Effects of orthodontic treatment on mandibular rotation and displacement in Angle Class II division 1 malocclusions

The aim of this retrospective cephalometric study was to investigate the effects of orthodontic treatment on rotation and displacement of the mandible in Angle Class II, division 1 malocclusions. Thirty patients in the treated group (15 boys and 15 girls; mean age at pretreatment, 12.27 +/- 1.36 years) were compared with 28 subjects who had untreated Class II, division 1 malocclusions (15 boys and 13 girls; mean age at T1, 12.01 +/- 0.07 years). The patients in the first group were treated nonsurgically, without extraction, and without the use of functional appliances. Cephalometric data were obtained from three lateral cephalograms per case representing pretreatment (T1), posttreatment (T2), and at least 2-years postretention (T3). Thirty-seven variables were measured representing craniofacial morphology, tooth measurements, and mandibular displacement. Some variables were obtained from cranial base, maxillary, or mandibular superimposition. Statistical significance was established at P < .05, P < .01, and P < .001. The findings indicated that orthodontic treatment of Class II, division 1 malocclusions induced a more vertical mandibular growth direction associated with an increased vertical displacement of pogonion. Occlusal or vertical movement of maxillary and mandibular molars was not correlated to mandibular rotation or horizontal displacement of pogonion. When compared with controls, the treated group did not exhibit a significant difference in mandibular rotation or occlusal movement of maxillary molars; however, it did show a greater occlusal movement of mandibular molars during treatment.     

Soft tissue profile changes following orthodontic treatment of Chinese adults with Class III malocclusion

Thirty-eight adult Chinese patients (mean age 24.3 +/- 3.2 years) exhibiting true Class III dental and skeletal malocclusions were treated orthodontically with the edgewise appliance and extractions of mandibular first premolars together with simultaneous anterior expansion of the maxillary arch. A retrospective cephalometric study was undertaken to determine the soft tissue profile changes at least 6 months postretention. Significant cephalometric changes included decrease in the mandibular incisor protrusiveness by 6.4 mm (P less than .001) and accompanying lower lip protrusiveness by 4.4 mm (P less than .01), together with a slight forward movement of the maxillary incisors by 1.7 mm (P less than .05) and, consequently, a slight increase in upper lip protrusiveness by 1.2 mm (P less than .05) and decrease in nasolabial angle (P less than .05). The overall improvement in lip profile provided by this mandibular arch contraction/maxillary arch expansion orthodontic approach appears to be a viable alternative in mild-to-moderate Class III patients who decline orthognathic surgery.     

Combined rapid maxillary expansion and protraction facemask in the treatment of class III malocclusions in growing children: A prospective long-term study

A prospective study of 28 growing children (mean age of 8 years 3 months) with Class III malocclusions was consecutively treated using rapid maxillary expansion and maxillary protraction. All patients were treated from a negative overjet to a positive overjet and from a Class III dental malocclusion to a Class I dental relationship. For each patient, a lateral cephalogram was taken before treatment (T1), immediately posttreatment (T2), and after an observation period (T3) averaging 2 years 5 months. Using analysis of variance, the cephalograms were analyzed to determine skeletal and dental changes resulting from treatment. Long-term changes (2 years 5 month observation period) were also evaluated. Results showed that immediately posttreatment, the maxilla moved anteriorly a mean of 1.54 mm and Sella-Nasion-A point increased 0.87°. The maxillary teeth moved anteriorly 2.73 mm and proclined 5.23°, while the mandible rotated in a downward and backward direction. Long-term, the anterior position of the maxilla was maintained, but some of the Class III correction was lost because of mandibular growth. Comparison of this study's results to Riolo's longitudinal Class I data showed that, overall, rapid palatal expansion and maxillary protraction produced a small orthopedic effect with a moderate dentoalveolar effect which together contributed to the correction of the Class III malocclusion.     

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review

OBJECTIVE: To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment. MATERIALS AND METHODS: Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies. RESULTS: The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective. CONCLUSIONS: This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.     

