[The orthodontic therapeutic principles for malocclusions concurring with temporomandibular joint disorders]

The biological nature of temporomandibular joint (TMJ) featuring adaptive remodeling allows for TMJ structural changes in response to external stimuli, including alterations in occlusion and in mandibular posture. Correlative susceptibility exists between malocclusions and TMJ disorders (TMD), evidenced by high incidence of TMD coinciding with skeletal originated malocclusion with facial prognathsim (Angle Class I skeletal II high angle). Clinical manifestations include markedly retruded mandible together with increased overjet, or mandibular transverse deviation, due to condylar pathological resorption. It is critically imperative to execute differential diagnosis between the routine malocclusions and those infringed with TMD. The prime stipulations governing the orthodontic procedures include the patient's notification of the existential TMD conditions prior to any orthodontic interventions, close inspections of TMD developments during the treatment, and a specially designed retention protocol aftermath. For the cases where severe overjet and mandibular displacement occur as a result of TMD, some specific orthopedic modalities can be implemented to improve the occlusion by restoring the shifted mandible. TMD conditions are also expected to be relieved with mandibular repositioning, which encourages new bone formation in the degraded condyles. The newly developed clear version of orthopedic appliances, namely, S8-SGTB, S8-SGHB, S9 and S10 are of promising efficacy in treating this category of patients.