordida cruzada anterior se caracteriza por la colocación inadecuada de los dientes anteriores superiores, que se superponen por dentro con respecto a los dientes inferiores. Esta discrepancia oclusal específica requiere una intervención oportuna para evitar el agravamiento, potencialmente hasta una etapa esquelética, en la edad adulta, donde la corrección a menudo requeriría procedimientos quirúrgicos ortognáticos. En este contexto, el propósito de este estudio fue realizar una revisión exhaustiva de la literatura para ilustrar la relevancia del tratamiento temprano de la mordida cruzada anterior, utilizando una adaptación del aparato ortopédico Bionator de Balters. Este método fue empleado con el fin de abordar la maloclusión de Clase III en la fase de dentición mixta. El análisis tuvo como objetivo determinar la eficacia de este enfoque cuando se implementa de manera temprana, con el fin de tratar de manera satisfactoria esta irregularidad oclusal.
The World Health Organization (WHO) emphasizes that malocclusion ranks third in the priorities of global public dental health issues, given its widespread prevalence, qualifying it as a matter of public health relevance. Anterior crossbite is characterized by the improper positioning of the upper anterior teeth, which overlap inside compared to the lower teeth. This specific occlusal discrepancy requires timely intervention to prevent worsening, potentially progressing to a skeletal stage in adulthood, where correction often demands orthognathic surgical procedures. In this context, the purpose of this study was to conduct a comprehensive literature review to illustrate the relevance of early treatment of anterior crossbite using an adaptation of the Bionator appliance by Balters. This method was employed to address Class III malocclusion in the mixed dentition phase. The analysis aimed to determine the effectiveness of this approach when implemented early, in order to satisfactorily address this occlusal irregularity.
Objective
Functional appliances are used in orthodontics to bring about correction of mandibular retrognathism by forward positioning and eventually remodeling the condyle- glenoid fossa to retain this new position. Research has shown that these appliances have a significant effect on pharyngeal airway of patients. The aim of this study was to evaluate changes in volume and minimum constriction area in the pharyngeal airway using CBCT imaging after correction of mandibular retrognathism with an Advansync2 Class II corrector.
Methods
This single-center study consisted of 20 Class II patients (mean age 14.8 years) who required correction of mandibular retrognathism. The patients were treated with the Advansync2 Class II corrector for an average of 26 weeks. CBCT records were taken at T0 (beginning of treatment) and T1 (end of functional phase). The airway was segmented into lower nasopharynx, velopharynx and oropharynx and analyzed for changes in partial volume, total volume, and minimum area using a CBCT software [NewTom 3G TM (Newtom- Cefla S.C., Verona, Italy)].
Results
The partial and total volumes were significantly larger at T1 than at T0 ( p = .003, .001). In addition, minimum area also improved in each part of the airway ( p = .005, .022, .001).
Conclusion
The Advansync2 fixed functional appliance can be used in Class II patients requiring improvement in their airway dimensions. However, additional long-term studies are recommended to confirm these findings.
Introduction:
This study aimed to quantify the outcomes of adolescent patients with Class II malocclusion treated with the Carriere Motion 3D Appliance (CMA) combined with full fixed appliances.
Methods:
Cone-beam computed tomography scans of 22 patients were available before orthodontic treatment (T1), at removal of the CMA (T2), and posttreatment (T3). The average age of the patients was 13.5 ± 1.6 years at T1, 14.1 ± 0.2 years at T2, and 15.6 ± 0.5 years at T3. The 3-dimensional image analysis procedures were performed using ITK-SNAP (version 3.6.0; www.itksnap.org, Hatfield, Pa) and SlicerCMF (version 4.11.0; http://www.slicer.org, Cambridge, Mass); skeletal and dentoalveolar changes relative to cranial base, maxillary, and mandibular regional superimpositions were evaluated.
Results:
Changes were analyzed with 1 sample t tests using the mean differences during the CMA phase (T1 to T2) and total treatment time (T1 to T3). Significant skeletal changes included a slight reduction of ANB from T1 to T3, mandibular growth (Co-Gn increment of 1.2 mm and 3.3 mm from T1 to T2 and T1 to T3, respectively), inferior displacement of point A, and anterior and inferior displacement of point B. The mandibular plane did not change significantly during treatment. During the CMA treatment, posterior tipping and distal rotation of the maxillary molars, tip back and inferior displacement of the maxillary canines, significant mesial rotation, and superior displacement of the mandibular molars were observed. These movements rebounded during the full fixed appliance phase except for the molar and canine vertical displacements. Clinically significant dental changes during treatment included a reduction in overjet and overbite, Class II correction of the molar and canine relationship, and proclination of the mandibular incisors.
Conclusions:
The CMA is an effective treatment modality for Class II correction in growing patients because of a combination of mesial movement of the mandibular molar, distal rotation of the maxillary molar, and anterior displacement of the mandible.
A Organização Mundial de Saúde (OMS) destaca que a maloclusão ocupa a terceira posição nas prioridades dos problemas odontológicos de Saúde Pública Global, devido à sua ampla prevalência, o que a qualifica como uma questão de relevância em saúde pública. A mordida cruzada anterior é caracterizada pelo posicionamento inadequado dos dentes anteriores superiores, que se sobrepõem por dentro em relação aos dentes inferiores. Essa discrepância oclusal específica requer intervenção oportuna para evitar o agravamento, potencialmente até um estágio esquelético, na idade adulta, onde a correção frequentemente demandaria procedimentos cirúrgicos ortognáticos. Nesse contexto, o propósito deste estudo consistiu em realizar uma revisão abrangente da literatura para ilustrar a relevância do tratamento precoce da mordida cruzada anterior, utilizando uma adaptação do aparelho ortopédico Bionator de Balters. Esse método foi empregado visando abordar a maloclusão Classe III na fase de dentição mista. A análise visou determinar a eficácia dessa abordagem quando implementada precocemente, no sentido de tratar de maneira satisfatória essa irregularidade oclusal.
Introduction
Class II division 1 malocclusion treatment with functional devices offers acceptable results. These devices can be removable or fixed, and the essential difference between them is the need for compliance. It is clinically important to investigate if there are differences in the treatment effects of these devices that present different characteristics.
Objective
This retrospective longitudinal study compared the treatment effects of Class II correction with the MARA appliance, Activator-Headgear (AcHg) combination, both followed by multibracket fixed appliances, and an untreated control group.
Material and Methods
Each experimental group was composed of 18 patients, with a baseline mean age of 11.70 and 10.88 years, treated for 3.60 and 3.17 years. The control group consisted of 20 subjects with baseline mean age of 11.07 years. The groups were evaluated before (T1) and after (T2) treatment. Lateral radiographs were used to evaluate the treatment changes with treatment (T2-T1), compared to the control group. Intergroup comparisons were performed using repeated-measures analysis of variance (ANOVA), followed by Tukey’s test.
Results
The AcHg group showed significantly greater maxillary growth restriction than the MARA, while the mandibular changes were due to natural growth. Both devices promoted significantly greater maxillary incisors retrusion, mandibular incisors labial inclination, and improvement of overjet and molar relationships, compared to the control.
Conclusions
Both functional devices followed by multibracket appliances were effective to correct Class II malocclusion. Nonetheless, the AcHg combination presents superior skeletal effects, due to significantly greater maxillary growth restriction compared to the MARA appliance. Moreover, the appliances presented similar dentoalveolar effects.