Camouflage of moderate Class III malocclusions with extraction of lower second molars and mandibular cervical headgear

Orthodontic camouflage in patients with slight or moderate skeletal Class III malocclusions, can be obtained through different treatment alternatives. The purpose of this paper is to present a treatment that has not been described in the literature and which consists of the extraction of lower second molars and distal movement of the posterior segments by means of mandibular cervical headgear (MCH) and fixed appliances as a camouflage alternative. The force applied by the MCH was 250 gr per side (14hr/day). The total treatment time was 1 1/2 years. CONCLUSION: the extraction of lower second molars along with the use of mandibular cervical headgear is a good treatment alternative for camouflage in moderate Class III patients in order to obtain good occlusal relationships without affecting facial esthetics or producing marked dental compensations.     

Growth modification treatment in class III malocclusions--an orthodontic case report

A number of treatment options for Class III malocclusions have been reported. Early intervention incorporating growth modification allows the clinician to attempt mandibular growth restraint and promote the forward growth of the maxilla. At the optimal age for growth modification, rapid maxillary expansion (RME) and protraction headgear can be used to produce these beneficial changes. The following case report describes the management of an 8.5-year-old patient who underwent treatment using RME, protraction headgear and fixed appliances.     

Nonextraction orthodontic therapy: posttreatment dental and skeletal stability

To assess the long-term stability of nonextraction orthodontic treatment, the dental cast and cephalometric records of 28 cases were evaluated. Thirty cephalometric and seven cast parameters were examined before treatment, posttreatment, and an average of almost 8 years postretention. Results showed overall long-term stability to be relatively good. Relapse patterns seen were similar in nature, but intermediate in extent, between untreated normals and four first premolar extraction cases. Significant decreases were seen in arch length and intercanine width during the postretention period despite minimal changes during treatment. Incisor irregularly increased slightly postretention; intermolar width, overjet, and overbite displayed considerable long-term stability. Mandibular incisor mesiodistal and faciolingual dimensions were not associated with either pretreatment or posttreatment incisor crowding. Class II malocclusions with large ANB values and shorter mandibular lengths showed increased incisor irregularity, shorter arch lengths, and deeper overbites at the postretention stage, suggesting that the amount and direction of facial growth may have been partially responsible for maturational changes seen during the postretention period.     

Cephalometric evaluation of Class II malocclusion treatment with cervical headgear and mandibular fixed appliances

The present study aimed to evaluate the cephalometric changes in Class II patients treated exclusively with cervical headgear (CHG) in the maxillary arch and fixed appliances in the mandibular arch as compared with a control group. The sample comprised 82 lateral cephalograms obtained pre- (T1) and post- (T2) treatment/observation of 41 subjects, divided into two groups: group 1-25 Class II division 1 patients (20 females and five males), with a mean pre-treatment age of 10.4 years, treated for a mean period of 2.5 years and group 2-16 Class II untreated subjects (12 females and four males), with a mean initial age of 9.9 years, followed for a mean period of 2.2 years. Treatment changes between the groups were compared by means of t-tests. The results showed restriction of maxillary forward displacement and also a restriction in maxillary length growth, improvement in the maxillomandibular relationship, restriction of mandibular incisor vertical development, reduction in overjet and overbite, and improvement in molar relationship. It was concluded that this treatment protocol corrected the Class II malocclusion characteristics primarily through maxillary forward growth restriction.     

Nonsurgical correction of Class III malocclusions: a new approach to treating late adolescents and adults

This article describes a new nonsurgical orthodontic technique for correcting Class III malocclusions in the adult dentition when orthognathic surgery is not an option. Following a review of the dental literature pertaining to other nonsurgical orthodontic techniques, a nonextraction treatment protocol was established that utilized a mandibular distalizer combined with a maxillary transpalatal unit. Four cases were treated with this new treatment protocol and produced consistent results: anterior and posterior crossbites were corrected; a Class I molar relationship was established; both overbite and overjet were corrected; and there was no undesirable tipping of the mandibular molars.     

