ArticleLiterature Review

Dispositifs intramaxillaires de distalisation des molaires en technique multi-attache et avec aligneurs

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Abstract

Introduction: Class II malocclusion is a dysmorphosis that can result from different skeletal and/or alveolar components of maxillary and/or mandibular origin. In dental class II cases due to mesial drift of the maxillary molars, it is sometimes interesting to retract the maxillary molars, in order to avoid in certain situations extractions of premolars. To this end, several devices have been described in the literature. The most recent intraoral devices allow a more controlled correction, and no longer require cooperation from the patient. In addition, in a number of cases of distalization, aligners now offer a useful therapeutic option since they are both esthetic and easy-to-use. Materials and methods: In this study, we carried out a review of the various studies in the literature describing intra-oral distalization of the maxillary molars in the multi-bracket technique as well as using aligners, with a clinical illustration of a Class II case treated by aligners.

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... Le taux global de publication a été de 0,6% (7/1031) alors que le taux de publication spécifique aux thèses de recherche a été de 3,1% (7/224). Sept thèses (11-17) ont été publiées dans des revues indexées et trois (11,13,15) ont servi de support à des publications dans des revues ayant un impact factor (Tableau 5). Ces articles ont été publiés dans six journaux différents. ...
... En se basant sur la répartition des thèses publiées par spécialité, on a trouvé que l'ODF avait trois publications dans des revues indexées. A l'exception du dernier article (17), tous les thésards ont été cités comme cosignataires au niveau des publications soit en deuxième position (11,(14)(15)(16) soit en troisième position (12,13). La période d'étude n'a pas été déterminée d'une façon arbitraire. ...
Article
Aim: To present the characteristics of dissertations defended at the faculty of dental medicine in Monastir. Methods: This was a descriptive study that interested all the dental medicine's dissertations during a period of five years, from 01/01/2014 to 31/12/2018. The theses available in the faculty library were included in the study. The writing quality of the research dissertations was reviewed. Then publication patterns of these were searched in the "Medline" and "Scopus" databases. Results: One thousand thirty one theses were included into this study. Synthetic research thesis and individual research ones represented respectively 9.4% and 21.7%; otherwise were a bibliographic synthesis. The number of directors was 1233. The most represented specialties were Fixed Prosthesis and Oral Medicine & Surgery with 190 (17.4%), 146 (13.3%) dissertations, respectively. The number of thesis per university hospital doctor per year was 2.3. For research theses, the score of the writing quality was 12.1±2.4. However, only seven (3.1%) theses were published in the journals indexed in PubMed database. Conclusion: This study displays a very low rate of published dissertations defended in the faculty of dental medicine. New strategies may be promoted in order improve thesis publication. Objectif : Dresser le profil bibliométrique des thèses soutenues à la Faculté de Médecine Dentaire de Monastir (FMDM). Méthodes : Il s'agit d'une étude descriptive qui a intéressé toutes les thèses soutenues pendant la période allant du 1/1/2014 au 31/12/2018. La qualité de la rédaction des thèses de recherche a été analysée en se référant aux instructions de rédaction du Groupe de Recherche Inter Facultaire sur le Devenir des Dissertations dans le domaine de la santé. Le devenir de la thèse, en termes de valorisation scientifique, a été étudié à travers une recherche documentaire dans les bases de données «Medline» et «Scopus». Résultats : Le nombre des thèses soutenues était de 1031. Les études de recherche synthétique et individuelle représentaient respectivement 9,4% et 21,7% ; Les autres thèses étaient des synthèses bibliographiques. Le nombre des directeurs des thèses étaient 1233. Les spécialités les plus représentées étaient la Prothèse Conjointe, la Médecine et Chirurgie Buccales avec respectivement 190 (17,4%), 146 (13,3%) thèses. La productivité globale moyenne à la FMDM était de 2,3 thèses/enseignant/année. Pour les thèses de recherche individuelle, le score de la qualité rédactionnelle était de 12,1±2,4. Cependant, seulement sept (3,1 %) thèses, parmi les 224 thèses ont été publiées dans des revues indexées. Parmi ces articles publiés, trois ont servi de support à des publications dans des revues ayant un impact factor. Conclusion : Cette étude a montré un faible taux de publication des thèses soutenues à la FMDM et une qualité réactionnelle moyenne. De nouvelles stratégies pour les valoriser doivent être développées.
... Several molar distalization systems have been used to correct class II dental offsets, namely: distal active concept, pendulum, elastic-based mechanics or even sliding by "jig" [5,6]. ...
