American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics

Published by Elsevier Masson
Online ISSN: 0889-5406
Publications
Article
The purpose of this study was to assess the effectiveness of a 0.12% chlorhexidine gluconate (CH) mouthrinse, Peridex, on orthodontic patients 11 through 17 years of age with established gingivitis. Thirty-four subjects were divided into two groups (CH and placebo) of 17 subjects each on the basis of gender, and they were evaluated at baseline, at 6 weeks, and at 12 weeks in a double-blinded manner. The gingival index (GI) of Löe and Silness, the plaque index (PI) of Silness and Löe, the Eastman Interproximal Bleeding Index, and the CWRU staining index were recorded for each subject. The subjects in the CH group, as compared with the placebo group, had statistically significant reductions, expressed as percent reductions against baseline, at the conclusion of this 3-month period: PI = 64.9%, GI = 60.0%, and gingival bleeding = 77.2%. Staining was in the moderate range, and it was concentrated on the mandibular lingual surfaces. Peridex, in combination with mechanical plaque removal, proved to be an important therapeutic agent in controlling gingival inflammation, bleeding, and plaque accumulation in orthodontic patients 11 through 17 years of age with established gingivitis.
 
Article
The purpose of this study was to determine whether conventional toothbrushing and twice daily use of a brush-on 0.4% stannous fluoride (SnF2) gel containing more than 90% available Sn2+ would be more effective for controlling plaque accumulation and gingivitis in the presence of orthodontic appliances than conventional toothbrushing alone. Consecutively treated adolescents who were to receive full-mouth fixed orthodontic appliances were assigned to one of two groups according to age and sex criteria. The first group (control, n = 35) used toothbrushing with a standard fluoride toothpaste, whereas the second group (treatment, n = 30) used toothbrushing supplemented with a 0.4% SnF2 gel used twice daily for the entire 18-month study period. Clinical assessments (Plaque Index, Gingival Index, bleeding tendency, and coronal staining) were made single blind before appliances were placed and 1, 3, 6, 9, 12, and 18 months after appliances were placed. Complete data were obtained for 32 control and 23 SnF2 gel subjects. The results indicated that the SnF2 gel group had significantly lower scores for plaque index (p < 0.01), gingival index (p < 0.001), and bleeding tendency (p < 0.001) at all examinations than did the control group. In the SnF2 group, one subject developed mild coronal staining, and two subjects developed moderate staining. We conclude that the use of a 0.4% SnF2 gel containing more than 90% available Sn2+ is an effective adjunct to mechanical tooth cleaning in preventing gingivitis in adolescents undergoing orthodontic treatment with fixed appliances.
 
Article
Patients with fixed orthodontic appliances often experience an absolute increase in the number of Streptococci mutans colony-forming units (cfu). The aim of this investigation was to study the development of biofilm and S. mutans cfu in connection with stainless steel ligatures and elastomeric rings in orthodontic patients treated with and without 0.4% stannous fluoride gel (SFG). Forty-seven patients were divided into 2 groups: those treated with 0.4% SFG for 4 minutes (experimental) and those without 0.4% SFG (control). In each patient, elastomeric rings were used for ligation on 1 side of the dental arch midline, and stainless steel ligatures were used on the opposite side. Saliva samples were collected before and after appliance placement. At 15 and 30 days after appliance placement, biofilm samples from the stainless steel ligatures and the elastomeric rings were collected and subjected to microbiologic procedures and scanning electron microscopy (SEM) analysis. The numbers of S. mutans cfu in the saliva and biofilm were not statistically different between the teeth fitted with elastomeric rings and stainless steel ligatures, or between the experimental and control groups. SEM analysis showed biofilm formation on both ligature ties. Topical application of 0.4% SFG in orthodontic patients with elastomeric rings or stainless steel ligatures does not cause a significant decrease in S. mutans cfu in the saliva and biofilm.
 
Article
In this double-blind and randomized controlled trial, we analyzed whether a lower concentration of chlorhexidine in dentifrices could reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis, bleeding, and dental plaque. Volunteers with fixed orthodontic appliances were randomly divided into 3 groups: control, 1100 ppm F, NaF (n = 27); experimental, chlorhexidine 0.50% (n = 27); and experimental, chlorhexidine 0.75% (n = 27). At baseline, and after 6 and 12 weeks, clinical examinations were carried out. Staining, calculus, gingivitis, bleeding, and dental plaque data were analyzed with Friedman tests to evaluate intragroup changes over time. To detect intergroup differences after 12 months, the data were evaluated with Kruskal-Wallis tests. Dunn tests were used in both situations for necessary post-hoc analyses. The groups were statistically similar for the stain, calculus, and plaque indexes, but there were statistically significant differences for the gingival and bleeding indexes. During the experimental periods, gingivitis and bleeding scores improved in all 3 groups. Only the 0.75% chlorhexidine dentifrice significantly increased the stain index, although most patients did not notice the stains. The intergroup comparison showed a statistically significant better performance of the experimental groups regarding the gingival and bleeding indexes. This study suggests that the use of dentifrices with lower concentration of chlorhexidine can reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis and bleeding in orthodontic patients.
 
