Evaluation of Pain and Functional Impairments When Treating Class III Malocclusion Using Two Treatment Procedures

Treating skeletal Class III malocclusion presents challenges. However, various methods have been implemented for treating Class III cases through growth modification during the primary and mixed dentition stages, such as the removable mandibular retractor (RMR) and recently bone-anchored intermaxillary traction (BAIMT) system. In orthodontics, there has been increasing interest in assessing patient-reported outcome measures (PROMs) for two reasons: First, the patient's psychosocial well-being enhances collaboration during treatment. Second, the results of orthodontic treatment may advance if the patient is informed and self-assured regarding their treatment.

Participants will be chosen from patients attending the Adib Al Lahham Centre at the Ministry of Health Damascus. Eligible patients with Class III malocclusion associated with maxillary constriction who meet the inclusion criteria will be asked to participate in this study following a screening conducted by the researcher. Informed consent will be acquired from all patients who consent to participate in the survey after receiving an information sheet.

For BAIMT with the RME group, a modified Hyrax palatal expander with posterior bite planes will be bonded. The expander will also have hooks welded distal to the first molars to attach elastic bands. Two self-drilling mini screws will be inserted buccally between the roots of the mandibular canine and the first premolar. Then, intermaxillary elastics will be placed between the hooks and the mandibular.

FOR RMR with SME group, patients in this group will be provided with an RMR appliance containing a midline split that included an expansion screw, and an anterior sagittal expansion screw which will be utilized when necessary to rectify the upper incisors axes.

A change in the relationship of the incisor from a negative overjet to a positive one (i.e., + 1.5 mm or greater) will be deemed a sign of successful treatment in the sagittal plane. If the defect in the transverse plane is addressed first, the expansion will be halted, and the patient will be asked to keep wearing the appliance until the deficiency in the sagittal plane is corrected. On the other hand, if the defect in the sagittal plane is corrected initially, the process will be reversed.

The levels of pain, functional impairment, and confidence will be self-reported using a questionnaire with a 4-point Likert scale administered at five evaluation times during the first 6 months of treatment initiation.

Inclusion criteria

• Growing patients between the ages of 12-15 of either gender.
• Angle's class III malocclusion.
• Skeletal class III (-4 < ANB < + 1).
• Anterior crossbite involving two or more teeth or edge-to-edge incisor relationship with or without a forward shift of the mandible during closure.
• The incisor mandibular plane's (IMPA) angle should be between 85° and 100°.
• Maxillary constriction necessitates expansion.

Exclusion criteria

• Skeletal class III malocclusion is mainly caused by maxillary retrognathism.
• Severe skeletal class III, mainly resulting from mandibular prognathism.
• Contraindications for the application of the mini-screws.
• The presence of supernumerary teeth or missing ones except for the third molars.
• The presence of cleft lip or craniofacial syndromes and/or palate abnormalities.