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Objective: To assess the scientific evidence related to the efficacy of clear aligner treatment (CAT) in controlling orthodontic tooth movement. Materials and methods: PubMed, PMC, NLM, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to June 2014 to identify all peer-reviewed articles potentially relevant to the review. Methodological shortcomings were highlighted and the quality of the studies was ranked using the Cochrane Tool for Risk of Bias Assessment. Results: Eleven relevant articles were selected (two Randomized Clinical Trials (RCT), five prospective non-randomized, four retrospective non-randomized), and the risk of bias was moderate for six studies and unclear for the others. The amount of mean intrusion reported was 0.72 mm. Extrusion was the most difficult movement to control (30% of accuracy), followed by rotation. Upper molar distalization revealed the highest predictability (88%) when a bodily movement of at least 1.5 mm was prescribed. A decrease of the Little's Index (mandibular arch: 5 mm; maxillary arch: 4 mm) was observed in aligning arches. Conclusions: CAT aligns and levels the arches; it is effective in controlling anterior intrusion but not anterior extrusion; it is effective in controlling posterior buccolingual inclination but not anterior buccolingual inclination; it is effective in controlling upper molar bodily movements of about 1.5 mm; and it is not effective in controlling rotation of rounded teeth in particular. However, the results of this review should be interpreted with caution because of the number, quality, and heterogeneity of the studies.
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The maxillary molar distalization is a valuable therapeutic option in some clinical cases. Its biomechanics is challenging and difficult to obtain. Historically, various devices have been described offering successful solutions to this problem such as the Hilgers Pendulum Appliance (1992) and variants linked to mini screws which recently have shown interesting clinical potential. This article presents a new Pendulum variant using a miniscrew, the "pendulis". It follows the original concept (titanium-molybdenum alloy distalization springs and polymethyl-methacrylate pellet) but dental support is replaced by a single palatal miniscrew (median adults, para-median in children) to which the device is fixed by means of a metal welded cap easily positioned and removable by the practitioner. This allows for better control of the oral hygiene and completely controlled extraoral activation. Fabrication steps are described and instruction of use is illustrated with clinical documentation. © EDP Sciences, SFODF, 2014.
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Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5 mm. every two weeks using clear aligners. A duplicate aligner was provided for the second week of each cycle. Weekly polyvinyl siloxane (PVS) impressions were taken, and digital models were fabricated to measure OTM. Initial and final cone beam computed tomography (CBCT) images were obtained to characterize OTM. Results were compared to data from a similar protocol, where subjects received a new aligner biweekly. No significant difference was found in the amount of OTM between the two groups, with mean total OTM of 1.11 mm. (standard deviation (SD) 0.30) and 1.07 mm. (SD 0.33) for the weekly aligner and biweekly control groups, respectively (P = 0.72). Over eight weeks, in two-week intervals, material fatigue does not play a significant role in the rate or amount of tooth movement.
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This prospective study aimed to evaluate the effects of the zygoma anchorage system (ZAS) in buccal segment distalization in comparison with cervical headgear (CH). Thirty patients with Class II dental malocclusions were included in the study and were divided into two equal groups: the first group (10 females and 5 males, mean age 14.74 years at T1) received buccal segment distalization with ZAS and the second group (8 females and 7 males, mean age 15.26 years at T1) with CH. The skeletal, dental, and soft tissue changes were measured on cephalograms obtained before (T1) and after (T2) distalization, and these changes were statistically evaluated using a repeated measures analysis of variance, Mann–Whitney U-test, and Wilcoxon test. The Class II buccal segment relationship was corrected to a Class I in an average period of 9.03 ± 0.62 months in the ZAS group and 9.00 ± 0.76 months in the CH group. Significant distalization was observed for the posterior teeth in both groups (P < 0.001). Distal tipping of all posterior teeth occurred in the CH group (P < 0.001), but only for the molars in the ZAS group (P < 0.001). The upper incisors retroclined, overjet decreased, and the upper and lower lips retruded in both groups. The ZAS provided absolute anchorage for distalization of the maxillary posterior teeth and can be used as an aesthetic and non-compliant alternative to extraoral traction in the treatment of Class II malocclusions.
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In this study, we compared the dentoalveolar changes of Class II patients treated with Jones jig and pendulum appliances. The experimental group comprised 40 Class II malocclusion subjects, divided into 2 groups: group 1 consisted of 20 patients (11 boys, 9 girls) at a mean pretreatment age of 13.17 years, treated with the Jones jig appliance for 0.91 years; group 2 comprised 20 patients (8 boys, 12 girls) at a mean pretreatment age of 13.98 years, treated with the pendulum appliance for 1.18 years. Only active treatment time of molar distalization was evaluated in the predistalization and postdistalization lateral cephalograms. Molar, second premolar, and incisor angular and linear variables were obtained. The intergroup treatment changes in these variables were compared with independent t tests. The maxillary second premolars showed greater mesial tipping and extrusion in the Jones jig group, indicating more anchorage loss during molar distalization with this appliance. The amounts and the monthly rates of molar distalization were similar in both groups. The Jones jig group showed greater mesial tipping and extrusion of the maxillary second premolars. The mean amounts and the monthly rates of first molar distalization were similar in both groups.