Article
This study compared the effects of local administrations of prostaglandin E2 (PGE2) and 1,25-dihydroxycholecalciferol (1,25-DHCC) on orthodontic tooth movement in rats. Thirty-seven 6-week-old male Sprague-Dawley rats, weighing 160 +/- 10 g were used. Five rats served as the baseline control group. A fixed appliance system exerting 20 g of distally directed force was applied on the maxillary incisors of 32 animals for 9 days. Eight rats served as the appliance control group; 8 received a 20-microL injection of dimethyl sulfoxide (solvent for 1,25-DHCC) on days 0, 3, and 6; 8 received 20 microL of 10(-10) mol/L 1,25-DHCC on days 0, 3, and 6; 8 received a single injection of 0.1 mL of 0.1 microg PGE2 only on day 0. There was no significant difference in tooth movement between the PGE2 and the 1,25-DHCC groups. Both PGE2 and 1,25-DHCC enhanced the amount of tooth movement significantly when compared with the control group. The numbers of Howship's lacunae and capillaries on the pressure side were significantly greater in the PGE2 group than in the 1,25-DHCC group. On the other hand, the number of osteoblasts on the external surface of the alveolar bone on the pressure side was significantly greater in the 1,25-DHCC group than in the PGE2 group. Thus, 1,25-DHCC was found to be more effective in modulating bone turnover during orthodontic tooth movement, because its effects on bone formation and bone resorption were well balanced.
 
Article
A cross-sectional and longitudinal (3.5 years) study on the craniofacial growth of 10 male rhesus monkeys, using metallic implants and a radiographic cephalometric technique based mainly on angular measurements, led to the following observations. (1) Maxilla and mandible were displaced in a forward and downward direction during growth, the sagittal changes being predominant over the vertical changes. (2) Maxillary and mandibular prognathism increased continuously during the whole time span. This increase was twice as great for the maxilla as for the mandible. (3) The inclination of the palatal plane and the mandibular plane changed very little over time. (4) Mandibular form remained constant, but the cranial base showed a significant flattening between approximately 1.5 and approximately 3 years of age. (5) Upper and lower occlusal plane angles changed little over time. (6) The interincisal angle decreased significantly until approximately 3 years of age in relation to the increase in proclination of the permanent incisors in the maxilla and mandible. The intermolar angle remained fairly constant. Changes in some of the variables reported (maxillary and mandibular prognathism, sagittal jaw relationship, mandibular length, interincisal angle, proclination of the upper and lower incisors, and opening of the cranial base angle) occurred as a function of age. The use of angular measurements allowed us to develop a series of templates that will provide a useful tool for a quick check of normal craniofacial morphology at three representative time points.
 
Article
The purpose was to study the results of applying the HLD (CalMod) Index to a very large population of patients. The materials were the study models of 1000 cases that had already been measured and approved for treatment. Each model was remeasured and studied. The average age of the patients was 14.138 years of age; 55% were females and 45% were males. Fifty-six percent were approved on the basis of a score of 26 or more, and 44% were approved as one of the exceptions in the index. Fifty-eight percent of the patients were Class I, 35% were Class II, and 7% were Class III. Surprisingly, 26% of all the approvals (19% adjusted for overlap) were for overjets greater than 9 mm. Reverse overjets occurred at the rate of 2% of approvals. Deep impinging overbites with tissue destruction comprised 12% of all approvals and crossbites of individual anterior teeth with tissue destruction 4%. Only 4 cleft palate cases were recorded, as they do not routinely enter the system through the index route. No traumatic deviations were found. The HLD (CalMod) Index has been field tested under a very heavy load. This study demonstrated that it selects a very wide range of malocclusions.
 
Article
Our objective was to study mandibular widening in untreated subjects with hemifacial microsomia. From the 3-dimensional files at the Department of Plastic and Reconstructive Surgery, Skane University Hospital in Malmö, Sweden, data of 11 subjects (3 girls, 8 boys) with hemifacial microsomia were retrieved. Their age range was 9 years 2 months to 13 years 2 months at the first examination. The mean observation period was 5 years 2 months. Each subject was studied by roentgen stereophotogrammetry with the aid of metallic implants. A significant widening of the mandible was found, with a mean total change of 0.31 mm (range, 0.08-0.79 mm) and a mean annual change of 0.07 mm (range, 0.03-0.12 mm). In 2 subjects, narrowing of the mandible was found: -0.16 and - 0.23 mm. The mandible got wider during adolescence in 9 of our subjects with hemifacial microsomia but to a lesser extent than has been reported in subjects without hemifacial microsomia and from ordinary orthodontic clinics. Sex difference was not addressed. It was suggested that chewing (forces and patterns) was responsible for the mandibular widening in our subjects; this is in line with previous research.
 
Article
There is still ambiguity about whether continuous or intermittent orthodontic forces produce more root resorption. This prospective randomized clinical trial was designed to compare root resorption with these 2 force application patterns. The sample consisted of 16 maxillary first premolars from 8 patients who required bilateral extractions as part of their orthodontic treatment. In each subject, a fixed experimental appliance was placed on the maxillary teeth on each side, allowing a buccally directed force. The force was generated by a segmental wire of beta-titanium-molybdenum alloy. The first premolar on 1 side received a buccally directed continuous force, and the contralateral premolar received intermittent force. The initial force magnitude for both sides was 225 cN. After 14 days of initial continuous force, the intermittent force application was obtained with subsequently repeated periods until the end of the eighth week of a 3-day rest period followed by a 4-day force application period. Force levels were set to 225 cN at each patient visit. After the experimental period of 8 weeks, the teeth were extracted under a strict protocol to prevent root surface damage and analyzed with a microcomputed-tomography scan system, and specially designed software was used for direct volumetric measurements. Intermittent force produced less root resorption than continuous force (P <0.05). Analysis by position showed that the buccal-cervical region had significantly more root resorption than the other positions (P <0.001), corresponding to a region of compression generated by tipping. The application of intermittent orthodontic forces of 225 cN for 8 weeks (14 days of force application, 3 days of rest, then 4 days of force application repeated for 6 weeks) caused less root resorption than continuous forces of 225 cN for 8 weeks. Although it might not be clinically practical, compared with continuous forces, intermittent forces might be a safer method to prevent significant root resorption. This regimen, however, could compromise the efficiency of tooth movement.
 
