CLASS II DIVISION 1 MALOCCLUSION

Evaluation of the efficacy of early treatment of skeletal class II patients with twin-block in conjunction with low intensity pulsed ultrasound on temporomandibular joint region: a prospective clinical trial

Rationale: Class II Division 1 malocclusion is characterized by upper anterior teeth protrusion resulting in upper lip protrusion and convex facial profile, which are considered esthetically unfavorable. Treatment of class II malocclusion due to maxillary protrusion can be done with bilateral maxillary first premolar extraction followed by en-masse retraction of upper anterior teeth using mini-implants placed at infrazygomatic or interradicular sites. Aims and Objectives: To evaluate the treatment changes achieved in class II division 1 malocclusion during en- masse retraction of upper anterior teeth using mini-implants placed at infrazygomatic crest versus interradicular sites. To compare patients' and orthodontist's perceptions of treatment being done in both the groups. Method of study: Treatment will be initiated by bilateral maxillary 1st premolar extraction followed by bonding 0.022" slot MBT preadjusted edgewise appliance. Maxillary arch will be stabilized with the help of 0.019"×0.025" stainless steel wire and then randomized allocation of the patients into 2 groups-G1 and G2 will be done. G1 will receive infrazygomatic crest mini-implants bilaterally and G2 will receive bilateral interradicular mini-implants. Hooks will be soldered on archwire used for stabilizing dentition. Ni-Ti closed coil spring will be used to apply force.

The investigators of this clinical trial aim to: * Compare the effectiveness and efficiency of Clark's Twin Block Appliance (CTB) vs Carriere Motion Appliance (CMA) in correcting Class II malocclusion when used in post-pubertal older adolescents, in terms of skeletal and dental change. * Evaluate potential negative oral health-related quality of life (OHRQoL) impacts during the active treatment phase with either CTB or CMA in post-pubertal adolescents. * Investigate the impact of Class II malocclusion on oral health-related quality of life (OHRQoL) in post-pubertal adolescents. Class II division 1 malocclusion is a dental condition where the upper teeth protrude significantly over the lower teeth. It is a common type of malocclusion observed in orthodontic practice, accounting for approximately 20-25% globally. Correcting Class II malocclusion in growing patients using functional appliances and Class II correctors is relatively predictable. In Ireland and the United Kingdom, the Clark's Twin Block (CTB) is the most commonly used functional appliance. The CTB consists of two components: one for the upper teeth and one for the lower teeth. These components are engineered to position the lower jaw forward, thereby promoting the desired dentoskeletal changes (moving the upper teeth back and lower forward). Another device used for Class II correction is the Carriere Motion Appliance (CMA). The CMA is gaining popularity as a treatment option for Class II malocclusion, inducing dental changes similar to those achieved with a CTB. However, uncertainty persists regarding the effectiveness of these appliances in older adolescents in the post-pubertal growth phase (aged approximately 14.5 years or above). Additionally, although both CTB and CMA are effective in growing patients in correcting dental and skeletal discrepancies, they may influence daily activities, comfort, and psychological aspects, which often results in poor compliance. Poor adherence to orthodontic treatment, whether with fixed or removable appliances, can lead to higher rates of treatment failure.

This Prospective study aims to simulate the maximum mandibular advancement in class II patients treated by Herbst MTH Appliance on the base on clinical overjet. Initial intraoral scans will be uploaded in Suresmile software, the upper incisors will be virtually aligned and the mandible will be advancement until an anterior occlusal contact will be reached. This virtual advancement will be compared to the real advancement obtained at the end of the Herbst phase. This protocol will be applied to two groups: one with traditional dental occlusion, the second one with Skeletal anchorage reinforcement and elastic chains