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The purpose of this study was to evaluate the skeletal and dental changes in patients who underwent distalization of their maxillary molars with pendulum appliances. The sample consisted of 31 patients (initial mean age, 14.58 years) with Angle Class II molar relationships and all permanent teeth up to the second molars. The maxillary molars were distalized with pendulum appliances for a mean period of 5.87 months. Lateral cephalograms, 45 degrees oblique radiographs, and dental casts were obtained before and after distalization. Changes produced by the pendulum appliance were analyzed with paired t tests. Maxillary first molar distalization accounted for 63.5% of the space opening; mesial movement of the maxillary first premolars contributed 36.5% of the space. The mean space opening on lateral cephalograms was 7.25 mm, and the rate of molar movement was 1.23 mm per month. The mean distalization of the maxillary molars was 4.6 mm, with a mean distal crown tipping of 18.5 degrees The maxillary molars experienced expansion, with a smaller effect on the first molars than on the second molars. The pendulum appliance produced symmetrical expansion, with a rate of 1.04 mm per month on the right and 1.10 mm per month on the left. The pendulum appliance is effective for distalization of the maxillary molars and the establishment of a Class I molar relationship in a relatively short time. However, caution is needed to control collateral effects, including mesial movement of the first premolars and distal tipping of the molar crowns.
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Introduction The purpose of this study was to evaluate the treatment effects of maxillary posterior tooth distalization performed by a modified palatal anchorage plate appliance with cephalograms derived from cone-beam computed tomography. Methods The sample consisted of 40 lateral cephalograms obtained from the cone-beam computed tomography images of 20 Class II patients (7 men, 13 women; average age, 22.9 years) who underwent bilateral distalization of their maxillary dentition. The lateral cephalograms were derived from the cone-beam computed tomography images taken immediately before placement of a modified palatal anchorage plate appliance and at the end of distalization. Paired t tests were used for comparisons of the changes. Results The distal movement of the maxillary first molar was 3.3 ± 1.8 mm, with distal tipping of 3.4° ± 5.8° and intrusion of 1.8 ± 1.4 mm. Moreover, the maxillary incisors moved 3.0 ± 2.7 mm lingually, with lingual tipping of 6.2° ± 7.6° and insignificant extrusion (1.1 mm; P = 0.06). The occlusal plane angle was increased significantly (P = 0.0001). Conclusions The maxillary first molar was distalized by 3.3 mm at the crown and 2.2 mm at root levels, with distal tipping of 3.4°. It is recommended that clinicians should consider using the modified palatal anchorage plate appliance in treatment planning for patients who require maxillary total arch distalization.
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Introduction The exact force systems as well as their progressions generated by removable thermoplastic appliances have not been investigated. Thus, the purposes of this experimental study were to quantify the forces and moments delivered by a single aligner and a series of aligners (Invisalign; Align Technology, Santa Clara, Calif) and to investigate the influence of attachments and power ridges on the force transfer. Methods We studied 970 aligners of the Invisalign system (60 series of aligners). The aligners came from 30 consecutive patients, of which 3 tooth movements (incisor torque, premolar derotation, molar distalization) with 20 movements each were analyzed. The 3 movement groups were subdivided so that 10 movements were supported with an attachment and 10 were not. The patients' ClinCheck (Align Technology, Santa Clara, Calif) was planned so that the movements to be investigated were performed in isolation in the respective quadrant. Resin replicas of the patients' intraoral situation before the start of the investigated movement were taken and mounted in a biomechanical measurement system. An aligner was put on the model, the force systems were measured, and the calculated movements were experimentally performed until no further forces or moments were generated. Subsequently, the next aligners were installed, and the measurements were repeated. Results The initial mean moments were about 7.3 N·mm for maxillary incisor torque and about 1.0 N for distalization. Significant differences in the generated moments were measured in the premolar derotation group, whether they were supported with an attachment (8.8 N·mm) or not (1.2 N·mm). All measurements showed an exponential force change. Conclusions Apart from a few maximal initial force systems, the forces and moments generated by aligners of the Invisalign system are within the range of orthodontic forces. The force change is exponential while a patient is wearing removable thermoplastic appliances.
