Management of Class II Division 1 Subdivision malocclusion using unilateral bicuspid extractions and fixed functional appliance: A Two Year Follow-Up

Introduction: Management of Class II Subdivision cases pose a clinical dilemma and require a careful diagnosis to ascertain the source of asymmetry. Various treatment modalities involving: different protocols of tooth extractions; molar distalization; fixed functional appliances or orthognathic surgery have been proposed for the same. Objective: This article reports a unique approach for management of a severe skeletal Class II with Angle’s Class II Division 1 subdivision malocclusion using unilateral bicuspid extractions in mandibular and maxillary arches and a fixed functional appliance. Results: A 13 year 1 month old male in CVMI transition stage was successfully treated. Extraction of #44 was done to alleviate crowding in the mandibular anterior region and #15 was extracted to protract #16 to achieve a Class II molar relationship. A pre-functional Class II molar and canine relationship with co-incident midlines was achieved. The functional phase consisted of a fixed functional appliance (Forsus FRD) for mandibular advancement to correct the severe skeletal Class II. Class I molar and canine relationships were achieved with reduction of facial convexity and overjet. Result remained stable 24 months after treatment. The improvement can be quantified by the reduction in scores of orthodontic indices measured pre and post treatment. Conclusions: Management of Class II subdivision malocclusion requires careful planning. This paper presents a unique approach utilizing unilateral extractions and fixed functional appliance to address severe skeletal Class II discrepancy and the subdivision dilemma.

Skeletal Class II Malocclusion Treated with AdvanSync 2 - A Case Report

Treatment of complex malocclusion poses a challenge for the orthodontist because of its multifactorial aetiology. Class II malocclusion is the most frequently encountered and treated malocclusion in orthodontic practice and affects approximately 14.6 % of the North Indian population.1 A common reason for Class II malocclusion is mandibular skeletal retrusion which is the most common characteristic, as reported by McNamara.2 This can be caused by genetic or hereditary factors. When evaluating treatment options for Class II patients, the extent of the skeletal discrepancy and the skeletal maturity of the patient needs to be considered. Treatment may range from dental compensation including camouflage with extractions to surgical procedures targeted at moving the jaw at fault. In growing patients, growth modification with functional appliances offers an intermediate treatment option. Functional appliances are basically of two types; Removable and Fixed. Removable functional appliances such as Activator, Bionator, Frankel Function regulator and Twin Block appliance change Class II relationship by the transmission of soft tissue tension to the dentition. Treatment success with these appliances relies heavily on patient compliance. Therefore, in non-compliant patients, fixed Class II correctors in conjunction with fixed orthodontic appliances are the best choice.3 Fixed functional appliances generate continuous stimuli for mandibular growth without break and permit better adaptation to functions like mastication, swallowing, speech and respiration.1 The Herbst fixed functional appliance has been used routinely for Class II patients and has undergone many design variations over time.4 The AdvanSync2 Class II corrector is a recently introduced fixed functional appliance. It has a much smaller size than the conventional Herbst appliances, is easier to place, activate and remove and most importantly, can be used in conjunction with full-arch fixed appliances throughout.3 Here we describe a case report of a patient treated with the AdvanSync2 Class II corrector and the findings observed in the sagittal and vertical dimensions

Fixed Functional Appliances

Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task. To describe the development of fixed functional appliances as well as our 20-year experience working with them. Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view in illustrating the different appliances. Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by class II elastics. They ultimately correct class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat class II in dolichofacial patients, in comparison to class II elastics. The electromyographic (EMG) activity of masticatory muscles was monitored longitudinally with chronically implanted EMG electrodes to determine whether functional appliances produce a change in postural EMG activity of the muscles. Pre-appliance and post-appliance EMG levels in four experiments that had been fitted with functional appliances were compared against the background of EMG levels in controls without appliances. The insertion of two types of functional appliance to induce mandibular protrusion was associated with a decrease in postural EMG activity of the superior and inferior heads of the lateral pterygoid, superficial masseter, and anterior digastric muscles; the decrease in the first three muscles was statistically significant. This decreased postural EMG activity persisted for approximately 6 weeks, with a gradual return towards pre-appliance levels during a subsequent 6-week period of observation. Progressive mandibular advancement of 1.5 to 2 mm every 10 to 15 days did not prevent the decrease in postural EMG activity. KEY WORDS Orthodontics, Class II Malocclusion, Fixed Functional Appliance.

Effect of Class II functional treatment on facial attractiveness, as perceived by professionals and laypeople

The literature offers different perspectives for and against two-phase treatment of skeletal Class II malocclusion. Facial attractiveness is an important aspect to take into account, given that children with skeletal Class II are often bullied by their peers and have low self-esteem and a lower social perception. The aim of the present study was to evaluate the aesthetic perception of facial profiles by a large number of observers, before and after treatment with a functional appliance, compared to untreated controls. The pre- and post-treatment cephalograms of 20 Class II subjects treated with Sander’s bite-jumping appliance and 20 untreated historical controls were collected and transformed into black and white silhouettes depicting only the lower third of the face. An online questionnaire comprising the silhouettes of the two groups, three “calibration” profiles and an “ideal” profile was submitted to dentists, orthodontists, undergraduates and laypeople, asking them to rate the profile’s attractiveness using a Visual Analogue Scale (VAS). The effect of treatment, and observers’ age, expertise and gender were analysed. The calibration images and the ideal profiles were used to evaluate the coherence of each observer’s judgement. The protocol was approved by the local Ethics Committee. Nine-hundred and ten questionnaires were collected. Treated subjects showed a larger improvement of facial attractiveness compared to controls. A significant effect of gender on the observer’s ratings was observed. Some observers showed incoherent judgement, which had a significant effect on the regression model. In conclusion, early treatment with functional appliances seems to improve patients’ facial aesthetics. This improvement is perceived equally by dental professionals and laypeople.

Evaluation of changes seen in TMJ after mandibular advancement in treatment of Class II malocclusions, with functional appliances, a CBCT study

Introduction and Aim: Various functional appliances are developed to remodel the glenoid fossa and, thereby change the position of the mandible and correct Class II malocclusion. Many diagnostic aids have already been used to evaluate the changes ,but Cone Beam computed tomography (CBCT), three -dimensional diagnostic tool is rarely used .So this study was conducted with an aim is to evaluate the changes seen in the temporomandibular joint (TMJ) after mandibular advancement in class II malocclusions with functional appliance therapy, using CBCT, and also to assess and compare the efficacy of Twin Block, Power Scope and Forsus Fatigue Device used for the correction of class II malocclusion.Materials and Methods: The retrospective study was performed using the 52 CBCT scans of 26 patients with class II malocclusion due to retrognathic mandible. The subjects were divided into three groups based on appliance (Twin Block, Power Scope and Forsus Fatigue Resistant Device) used for the treatment. The changes seen in TMJ after mandibular advancement and condylar response to functional therapy was evaluated using the six. Data obtained were subjected to one-way Anova analysis with Posthoc Tukey test. Software SPSS version 20 was used to analyse the data. The level of significance was set at p < 0.05.Results: In subjects treated with Twin Block, the condyle was displaced slightly downwards and anteriorly; and condylar height was reduced. The decrease in the anterior and superior joint spaces were also found. In subjects treated with PowerScope and Forsus Fatigue Resistant Device, there was an increase in condylar height and width with a decrease in anterior and superior joint space.Conclusion: All three appliances were found to bring about changes in TMJ structures, but amongst them the Twin block has proved to be more efficient.