Molar Correction Research Articles

Comparison between clear aligners and twin-block in treating class II malocclusion in children: a retrospective study.

The study herein evaluated and compared the efficacy of Clear Aligners (CA) and Twin-Block (TB) appliances as the early orthodontic treatments of developing class II division 1 malocclusion. Twenty-four patients each for CA (11.73 ± 0.33 y) and TB (11.87 ± 0.34 y) groups were selected according to the inclusion and exclusion criteria. The cephalometric X-rays and intraoral photos were taken for the patients after nearly 12 months of treatment. Treatment impacts were evaluated by the molar correction and overjet reduction. The vertical and sagittal changes were analyzed through cephalometric measurements. Sella-nasion-point B angle (SNB), point A-nasion-point B angle (ANB), Wits Appraisal (AO-BO) and overjet were statistically significant regarding the sagittal changes analyzed before and after the treatments in both groups, respectively. So, no significant difference was noted in the sagittal changes between CA and TB groups. However, for the vertical changes, OP (occlusal plane) angle of CA group and OP angle, AFH (anterior facial height) and PFH (posterior facial height) of TB group were statistically significant. Moreover, the Z angle and cranial facial difficulty (C.F. difficulty) were also statistically significant in both groups. Class II children with retrognathic mandible are effectively treated by employing the CA, which has almost the same impact as of TB in sagittal and vertical changes. Resultantly, the patient profile is improved. The CA and TB treatments thus minimize the subsequent treatment difficulty by reducing the C.F. difficulty.

Dental and Skeletal Effects of Herbst Appliance, Forsus Fatigue Resistance Device, and Class II Elastics-A Systematic Review and Meta-Analysis.

Background: Our study aimed to systematically summarize the dentoskeletal effects of Herbst appliance; Forsus fatigue resistance device; and Class II elastics in adolescent Class II malocclusion. Methods: Five databases; unpublished literature; and reference lists were last searched in August 2022. Randomized clinical trials and observational studies of at least 10 Class II growing patients that assessed dentoskeletal effects through cephalometric/CBCT superimpositions were eligible. The included studies quality was assessed with the RoB 2 and ROBINS-I tools. A random-effects model meta-analysis was performed. Heterogeneity was explored with subgroup and sensitivity analyses. Results: Among nine studies (298 patients); two-to-three studies were included in each meta-analysis. Less post-treatment upper incisor retroclination (<2) and no overbite; overjet; SNA; SNB; and lower incisor inclination differences were found between Herbst/Forsus and Class II elastics. No differences in maxilla; condyle; glenoid fossa; and most mandibular changes were found between Herbst and Class II elastics; except for a greater 1.5 mm increase in mandibular length and right mandibular ramus height (1.6 mm) with Herbst. Conclusions: Herbst and Class II elastics corrected the molar relationship; but Herbst moved the lower molars more mesially. Apart from an additional mandibular length increase; no other dental and anteroposterior skeletal difference was found. Forsus was more effective in molar correction; overjet reduction; and upper incisor control than Class II elastics. Trial registration number OSF: 10.17605/OSF.IO/8TK3R.

Analysis of Variations in Maxillary Second Molar Buccopalatal Inclination in Angle's Class I, Angle's Class III Malocclusion, and Unilateral Cleft Lip and Palate (UCLP) Cases: A Comparative Observational Study.