Article
Interest in nonextraction therapy has accelerated the use and development of several molar distalizing appliances requiring minimal patient compliance. The Pendulum appliance, developed by Hilgers, has become one of the more popular designs. This study attempts to evaluate the performance of the Pendulum appliance in correcting Class II malocclusions via molar distalization. Seven patients were treated using this appliance. Lateral cephalographs were taken before treatment and immediately after removal of the appliance. Measurements were taken to evaluate molar movement and changes in angulation. Anchorage loss was measured by evaluating mesial incisor movement and angular changes. Changes in vertical dimension were also noted. Distalization occurred quite rapidly with overcorrection beyond a Class I molar relationship completed in an average time of 3.4 months. Mean distal movement of the upper first molars was 5.1 mm. This movement was accompanied by a mean change in angulation of 15.7°. Anchorage loss was evident with a mean increase in incisor angulation of 4.9° and an average advancement atthe incisal edge of 3.7 mm. Vertical dimension was virtually unaffected. This appliance was an effective means of distalizing molars into a Class I relationship with little patient cooperation. Some side effects were evident such as anchorage loss in the form of increased overjet and molar tipping. These side effects must be taken into account for when considering the use of this appliance.
Article
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The aims of this meta-analysis were to quantify and to compare the amounts of distalization and anchorage loss of conventional and skeletal anchorage methods in the correction of Class II malocclusion with intraoral distalizers. The literature was searched through 5 electronic databases, and inclusion criteria were applied. Articles that presented pretreatment and posttreatment cephalometric values were preferred. Quality assessments of the studies were performed. The averages and standard deviations of molar and premolar effects were extracted from the studies to perform a meta-analysis. After applying the inclusion and exclusion criteria, 40 studies were included in the systematic review. After the quality analysis, 2 articles were classified as high quality, 27 as medium quality, and 11 as low quality. For the meta-analysis, 6 studies were included, and they showed average molar distalization amounts of 3.34 mm with conventional anchorage and 5.10 mm with skeletal anchorage. The meta-analysis of premolar movement showed estimates of combined effects of 2.30 mm (mesialization) in studies with conventional anchorage and -4.01 mm (distalization) in studies with skeletal anchorage. There was scientific evidence that both anchorage systems are effective for distalization; however, with skeletal anchorage, there was no anchorage loss when direct anchorage was used.
Article
Conventional anchorage appliances rely exclusively on intraoral anchorage for noncompliance molar distalization. The partial coverage of the palate, in particular, often results in compromised oral hygiene. An innovative alternative combines a skeletonized distal jet appliance with 2 paramedian miniscrews for additional anchorage. The objectives of this study were to investigate the suitability of the skeletonized distal jet for translatory molar distalization and to check the quality of the supporting anchorage setup. Two paramedian miniscrews (length, 8-9 mm; diameter, 1.6 mm) were placed into the anterior area of the palate in 10 patients. Skeletonized distal jet appliances fitted with composite to the first premolars and the collars of the miniscrews were used for bilateral molar distalization, and the coil springs were activated with a distalization force of 200 cN on each side. The study confirmed the suitability of the appliance for translatory molar distalization (3.92 +/- 0.53 mm) with slight mesial inward rotation (on average, 8.35 degrees +/- 7.66 degrees and 7.88 degrees +/- 5.50 degrees ). The forces acting reciprocally on the anchorage setup were largely absorbed by the anchorage unit involving 2 anchorage teeth and 2 miniscrews. Significant anchorage loss, in the form of first premolar mesialization of 0.72 +/- 0.78 mm, was found. The skeletonized distal jet appliance supported by additional miniscrew anchorage allows translatory molar distalization. Although the anchorage design combining 2 miniscrews at a paramedian location and the periodontium of 2 anchorage teeth does not offer the quality of stationary anchorage, it achieves greater molar distalization in total sagittal movement than conventional anchorage designs with an acrylic button.
Article
The objective of this prospective study was to describe the clinical effects of a bone-supported molar distalizing appliance, the dual-force distalizer. The study group included 16 patients (mean age, 14.3 years) with Class II molar relationships. Study models and lateral cephalograms were taken before and after the distalizing movement to record significant dental and skeletal changes (Wilcoxon test). The average distalization time was 5 months, with a movement rate of 1.2 mm per month; the distalization amounts were 5.9 +/- 1.72 mm at the crown level and 4.4 +/- 1.41 mm at the furcation level. The average molar inclination was 5.6 degrees +/- 3.7 degrees ; this was less than the amount of inclination generated by bone-supported appliances that use single distalizing forces. The correlation between inclination and distalization was not significant, indicating predominantly bodily movement. The teeth anterior to the first molar moved distally also; the second premolars distalized an average of 4.26 mm, and the incisors retruded by 0.53 mm. The dual-force distalizer is a valid alternative distalizing appliance that generates controlled molar distalization with a good rate of movement and no loss of anchorage.