Keywords:
Headgear; Functional; Orthodontics; corrective
Objectives
To evaluate the treatment outcomes between Twin Block and AdvanSync2 ® appliances by comparing the skeletal, dentoalveolar, and soft tissue changes.
Materials and Methods
Radiographic data of 20 patients were retrospectively analyzed. Data were selected from patients in their skeletal growth spurt as evaluated by the cervical vertebral maturation method (CVMI 2, 3, and 4), with class II malocclusion characterized with retrognathic mandible (ANB > 4°, SNB < 77°, FMA = 25 ± 5°, overjet > 5 mm). There were 10 patients in each group that underwent orthodontic correction for class II malocclusion: either using Twin Block or AdvanSync2 ® . Independent t test and Paired t test and chi-square tests were used for the data analysis. The level of statistical significance was set at P value ≤.05.
Results
The chronological and skeletal age were similar in both the groups. Records were taken for the functional treatment with mean treatment span of 8 ± 1 month. Changes in SNB (group I = 1.59°, group II = 3.11°) ( P < .01), Co-Gn (group I = 2.89 mm, group II = 5.34 mm), and U1-L1° (group I = −1.51°, group II = 2.97°) showed statistically different outcome between the groups, when the pre-post data were studied. Rest of the variables—cranial base, maxillary skeletal, mandibular skeletal, intermaxillary, vertical skeletal, maxillary dentoalveolar, mandibular dentoalveolar, and soft tissue—showed similar outcome ( P > .05).
Conclusion
Both appliances lead to desirable outcomes in the correction of class II malocclusion. AdvanSync2 ® resulted in inducing more of changes in SNB and effective mandibular length as compared to Twin Block. Overjet and molar relation improved significantly with both the appliances. Both the appliances resulted in similar skeletal, dentoalveolar, and soft tissue changes.
The distinguishing features of Class I, Class II and Class III craniofacial growth have been subjects of orthodontic research since the middle of the 20th century. However, the moral and practical issues related to studying craniofacial growth in modern times have presented unresolved challenges to researchers. While previous longitudinal growth investigations are typically based on historical data sets, the cephalometric growth studies of contemporary populations must now rely on cross-sectional data. Furthermore, clinical orthodontic research has faced similar ethical challenges in which therapeutic outcomes are analysed using historical control data. These limitations, amongst others, have obscured the conclusions that can be drawn from both types of studies. This article begins with a review of the defining characteristics of Class I, Class II and Class III growth and then explores the limitations of growth studies and the use of historical control groups in orthodontic research.
Objective
This study aimed to compare cephalometric changes of Class II malocclusion patients treated with Jasper Jumper and Forsus, associated with fixed appliances.
Methods
The sample consisted of 62 individuals divided into 3 groups: group 1 included 22 subjects with a mean initial age of 12.39 years, treated with Jasper Jumper associated with fixed appliances for a mean period of 2.43 years; group 2 included 19 subjects with a mean initial age of 12.43 years, treated with Forsus associated with fixed appliances for a mean period of 3.54 years; and group 3 included 22 Class II malocclusion untreated subjects at a mean age of 12.14 years, followed for a mean period of 1.78 years. Intergroup comparison was performed with one-way ANOVA, followed by Tukey test.
Results
Both treated groups had similar dentoskeletal changes: restrictive effect on the maxilla; clockwise rotation of the occlusal plane; mild increase in lower anterior facial height; limitation on the vertical development of the maxillary molars; labial tipping and intrusion of the mandibular incisors; extrusion of mandibular molars; improvements of the maxillomandibular relationship, overjet, overbite, molar relationship; and retrusion of the upper lip. The mandibular incisors exhibited greater protrusion in group 1 compared to the other groups. In addition, group 2 presented mild protrusion of the lower lip, and groups 1 and 3 showed mild retrusion.
Conclusion
The Jasper Jumper and Forsus appliances were effective and showed similar changes in the treatment of Class II malocclusion.
use of class ii corrector
Amaç: Bu retrospektif çalışmanın amacı, iskeletsel destekli (İD) Forsus FRD ve Twin-blok (TB) apareylerinin iskeletsel, dentoalveolar ve faringeal hava yoluna olan etkilerini değerlendirmektir. Gereç ve Yöntem: Çalışmamız, Sınıf II maloklüzyonu olan, mandibular simfiz bölgesine bilateral yerleştirilmiş miniplaklardan destek alan İD Forsus apareyi veya TB ile tedavi edilmiş hastaların tedavi başı ve tedavi sonu lateral sefalogramları üzerinde yapılan iskeletsel, dentoalveolar ve faringeal ölçümler kullanılarak yürütülmüştür. İD Forsus grubu, 20 hasta (9 kadın ve 11 erkek; ortalama yaş: 14.12 ± 1.66 yıl) ve TB grubu, 20 hasta (10 kadın ve 10 erkek; ortalama yaş: 13.95 ± 1.32yıl) olmak üzere, büyüme gelişim evresi peak sonrasında olan toplam 40 hasta verisi kullanılmıştır. Gruplar arasındaki farklılıkların değerlendirilmesi için bağımsız örneklem t-testi, grup içi farkın karşılaştırılması için bağımlı örneklem t-testi kullanılmıştır. Bulgular: Sınıf II malokluzyon her iki grupta da, SNA'da azalma ve SNB'de artış ile düzeltildi (p<0.01). Her iki gurupta da Co-A uzunluğu istatistiksel olarak anlamlı azalırken, Co-Gn uzunluğu anlamlı artış gösterdi (p<0.001). IMPA değerleri TB grubunda artarken, İD Forsus grubunda anlamlı olarak azaldı(p<0.001). Nazofaringeal havayolu bölgesinde artış anlamlı değilken (p>0.05), orofaringeal havayolu ölçümlerinde istatistiksel olarak anlamlı artış gözlendi (p<0.01). Sonuç: Her iki grupta da malokluzyon başarılı şekilde tedavi edilmiştir. İskeletsel, dentoalveolar ve faringeal ölçümler, tedavi edilen tüm hastalarda önemli ölçüde artmış, iki grup arasında anlamlı bir fark gözlenmemiştir. Anahtar kelimeler: Faringeal havayolu, fonksiyonel apareyler, iskeletsel destekli Forsus, Twin-blok
Objective: To evaluate dentoskeletal, soft tissue and airway changes in Class II malocclusion patients treated with AdvanSync2 Class II corrector in conjunction with fixed appliances. Methods: Forty-five subjects with skeletal and dental Class II malocclusion requiring fixed functional therapy were included. Pre-treatment cephalograms served as control group (Group 1), post treatment cephalograms of patients treated using AdvanSync2, as experimental group (Group 2). Changes in skeletal, dental, soft tissue profile and airway were analyzed on lateral cephalograms using 21 variables from multiple cephalometric analysis. Results were tabulated and data was analyzed using Wilcoxon signed rank test for linear parameters and paired student t test for angular parameters. Results: Maxillary skeletal and dental effects included restriction of growth, upper incisor retrusion and retroclination at p<0.001. Mandibular incisors proclined during treatment. Forward mandibular relocation was noted, though not statistically significant. Upper and lower lip repositioning was achieved, establishing lip competency. Changes in Z angle and nasolabial angle were positive, reducing facial convexity. Significant airway dimensional improvements were noted. Conclusion: AdvanSync2 Class II corrector was effective in treating skeletal Class II malocclusions with mandibular retrognathism. It produced its effects mainly through maxillary restriction and mandibular dentoalveolar changes which furthermore helped in achieving good soft tissue profiles in patients. Positive airway changes were also noted.