Introduction Cleft of the lip and/or the palate iscommonly inheriteddefect which involves cleft of lip and palate. Maxillary second molar inclination has been studied in various malocclusion. Every abnormality in body is compensated to some extend by compensation. Our objectives were to evaluate maxillary second molar inclination in Angle's Class I, Class III malocclusion, and unilateral cleft lip and palate (UCLP) patients in transverse plane and to compare variation in maxillary second molar inclination in Angle's Class I, Class III malocclusion, and UCLP cases buccopalatally in transverse plane. Material and method Model of 45 subjects were analyzed.The maxillary second molar inclination was measured using aid of protractor fixed on the surveyor. Axis under consideration was the axis along the long axis of the central fossa of maxillary second molar. Various standardization regarding measurement of second molar inclination were set. The maxillary second molar inclination was compared among 3 groups Angle's Class I, Class III malocclusion, and UCLP cases. Results Data was analyzed using one-way analysis of variance (ANOVA) and post-hoc Tukey test. There was a significant difference between inclination of maxillary second molar when Angle's Class I malocclusion was compared with Angle's Class III malocclusion and UCLP cases (p = 0.003 and p = 0.011, respectively). There was not a significantdifference betweenAngle's Class III malocclusion and UCLP cases (p = 0.87). Conclusion Amongst Class III patients and UCLP patients the inclination of maxillary second molar had greater buccal inclination. Maxillary second molar correction would alleviate the effect of deleterious force on periodontium and bone generated by malpositioned teeth.

Total arch maxillary distalization using infrazygomatic crest miniscrews in the treatment of Class II malocclusion: a prospective study.

To evaluate treatment effects in Class II patients using infrazygomatic crest (IZC) miniscrews (MS). A prospective sample of 25 adolescents (14 females and 11 males; mean age: 13.6 ± 1.5 years) who underwent maxillary dentition distalization treatment with IZC MSs were recruited. Lateral cephalograms and digital models at the beginning of treatment (T1) and after Class II molar correction (T2) were obtained. To compare cephalometric and digital model changes, paired t-test and Wilcoxon test were used. A significance level of 5% was used. All patients achieved Class II molar correction over a mean period of 7.7 ± 2.5 months. The IZC MS therapy provided 4 mm of distalization; there was 1.2 mm of intrusion of the first molar with 11.2° distal tipping. The maxillary incisors were retracted 4.7 mm and tipped lingually 13.4°. Overjet and overbite showed a reduction of 3.6 mm and 2.4 mm, respectively. The occlusal plane rotated clockwise 2.8°. The upper lip was retracted by 1 mm and the nasolabial angle increased 5.1°. There was an increase in the interpremolar and intermolar distances. Total arch distalization of the maxillary dentition using IZC MS was effective in the treatment of Class II malocclusions.

Skeletal and dentoalveolar contributions during ClassII correction with Forsus™ FRD appliances : Quantitative evaluation.

Primary objective of the study is to quantify and evaluate the skeletal and dental contributions during sagittal ClassII correction with the Forsus™ fatigue resistant device (FRD; 3M Unitek Corp., Monrovia, CA, USA). Secondary objective is to evaluate the overall vertical, soft tissue and chin-throat relation changes with the Forsus™ appliance. Aretrospective sample of 27ClassII patients treated with the Forsus™ FRD appliance was compared to 20untreated control subjects who were matched according to age and craniofacial morphology. Pre-Forsus™ (T0) and Post-Forsus™ (T1) cephalograms were subjected to composite cephalometric analysis. Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. The data were analyzed using Student's t‑test and independent ttest. Significant differences were found between the treated and the control group in 16of 29measured variables. The overjet and molar relation improved by 4.23 mm and 4.49 mm, respectively. This was mainly achieved by backward movement of maxillary incisors (1.4 mm) and molars (1.22 mm) and forward movement of mandibular incisors (2.26 mm) and molars (2.70 mm). Overbite decreased by 2.24 mm with no changes in mandibular and nasal plane angles. The Forsus™ FRD was effective in correcting ClassII malocclusion mainly at the dentoalveolar level. The net skeletal and dentoalveolar contributions towards both overjet and molar correction was 13% and 87%, respectively. The improvement in soft tissue profile and chin-throat configuration was statistically insignificant.