Article
For orthodontists, the post-World War II era was characterized by the introduction of fluoridation, sit-down dentistry, and an upswing in extractions. Postwar prosperity, the baby boom, and increased enlightenment of parents contributed to what was later called the "golden age of orthodontics." The subsequent clamor for more orthodontists led to a proliferation of graduate departments and inauguration of the AAO Preceptorship Program. There was also an increase in mixed-dentition treatment, requiring improved methods of analyzing arch lengths.
 
Article
This case report demonstrates the interdisciplinary treatment of an adult patient with a Class II malocclusion, convex profile, incompetent lips, gummy smile, and advanced periodontal loss. Initial periodontal-endodontic treatment was followed by orthodontic and orthognathic surgical therapies. An esthetic facial profile, a pleasing smile, an appropriate occlusion, and overall good treatment outcomes, including the periodontal condition, remained stable 11 years after active orthodontic treatment.
 
Article
The aims of the study were to compare the opinions of both the children and the parents with an orthodontist's assessment of treatment need, to investigate the children's self-esteem, and parents' opinion of treatment results. The study group of 359 children (51% girls, 49% boys, mean age 10.6 years) and their parents were asked about their opinions in separate questionnaires. The self-esteem of the children was measured by the global negative self-evaluation scale (GSE). An orthodontist assessed the children's dental casts with the index of Orthodontic Treatment Need (IOTN). Allocated to the dental health component (DHC) of IOTN, 53.2% children had very great to moderate need and 46.8% had little to no need. No sex difference was noted. The children's own assessments of the aesthetic component (AC) of IOTN were closer to the attractive end of the scale than the orthodontist's (p < 0.05). Desire for treatment was more frequent than dissatisfaction with children's occlusion (p < 0.001). The patients' orthodontic concern correlated significantly with both DHC and AC grades (p < 0.001). The children's GSE scores were not correlated to components of IOTN. For children with very great need, high self-esteem was related to orthodontic concern. The parents (90.8%) perceived dental esthetics to be equally important for girls and boys. Most parents (93.0%) thought the results of orthodontic treatment were good. The results indicate meaningful association between orthodontic concern and orthodontic treatment need assessed by IOTN. However, some patients with great need do not express orthodontic concern, whereas others with near ideal occlusion express concern.
 
Article
In this retrospective longitudinal study, we aimed to study differences in the soft-tissue profiles in growing children with clefts in comparison with controls through the period of facial growth from 7 to 18 years. Lateral cephalometric measurements made at 7 years (T1), 11.1 years (T2), and 17.9 years (T3) of age of 70 white children (35 boys, 35 girls) with complete unilateral cleft lip and palate (UCLP) who received primary lip and palate repair surgeries at The Hospital for Sick Children, Toronto, were compared with those of a control group of similar ages, sexes, and racial backgrounds, and having skeletal Class I facial growth, selected from the Burlington Growth Study. None of the included subjects had received any surgeries other than the primary lip and palate repairs, and none had undergone nasal septum surgery or nasal molding during infancy. Between-group comparisons were made at each time point using generalized linear models adjusted for age and sex effects. Longitudinal comparisons across all time points were conducted using the mixed model approach, adjusting for these effects and their interactions with time. Bimaxillary retrognathism, progressive maxillary retrognathism, and increasing lower anterior face height with downward and backward growth rotation of the mandible in the UCLP group were seen. Unlike the hard-tissue face height ratio, their soft-tissue face height ratio was not affected. The upper lips in the UCLP group were shorter by 1.81 mm at T2 (P <0.001) and by 1.16 mm at T3 (P = 0.018), whereas their lower lips were 2.21 mm longer at T3 (P = 0.003). A reduced upper lip to lower lip length ratio at T2 and T3 (P <0.001) resulted. Their upper lips were relatively retruded by 1.44 mm at T1, 1.66 mm at T2, and 1.86 mm at T3 (all, P <0.001), and their lower lips were relatively protruded by 1.07 mm at T1 (P = 0.003), 1.40 mm at T2 (P <0.001), and 1.62 mm at T3 (P <0.001). Nose depths in the UCLP group were shallower by at least 1 mm from T1 to T3, and columellar length was shorter by almost 2 mm (all, P <0.001). Their columellae and nose tips rotated downward with growth, with the most significant rotations experienced from T2 to T3, and progressive reductions in their soft-tissue profile convexity were seen from T1 to T3 (P <0.001). Key attributes of the imbalance in the soft-tissue profile in children with repaired UCLP were identified in the lip and nose regions. Although many profile differences were visible as early as 7 years of age, they became more apparent by 11 years of age and increased in severity thereafter. The short upper lip combined with a long lower lip resulted in the characteristic lip length imbalance, whereas the progressively retruding upper lip and protruding lower lip led to developing a step relationship in the sagittal lip profile during the adolescent growth period. Their columellae and nose tips rotated downward during this time.
 