Introduction
The objective of this research was to compare the 2 treatment protocols including a functional mandibular advancer (FMA; Forestadent, Pforzheim, Germany) followed by multibracket appliances (MBAs) vs a Forsus device (3M Unitek, Monrovia, Calif) in combination with MBA concerning treatment outcomes and posttreatment stability.
Methods
This study was conducted using lateral cephalograms of patients who were treated with MBA, which was used either after an FMA or concurrently with a Forsus device, and of patients who had untreated Class II malocclusion (control group). Each group consisted of 19 subjects in cervical stage 2 or cervical stage 3 stages according to the cervical vertebral maturation index. Cephalograms were taken for the treated groups at T1 (pretreatment), T2 (completion of the MBA treatment), and T3 (at least 2 years after T2).
Results
Significant intergroup differences at the T1-T2 period were observed in favor of the FMA concerning mandibular advancement, intermaxillary relationship, and mandibular elongation. With Forsus treatment, restrained maxillary growth and a slightly improved intermaxillary relationship rebounded after treatment (P <0.05). At the end of treatment, mandibular incisor protrusion and occlusal plane rotation were greater in the Forsus group than in the FMA group (P <0.05), and maxillary incisor retroclination was significant in the Forsus group. During the posttreatment period, although no significant changes were present in the incisors' inclination, relapses of the T1-T2 improvements in overjet and overbite and the recidive of the occlusal plane rotation were significantly higher in the Forsus group.
Conclusions
Treatment protocol including an FMA was found to be more effective with mandibular skeletal effects and was more stable with a lesser degree of relapse in overjet and overbite than the Forsus protocol.
Objective
To assess the cephalometric skeletal and soft-tissue of functional appliances in treated versus untreated Class II subjects in the long-term (primarily at the end of growth, secondarily at least 3 years after retention).
Search methods
Unrestricted electronic search of 24 databases and additional manual searches up to March 2018.
Selection criteria
Randomised and non-randomised controlled trials reporting on cephalometric skeletal and soft-tissue measurements of Class II patients (aged 16 years or under) treated with functional appliances, worn alone or in combination with multi-bracket therapy, compared to untreated Class II subjects.
Data collection and analysis
Mean differences (MDs) and 95% confidence intervals (95% CIs) were calculated with the random-effects model. Data were analysed at 2 primary time points (above 18 years of age, at the end of growth according to the Cervical Vertebral Maturation method) and a secondary time point (at least 3 years after retention). The risk of bias and quality of evidence were assessed according to the ROBINS tool and GRADE system, respectively.
Results
Eight non-randomised studies published in 12 papers were included. Functional appliances produced a significant improvement of the maxillo-mandibular relationship, at almost all time points (Wits appraisal at the end of growth, MD -3.52 mm, 95% CI -5.11 to -1.93, P < 0.0001). The greatest increase in mandibular length was recorded in patients aged 18 years and above (Co-Gn, MD 3.20 mm, 95% CI 1.32 to 5.08, P = 0.0009), although the improvement of the mandibular projection was negligible or not significant. The quality of evidence was ‘very low’ for most of the outcomes at both primary time points.
Conclusions
Functional appliances may be effective in correcting skeletal Class II malocclusion in the long-term, however the quality of the evidence was very low and the clinical significance was limited.
Systematic review registration
CRD42018092139
A prospective clinical study with a random allocation of 47 adolescent patients to three different functional appliance groups was established and compared with an untreated control group over a 9-month period. Treatment was undertaken with either a Bionator, Twin Block, or Bass appliance. Pre- and post-treatment cephalograms were used to quantify the skeletal and dentoalveolar changes produced by the appliances and compared with those observed in the control group as a result of growth. Both the Bionator and Twin Block appliances demonstrated a statistically significant increase in mandibular length (3.9 +/- 2.7 mm; 3.7 +/- 2.1 mm, respectively) compared with the control group (P < 0.05), with an anterior movement of pogonion and point B. Highly statistically significant increases (P < 0.01) were seen in lower face heights for all the appliance groups compared with the control group. The Twin Block group showed the least forward movement of point A due to a change in the inclination of the maxillary plane. The Bionator and Twin Block groups showed statistically significant reductions in the inclination of the upper incisors to the maxillary plane (P < 0.05). The Bass group showed minimal change in the inclination of the lower labial segment to the mandibular plane. The Bionator group demonstrated the greatest proclination of the lower labial segment (4.0 +/- 3.6 degrees). Clinically important changes were measured in all the appliance groups when compared with the control group. Differences were also identified between the functional appliance groups. The Twin Block appliance and, to a lesser extent, the Bionator appeared the most effective in producing sagittal and vertical changes.
A prospective clinical study with a random allocation of 47 patients to three different functional appliance groups was established and compared with a slightly younger control group over a 9-month period. The cephalometric hard tissue changes were assessed in relation to the soft tissue changes produced and the patients were also assessed by three-dimensional (3D) laser scanning of the facial soft tissues. Each 'averaged' appliance group scan was compared with the 'averaged' control group face. Statistically and clinically significant changes occurred in the group treated with the Twin Block appliance, and to a lesser extent in the group treated with the Bionator appliance. No statistically significant facial soft tissue changes could be demonstrated in the Bass appliance group. Upper lip position remained stable despite the significant overjet reduction attained in the three appliance groups. Lower lip protrusion (up to 3.8 mm), lower lip length (up to 4.0 mm), and soft tissue lower and total face height increased significantly in all appliance groups by varying amounts. The long-term effect of these changes needs to be fully evaluated. The laser scanning system was found to be a sensitive and accurate method of quantitatively assessing small changes in the soft tissue facial form. Significant changes of the facial tissues in the transverse plane were highlighted by this technique.
We measured the skeletal effects of Herbst appliance treatment in a retrospective sample of 25 boys (aged 10.7-14.5 years) and 25 girls (aged 10.7-14.3 years). Selection criteria were (1) a pretreatment full Class II molar relationship (ANB angle: average, 6.7 degrees; range, 2.5-10.5 degrees) and (2) a posttreatment full Class I or overcorrected Class I molar relationship within 6-8 months. A first t-test was used to evaluate variations between pre- and posttreatment cephalometric measures. Then, compared with the appropriate age- and sex-matched European norm, every pre- and posttreatment value was transformed into a z-score on the distribution of the norm value and a second t-test was performed. The second t-test was to study variations between pre- and posttreatment z-scores in order to neutralize the effect of natural growth. Posttreatment, the mandible showed a remarkable forward repositioning without opening of the gonial angle, particularly in males. Only ANB and Xi-CF-PTV angles were significantly different when the effect of normal growth was excluded. In males, ramus height and mandibular basal length were significantly increased when total variation was considered (ie, not excluding the effect of normal growth). In females, only the mandibular ramus height was significantly increased. In conclusion, even short-term Herbst therapy can be efficacious, with the most frequent effect being mandibular forward repositioning followed by mandibular ramus elongation. The statistical procedure used counteracts the effect of growth and sex on the results. Moreover, z-scores are adimensional measures with which any kind of parameter may be compared and scaled to each other in the perspective of a more reliable mutivariated interpretation of cephalometric variables.