English

BACKGROUND To provide efficient and well-planned orthodontic treatment orthodontists must be able to assess the type of malocclusion and the complexity involved in its treatment. Hence, the purpose of this study was to validate index of orthodontic treatment complexity (IOTC) as a reliable index to assess the treatment complexity in treating different malocclusion groups. METHODS A retrospective study with sample of 120 pairs of orthodontic study model consisting of treated and untreated cases, were collected and equally divided into class I, class II including both division 1 and division 2 and class III malocclusions based on Angles system of classification of malocclusion. Study casts were scored according to criteria given by the index of orthodontic treatment complexity and the degree of complexity is established for each of the malocclusion groups and the occlusal traits. RESULTS The Spearman correlation coefficients test shows that occlusal traits like overjet, centreline discrepancy, molar correction, overbite, crowding, posterior cross bite, alone significantly correlated with degree of complexity. Multiple regression analysis and one way ANOVA tests were performed for the three types of malocclusion and the test showed that in individual classes of malocclusion, the predictor variable (occlusal traits) significantly predicts the degree of complexity in class I and class II malocclusion cases, but not in class III. CONCLUSIONS Overjet, centreline discrepancy, molar correction, overbite, crowding, posterior cross bite correlated with degree of complexity. IOTC forecasts the degree of complexity in class I and class II malocclusion cases, but not in class III. KEY WORDS IOTC, Malocclusion, Occlusal Traits

Skeletal and dental changes induced by the Flip-Lock Herbst appliance in the treatment of Angle's class II division 1 malocclusion during active growth period: A preliminary study.

Background. The Flip-Lock Herbst (TP Orthodontics Inc.) is a fixed functional appliance, a variant of the Herbst appliance, introduced by Miller. It is claimed to have better patient tolerance due to its increased freedom for the mandible’s lateral movements. There have been no studies on the flip lock Herbst till date. This study was undertaken to assess the efficiency of the Flip-Lock Herbst appliance in correcting Angle’s class II division 1 malocclusion. Methods. Eight subjects in their active growth period with class II division 1 malocclusion due to a retrognathic mandible were included in the study. Standardized lateral cephalometric radiographs were used to evaluate skeletal and dental changes with the SO analysis. Paired samples t-test was used to assess statistical significance. Results. Statistically significant increases in mandibular length (pg/OLp) and effective mandibular length (ar/OLp + pg/OLp) were observed. There was a significant maxillary restraining effect. Dental effects were significant and exhibited class II correction features except for the position of lower incisors within the mandible (ii/OLp - pg/OLp). Skeletal changes accounted for 61% and dental changes for 39% of the total treatment for molar correction. For overjet correction, skeletal changes contributed to 63% and dental changes to 37% of the total treatment. Conclusion. The Flip-Lock Herbst appliance was efficient in correcting Angle’s class II division 1 malocclusion due to a retrognathic mandible. Both skeletal and dental changes were evident, with the former predominating (60:40).

Keys to Class II correction: A comparison of 2 extraction protocols

The purpose of this study was to evaluate the effects of 2 extraction patterns on incisor and molar movements in patients with growing Class II Division1. The sample included 54 patients 10-17years of age treated by 2 private practice orthodontists using Tweed directional force mechanics, 4 premolar extractions, J-hook headgears, and Class II elastics or Saif springs. The sample was divided on the basis of having maxillary and mandibular first premolars (4/4) or maxillary first and mandibular second premolars (4/5) extracted. Each group included 27 patients. Treatment lasted 2.8±0.60years and 2.6±0.54years for the 4/4 and 4/5 groups, respectively. Pretreatment (T1) and posttreatment lateral cephalograms and dental casts were evaluated. Cranial base, mandibular, and maxillary superimpositions were performed to quantify tooth movements and displacements. There were no statistically significant T1 between-group differences in crowding or in the SNA, SNB, ANB, and MPA angles. Analyses of covariance, controlling for statistically significant (P<0.05) differences in T1 mandibular incisor position, showed that mandibular first premolars extractions produced greater (1.6mm) mandibular incisor retraction than second premolar extractions. The mandibular first molars were protracted significantly more (0.7mm) after the second premolar than the first premolar extractions. Within-group changes of the MPA, between-group differences in the changes in MPA, and the amount of vertical eruption of the maxillary and mandibular molars were not significantly different between the 2 extraction patterns. Extraction of mandibular second premolars enhances Class II molar correction, with greater mesial first molar movement and less distal incisor movement. Neither extraction pattern has an effect on the MPA or the vertical dimension (ie, there was no "wedge effect").