Article
Since the end of the 1970s, various appliances with intramaxillary anchorage for distalization of the upper molars have been described as an alternative to headgear. The major advantages of these innovative appliances are that they act permanently and are independent of patient compliance. The purpose of this study was to compare the efficiency, both quantitatively and qualitatively, of various appliance types with intramaxillary anchorage for non-compliance molar distalization. Eighty-five papers were reviewed, and 22 were identified as being suitable for inclusion. The selection was based on compliance with the following criteria: treatment group with at least 10 non-syndromal patients, conventional intraoral anchorage design using a palatal button and anchorage teeth, consistent cephalometric measurements in clinical–epidemiological studies, exact data on the course of treatment, and statistical presentation of the measured outcomes and their standard deviations. The results show that non-compliance molar distalization is possible with numerous different appliances. While molar distalization with standard pendulum appliances exhibited the largest values for dental-linear distalization, it also resulted in concurrent, substantial therapeutically undesirable distal tipping. However, specific modifications to the pendulum appliance allow achievement of almost bodily molar distalization. Different outcomes are quoted in the studies for the efficiency of loaded spring systems for distal molar movement, but it seems that the first class appliance and the palatal distal jet are more efficient than the vestibular Jones Jig. The studies identify anchorage loss as being found in the area of the incisors rather than the area of the first premolars. There was a trend for more substantial reciprocal side-effects to occur when only two teeth were included in the anchorage unit. Vertical components acting on the molars, premolars, and incisors, such as intrusion and extrusion, tended to be of secondary importance and, therefore, may be disregarded.
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In this report, three patients were treated with a new treatment protocol for Invisalign to demonstrate that a variety of complex malocclusions can be successfully treated using this protocol, including correction of moderate crowding, correction of moderate Class II division 1, and deep overbite. Previous studies of Invisalign showed significant limitations for more complex orthodontic treatment, although a few recent case reports have shown successfully completed moderate to difficult orthodontic malocclusions. One reason for the discrepancy is that the earlier studies were done during the first four years of the appliance development (now ten years of clinical use), when significant problems existed with accomplishing bodily movement, torquing of roots, extrusions, and rotations of premolars and canines. The new protocol included new methods for anterior/posterior corrections, showing on the computer the effect of elastics for Class II treatment simulated as a one-stage anterior/posterior movement at the end of treatment. Staging for interproximal reduction (IPR) is now automatically staged when there is better access to interproximal contacts to avoid IPR where significant overlap between teeth is present to avoid performing IPR on surfaces that may be damaged by instruments such as burs, strips, and disks when cut on a sharp angle. Staging for tooth movements is now also done to enable combination movements to occur simultaneously for each tooth with the tooth that needs to move the most (the lead tooth) determining the minimum number of stages required. All other teeth move at a slower rate than the lead tooth throughout the duration of treatment. Attachments are now placed in the middle of the crown automatically for rotation and automatically sized in proportion to the clinical crown. Use of 1 mm thick (buccal-lingual dimension) horizontal beveled rectangular attachments is standard on premolars for retention of aligners during intrusive movements, such as leveling the lower curve of Spee in deep overbite for extrusions and for control of the tooth long axis during torquing movements. Staging of tooth movements now track linear and rotational velocities of teeth separately with the number of treatment stages determined by the lead tooth based on its rotational or linear maximum velocities at no more than two degrees of rotation per stage. Simultaneous movements are done for all teeth providing visible space (approximately 0.05 mm) between teeth during movements past other teeth using expansion instead of IPR as a primary way to increase space available for correction of crowding.
Article
The objectives of our study were to achieve bodily molar distalization, avoid distal tipping of molars, eliminate the need for patient cooperation (no headgear, no elastics, and no esthetic and social concern), and finally to minimize the treatment period and maximize the treatment efficiency. The study was carried out on 5 males and 10 females, a total of 15 patients. Mean age for the study group was 13.53 years. Dentally, all the patients had Class II molar relationship on both sides. The patients were in permanent dentition, second molars were erupted, and the lower dental arch was well aligned. Patients showed normal or sagittally directed growth pattern. Lateral cephalograms and study models were taken and analyzed before and after molar distalization. In the present study, in order to achieve maxillary molar distalization, a new intraoral appliance was developed. The intraoral bodily molar distalizer (IBMB) was composed of 2 parts: the anchorage unit and the distalizing unit. The anchorage unit was a wide Nance button, and the active unit consisted of distalizing springs. The springs had 2 components: the distalizer section of the spring applied a crown tipping force, while the uprighting section of the spring applied a root uprighting force on the first molars. A total of 230 g of distalizing force was used on both sides. After the distal movement of the first molars, the cephalometric results of 15 patients showed the following. Maxillary first molars were moved distally by an average of 5.23 mm (P <.001) without tipping or extrusion. Maxillary first premolars were moved 4.33 mm mesially (P <.001), tipped 2.73 degrees distally (P <.05), and extruded by 3.33 mm (P <.001). Maxillary central incisors were proclined by an average of 4.7 mm (P <.001) and tipped 6.73 degrees labially (P <.01). Model analysis showed that maxillary first molars were not rotated, and intermolar distance did not change after distal movement of molars. In conclusion, unlike most of the other molar distalization mechanics, this newly developed device achieved (1) bodily distal movement of maxillary molars and (2) eliminated dependence on patient cooperation and did not require headgear wear for molar root uprighting.