The aim of the study was to evaluate the cephalometric changes produced by the Twin Block appliance. Lateral cephalometric radiographs were taken before and after Twin Block appliance treatment on 30 consecutive patients (14 male, 16 female, mean age 12 years 6 months). Published normative data tables were used to produce control data, which were individually matched to the test group for age, sex, and treatment time. Alteration in shape was assessed by measuring percentage change in linear dimensions as opposed to change in cephalometric angles used in previous investigations. The differential average percentage change was calculated by subtracting the control value from the Twin Block value. Clinically significant changes (2 per cent and greater) were found in lower anterior (6.6 per cent) and posterior (4.6 per cent) face heights, upper incisor to maxillary plane (4.9 per cent), i.e. upper incisor retraction, and increase in mandibular length (Co-B 3.3 per cent, Co-Po 2.6 per cent, Ar-B 3.5 per cent, Ar-Po 2.2 per cent).
The purpose of this retrospective investigation was to evaluate the dentoalveolar and skeletal cephalometric changes of the Bionator appliance on individuals with a Class II division 1 malocclusion. Lateral cephalograms of 44 patients were divided into two equal groups. The control group comprised 22 untreated Class II children (11 males, 11 females), with an initial mean age of 8 years 7 months who were followed without treatment for a period of 13 months. The Bionator group (11 males, 11 females) had an initial mean age of 10 years 8 months, and were treated for a mean period of 16 months. Lateral cephalometric headfilms were obtained of each patient and control at the beginning and end of treatment. The results showed that there were no changes in forward growth of the maxilla in the experimental group compared with the control group. However, the Bionator treatment produced a statistically significant increase in mandibular protrusion, and in total mandibular and body lengths. There were no statistically significant differences in craniofacial growth direction between the Bionator group and the control group, although the treated patients demonstrated a greater increase in posterior face height. The Bionator appliance produced labial tipping of the lower incisors and lingual inclination of the upper incisors, as well as a significant increase (P < 0.01) in mandibular posterior dentoalveolar height. The major effects of the Bionator appliance were dentoalveolar, with a smaller significant skeletal effect. The results indicate that the correction of a Class II division 1 malocclusion with the Bionator appliance is achieved not only by a combination of mandibular skeletal effects, but also by significant dentoalveolar changes.
Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/23745/1/0000717.pdf
The purpose of this study was to investigate the effect of continuous bite jumping with the Herbst appliance on the occlusion and craniofacial growth. The material consisted of twenty growing boys with Class II, Division 1 malocclusion. Ten of the boys were treated with the Herbst appliance for 6 months. The other ten boys served as a control group. Dental casts, profile roentgenograms, and TMJ radiographs were analyzed before and after 6 months of examination. The following treatment results were found: 1. Normal occlusal conditions occurred in all patients. 2. Maxillary growth may have been inhibited or redirected. The SNA angle was reduced slightly. 3. Mandibular growth was greater than average. The SNB angle increased. 4. Mandibular length increased, probably because of condylar growth stimulation. 5. Lower facial height increased. The mandibular plane angle, however, remained unchanged. 6. The convexity of the soft- and hard-tissue profile was somewhat reduced.
The purpose of this investigation was to assess the number of, and the interrelation between, skeletal and dental components that contribute to Class II relapse after Herbst treatment. A comparison was made between 15 relapse and 14 stable cases at least 5 years after treatment. Lateral cephalograms taken before and immediately after Herbst treatment, as well as 6 months and 5 to 10 years after treatment, were analyzed. The results revealed that relapse in the overjet and sagittal molar relationship resulted mainly from posttreatment maxillary and mandibular dental changes. In particular, the maxillary incisors and molars moved significantly (p less than 0.05) to a more anterior position in the relapse group than in the stable group. The interrelation between maxillary and mandibular posttreatment growth was favorable and did not contribute to the occlusal relapse. It is hypothesized that the main causes of the Class II relapse in patients treated with the Herbst appliance were a persisting lip-tongue dysfunction habit and an unstable cuspal interdigitation after treatment.
A group of 20 subjects who underwent successful Bionator treatment was compared with 20 subjects who were treated less successfully with the same appliance. Both groups had similar advancements in their bite registrations, as well as similar treatment times and growth-prediction parameters. Success was judged not on the final occlusion (all patients were treated to a Class I molar relationship) but on the posttreatment position of skeletal pogonion. The successful group experienced 3.5 mm or more of advancement in skeletal pogonion, whereas the less successful group had less than 3 mm of advancement of this point. The two groups were comparable in all features except, as may be expected, total mandibular growth, which was greater in the group with the larger anterior pogonion advancement. The results of this study suggest that persons who have small mandibles (as determined by comparison with published growth standards) may benefit more from functional appliance therapy than patients with normal-sized mandibles. The subjects with delayed growth may experience more mandibular development than those with average growth during treatment under the favorable growth environment created by functional appliance therapy.
The purpose of this article is to test the hypothesis that the establishment of nasal respiration in children with severe nasopharyngeal obstruction can be eliminated as a factor in determining mandibular growth direction. The article describes the changes in mandibular growth direction (MGD) in a 5-year period after adenoidectomies and the establishment of nasal breathing in a population of Swedish children. Measurements of mandibular growth directions were obtained from serial cephalometric radiographs after adenoidectomies in 38 Swedish children aged 7 to 12 years with previous nasopharyngeal obstructions. These were compared with the growth directions in a control sample of 37 Swedish children with clear airways and matched for age and sex. The adenoidectomy sample initially showed significantly longer lower face heights, steeper mandibular plane angles, and more retrognathic mandibles than the matched controls. Analysis showed that during the 5 years after adenoidectomies, the girls had a more horizontal MGD (P less than 0.02) than did the female controls. A corresponding but not significant trend was found for the boys. The individual growth directions that were obtained following adenoidectomies were more variable than those found in the controls.
A survey is presented of experience with the implant method in the study of facial growth, with particular emphasis on prediction of mandibular growth rotation. Three methods of prediction are discussed. (1) A longitudinal method, which consists of following the course of development by annual x-ray cephalograms, is shown to be of limited use for this purpose, as the remodeling process at the lower border of the mandible to a large extent masks the actual rotation. (2) A metric method, which aims at prediction based on a metric description of the facial morphology at a single stage of development, has so far not proved of value. (3) A structural method is described by which it may be possible to predict, from a single cephalogram, the course of rotation, where this feature is marked. This method is based on information gained from implant studies of the remodeling process of the mandible during growth.
By means of computer-based statistical methods, several types of Class II malocclusion have been discovered with defining horizontal and vertical characteristics. Of the six horizontal types, four are severe syndromes, one is a loose, ill-defined grouping of cases with mild skeletal features, and one has only the dental features of Class II. Five vertical types associates with Class II were also revealed, although each vertical is not associated with all horizontal types. A simplified simulation of the computerized procedures has been developed for routine use in clinical practice.
There is an intimate relationship between the functional and structural components of the craniofacial region. Any intervention in this region, whether through experimental or therapeutic means, results in an alteration in the existing balance between the various hard and soft tissue components of the craniofacial region. Functional adaptations tend to occur very rapidly but are always gradually followed by structural adaptations, the nature of which depends on the age of the individual. If we carry this philosophy to the diagnosis and clinical treatment of patients, we must always be aware that any existing malocclusion is in a state of balance regardless of the nature of the individual components. In planning the ideal therapeutic regime, the goals of treatment should include the achievement of long-term stability, which can be obtained only if the resultant skeletal and dentoalveolar configuration exists in harmony with the associated musculature and other soft tissues following treatment. If this goal is achieved, the concept of 'relapse' as used in orthodontics can be limited primarily to alterations in tooth position. Theoretically there should be no need to retain mechanically a structural relationship which has been achieved concomitant with the elimination of compensatory muscle function. Only by taking into account functional as well as structural imbalances can we provide the best treatment for our orthodontic patients.