Skeletal open bite Class III compensatory treatment with biofunctional therapy

Introduction: Class III skeletal malocclusion in adult patients presents mainly two treatment options: the surgical-orthodontic approach or compensatory treatment. Case Report: In the present report, it was described the case of a 23-year-old male patient who presented skeletal Class III malocclusion associated with anterior open bite. The patient refused surgical-orthodontic treatment. Thus, the compensatory orthodontic treatment was performed with the biofunctional technique, consisting of preadjusted brackets with accentuated palatal torque on the maxillary incisors and accentuated buccal torque on mandibular incisors. This prescription aims to minimize the effects of Class III intermaxillary elastics, promoting more bodily movement than tipping of the anterior segments and improve bone remodeling. The anterior open bite was treated with lingual spurs, differentiated bonding of the accessories and early intermaxillary elastics. After 23 months of treatment, a functional occlusion was observed with bilateral Class I canine and molar relationships, overbite correction, and satisfactory smile esthetics. Conclusion: The great outcomes indicate that compensatory orthodontic treatment is possible in skeletal discrepancies, with the correct diagnosis and considering patient compliance. The biofunctional technique provided a favorable dental positioning for Class III correction.

An Integrated Approach, Orthodontic and Prosthetic, in a Case of Maxillary Lateral Incisors Agenesis

Background: Among tooth anomalies, missing teeth is one of the most frequent, and it can be related to different therapeutical sets of problems. Often, an integrated approach that interests both orthodontists and prosthodontists is necessary, and in some cases also the periodontists. Methods: In this paper the authors report a clinical case of a 14-year-old patient, affected by maxillary bilateral incisors agenesis, molar bilateral II class and deep bite, treated in the Department of Orthodontics and Pedodontics of the University of Messina. The orthodontic treatment target was the distal movement of the maxillary molar, and the recovery of the space necessary for the prosthetic restoration of the missing lateral incisor. Maxillary molars distal movement was performed with a Distal Jet apparatus, skeletally supported by two miniscrews (Distal-Screw, American Orthodontics, Sheboygan, WI, USA). After molar relationship correction, a multi-bracket bimaxillary orthodontic appliance was bonded using Empower Brackets (American Orthodontics, Sheboygan, WI, USA). At the end of orthodontic treatment a Maryland bridge, bonded on the central incisors and cuspids, was used in order to maintain the space necessary for the insertion of dental implants in the region of 1.2 and 2.2 Results: A class II molar relationship was corrected, with an improvement of the deep bite, and the space necessary for implant insertion was recovered Conclusion: A skeletally supported Distal Jet was efficient for molar distalization, with the advantage of not having any loss of anchorage in the anterior part of the dental arch. This apparatus does not need patient compliance, have favorable aesthetics and also give the possibility to perform asymmetric activations.

Residents' journal review

Residents' journal review

Class II correction in orthodontic patients utilizing the Mandibular Anterior Repositioning Appliance (MARA).

To evaluate skeletal and dentoalveolar changes produced by the Mandibular Anterior Repostioning Appliance (MARA) in the treatment of Class II malocclusion in adolescent patients. Lateral cephalograms of 24 patients, mean age 12.40 years, with a Class II malocclusion consecutively treated with MARA were compared with a historical control group. Changes were evaluated using the Pancherz superimposition and grid analysis pre- and posttreatment. Independent sample t-test, Mann-Whitney U-test, and Pearson correlation coefficient analysis were performed. Significant differences were seen between the treatment and control groups during the 12 month period. Improvement in Class II relationship in the MARA group resulted from skeletal and dentoalveolar changes. There was a 7-mm molar correction and a 4.7-mm overjet reduction. There was also an increase in the mandibular base of 3.3 mm with the lower molar and incisor coming forward 2.6 mm and 2.2 mm, respectively. No significant headgear effect was shown on the maxilla. The maxillary incisor position remained unchanged, whereas the molar distalized 1.8 mm. The anterior lower facial height had an overall increase of 2.2 mm. The MARA was successful in achieving a Class I molar relationship and reducing the overjet in Class II malocclusions. This was the result of both skeletal and dentoalveolar changes.