Article
The temporomandibular joint has always been the practitioner's no-man's land. Who's in charge here? The general dentist, the prosthodontist, the oral surgeon, the otolaryngologist, the psychiatrist, or the orthodontist? Theories about the cause of problems are as varied as the specialties involved. Is the cause anatomic, occlusal, neuromuscular, myofascial, psychological, or multifactorial? In another adjunctive domain, the major early advances in orthognathic surgery were the discovery of anesthesia, the experiences of World War I surgeons, and the refinement of maxillary techniques.
 
Article
The reparative process of root absorption begins in the periodontium when orthodontic force is discontinued or reduced below a certain level. Our aim was to evaluate cementum repair at 4 and 8 weeks of retention after 4 weeks of continuous light and heavy orthodontic forces. The effects of age, tooth movement, and fluoride exposure were also investigated. Forty patients were recruited and divided into 4 groups of 10. The maxillary first premolars were loaded with either light (25 g) or heavy (225 g) orthodontic force. After 4 weeks of loading, the maxillary left first premolars were extracted as the positive control group, and the maxillary right first premolars were placed in retention for 4 or 8 more weeks before extraction; these were the experimental groups. The extracted teeth were studied with microcomputed tomography. To assess cementum repair, volumetric changes of the resorption craters were measured with specially designed computer software. Tooth movement was also measured on study casts taken before and after the extractions. Root resorption continued for 4 weeks after orthodontic force ceased. The resorptive activity was more pronounced from heavy forces. Passive retention after 4 weeks of light force had the least root resorption crater volume (cube root scale). The total amount of the cementum repaired did not depend on magnitude of orthodontic force or retention time within our parameters (P >0.05). This might indicate concurrence of resorption and repair during passive retention. Most repair seemed to occur after 4 weeks of passive retention following the 4 weeks of heavy forces. The volume of root resorption craters positively depended on tooth movement (P = 0.02) and negatively correlated with chronologic age (P <0.01). Although there was no significant difference in the amounts of repair between groups, root resorption continued for 4 weeks after orthodontic force stopped. Resorptive activity was more pronounced after the heavy forces. The reparative processes were different between the light and heavy forces, with marked individual variations. Repair seemed to become steady after 4 weeks of passive retention following 4 weeks of light force application, whereas most repair occurred after 4 weeks of passive retention following 4 weeks of heavy force application. Root resorption crater volume positively depended on tooth movement and negatively correlated with chronologic age.
 
Article
The literature on preeruptive intracoronal resorption is sparse, comprising mainly reports of single patients. This study includes 13 patients with preeruptive intracoronal resorption, forwarded for consultation regarding diagnostics and etiology. The purposes were to determine which teeth are affected by the condition and describe how the defect is manifested radiographically. We used visual analyses of dental or panoramic radiographs. The mandibular second molar appears to be the tooth that is most often affected by preeruptive intracoronal resorption. The resorption of the dentin in the molar crown was in the initial phases often seen in the medial aspects. The dentin in the crown could also be completely resorbed. The enamel contour encircling the dentin persisted as shown on the radiographs. In 1 maxillary canine, the dentin and enamel structures were completely disorganized by the resorption processes. Specialists in orthodontics are often the first to see radiographs of unerupted permanent teeth; therefore, they have a responsibility to be aware of the condition and refer these patients to an endodontist for treatment planning and prognosis before a decision is made regarding orthodontic treatment.
 
Article
Since its inception in 1975, the SPEED appliance has undergone many significant design improvements. This article is intended to describe the various integral components of the SPEED appliance and review the function of each.
 
Article
The developing face is of interest to orthodontists, especially if orthodontic treatment can influence the outcome of facial growth. New 3-dimensional (3D) modalities have enabled clinicians to better understand the facial changes in a developing child. Fifty-nine children with normal body mass indexes were evaluated with a previously validated 3D laser imaging device over a 2-year period. Surface changes were evaluated on normal and average faces. These changes were seen as mean surface changes and color maps. The results suggest that the surface areas of change in average faces were generally downward and forward with respect to the nose and soft-tissue nasion. The lips also translated in a downward direction as the nose grew, and there was a general increase in the vertical dimension. Some subjects were in the "great changes" category, boys significantly more so than girls. The following conclusions can be made from this 3D study of changes of facial morphology in children: (1) surface changes are greater in boys than in girls; (2) differences in the timing of surface changes in boys and girls are clinically significant, with boys exhibiting more changes later; (3) positive surface changes occur in the nose, brows, lips, and vertical dimensions of the face; (4) the eyes deepen, and the cheeks become flatter; and (5) 3D imaging is a useful tool in analyzing changes to the face over time.
 