A comparison of the MARA and the AdvanSync functional appliances in the treatment of Class II malocclusion

Abstract Objectives: To determine the skeletal and dentoalveolar effects produced by the MARA and the AdvanSync functional appliances in the treatment of growing patients with Class II malocclusion. Materials and Methods: A retrospective study was conducted using lateral cephalograms of patients consecutively treated with MARA (n = 40) and AdvanSync (n = 30) during their skeletal growth spurt as evaluated by the improved cervical vertebral maturation method. A comparison was made with 24 untreated Class II control subjects obtained from the University of Michigan growth study and matched with the experimental groups for skeletal age, sex, and craniofacial morphology. Cephalograms were taken at three time points: (T1) pretreatment, (T2) postfunctional appliance treatment, and (T3) fixed orthodontic treatment completion. Treatment changes were evaluated between the time points using 35 variables. Data were analyzed using one-way analysis of variance and Scheffe's post hoc test. Results: At the postfunctional appliances' phase (T2-T1), both appliances showed significant increases in total mandibular length, ramus height, and anterior/posterior facial height. The AdvanSync resulted in significant restriction of maxillary growth, 1° more than MARA. This effect continued during the fixed orthodontic treatment stage (T3-T2). The net changes (T3-T1) revealed significant mandibular growth enhancement with MARA (+2.7mm) and significant headgear effect with AdvanSync. Both appliances caused 5° flaring in mandibular incisors as well as significant decreases in overjet and overbite. The treatment time for AdvanSync was 1 year less than MARA. Conclusion: The MARA and the AdvanSync resulted in normalization of the Class II malocclusion. The AdvanSync showed more headgear effect but less mandibular length enhancement than MARA did. Both appliances showed similar dentoalveolar changes.     

Long-term outcome of skeletal Class II Division 1 malocclusion treated with rapid palatal expansion and Kloehn cervical headgear.

The treatment of a patient with a skeletal Class II Division 1 malocclusion, with excessive overjet, complete overbite, airway obstruction, and severe arch length deficiency in the mandibular dental arch, is presented. The maxilla was narrow compared with the mandible, and the posterior teeth were compensated, with the maxillary teeth inclined buccally and the mandibular teeth inclined lingually. The palatal vault was extremely high. Treatment included rapid palatal expansion to correct the transverse maxillary deficiency and Kloehn cervical headgear to correct the anteroposterior skeletal discrepancy. Long-term stability (12-year follow-up) is reported.     

Dentoskeletal treatment changes in Class II subdivision malocclusions in submentovertex and posteroanterior radiographs.

The objective of this study was to evaluate the dentoskeletal changes consequent to orthodontic treatment in subjects with Class II subdivision malocclusions, treated with asymmetric extractions, compared with a normal-occlusion control group. The sample consisted of 3 groups, with 30 subjects in each: normal-occlusion subjects (group 1), untreated Class II subdivision subjects (group 2), and Class II subdivision patients treated with asymmetric extractions (group 3). All subjects had a full complement of permanent teeth at the beginning of treatment. The average ages of the subjects were 22.42, 15.76, and 18.57 years, respectively, in groups 1, 2, and 3. Measurements of relative differences in the spatial position of dental and skeletal bilateral landmarks were obtained from the submentovertex and posteroanterior cephalometric (PA) radiographs. The t test for independent samples was used to compare group 1 with groups 2 and 3 at different times. Results from the submentovertex radiograph showed that asymmetric extractions in Class II subdivision malocclusions will maintain the differences in the anteroposterior positions of right and left, maxillary and mandibular first molars, as would be expected with the treatment protocols used. There were no significant skeletal changes that could be attributed to the treatment approaches investigated or transverse collateral effects with the asymmetric mechanics used. It was also demonstrated that treatment of Class II subdivision malocclusions with asymmetric extractions produced corrections of maxillary and mandibular dental midline deviations with the midsagittal plane, without canting the occlusal plane or any other investigated horizontal plane, as seen in the PA radiograph. Treatment of Class II subdivision malocclusions with asymmetric extractions constitutes a beneficial approach to this problem.     