Evaluation of Sagittal Changes in Class II Div 2 Patients with Decelerating Phase of Growth by PowerScope Appliance: A Retrospective Cephalometric Investigation.

Background:Restricted mandibular growth is observed in Class II Div 2 malocclusions. The fixed functional appliances are used to effect the skeletal changes in patients with end stages of skeletal maturity.Aim:This cephalometric study aimed to distinguish the skeletal and dental corrections done in the mandible on skeletal Class II Div 2 subjects when treated with PowerScope appliance (American Orthodontics, Sheboygan, WI).Materials and Methods:This is a cephalometric study based on the retrospective data. The patients selected for this study were with Class II Div 2 malocclusion and assessed to be in decelerating phase of skeletal growth. A total of 12 patients were selected after applying inclusion and exclusion criteria. A PowerScope was placed after incisor correction and followed up till Class I molar relation was achieved. The initial values (T1) at the time of placement of the appliance and the final values at the end of the molar correction (T2) were noted. The cephalometric parameters at T1 and T2 were assessed using sagittal occlusal (SO) analysis by Pancherz. The paired Student’s t-test was used to analyze pre- and posttreatment changes.Results:There was sufficient lengthening of the mandible (4.38 mm). Both the dental and skeletal alterations were observed in the mandible. These changes were marked compared to the maxilla. The pre- and posttreatment changes were statistically significant for the mandibular skeletal changes (P < 0.001) as well as mandibular incisor proclination (P < 0.001).Conclusion:The PowerScope can be used as a propeller for sagittal mandibular correction in Class II Div 2 patients.

Long-term skeletal effects of high-pull headgear followed by fixed appliances for the treatment of Class II malocclusions.

The long-term skeletal effects of Class II treatment in growing individuals using high-pull facebow headgear and fixed edgewise appliances have not been reported. The purpose of this study was to evaluate the long-term skeletal effects of treatment using high-pull headgear followed by fixed orthodontic appliances compared to an untreated control group. Changes in anteroposterior and vertical cephalometric measurements of 42 Class II subjects (n = 21, mean age = 10.7 years) before treatment, after headgear correction to Class I molar relationship, after treatment with fixed appliances, and after long-term retention (mean 4.1 years), were compared to similar changes in a matched control group (n = 21, mean age = 10.9 years) by multivariable linear regression models. Compared to control, the study group displayed significant long-term horizontal restriction of A-point (SNA = -1.925°, P < .0001; FH-NA = -3.042°, P < .0001; linear measurement A-point to Vertical Reference = -3.859 mm, P < .0001) and reduction of the ANB angle (-1.767°, P < .0001), with no effect on mandibular horizontal growth or maxillary and mandibular vertical skeletal changes. A-point horizontal restriction and forward mandibular horizontal growth accompanied the study group correction to Class I molar, and these changes were stable long term. One phase treatment for Class II malocclusion with high-pull headgear followed by fixed orthodontic appliances resulted in correction to Class I molar through restriction of horizontal maxillary growth with continued horizontal mandibular growth and vertical skeletal changes unaffected. The anteroposterior molar correction and skeletal effects of this treatment were stable long term.

The Evaluation and Clinical Efficiency of Power Scope: An Original Research.