Article
White spots (WS) related to orthodontic treatment are severe cariologic and cosmetic complications, but they are shown to be partially reduced by remineralization or abrasion in short-term follow-ups. In this prospective study, we quantitatively analyzed changes in WS in general and in treatment-related white spot lesions (WSL) during orthodontic treatment and at a 12-year follow-up after treatment. In addition, we quantitatively compared the effects of an acrylic bonding material vs a glass ionomer cement (GIC) on WSL. Sum areas of WS and WSL were calculated on scans of standardized photos of the vestibular surfaces of 4 teeth in consecutive orthodontic patients (median treatment time, 1.7 years) bonded with the 2 materials in a split-mouth design. Comparisons were made in 59 patients before treatment (BF), at debonding (T0), at 1 year (T1), and at 2 years (T2), and in 30 patients at a 12-year follow-up (T3) with the Friedman test followed by pairwise comparisons with the Wilcoxon matched-pairs signed rank test. Differences of the effects of acrylic vs GIC on the sum areas of WSL were tested for each observation period with the Mann-Whitney U test. Increases in the sum areas of WS and WSL from BF to T0 (P <0.001) were followed by significant decreases at T1 (P <0.001) and T2 (P <0.01 for WS; P <0.001 for WSL). Significant changes were also found in the sum areas for WS at T3 compared with T2 (P <0.01), but not for WSL (P = 0.328). The sum areas of WS and WSL at T3 did not return to BF levels (P <0.001). Sum areas of WSL were higher for surfaces bonded with acrylic compared with GIC for each observation period from BF to T2 (P >0.001), and from T2 to T3 (P >0.05). Although significantly reduced during the 12-year follow-up and significantly lower with the GIC than the acrylic material at bonding, WSL are a cariologic and cosmetic problem for many orthodontic patients.
 
Article
Orthodontic force magnitude is a primary factor in root resorption. Quantitative studies of root resorption after force application for 4 and 8 weeks have been conducted. In this study, we investigated the root surface topography and the amount of root resorption after the application of controlled light and heavy forces in a buccal direction for 12 weeks. In addition, the amounts of root resorption when controlled light and heavy forces were applied to the maxillary and mandibular first premolars were quantified. Forty maxillary and mandibular first premolars were collected from 10 orthodontic patients (age range, 12.7-18.2 years; mean, 14.3 years). A light buccally directed orthodontic force of 25 g was applied to the experimental tooth on 1 side, and a heavy orthodontic force of 225 g was applied on the contralateral premolar. After 12 weeks of force application, the experimental teeth were extracted and scanned with the microcomputed tomography x-ray system. Resorption craters were analyzed with specially designed software for direct volumetric measurements. The tooth movements produced by light and heavy forces were also measured. There was individual variation in all comparisons. The light force produced significantly less root resorption than did the heavy force. The maxillary first premolars were more likely to suffer from orthodontically induced inflammatory root resorption than the mandibular first premolars (P = 0.036). There was a significant difference between buccal and lingual surfaces (P = 0.003), with greater root resorption on the buccal surface. The distribution pattern of the resorption cavities was greatest in the buccal-cervical, buccal-middle, lingual-middle, and lingual-apical areas in both the light-force and heavy-force groups, corresponding with the pressure zones of tipping movement. The mean amount of tooth movement in the heavy-force group was almost twice as much as in the light-force group. The volume of root resorption craters induced by buccally directed forces for 12 weeks on the maxillary and mandibular first premolars was directly proportional to the magnitude of the force. The maxillary premolars seemed to be more susceptible to orthodontic root resorption than did the mandibular premolars.
 
Article
Evaluations of the dental arch widths and mandibular-maxillary base are needed for a comprehensive dentofacial analysis in subjects with Class III malocclusion. The aim of this study was to analyze the development of the dental arches and the skeletal mandibular-maxillary bases in untreated subjects with Class III malocclusions. Two groups of subjects, 1 with Class III malocclusion and the other with Class I malocclusion, were examined. Maxillary skeletal base width, biantegonial widths, and maxillary and mandibular intermolar widths were determined on posteroanterior cephalograms at annual intervals between the ages of 10 and 14 years. Maxillary skeletal base widths and intermolar widths in the Class III subjects were significantly smaller than those in the Class I subjects (P <.05). No statistically significant differences were found among the groups for skeletal mandibular width or intermolar width for the total observation period. The deviations in molar differences increased from ages 10 to 14 in the Class III group. The main transverse deficiencies in the Class III group were maxillary deficiencies in both skeletal and dental widths. The deviations in molar differences appear to become larger from age 10 to age 14.
 
Article
Around 1970, after overcoming obstacles related to anesthesia, infection, and blood supply, orthognathic surgeons come into their own. The history of cleft lip and palate treatment has a much earlier beginning because a deformed infant evokes a strong desire to intervene. Angle's belief that orthodontists can grow bone finally came to fruition with the advent of distraction osteogenesis, which developed from the limb-lengthening procedures of Ilizaroff in Russia. Now distraction osteogenesis has replaced osteotomies in many applications.
 
Article
The purpose of this study was to describe and analyze the craniofacial and dentofacial skeletal characteristics associated with Angle's Class II, Division 1 malocclusion. The material examined included 613 lateral head radiographs comprising 2 series: (1) 278 films of children with "normal" occlusion and (2) 335 films of children with Class II, Division 1 malocclusion. Each series was subdivided into 6 samples (3 female and 3 male; skeletal ages 10, 12, 14, [+/-6 months]), representing children with chronological ages ranging from 8.5 to 15.5 years. The radiographs were converted to computer-readable X and Y coordinate data and 52 linear, angular, and coordinate axis measurements were taken. Findings were visually verified by superimposing the computer-drawn composite plots of the Class II, Division 1 series over those of the normal series. In all 6 intergroup comparisons, it was found that: (1) the mandible and its dentition is similar to the controls in size, form, and position except for the position of the lower incisors in males; (2) the forehead (Gl), anteriorcranial base (Nas), maxilla (A) and dentition (molars and incisors) are protrusive (mesial positioned), with an increased frontal bone thickness at the level of the sinus, and a larger A-P maxilla, the palate of which is inclined superiorly at its anterior half; (3) no vertical dysplasia was evident; (4) the cranial base angle is larger, as are the anterior and posterior sections that compose it, but it is not related to mandibular position; (5) angular indexes of maxillary and mandibular position that included point Nasion are highly misleading indicators of maxillary and mandibular size and position. Visualized diagnosis via a composite norm based on age and sex might offer a more reliable alternative or supplement to the numeric reference standards now in use. Enlarged sinuses may contribute to the cause of Class II, Division 1 malocclusion.
 