Article
The purpose of the study was to examine the dentoalveolar and skeletal effects of the pendulum appliance in Class II patients at varying stages of dental development and with varying facial patterns (high, neutral, and low mandibular plane angles). Specifically, the amount and nature of the "distalization" of the maxillary first molars and the reciprocal effects on the anchoring maxillary first premolars and incisors were studied, as were skeletal changes in the sagittal and vertical dimensions of the face. Pretreatment and posttreatment cephalometric radiographs obtained from 13 practitioners were used to document the treatment of 101 patients (45 boys and 56 girls). The average maxillary first molar distalization was 5.7 mm, with a distal tipping of 10.6 degrees. The anchoring anterior teeth moved mesially, as indicated by the 1.8-mm anterior movement of the upper first premolars, with a mesial tipping of 1.5 degrees. The maxillary first molars intruded 0.7 mm, and the first premolars extruded 1.0 mm. Lower anterior facial height increased 2.2 mm; there was no significant difference in lower anterior facial height increase between patients of high, neutral, or low mandibular plane angles. In patients with erupted maxillary second molars, there was a slightly greater increase in lower anterior face height and in the mandibular plane angle and a slightly greater decrease in overbite in comparison to patients with unerupted second molars. Similar findings were observed in patients with second premolar anchorage versus those with second deciduous molar anchorage. The results of this study suggest that the pendulum appliance is effective in moving maxillary molars posteriorly during orthodontic treatment. For maximum maxillary first molar distalization with minimal increase in lower anterior facial height, this appliance is used most effectively in patients with deciduous maxillary second molars for anchorage and unerupted permanent maxillary second molars, although significant bite opening was not a concern in any patient in this study.
Article
This study analyzed molar distalization with the distal jet appliance, its effect on the anchor teeth, and the outcome at the completion of orthodontic treatment. Pretreatment, after distalization, and posttreatment lateral cephalometric radiographs were evaluated for 21 adolescent girls and 12 adolescent boys. The mean age of the subjects at the time of the pretreatment radiograph was 12.8 +/- 2.2 years. The mean time for the correction of the Class II molar relationship was 6.7 +/- 1.7 months, and the mean total treatment time was 25.7 +/- 3.9 months. The results of this study showed that the distal jet appliance distalized the maxillary molars, but there was significant loss of anchorage. The distal jet also showed less tipping of the maxillary molars and better bodily movement of molars because the force was applied closer to the center of resistance. The observations of treatment outcome indicate that the 1.8-mm mean net anterior movement of the maxillary first molar was more than offset by the 4.8-mm mesial movement of the mandibular first molar. There was no significant increase in lower face height. Consequently the effect on the facial balance was negligible.
Article
Fifteen patients, eight males and seven females with a mean age of 13.32 years, were selected for unilateral molar distalization. Dentally, all presented with a unilateral Class II molar relationship. The subjects were all in the permanent dentition with second molars erupted and with a well aligned lower dental arch. For maxillary molar distalization a new intra-oral appliance was developed, the Keles Slider, which comprised two premolar and two molar bands. The anchorage unit was a Nance button with an anterior bite plane. From the palatal side, the point of distal force application was carried towards the level of centre of resistance of the maxillary first molar. A Ni-Ti coil spring was used and 200 g distal force was applied to the Class II first molar. Lateral cephalograms were taken and analysed before and 2 months after molar distalization. The Class II molars were distalized bodily, on average, 4.9 mm (P < 0.001). Mesial migration of the Class II first premolars was 1.3 mm (P < 0.05), incisor protrusion was 1.8 mm (P < 0.05) and incisor proclination 3.2 degrees (P < 0.05). The overbite was reduced by 3.1 mm (P < 0.001) and the overjet increased 2.1 mm (P < 0.01). For stabilization, the corrected Class II unilateral molar relationship was maintained with a Nance button for 2 months. The results show that this newly developed device achieved bodily distal molar movement with minimum anchorage loss.