Aims and Objectives:Managing mild-to-moderate Class II malocclusion is one of the common and major challenges to orthodontists. Class II discrepancies with mandibular deficiency during active growth are usually treated using myofunctional appliances. Fixed functional appliances evolved due to the noncompliance with conventional myofunctional appliances. One of the latest Class II correctors is the PowerScope appliance. The purpose of this study was to determine the amount, time, and rate of molar correction and efficacy of PowerScope.Materials and Methods:A total of 10 participants, between 15 and 19 years’ age group (mean = 16.8 years; 5 males and 5 females), requiring treatment of Class II malocclusion were considered for this study. All routine records were made. After initial leveling and alignment, lateral cephalogram was taken in standardized natural head position using Planmeca ProMax unit. Later, PowerScope was installed and a patient was monitored every month for further adjustment and reactivation. On achieving Class I molar relation, skeletal, dental, and soft-tissue linear and angular parameters were measured using Dolphin Imaging Software. Amount, rate, and total treatment time for molar correction were measured. Molar correction was calculated by taking S vertical as reference plane. The obtained values were statistically analyzed using paired t-test.Results:There were statistically significant changes seen in dentoalveolar parameters such as lower incisor proclination, mandibular molar advancement, and reduction in both overjet and overbite. In skeletal parameters, due to the anterior positioning of the mandible, sagittal parameters showed statistically significant changes. In the soft tissue, a significant improvement in facial profile was seen, due to the anterior movement of soft-tissue pogonion.Conclusion:The results of this study have shown that statistically significant differences were found in dentoalveolar, soft-tissue, and skeletal parameters.

Evaluation of Skeletal and Dental Effects of Modified Jasper Jumper Appliance and Delaire Face Mask with Pancherz Analysis.

The aim of this study was to evaluate the skeletal and dental changes in Class III patients treated with Modified Jasper Jumper appliance and Delaire face mask before the growth peak. A study sample comprising 16 patients with functional Class III malocclusion treated with Modified Jasper Jumper appliance and 17 patients treated with Delaire face mask was compared with a control group comprising 13 patients. Pancherz analysis was used as the analysis method. In both treatment groups forward movement of maxillary base and incisors and an increase in the overjet while no positional change in the mandibular base was observed. In the Modified Jasper Jumper group, 4.63 mm overjet correction was due to 51.4% skeletal and 48.6% dental changes; 4.77 mm Class III molar correction was due to 49.9% skeletal and 50.1% dental changes. In the Delaire face mask group, 5.17 mm overjet correction was due to 70.6% skeletal and 29.4% dental changes and 4.87 mm Class III molar correction was due to 75% skeletal and 25% dental changes. It was shown that both appliances were skeletally and dentally effective. Therefore, Modified Jasper Jumper therapy may be an alternative treatment modality for patients with poor cooperation, who are not ideal recipients for Delaire face mask.

Skeletal Correction of Class II with Unilateral Fixed Functional Appliance-A Case Report

Fixed functional appliances are designed to provide a simple non-compliant solution to orthodontic Class II treatment. Molar correction can be achieved very quickly using these appliances [1, 2]. Unilateral fixed functional appliance has been used often to correct Class II molar or correct midline discrepancies (Ross et al. J Orthod 2007; 34(March): 2–5). This case report documents correction of Class II division I using a unilateral fixed functional appliance.

Treatment Effects and Posttreatment Follow-up of Miniscrew Anchorage-Supported Forsus FRD Appliance: Report of 2 Severe Class II Cases

ABSTRACT This case report presents the treatment and posttreatment follow-up of 2 boys with severe skeletal Class II malocclusion with miniscrew anchorage-supported Forsus Fatigue Resistance Device (FRDMS). Miniscrews were inserted between the mandibular canine and first premolar root area bilaterally. The FRDMS treatment duration was 13 months in the first case and 11 months in the second case. The patients were treated with fixed orthodontic treatment afterward. The first patient was followed up for 1 year and 6 months and the second patient for 2 years and 8 months after fixed orthodontic treatment Essix retainers were worn full-time for a period of 6 months and only at nighttime for the following 6 months in both cases after the fixed appliances. Lower incisor proclination was observed in both cases, although lower dentition anchorage was reinforced with miniscrews during Forsus FRD treatment. Favorable sagittal movement of the mandible was achieved in only 1 case. Overjet and molar correction were ma...