Article
Growth changes in the dentition and the facial skeleton of boys and girls with Class I malocclusion from 10 to 14 years of age are presented, and the changes are compared with those for children with Class II Division 1 malocclusion. Radiographs of 335 children with Class II Division 1 malocclusion and 273 Class I controls were assessed. Radiographs were converted to x and y coordinate data, and 52 commonly used linear, angular, and coordinate axis measurements were made. Both the Class II Division 1 and the control groups were subdivided into 6 samples according to sex and skeletal age (10, 12, and 14 years +/- 6 months; chronological age ranged from 8.5 to 15.5 years). The mean plots from the coordinate data for the Class I boys and girls at 14 years were superimposed over the mean plots for the 10-year-old groups, creating circumpubertal growth standards. The standards are supported by growth vector diagrams and other data and lead to the following conclusions: (1) boys and girls with Class I malocclusion differ distinctly from each other in the amount and the direction of circumpubertal growth; (2) radiographic composite standards are useful and accurate clinical tools to show mean dentofacial skeletal growth and change between 10 and 14 years of age; (3) compared with the controls, the maxillary dentition of girls with Class II Division 1 malocclusion grows more horizontally, the maxillary (but not the mandibular) incisors procline farther, and the mandible grows more horizontally; (4) compared with the controls, the midfacial convexity in Class II Division 1 boys is markedly increased, due to more horizontal growth at A-point and less horizontal growth at nasion and pogonion, and maxillary and mandibular anterior teeth are proclined farther; (5) angular measurements involving S, N, A-point, B-point, and Pog are useful only when the position of N is known; and (6) cranial base flexure bears no relationship to the development of Class II Division 1 malocclusion.
 
Article
The aims of this study were to determine reasons for orthodontic-surgical treatment, to quantify the perceptions of possible improvement 10 to 14 years after treatment, and to assess factors that affect treatment satisfaction and socio-dental impacts on quality of life. The participation rate was 36 of 78 patients; their mean age was 45.7 years (SD, 10.7 years; range, 29-62 years). The presurgical anatomic occlusions were measured on dental casts. Visual analog scales allowed the participants to rate their perceived treatment outcome on 7 oral health-related items. A 3-point scale rated satisfaction with orthodontic-surgical treatment. The oral impact of daily performances index was included to assess socio-dental impacts on quality of life. Most responders reported improvements on the 7 items. The most significant change was reported for chewing. "Very satisfied" with the treatment was reported by 13 responders; 19 of 36 persons were "reasonably satisfied." Reporting "very satisfied with treatment" was 8 times more likely when peers had noticed a changed in the participant's appearance after surgery. Sex was significantly associated with quality of life. The most frequently reported reason for treatment was to improve chewing, and the item that showed the most pronounced improvement was also chewing. Most responders were only reasonably satisfied with the treatment. Whether peers noticed a change in appearance after treatment was a significant factor affecting both treatment satisfaction and reporting a good quality of life.
 
Article
The objective of this study was to determine the magnitude and the direction of postpubertal mandibular and maxillary facial growth in females. The sample consisted of 37 untreated subjects who had Class I skeletal and dental characteristics and whose lateral cephalograms were taken at 14, 16, and 20 years of age. Mandibular growth was determined to be significant for the age periods of 14 to 16 years and 16 to 20 years. Overall mandibular growth as measured from Co-Gn was approximately twice that of the overall maxillary growth as measured from Co-A. Correlation analysis revealed a statistically significant relationship between the estimates of incremental mandibular growth from either articulare or condylion. The mandibular growth rate was found to be twice as large for age period 14 to 16 years as for age period 16 to 20 years. The increase in posterior vertical face height was slightly more than the increase in anterior vertical face height. The mandibular plane angle decreased 1.1 degrees during the age period of 14 to 20 years, suggesting a tendency for a closing rotation of the mandible. Mandibular incisors appeared to tip labially with advancing age. Although variable, the potential for significant maxillary and mandibular facial growth in females during late adolescent has been demonstrated.
 
Article
Dental arch space and permanent tooth size in the mixed dentition were studied in 4 cohorts: (1) 48 skulls from the 14th to the 19th centuries from The Schreiner Collection in the Department of Anatomy, University of Oslo; (2) 39 boys and 34 girls of Sami origin born in the 1980s living in northern Norway; (3) 31 boys and 30 girls born in the 1960s living in southern Norway; and (4) 32 boys and 26 girls born in the 1980s living in the same part of southern Norway as the previous group. The sexes were unknown in the skeletal sample, and the groups were analyzed with the sexes pooled. The crown sizes of the permanent teeth in the mixed dentition of the Norwegian children who had lived between the 14th and the 19th centuries were smaller than those of contemporary children living in the same country. Probable reasons for this increase in tooth size include improved nutrition and reduced morbidity, because this study ruled out attrition as a major cause of the discrepancy in tooth size. The relative space (arch perimeter minus tooth size) in the group born in the 1960s deviated from that in the other 3 groups, indicating a greater degree of crowding in this group. The relative space in the skulls did not differ significantly from that in the groups born in the 1980s. This means that the improved caries situation during the last decades has changed the dental arch space in these populations. The irregularity index of the 4 mandibular permanent incisors was larger in the skulls than in the modern samples.
 