Effects of cervical headgear and edgewise appliances on growing patients.

Maxillary basal bone, dentoalveolar, and dental changes in Class II Division 1 patients treated to normal occlusion by using cervical headgear and edgewise appliances were retrospectively evaluated. A sample of 45 treated patients was compared with a group of 30 untreated patients. Subjects were drawn from the Department of Orthodontics, Araraquara School of Dentistry, Brazil, and ranged in age from 7.5 to 13.5 years. The groups were matched based on age, gender, and malocclusion. Roughly 87% of the treated group had a mesocephalic or brachicephalic pattern, and 13% had a dolicocephalic pattern. Cervical headgear was used until a Class I dental relationship was achieved. Our results demonstrated that the malocclusions were probably corrected by maintaining the maxillary first molars in position during maxillary growth. Maxillary basal bone changes (excluding dentoalveolar changes) did not differ significantly between the treated and the untreated groups. Molar extrusion after the use of cervical headgear was not supported by our data, and this must be considered in the treatment plan of patients who present similar facial types.     

Dental arch widths and mandibular-maxillary base width in Class III malocclusions with low, average and high MP-SN angles

OBJECTIVE: To analyze the development of the dental arches and skeletal mandibular-maxillary bases in untreated Class III malocclusions with low averages and high mandibular plane angles in subjects aged 10 to 14. MATERIALS AND METHODS: The records of 50 untreated Japanese girls with Class III malocclusions at age 10 were selected from the files of patients pending orthodontic surgery. The patients included those with low (< or =27 degrees), average (27 degrees through 37 degrees) and high (>37 degrees) mandibular plane angles. The maxillary skeletal base width, biantegonial width, and maxillary and mandibular intermolar width were determined on posteroanterior cephalograms obtained at annual intervals when subjects were between 10 and 14 years of age. The difference between the maxillary and mandibular intermolar width was also calculated and reported. RESULTS: All skeletal and dental transverse widths in the high-angle group were significantly smaller than those in the low-angle group (P < .05) from ages 10 to 14. On the other hand, the maxillary to mandibular molar difference was the same for the three groups (P > .05) at each age. The deviations in molar differences did increase from age 10 to age 14 in all three groups. CONCLUSION: Mandibular plane angles might play a stronger role in the transverse skeletal growth of the maxilla and the mandible than the transverse dental growth of the maxilla and the mandible.     

Effects of cervical headgear and fixed appliances on the space available for maxillary second molars.

INTRODUCTION: This study examined the effects of cervical headgear and fixed appliances on the space available for the eruption of the maxillary second molars. Cervical headgear was the only intervention until a Class I molar relationship was achieved. METHODS: Thirty-four patients (18 girls, 16 boys) with Class II molar occlusions, treated without extractions, were included in this study. Five linear and 4 angular cephalometric measurements were made from pretreatment and posttreatment radiographs. RESULTS: Treatment prevented the mesial drift of the maxillary first permanent molars and the forward displacement of the maxilla, displaced the pterygomaxillary fissure posteriorly, and uprighted the first permanent molars. In the male group, the only significant changes were molar uprighting and clockwise rotation of the maxilla. CONCLUSIONS: These results suggest that posterior displacement of the pterygomaxillary fissure by treatment and growth at the maxillary tuberosity compensated for the restricted anterior movement of the maxillary first molars, allowing the second molars to erupt.     

A comparison of chincap and maxillary protraction appliances in the treatment of skeletal Class III malocclusions

The purpose of this retrospective investigation was to compare cephalometrically the treatment effects of chincap and maxillary protraction appliances in subjects with a Class III skeletal malocclusion with a combination of an underdeveloped maxilla and prominent mandible. Twenty-four patients were divided into two groups according to the treatment type; the chincap group (mean age 11.03 years, n = 12) and the Delaire type maxillary protraction appliance group (mean age 10.72 years, n = 12). In both groups, a significant increase in ANB, molar relationship, and overjet showed the effect of the appliances in the treatment of Class III malocclusions. In comparing the two groups, the maxilla was displaced more anteriorly and the molar relationship correction was greater in the maxillary protraction appliance group (P < 0.05). Angular and dimensional parameters for lower incisor/NB and nasolabial angle showed significant differences between the groups (P < 0.05).     