Article
The Invisalign System of tooth movement has been available to orthodontists since 1999 and has now become available to the entire dental profession. This paper explores the role of this system within the dental armamentarium and describes the clinical evolution of the appliance, based on a feasibility study initiated at the University of the Pacific in 1997.
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This study compared the dentoalveolar and skeletal effects on Class II malocclusions of the distal jet with concurrent full fixed appliances and the pendulum appliance both followed by fixed appliances. The 2 samples each consisted of 32 subjects (19 girls and 13 boys) with mean ages at the start of treatment of 12 years 3 months in the distal jet group and 12 years 6 months in the pendulum group. The durations of the distalization phase of treatment were 10 months in the distal jet group and 7 months in the pendulum group, and the durations of the second phase of treatment with fixed appliances were 18 months in the distal jet group and 24 months in the pendulum group. Lateral cephalograms were analyzed at 3 observation times: before treatment, after distalization, and after orthodontic treatment. During molar distalization, the pendulum subjects showed significantly more distal molar movement and significantly less anchorage loss at both the premolars and the maxillary incisors than the distal jet subjects. The distal jet used simultaneously with fixed appliances and the pendulum were equal in their ability to move the molars bodily. Very little change occurred in the inclination of the mandibular plane at the end of the 2-phase treatment (less than 1 degrees ) in both groups. At the end of comprehensive treatment, the maxillary first molars were 0.6 mm mesial to their original positions in the distal jet group and 0.5 mm distal in the pendulum group. Nevertheless, total molar correction was identical in the 2 groups (3.0 mm), and both appliances were equally effective in achieving a Class I molar relationship. Simultaneous edgewise orthodontic treatment during molar distalization in the distal jet group shortened the overall treatment time but produced significant flaring of both maxillary and mandibular incisors at the end of treatment. The impact on the soft tissue profile was minimal with both appliances.
Article
The conventional anchorage design of an appliance for non-compliance molar distalization anchored exclusively intraorally combines an acrylic pad or button placed on the palatal mucosa with involvment of the anchoring-teeth’s periodontium. Disadvantages of this anchorage design include the difficulties it causes for proper oral hygiene, reactive forces and moments exerted on the anterior dentition, and relative contraindications based on certain dentition stages and local conditions. In this article we describe alternative anchorage designs, concentrating on types of anchorage that are applied with orthodontic anchoring implants of reduced diameter and length. Such implants offer several key advantages be yond that of facilitating proper hygiene, namely that they cause fewer or no side-effects in the anterior maxillary dentition area, and that a wider range of indications apply to children, adolescents and adults.
Article
The authors conducted a systematic review of the literature to determine the treatment effects of the Invisalign orthodontic system (Align Technology), Santa Clara, Calif.). The authors reviewed clinical trials that assessed Invisalign's treatment effects in nongrowing patients. They did not consider trials involving surgical or other simultaneous fixed or removable orthodontic treatment interventions. The authors searched electronic databases (PubMed, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Evidence Based Medicine Reviews, EMBASE Excerpta Medica, Thomsen's ISI Web of Science and LILACS) with the help of a senior health sciences librarian. They used "Invisalign" as the sole search term, and 22 documents appeared in the combined search. Thereafter, they used "clinical trials," "humans" and "Invisalign treatment effects" as abstract selection criteria. Only two published articles met these inclusion criteria, though after reading the actual articles, the authors determined that they did not adequately evaluate Invisalign treatment effects. Both articles identified methodological issues. The inadequately designed studies the authors found represented only a lower level of evidence (level II). Therefore, the authors found that no strong conclusions could be made regarding the treatment effects of Invisalign appliances. Future prospective randomized clinical trials are required to support, with sound scientific evidence, the claims about Invisalign's treatment effects. Clinicians will have to rely on their Invisalign clinical experience, the opinions of experts and the limited published evidence when using Invisalign appliances.
Article
It is now possible to predictably move maxillary molars distally in nongrowing patients with the skeletal anchorage system (SAS) and to improve malocclusions without having to extract the premolars and regardless of the patient's compliance. The purposes of this study were to investigate the amount of distal movement of the maxillary first molars, the type of movement, the difference between actual and predicted amounts of distalization, and the relationship between the amount of distalization and age. Twenty-five nongrowing patients (22 female, 3 male) successfully treated with the SAS were the subjects in this study. The amount and the type of distalization, the difference between predicted and resulting amounts of distalization, and the relationship between the patient's age and the amount of distalization were analyzed with wide-opening cephalometric radiographs. The average amount of distalization of the maxillary first molars was 3.78 mm at the crown level and 3.20 mm at the root level. The amount of distalization at the crown level was significantly correlated with the average value of treatment goals (3.60 mm). The maxillary molars were predictably distalized in accordance with the individualized treatment goals without regard to patient age and extraction of the third or second molars. The SAS is a viable noncompliance modality to move maxillary molars for distally correcting maxillary protrusions and malocclusions characterized by maxillary incisor crowding.