Stability of early Class III orthopedic treatment

The objective of the article is to determine the stability of early Class III orthopedic treatment in the primary and early mixed dentitions. A total of 23 patients with Class III malocclusion in the primary or early mixed dentition (mean age=6.2 ±1.5 years, CVM=1) were treated consecutively by one of the investigators (T.K.) using maxillary expansion and protraction appliances. The average treatment time was 9.1 ± 2.3 months. For each patient, a lateral cephalogram was taken at pre-treatment (T1), post-treatment (T2), and 2 years post-treatment (T3). Each patient served as his/her own control. Cephalometric analysis described by Bjork (1947) and Pancherz (1982) was used. Sagittal and vertical measurements were made along the occlusal plane (OLs) and the occlusal plane perpendicular (Olp), and superimposed on the mid-sagittal cranial structure. Data were analyzed using paired t -test. All patients in the study were treated to Class I or overcorrected to Class II dental arch relationships. Overjet and sagittal molar relationships improved by an average of 4.1 and 1.8mm, respectively (T2–T1). This was a result of 2.6mm of forward maxillary growth, .7mm of forward mandibular growth, 1.2mm of labial movement of maxillary incisors, 1.0mm of lingual movement of mandibular incisors, and .1mm of greater mesial movement of mandibular than maxillary molars. The mean overbite reduction was .9mm. The maxillary and the mandibular molars were erupted occlusally by 1.5 and 1.0mm, respectively. The mandibular plane angle was increased by .9° and the lower facial height by 3.2mm. Overall, 2 years follow-up observation (T3–T2) revealed a decrease in the overjet and the molar relationship by .3 and .2mm, respectively. This was contributed by 2.2mm of excess forward mandibular growth that was compensated by 1.9-mm dentoalveolar compensation. Overall, the changes in the overjet and the molar relationship were 3.8 and 1.5mm, respectively. The overbite reduction was .6mm. Significant overjet and overbite corrections can be obtained with maxillary protraction in the primary or early mixed dentition. Overjet and molar relationship corrections were stable 2 years post-treatment. A combination of dentoalveolar compensation and skeletal changes accounted for this stability.

Classification and treatment of Class II subdivision malocclusions

Patients with Class II subdivision malocclusions are a challenge for clinicians because reestablishing symmetry in 1 arch or both arches is often a treatment goal. In patients with mandibular skeletal asymmetry, surgery is often a treatment option. However, patients may be unwilling to undergo surgery, and other options might have to be considered. The aim of this study was to evaluate the etiologies and outcomes of Class II subdivision patients treated at the University of Washington graduate orthodontic clinic in Seattle from 1995 through2011. A search of patients treated between 1995 and 2011 resulted in the identification of 110 consecutively treated Class II subdivision subjects with complete records. Ninety-eight subjects could be classified into 1 of 3 groups, based on midline position and dental or skeletal etiology. Initial and final models were used to measure the peer assessment rating scores, midlines, overjet, overbite, and molar positions. Initial and final cephalograms were traced and measured. Charts were reviewed for information regarding treatment. Twenty-five percent of the 98 subjects had their maxillary and mandibular midlines coincident with the facial midline; their asymmetries were due to a maxillary posterior dental asymmetry. Another 15% had maxillary midlines deviated from their facial midlines, caused by maxillary anterior and posterior dental asymmetry. About 50% of the subjects had mandibular midlines that were not coincident with their facial midlines, and most of them exhibited some degree of mandibular skeletal asymmetry. Over the past 15 years, treatment strategies used at the University of Washington indicated trends toward less surgery, fewer extractions, less use of headgear, and more reliance on fixed functional appliances. Ideal correction of midlines was not always achieved, especially in patients with mandibular skeletal asymmetry, with undercorrection occurring more commonly than overcorrection. Final peer assessment rating scores were comparable, regardless of the origin of the asymmetry or the extractions status. Mandibular incisor proclination was increased when fixed functional appliances were used, as well as when a Class I molar relationship was the target for the Class II side. Class II subdivision malocclusions were grouped into 3 main categories; the largest category was mandibular asymmetry. Interesting trends were noted with regard to treatment strategies, midline and molar corrections, and mandibular incisor proclination.