Treatment planning in Class III malocclusion

In Class III malocclusion, the overjet is reduced and may be reversed, with one or more incisor teeth in lingual crossbite. In the early mixed dentition, and in older patients with mild skeletal discrepancies, orthodontic treatment usually involves proclining the maxilliary anterior teeth into positive overjet. When the permanent dentition has established, orthodontic therapy is usually aimed at compensating for the underlying mild-moderate Class III skeletal discrepancy by proclining and retroclining the maxillary and mandibular incisors, respectively. In contrast, adolescent and non-growing patients with severe Class III skeletal discrepancies require a combination of orthodontic treatment and orthognathic surgery to correct the underlying skeletal pattern. Adolescent patients with moderately severe skeletal discrepancies require careful treatment planning because they are often at the limits of orthodontic compensation, and further mandibular growth may prevent a stable Class I occlusion from being maintained with growth. In this situation, treatment should be limited to aligning the maxillary arch, accepting that orthognathic surgery will be required to correct the underlying Class III skeletal discrepancy when skeletal growth has been completed. This article will inform dental professionals about the aetiology, assessment, diagnosis and treatment of patients with Class III malocclusions. Specifically, the types of orthodontic treatment that can be completed at the various stages of dental development and skeletal growth will be discussed.     

Mandibular incisor extraction--postretention evaluation of stability and relapse.

Pretreatment, posttreatment and 10-year postretention dental cast and lateral cephalogram records of 42 patients were evaluated. Each patient had undergone edgewise orthodontic treatment following removal of one or two mandibular incisors and various maxillary teeth. Seven of 24 patients (29%) in the single-incisor extraction group and 10 of 18 (56%) patients in the two-incisor extraction group demonstrated unacceptable mandibular incisor alignment at the postretention stage. This result was considerably more favorable than the results of previously reported premolar extraction cases (70% unacceptable alignment at postretention). Intercanine width decreased during treatment and continued to decrease postretention in most cases. Overbite and overjet remained acceptable. No associations could be found to predict the amount of relapse.     

Treatment effects of simple fixed appliance and reverse headgear in correction of anterior crossbites

The aim of this study was to compare the skeletal and dental changes contributing to the correction of Class III malocclusion using a 2 x 4 appliance and reverse headgear in the mixed dentition. Seventeen consecutive patients (mean age, 9.7 years) with pseudo-Class III malocclusions and an anterior functional shift and straight or concave facial profile were treated with a simple fixed appliance. Another 20 consecutive patients (mean age, 8.5 years) with Class III incisor relationship and straight or concave facial profiles, were treated with reverse headgear. Lateral cephalometric films taken at the beginning of treatment, the end of the treatment, and 1 year after the active treatment, were analyzed with the modified Pancherz analysis. After active treatment, the overjet correction, 5.2 mm and 6.5 mm on average, respectively, were achieved using the 2 x 4 and reverse headgear. The overjet correction by the 2 x 4 appliance was due to dental changes only. In the reverse headgear group, 60% of the overjet correction was due to dental changes and 40% due to skeletal changes. During the 12 months follow-up period, the overjet was unchanged in the 2 x 4 group (1.6 mm) and decreased in the reverse headgear group, the difference being statistically significant (P <.05). The change of jaw relationship was similar between the 2 x 4 and reverse headgear groups. During the follow-up period, a decrease in overjet in the reverse headgear group was mainly due to forward growth of the mandible and proclination of lower incisors. The overjet in the 2 x 4 group was unchanged due to dental compensation (1.6 mm). To conclude there was a similar amount of overjet correction in the 2 x 4 and reverse headgear groups. Overjet correction by the simple fixed appliance was produced by dental changes whereas in the reverse headgear group, it was produced by both dental and skeletal changes.