Article
Root resorption is a side effect of orthodontic treatment that occurs with the removal of hyalinized tissue. Studies have shown that a reparative process in the periodontium begins when the applied orthodontic force is discontinued or reduced below a certain level. However, quantitative 3-dimensional evaluation of root resorption repair has not been done. The aim of this study was to quantitatively assess the 2- and 3-dimensional changes of root resorption craters after 2 weeks of continuous mesially applied orthodontic forces of 50 g on rat molars and 2- to 16-week retention periods. We used 60 male Wistar rats (10 weeks old). Nickel-titanium closed-coil springs were used to apply 50-g mesial forces for 2 weeks to move the maxillary left first molars. The rats were randomly allocated to 6 groups. Those in the zero-week retention group were killed after force application. In the remaining 5 groups, the interdental spaces between the maxillary first and second molars were filled with resin to retain the molars. The molars were extracted after periods of retention from 2 and 16 weeks. The maxillary right molars were used as the controls. Mesial and distal roots (distobuccal and distopalatal) were examined by using scanning electron and 3-dimensional scanning laser microscopes. The surface area, depth, volume, and roughness of the root resorption craters were measured. The area, depth, and volume of the craters decreased gradually and showed similar trends over the retention time, approaching a plateau at the 12th week. After 16 weeks of retention, the volumes of the resorption craters of the distobuccal and distopalatal roots reached recovery peaks of 69.5% and 66.7%, respectively. Small pits on the mesial roots showed recovery of 62.5% at the 12th week. The healing patterns in distal roots with severe resorption and mesial roots with shallow resorption had no significant differences. The resorption and repair processes during the early stages of retention are balanced, and most of the reparative process occurs after 4 weeks of passive retention after the application of orthodontic force. Frequent orthodontic reactivations should be avoided to allow recovery and repair of root surface damage.
 
Article
Postpubertal craniofacial skeletal and dental changes were examined from lateral cephalograms taken when subjects were 16, 18, and 20 years of age. The sample consisted of males with no previous orthodontic treatment who had Class I skeletal and dental characteristics. Mandibular growth was found to be statistically significant for the age periods of 16 to 18 years and 18 to 20 years. Growth from 16 to 18 years was greater than that from 18 to 20 years. Maxillary and mandibular growth were highly correlated at each age period. However, overall mandibular growth was approximately twice that of overall maxillary growth. Mandibular growth was found to involve an upward and forward rotation, a result of posterior vertical growth exceeding anterior vertical growth. Lower incisors were found to tip lingually with increasing age. Incremental changes in mandibular cephalometric measurements were found to be equivalent when measured from either articulare or condylion, indicating the interchangeability of the landmarks for growth estimates.
 
Article
Orthodontic force duration can affect the severity of root resorption. The aim of this clinical study was to investigate the amounts of root resorption volumetrically after the application of controlled light and heavy forces in the buccal direction for 4, 8, and 12 weeks. The sample consisted of 54 maxillary first premolars in 36 patients (mean age, 14.9 years; 21 girls, 15 boys) who required first premolar extractions as part of their orthodontic treatment. The teeth were allocated into 3 groups that varied in the duration of force application: 4, 8, or 12 weeks. The right or left first premolars were randomly selected to receive 2 levels of forces. A light buccally directed orthodontic force of 25 g was applied to the experimental tooth on 1 side, while a heavy orthodontic force of 225 g was applied on the contralateral premolar. At the end of the experimental period, the teeth were extracted and scanned with the microcomputed-tomography x-ray system. Resorption crater analysis was performed with specially designed software for direct volumetric measurements. Significant differences in the extent of root resorption were found between 4, 8, and 12 weeks of force application (P <0.001), with substantially more severe resorption in the longer force duration groups. The light force produced significantly less root resorption than did the heavy force. After 4, 8, or 12 weeks of buccally directed orthodontic forces applied on the maxillary first premolars, the volumes of root resorption craters were found to be related to the duration and the magnitude of the forces.
 
Article
Ever since Edward Angle introduced his edgewise appliance in 1925, orthodontic innovators have been working to improve on not only its original design, but also the method of attachment. Our "strap-ups" have evolved from banding to bonding, from labial to lingual, and from metallic to clear. But, as Angle would be pleased to learn, we still call it edgewise.
 