The effect of continuous bite jumping on the dentofacial complex was investigated in ten consecutive Class II, Division 1 malocclusion cases treated with the Herbst appliance. All patients were growing boys with a skeletal Class II jaw base relationship. Ten boys of the same age and with the same dentofacial morphology served as a control group.
Dental casts and profile roentgenograms were analysed before treatment, after six months of treatment when the appliance was removed and six and twelve months post-treatment.
All Class II malocclusions were treated successfully by continuous bite jumping. Twelve months post-treatment normal sagittal dental arch relationships were found in 7 cases, while partial relapse was seen in 3 cases, resulting from unstable cuspal interdigitations after treatment.
Sagittal mandibular growth was accelerated by continuous bite jumping. During treatment mandibular length and the SNB angle increased significantly more than in the control group. No adverse changes in sagittal mandibular growth were seen during the 12 months after treatment.
The influence of bite jumping on maxillary growth appeared to be reversible. Maxillary prognathism (SNA angle) was significantly reduced during treatment but during the follow-up period maxillary growth caught up and the SNA angle returned almost to pretreatment values.
The purpose of this paper has been to explore the relationship between upper airway obstruction and craniofacial growth. A review of the literature and of a preliminary study by the author in collaboration with investigators at the Children's Hospital of Pittsburgh indicate both the spectrum of skeletal and dental configurations which are associated with upper airway obstruction and the significant changes in patterns of facial growth which are observed following removal of the obstruction. Four clinical cases were presented. While admittedly only case reports, these do illustrate the potential interaction between alterations in respiratory function and craniofacial growth pattern. The four clinical cases are representative of one type of facial problem which has been classically associated with the mouth-breathing individual; that is a steep mandibular plane. We fully recognize that there are many other manifestations of the environmental problem of upper respiratory obstruction. However, these cases do illustrate the relationship between function and form (i.e. obstruction and deviant facial growth). In order for this relationship to be more fully documented, data from controlled randomized clinical trials must be analyzed.
Sagittal skeletal and dental changes contributing to Class II correction in Herbst appliance treatment were evaluated quantitatively on lateral roentgenograms. The material consisted of forty-two Class II. Division 1 malocclusion cases. Twenty-two of these were treated with the Herbst appliance for 6 months. The other twenty cases served as a control group. The results of the investigation revealed the following: (1) Bite jumping with the Herbst appliance resulted in Class 1 occlusal relationships in all treated cases. (2) The improvement in occlusal relationships was about equally a result of skeletal and dental changes. (3) Class II molar correction averaging 6.7 mm. was mainly a result of a 2.2 mm. increase in mandibular length, a 2.8 mm. distal movement of the maxillary molars, and a 1.0 mm. mesial movement of the mandibular molars. (4) Overjet correction averaging 5.2 mm. was mainly a result of a 2.2 mm. increase in mandibular length and a 1.8 mm. mesial movement of the mandibular incisors. (5) Anterior condylar displacement (0.3 mm.), redirection of maxillary growth (0.4 mm.), and distal movement of the maxillary incisors (0.5 mm.) were of minor importance in the improvement in molar and incisor relationships seen. (6) A direct relationship existed between the amount of bite jumping at the start of treatment and the treatment effects on the occlusion and on mandibular growth. For a maximal treatment response, it is suggested that the Herbst appliance be constructed with the mandible jumped anteriorly as much as possible, namely, to an incisal edge-to-edge position. The clinician should be aware of the dental changes occurring during Herbst appliance treatment and make sure that these changes are not incongruous with his over-all treatment goal.
In the treatment of Class II malocclusion, an early phase of functional appliance treatment is commonly used to simplify subsequent fixed appliance therapy and to optimize the development of the facial skeleton. Unfortunately, these expectations enjoy little support in the refereed literature. The present study therefore was undertaken to examine the benefits of a two-stage bionator/edgewise regimen in comparison to the more conventional one-stage edgewise alternative. To minimize proficiency bias, we examined the records of the one- and two-stage Class II nonextraction patients who received treatment between 1980 and 1990 by a single experienced clinician. On the basis of descriptive data from 96 sets of initial study models and lateral cephalograms, discriminant analysis was used to identify two subsamples of 36 patients who were relatively similar before treatment and thus equally susceptible to the two treatments. Of these 72 "borderline" patients, 19 subsequently underwent a change in treatment plan (to extraction or surgery), leaving 25 two-stage and 28 single-stage nonextraction patients on whom to base a comparison of treatment effects. Except for a slight posttreatment difference in age (and, hence, size), the two groups underwent skeletal changes that left them essentially indistinguishable at the end of treatment. In both groups, these skeletal changes were largely responsible for molar and overjet corrections that were nearly identical in the two groups. The rates of change, however, differed significantly. As a result, the two-stage treatments started earlier and finished later. Although the present data do not address the relative impact of the two strategies on the 10% to 15% at each tail of the distribution, the early phase of functional appliance treatment conferred no obvious, measurable benefits on the central 75%. Therefore for most nonextraction Class II patients, the choice of treatments may well constitute a practice management, rather than a biologic, decision.
The short- and long-term effects of the Herbst appliance on the facial profile were determined in 69 Class II, division 1 malocclusions treated for 7 months and followed for 5-10 years post-treatment. Forty-nine subjects exhibited a stable long-term treatment result, while 20 cases relapsed. Lateral cephalometric radiographs from before treatment, after treatment, 6 months post-treatment, and 5-10 years post-treatment were analysed. As a rule Herbst treatment resulted in a reduction of the facial hard and soft tissue profile convexity. In relation to the E-line, the upper lip became retrusive, while the lower lip remained, on average, unchanged. During the post-treatment period of 5-10 years the hard tissue profile convexity was, on average, reduced in both the stable and relapse groups. When excluding the nose in the soft tissue profile evaluation, the facial profile convexity was, on average, reduced in the stable group while it remained unchanged in the relapse group. When including the nose in the evaluation, an average increase in the profile convexity occurred in both examination groups. Furthermore, the upper and lower lips became retrusive in both groups. For all the variables, however, large individual variations existed. In conclusion, it can be said that the Herbst appliance improves the facial hard and soft tissue profiles. Due to post-treatment growth changes the long-term effects of therapy are, however, variable and unpredictable.
In this investigation of the long-term effect of mandibular protrusive function in children with severe Class II malocclusions, a group of children age 8 years 8 months were initially treated for 5 months with a headgear-Herbst appliance followed by a 3- to 5-year period of activator retention. The patients were studied out of retention at the mean age of 17 years 4 months and compared with an untreated control group. Part of the sagittal correction relapsed. As compared with the control group, the average 3.9 mm protrusive effect of treatment on the mandible decreased to a nonsignificant 1.5 mm out of retention. The significant 2.0 mm therapeutic increase of the condylion-gnathion distance decreased to 1.3 mm and was not significantly different from control values at age 17 years 4 months. However, the 1.5 mm posterior effect of treatment on the maxilla continued to increase during activator retention and the difference compared with the control group was 2.3 mm postretention. This effect on the maxilla partly compensated the relapse tendency observed in the mandible so that 3.8 mm of the 5.4 mm posttreatment sagittal improvement still remained out of retention. Because of the sample size and individual variability, the results should be interpreted cautiously, but the findings indicate that maxillary sutural remodeling might be more receptive long-term to orthopedic treatment than the mandibular condylar growth process.