Article
Maxillary molar distalization is a common treatment approach for patients with Class II malocclusions who do not require extractions. Despite the many advantages of pendulum appliances, the maxillary incisors and premolars tend to shift mesially as the maxillary molars move distally. The purpose of this study was to investigate anchorage loss in patients treated with palatal osseointegrated implants combined with pendulum springs. Pretreatment and posttreatment lateral cephalometric films of 30 consecutively treated patients were examined. One group (n = 15) had been treated with conventional pendulum appliances, and the other group (n = 15) was treated with palatal osseointegrated implants combined with pendulum springs. In the pendulum group, significant distal tipping of the maxillary first molars and mesial tipping of the maxillary premolars were noted. Distalization of the maxillary first molars, mesialization of the maxillary first premolars, and proclination of the maxillary left central incisor were significant in the linear measurements. In the implant group, the distal tipping of the maxillary first molars and first premolars and the increases in SNGoGn, FMA, Na Me, and Na ANS were significant. Intergroup comparisons showed that changes in the maxillary first premolars, maxillary central incisors, and vertical measurements were significant. The use of palatal osseointegrated implants is reliable and provides absolute anchorage.
Article
A modified pendulum appliance with 2 endosseus screws for anchorage in the palatal area was used for maxillary molar distalization in each of 15 patients (average age, 13 +/- 2.1 years). Study models and lateral and panoramic x-rays were taken at the beginning and end of the movement to record the dental and skeletal changes. The mean treatment time was 7.8 +/- 1.7 months, the average distal movement of the maxillary molars was 6 mm, and the inclination was 11.3 degrees +/- 6.2 degrees. The second premolars were distalized an average of 4.85 +/- 1.96 mm with inclinations of 8.6 degrees +/- 5 degrees. The maxillary anterior teeth were retruded 0.5 +/- 1.33 mm and palatally inclined 2.5 degrees +/- 2.98 degrees. The mandibular plane rotated posteriorly 1.27 degrees +/- 1.1 degrees. No loss of dental anchorage was observed during the distal movement.
Article
The purpose of this study was to evaluate skeletal and dentoalveolar changes due to unilateral distalization and to determine side effects. Cephalograms and dental casts before and after distal movement of the maxillary molars with pendulum appliances in 15 consecutively treated patients (5 girls and 10 boys, 12.06 +/- 1.32 years), were included in this study. The duration of distalization was 8.46 +/- 2.23 months. Cephalometric analysis showed no remarkable growth between the 2 measurement times. The mean value for distalization of the first molars was 3.83 +/- 1.09 mm, with distal tipping of 6.45 degrees . The maxillary second molars were also moved distally 2.83 +/- 1.32 mm and tipped distally 14.7 degrees . No significant changes in the position of the third molars were measured. The mean reciprocal mesial movement of the premolars was 1.18 +/- 1.31 mm, with distal tipping of 1.94 degrees . The incisors moved 0.84 +/- 0.79 mm mesially, with mesial tipping of 0.02 degrees and extrusion of 1.21 mm. There was also a significant influence on the contralateral anchorage unit. However, unilateral distalization reduced incisor proclination and induced moderate distal movement of the contralateral anchorage unit based on rotation around a virtual axis perpendicular to the Nance button. Effective distal molar movement and less anchorage loss at the front teeth are advantages of unilateral distalization.
Article
The purpose of this prospective study was to evaluate the effects of maxillary molar distalization in patients treated with a miniplate skeletal anchorage system. Thirty-one miniplates were placed on the infrazygomatic crests of 17 nongrowing patients consecutively selected for Class II treatment with skeletal anchorage. Three weeks after surgery, a 150-g force was applied to distalize the molars. No appliances were placed in the mandible. Models made before treatment and after molar distalization were scanned. Linear measurements were made on the digitized casts. Molar movement was measured on the superimposed maxillary arches before and after distalization, coregistered on the untreated mandibular models. A molar hyper Class I relationship was reached in all patients 7.0 +/- 2.0 months after miniplate loading. The maxillary molars were moved distally a mean distance of 3.27 +/- 1.75 mm. In patients without contact between the maxillary and the mandibular incisors, overjet decreased by 0.99 +/- 1.32 mm. Intermolar width increased by 2.78 +/- 1.38 mm. Maxillary molar distalization with miniplates for skeletal anchorage is an efficient, noncompliance-dependent, and predictable treatment modality for patients with Class II molar relationship.
  • Fortini