Two mandibular second premolars were transplanted to maxillary anterior region in 1970 and 1971, respectively, to substitute for congenital absence of 4 anterior teeth (A). Both right and left canines and lateral incisors were absent. Operations were performed when patient was 11.4 (left side) and 12.0 years old (right side), respectively (B). Intraoral photographs show clinical appearance in 1978 (C) and 27 years after operation in 1997 (D-E). Radiographs in F demonstrate usual appearance for autotransplanted premolars and confirm continued root development, with pulpal obliteration in part of tooth that was formed at time of operation, but not afterwards. Root of right premolar is somewhat shorter than that of left transplant (arrows in F), but crown-to-root ratio is still satisfac- tory.  
Patients' responses to questionnaire regarding their perception of tooth transplantation using 50-mm visual analogue scales (see text). Numbers below lines represent means and ranges.  
Life-table analysis for 33 autotransplanted teeth. Number of teeth present and at risk at time shown after operation is stated below.  
Because of agenesis of mandibular right second premolar in 12-year-old girl, maxillary second premolar in same side was transplanted to mandible in 1972 (arrow in A). Root development continued (arrow in B), and eventually root achieved similar length as that of neighboring first premolar (E). Intraoral photographs show result in 1978 (C, D) and 19 years later (G, H) with buccal crossbite of graft (C). Note normal radiographic appearance, albeit with some continuation of pulp obliteration (compare F with E).  
Three missing neighboring teeth in maxillary left quadrant (lateral incisor, canine, first premolar ) in 12-year-old girl. Mandibular right first premolar was transplanted to maxillary canine area in 1959 (arrow in A). Spaces were closed orthodontically, and persisting deciduous left canine was crowned. Continued root development is shown in B and C, and long-term radiographic appearance 38 years later is shown in D. Despite lingual amalgam and buccal composite resin fillings (E, F), radiographic and clinical appearance 41 years after operation is uneventful, with no signs of pathology, except some gingival hyperplasia.  
Article
The literature contains no follow-up studies of transplanted teeth with mean observation times exceeding 10 years. This article describes long-term outcomes, including gingival and periodontal conditions, and the patients' attitudes about treatment and outcome. The material comprised all accessible patients in the files of the Department of Orthodontics, University of Oslo, Norway, on whom treatment had been performed at least 17 years ago (n = 28). Established clinical criteria were used to assess tooth mobility, plaque and gingival indexes, and probing pocket depth. Standardized radiography was used to evaluate the presence of pathology, pulp obliteration, and root length. Similar recordings were obtained from the in situ tooth contralateral to the initial position of the grafted tooth. Criteria for determining treatment success were established. All patients responded to questions about their treatment using visual analogue scales. The mean age at surgery was 11.5 years, and the mean observation period was 26.4 years (range, 17-41 years). Of the 33 teeth transplanted in the 28 patients, 3 teeth were lost after 9, 10, and 29 years, respectively. Therefore, the 30 teeth in the 25 patients we examined yielded a survival rate of 90%. The success rate was 79% because 2 transplants had ankylosed, and 2 others failed to fulfill the proposed criteria. The patients generally responded very favorably regarding their perception of the treatment. Their only hesitation was related to some discomfort during surgery. It was concluded that survival and success rates for teeth autotransplanted when the root is partly developed compare favorably in a long-term perspective with other treatment modalities for substituting missing teeth.
 
Article
Root resorption is an undesirable consequence of orthodontic tooth movement. The severity is unpredictable, and, despite extensive research, the etiology remains unknown. Torque has been acknowledged as a risk factor for root resorption. The aims of the study were to evaluate and quantify the extent of root resorption after the application of 2.5° and 15° of buccal root torque for 4 weeks. Fifteen patients requiring bilateral extraction of their maxillary first premolars for orthodontic treatment were recruited to the study. By using a standardized experimental protocol, the right and left premolars were randomly subjected to either 2.5° or 15° of buccal root torque. At the end of the 4-week experimental period, the premolars were extracted. A volumetric analysis of root resorption was performed by using microcomputed tomography and measured with specially designed software. Overall, the amounts of root resorption were comparable after the application of 2.5° or 15° of buccal root torque (P = 0.59). There was a significant difference between the 2 force levels only at the apical region (P = 0.034). More root resorption occurred in areas of compression than in areas of tension. The variables of age and sex were not statistically significant. Root resorption was evident after 4 weeks of buccal root torque application. More root resorption was seen at the apical region than at the middle and cervical regions. Higher magnitudes of torque might cause more root resorption, particularly in the apical region. As shown in previous studies, the etiology of root resorption is multi-factorial and cannot be explained by mechanical factors alone.
 
Article
The longitudinal growth and development of the soft tissue drape for boys and girls with long and short vertical patterns was examined from age 7 to 17 years. The sample was taken from the Denver Growth Study and consisted of 32 subjects who were selected on the basis of their percentage of lower anterior vertical face height. All subjects were of northern European ancestry, and none had undergone orthodontic treatment. The sexual dimorphism was evident as anticipated for several soft tissue measurements. The boys showed continued growth through age 16 years in contrast to the girls who attained the adult size of the soft tissue integument around 14 years. A significant difference between vertical facial patterns was reported for all soft tissue variables with the exception of the soft tissue thickness at A point and the upper lip height. The boys and girls with long vertical patterns exhibited a thicker and longer soft tissue drape for the most variables when compared with those with short facial patterns. These soft tissue differences are believed to be compensatory mechanisms in long-face subjects, which may attempt to mask the vertical dysplasia, thereby producing a more normal facial profile. Individual growth assessments revealed that the perioral soft tissues follow a pattern similar to that of the mean group patterns. The subjects with long vertical facial patterns experienced their pubertal growth spurt earlier than the short-face subjects. This may have clinical implications in the timing of orthodontic intervention and treatment.
 
Top-cited authors
Ravindra Nanda
  • UConn Health Center
James A McNamara
  • University of Michigan
Peter H Buschang
  • Baylor College of Dentistry
Bjørn Øgaard
  • University of Oslo
Peter M Sinclair
  • University of Southern California