A group of 25 untreated subjects with Class II malocclusion in the deciduous dentition (featuring the concomitant presence of distal step, Class II deciduous canine relationship, and excessive overjet) was compared with a control group of 22 untreated subjects with ideal occlusion (flush terminal plane, Class I deciduous canine relationship, minimal overbite, and overjet) at the same dentitional stage. The subjects were monitored during a 2 1/2-year period in the transition from the deciduous to the mixed dentition, during which time no orthodontic treatment was provided. Occlusal analysis of the Class II group in the deciduous dentition revealed an average interarch transverse discrepancy due to a narrow maxillary arch relative to the mandible. All occlusal Class II features were maintained or became exaggerated during the transition to the mixed dentition. The skeletal pattern of Class II malocclusion in the deciduous dentition typically was characterized by significant mandibular skeletal retrusion and mandibular size deficiency. During the period examined, cephalometric changes consisted of significantly greater maxillary growth increments and smaller increments in mandibular dimensions in the Class II sample. Moreover, a greater downward and backward inclination of the condylar axis relative to the mandibular line, with consequent smaller decrements in the gonial angle, were found in the Class II group, an indication of posterior morphogenetic rotation of the mandible in patients with Class II malocclusion occurring during the period examined. The results of this study indicate that the clinical signs of Class II malocclusion are evident in the deciduous dentition and persist into the mixed dentition. Whereas treatment to correct the Class II problem can be initiated in all three planes of space (e.g., RME, extraoral traction, functional jaw orthopedics), other factors such as patient cooperation and management must also be taken into consideration before early treatment is started.
Preadolescent children with overjet greater than 7 mm were randomly assigned to observation only, headgear (combination), or functional appliance (modified bionator) and were monitored for 15 months. Of the 166 patients who completed this first phase of the trial, 147 continued to a second phase of treatment. The data from the first 107 patients to complete phase 2 are available and form the basis of this progress report. During phase 1, on average there was no change in the jaw relationship of untreated children, but 5% showed considerable improvement and 15% demonstrated worsening. Both early-treatment groups had a significant average reduction in ANB angle, more by change in maxillary dimensions in the headgear group and mandibular growth in the functional appliance group. There were wide variations in response, however, with only 75% of the treated children showing favorable skeletal response. Failure to respond favorably could not be explained by lack of cooperation alone. The preliminary results from phase 2 show that, on average, time in fixed appliances was shorter for children who underwent early treatment, but the total treatment time was considerably longer if the early phase of treatment was included. Only small differences were noted in anteroposterior jaw position between the groups at the completion of treatment, and the changes in dental occlusion, judged on the basis of Peer Assessment Rating scores, were similar between groups. Neither the severity of the initial problem nor the duration of treatment was correlated with the occlusal result. The number of patients who required extraction of permanent teeth was greater in the early functional appliance group than in the headgear or control group. The option of orthognathic surgery was presented more often in the cases of children who did not undergo early treatment, but surgery was accepted or was still being considered almost as frequently in the previous headgear group as in the controls, less often in the patients previously treated with functional appliances.
The aim of this investigation was to analyze three possible adaptive TMJ growth processes contributing to the increase in mandibular prognathism accomplished by Herbst appliance therapy: (1) condylar remodeling; (2) glenoid fossa remodeling; and (3) condyle-fossa relationship changes. The subjects were 15 consecutive Class II malocclusions (11 males and four females, aged 11.5-17.5 years) treated with the Herbst appliance for an average period of 7 months. Condylar remodelling, glenoid fossa remodelling, and condyle-fossa relationship changes were analyzed by means of magnetic resonance imaging (MRI). From each subject, four MR images were evaluated: before treatment, start of treatment (when the Herbst appliance was placed), during treatment (6-12 weeks after appliance placement), and after treatment (when the appliance was removed). 'Effective condylar growth' (= the sum of condylar remodelling, fossa remodelling, and condyle-fossa relationship changes) was analyzed with the aid of pre- and post-treatment lateral cephalometric roentgenograms. In all 15 subjects, Herbst therapy resulted in an increase in mandibular prognathism. After 6-12 weeks of treatment MRI-signs of condylar remodelling were seen at the posterior-superior border in 29 of the 30 condyles. MRI-signs of glenoid fossa remodelling at the anterior surface of the postglenoid spine were noted in 22 of the joints. Condylar remodelling seemed to precede fossa remodelling. The condyle-fossa relationship was, on average unaffected by Herbst therapy. 'Effective condylar growth' during treatment was, on average, approximately five times larger in the Herbst group than in an untreated group with ideal occlusion (Bolton Standards) and the direction of the growth changes was relatively more horizontal in the treated cases. The results indicate that condylar as well as glenoid fossa remodelling seem to contribute significantly to the increase in mandibular prognathism resulting from Herbst treatment, while condyle-fossa relationship changes are of less importance. MRI renders an excellent opportunity to visualize temporomandibular remodelling growth processes.
In 98 Class II Division 1 malocclusions treated with the Herbst appliance "effective condylar growth" (a summation of condylar remodeling, glenoid fossa remodeling, and condylar position changes within the fossa) and its influence on the position of the chin was analyzed. Lateral head films in habitual occlusion from before and after 0.6 years of Herbst treatment as well as 0.6 years and 3.1 years posttreatment were evaluated. All patients were treated to Class I or overcorrected Class I dental arch relationships. During the treatment period, effective condylar growth was relatively more backward directed and about three times larger than that in untreated subjects with ideal occlusion (Bolton Standards). During the first posttreatment period of 0.6 years, effective condylar growth recovered with respect to both the direction and amount of changes. During the second posttreatment period of 2.5 years, effective condylar growth was "normal." The corresponding chin position changes during the different examination periods were a mirror image of effective condylar growth provided no mandibular autorotation occurred. In cases with anterior mandibular autorotation, relatively more forward and in cases with posterior mandibular autorotation relatively more backward directed chin position changes resulted.
This investigation is a continuation of a previously published study assessing the treatment effects of the Twin Block appliance. All active treatment was carried out during the mixed dentition stage (mean starting age, 9 years 1 month) with final follow-up for the treatment group occurring in the permanent dentition (mean age, 13 years 1 month). Of the original group consisting of 28 consecutively treated severe skeletal Class II patients, 26 were available for follow-up. A comparison group of 28 untreated Class II subjects matched for age, sex, and vertical facial type was obtained from the Burlington Growth Centre according to the original study design. Of these 28 control subjects, 24 had 4-year follow-up cephalometric films available. The mean age of the controls was 12 years 11 months at the time of follow-up. During the active treatment phase, the Twin Block group experienced an average increase in mandibular unit length of 6.5 mm over a mean of 14 months (annualized rate of change of 5.6 mm per year). In comparison, the control group experienced a 2.3 mm increase in mandibular unit length during the 13-month observation period (annualized rate of 2.1 mm per year). In the posttreatment phase, the change in mandibular unit length for the Twin Block group was 6.0 mm over a 36-month period (annualized rate of change of 2.0 mm per year). The control group experienced an average increase in mandibular unit length of 6.7 mm over the posttreatment assessment period that was 34 months in duration (annualized rate of change of 2.4 mm per year). Although there was a slight reduction in mandibular growth rate after treatment, much of the significant increase in mandibular length achieved during the active phase of treatment with the Twin Block appliance was still present 3 years later when the subjects had matured into the permanent dentition stage.
