Long-term outcomes of mandibular kinematics following class II malocclusion therapy with removable functional appliance therapy.

Objective: To evaluate mandibular kinematics in class I adults following class II therapy with removable functional appliances (RFAs) during the growth period in comparison with orthodontically untreated class I and II individuals.

Methods: Condylar (CRoM) and incisal range of motion (InRoM), velocity during opening and closing, and the mandibular rotation angle were recorded using an ultrasound-based jaw-tracking system in 36 test patients (mean age = 28.03 ± 6.58 years).

Results: Significant group effects were found for CRoM towards the posterior in the right joint (p = 0.002) and InRoM towards the anterior (p = 0.043). The post hoc Tukey test indicates a significantly longer CRoM (posterior) for the right condyle in class II (p = 0.003) and RFA individuals (p = 0.023).

Discussion: The kinematic data imply greater dentoalveolar effects due to RFA therapy than adaptive remodeling of the temporomandibular joint. The class I relationship in the RFA group following treatment indicates stable long-term outcomes.