This cephalometric study evaluated skeletal and dentoalveolar changes induced by the Twin-block appliance in 2 groups of subjects with Class II malocclusion treated at different skeletal maturation stages in order to define the optimal timing for this type of therapy. Skeletal maturity in individual patients was assessed on the basis of the stages of cervical vertebrae maturation. The early-treated group was composed of 21 subjects (11 females and 10 males). Mean age of these subjects at time 1 (immediately before treatment) was 9 years +/- 11 months, and at time 2 (immediately after discontinuation of the Twin-block appliance) was 10 years 2 months +/- 11 months. According to the cervical vertebrae maturation staging at times 1 and 2, the peak in growth velocity was not included in the treatment period for any of the subjects in the early group. The late-treated group consisted of 15 subjects (6 females and 9 males). Mean age of this group was 12 years 11 months +/- 1 year 2 months at time 1 and 14 years 4 months +/- 1 year 3 months at time 2. In the late group, treatment was performed during or slightly after the onset of the pubertal growth spurt. Both treated samples were compared with control samples consisting of subjects with untreated Class II malocclusions also selected on the basis of the stage in cervical vertebrae maturation. A modification of Pancherz's cephalometric analysis was applied to the lateral cephalograms of all examined groups at both time periods. Linear and angular measurements for mandibular dimensions, cranial base angulation, and vertical relationships were added to the original analysis. Annualized differences for all the variables from time 1 to time 2 were calculated for both treated groups and contrasted to the annualized differences in the corresponding untreated groups by means of nonparametric statistics. The findings of this short-term cephalometric study indicate that optimal timing for Twin-block therapy of Class II disharmony is during or slightly after the onset of the pubertal peak in growth velocity. When compared with treatment performed before the peak, late Twin-block treatment produces more favorable effects that include: (1) greater skeletal contribution to molar correction, (2) larger increments in total mandibular length and in ramus height, and (3) more posterior direction of condylar growth, leading to enhanced mandibular lengthening and to reduced forward displacement of the condyle in favor of effective skeletal changes. The importance of the biological evaluation of skeletal maturity in individual patients with Class II disharmony to be treated with functional appliances is emphasized.
The purpose of this study was to analyze the validity of 6 stages of cervical vertebral maturation (Cvs1 through Cvs6) as a biologic indicator for skeletal maturity in 24 subjects (15 females, 9 males). The method was able to detect the greatest increment in mandibular and craniofacial growth during the interval from vertebral stage 3 to vertebral stage 4 (Cvs3 to Cvs4), when the peak in statural height also occurred. The prevalence rate of examined subjects who presented with the peak in body height at this interval was 100% for boys and 87% for girls. Statural height and total mandibular length (Co-Gn) showed significant increments during the growth interval Cvs3 to Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration occurred during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showed significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Cervical vertebral maturation appears to be an appropriate method for the appraisal of mandibular skeletal maturity in individual patients on the basis of a single cephalometric observation and without additional x-ray exposure. The accuracy of the cervical vertebral method in the detection of the onset of the pubertal spurt in mandibular growth provides helpful indications concerning treatment timing of mandibular deficiencies.
The aim of this study was to assess the efficiency of early and late Class II Division 1 treatment in the mixed and permanent dentition. Treatment efficiency was defined as a better result in a shorter treatment time. We examined 204 patients with Class II Division 1 malocclusions treated in the early mixed dentition (n = 54), late mixed dentition (n = 104), and permanent dentition (n = 46). The pretreatment and posttreatment dental casts were evaluated with the peer assessment rating (PAR) index. The duration of treatment decreased with progressing dental development: patients in the early mixed dentition (dental stage [DS] 2) were treated for 57 months, patients in the late mixed dentition (DS 3) for 33 months, and patients in the permanent dentition (DS 4) for 21 months. Patients treated exclusively with fixed appliances had a shorter treatment duration (19 months for Herbst and 24 months for multibracket) than did patients treated with functional appliances or a combination of appliances (38 months for functional appliances and 49 months for a combination). The PAR score reduction (improvement) increased with progressing dental development: DS 2 patients had a PAR score reduction of 64%, DS 3 patients had a reduction of 73%, and DS 4 patients had a reduction of 77%. Patients treated exclusively with fixed appliances had a greater PAR score reduction (77%) than did patients treated with functional appliances or a combination (60% for fixed appliances and 71% for functional or a combination). Based on the results of this investigation, we concluded that treatment of Class II Division 1 malocclusions is more efficient in the permanent dentition (late treatment) than it is in the mixed dentition (early treatment).
The purpose of this study was to examine and report the effectiveness of early treatment with the headgear/biteplate and the bionator in patients with Class II malocclusion regardless of the mechanism of correction and to compare early-treatment results with changes over a similar time period in an observation group. The role of factors such as compliance was examined to determine their contribution to effective treatment. The experimental design was a prospective, longitudinal, randomized controlled trial. At the end of the early-treatment period, all 3 groups differed significantly (overall, P = .001) in percentage of treatment goal achieved, with median values of 83% for the bionator group, 100% for the headgear group, and 14% for the observation group. In both treated and observation subjects, the percentages of goal achieved varied by initial molar class severity (treated, P =.0205; observation, P = .0040) and race (treated, P = .0314; observation, P = .0416). Significant correlations in the treated subjects were identified between percentage of goal achieved and bone age (13 bones) (r = 0.16; P = .037), bone age (20 bones) (r = 0.16; P = .043), compliance (r = 0.26; P = .0005), and initial overjet (r = -0.26; P = .0095). Significant correlations were not detected in the observation group. Sex, treatment group, age, mandibular plane angle, pretreatment, and retention did not significantly affect percentage of goal achieved among the treated and the observation subjects. Correlation between normalized compliance scores and percentage of goal achieved was high for both bionator (r = 0.50) and headgear subjects (r = 0.49) at the end of treatment. Multivariate analysis suggested that headgear may be superior to bionator/biteplane in achieving a Class II correction during early treatment.
The aim of this longitudinal cephalometric study was to investigate early characteristics of favorable and unfavorable growth. Two groups of untreated subjects with skeletal Class II pattern were formed on the basis of an ANB angle at least 2.5 degrees above the individual norm, according to Järvinen, at age 5. The subjects were followed longitudinally until age 12. The favorable growth group (n = 13) consisted of subjects who exhibited a decrease in the individualized ANB angle of at least 1.5 degrees during follow-up. The unfavorable growth group (n = 10) was characterized by an increase in the individualized ANB angle during the growth period from 5 to 12 years. Early characteristics of unfavorable growth included increased mandibular plane angle (measured to the sella-nasion line and the palatal plane, P <.05), increased lower gonial angle (P <.05), and a decreased ratio of posterior-to-anterior face height (P <.05) [corrected]. At the longitudinal follow-up at age 12, the 2 groups showed significant differences in SNB (P <.01) and individualized ANB (P <.01). The improved sagittal jaw relationship in the favorable growth group was the result of changed mandibular position. Morphogenetic posterior rotation seems to occur early in patients with skeletal Class II pattern and unfavorable growth and might be part of an adaptive mechanism compensating for insufficient mandibular growth.
Am J Orthod Dentofacial Orthop 2002;121:572-4
The present study aimed to provide a version of the Cervical Vertebral Maturation (CVM) method for the detection of the peak in mandibular growth based on the analysis of the second through fourth cervical vertebrae in a single cephalogram. The morphology of the bodies of the second (odontoid process, C2), third (C3), and fourth (C4) cervical vertebrae were analyzed in six consecutive cephalometric observations (T1 through T6) of 30 orthodontically untreated subjects. Observations for each subject consisted of two consecutive cephalograms comprising the interval of maximum mandibular growth (as assessed by means of the maximum increment in total mandibular length, Co-Gn), together with two earlier consecutive cephalograms and two later consecutive cephalograms. The analysis consisted of both visual and cephalometric appraisals of morphological characteristics of the three cervical vertebrae. The construction of the new version of the CVM method was based on the results of both ANOVA for repeated measures with post-hoc Scheffé's test (P < .05) and discriminant analysis. The new CVM method presents with five maturational stages (Cervical Vertebral Maturation Stage [CVMS] I through CVMS V, instead of Cvs 1 through Cvs 6 in the former CVM method). The peak in mandibular growth occurs between CVMS II and CVMS III, and it has not been reached without the attainment of both CVMS I and CVMS II. CVMS V is recorded at least two years after the peak. The advantages of the new version of the CVM method are that mandibular skeletal maturity can be appraised on a single cephalogram and through the analysis of only the second, third, and fourth cervical vertebrae, which usually are visible even when a protective radiation collar is worn.
This retrospective study was undertaken to determine the presence of any features on a pretreatment lateral cephalogram that may be used to predict the success of improvement in the sagittal dental base relationship during functional appliance therapy in patients with a Class II skeletal pattern. Seventy-two patients judged to have been successfully treated with a functional appliance were selected for the study. Pre- and posttreatment radiographs were analyzed and the change in the ANB angle was used to determine the skeletal response to treatment. Within the total sample size of 72 patients, two groups were selected. One group of 13 patients who demonstrated a reduction in ANB angle of 3.0 degrees or more were identified as the skeletal group. A second group of 15 patients who demonstrated a change in ANB angle equal to or less than 0.5 degrees were identified as the nonskeletal group. Statistical analysis of these two groups revealed the presence of skeletal and dentoalveolar differences on the pretreatment lateral cephalogram. In the skeletal group, which responded with a favorable skeletal change, the mandible was smaller both in length (P < .01) and ramus height (P < .05) and the anterior and posterior lower face heights were smaller (P < .05). The cranial base was also smaller when compared with the respective lengths in the nonskeletal group.
The mandibular anterior repositioning appliance (MARA) is a tooth-borne functional appliance for use in patients with Class II malocclusions; it positions the mandible forward into a Class I occlusion. The aim of this study was to investigate the MARA's dental and skeletal effects on anterior, posterior, and vertical changes in 30 Class II patients. The treatment group consisted of 12 boys with an average age of 11.2 years and 18 girls with an average age of 11.3 years. A pretreatment cephalometric radiograph was taken 2 weeks before treatment, and a posttreatment cephalometric radiograph was taken 6 weeks after removal of the MARA, with an average treatment time of 10.7 months. The mean and standard deviation were calculated for each cephalometric variable, and Student t tests were performed to determine the statistical significance of the changes. The results of the study showed that the MARA produced measurable treatment effects on the skeletal and dental elements of the craniofacial complex. These effects included a considerable distalization of the maxillary molar, a measurable forward movement of the mandibular molar and incisor, a significant increase in mandibular length, and an increase in posterior face height. The effects of the MARA treatment were then compared with those of the Herbst and Fränkel appliances. The treatment results of the MARA were very similar to those produced by the Herbst appliance but with less headgear effect on the maxilla and less mandibular incisor proclination than observed in the Herbst treatment group.
The aim of the present investigation was to provide information about the long-term effects and optimal timing for class-II treatment with the Bionator appliance. Lateral cephalograms of 23 class-II patients treated with the Bionator were analyzed at three time periods: T1, start of treatment; T2, end of Bionator therapy; and T3, long-term observation (after completion of growth). T3 includes a phase with fixed appliances. The treated sample was divided into two groups according to their skeletal maturity as evaluated by the cervical vertebral maturation (CVM) method. The early-treated group (13 subjects) initiated treatment before the peak in mandibular growth, which occurred after completion of Bionator therapy. The late-treated group (10 subjects) received Bionator treatment during the peak. The T1-T2, T2-T3, and T1-T3 changes in the treated groups were compared with changes in control groups of untreated class-II subjects by nonparametric statistics (P < .05). The findings of the present study on Bionator therapy followed by fixed appliances indicate that this treatment protocol is more effective and stable when it is performed during the pubertal growth spurt. Optimal timing to start treatment with the Bionator is when a concavity appears at the lower borders of the second and the third cervical vertebrae (CVMS II). In the long-term, the amount of significant supplementary elongation of the mandible in subjects treated during the pubertal peak is 5.1 mm more than in the controls, and it is associated with a backward direction of condylar growth. Significant increments in mandibular ramus height also were recorded.
The objective of this study was to compare the treatment outcomes and stability of patients with Class II malocclusion treated with either functional appliances or surgical mandibular advancement.
The early-treatment group consisted of 30 patients (15 girls, 15 boys), with a mean age of 10 years 4 months (range, 7 years 5 months to 12 years 5 months), who received either Fränkel II (15 patients) or Herbst appliances (15 patients). The surgical group consisted of 30 patients (23 female, 7 male), with a mean age of 27 years 2 months (range, 13 years 0 months to 53 years 10 months). They were treated with bilateral sagittal split ramus osteotomies with rigid fixation. Lateral cephalograms were taken for the early-treatment group at T1 (initial records), T2 (completion of functional appliance treatment), and Tf (completion of comprehensive treatment). In the surgical group, lateral cephalograms were taken at T1 (initial records), T2 (presurgery), T3 (postsurgery), and Tf (completion of comprehensive treatment). The average times from the completion of functional appliance treatment or surgery to the final cephalograms were 35.8 months and 34.9 months, respectively. A mixed-design analysis of variance was used to compare changes within and between groups.
In the functional appliance group, the mandible continued to grow in a favorable direction even after discontinuation of the functional appliance. Both groups had stable results over time. Both groups finished treatment with the same cephalometric measurements. Significant skeletal and soft tissue changes were noted in the treatment groups due to either functional or surgical advancement of the mandible. More vertical relapse was noted in the surgical group than in the functional group.
This study suggests that early correction of Class II dentoskeletal malocclusions with functional appliances yields favorable results without the possible deleterious effects of surgery.
The purpose of this investigation was to evaluate the dentoalveolar and skeletal cephalometric changes produced by headgear (HG) biteplane and bionator appliances in subjects with Class II Division 1 malocclusion.
The sample comprised 60 patients with Class II Division 1 malocclusion; 30 (15 boys, 15 girls; mean age, 10.02 years) were treated with the HG biteplane for a mean period of 1.78 years, and 30 (15 boys, 15 girls; mean age, 10.35 years) were treated with a bionator for a mean period of 1.52 years. For comparison, a control group of 30 untreated Class II children (15 boys, 15 girls) with an initial mean age of 10.02 years, followed for 1.48 years, was established. Lateral cephalometric headfilms were obtained at the beginning and at the end of the treatment or observation period.
The results showed that forward growth of the maxilla was restricted in the HG biteplane group. Bionator treatment, however, produced a statistically significant increase in mandibular protrusion. Both appliances provided increases in total mandibular and ramus lengths. There were no statistically significant differences in craniofacial growth direction. The mandibular incisors were tipped labially with bionator treatment and lingually in the HG biteplane group. The maxillary incisors were retruded with both appliances; there also were a significant increase in mandibular posterior dentoalveolar height and a restriction in the vertical development of the maxillary molars.
Class II treatment with HG biteplane and bionator appliances is efficient over the short term, with pronounced dentoalveolar movements and smaller but still significant skeletal effects. The stability of these results should be examined in a long-term study.
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