Abstract: Objective: To evaluate the influence of orthodontic treatment on temporomandibular joint after surgery of condylar hyperplasia (CH) , and to explore the stability of TMJ after surgery. Methords: Twenty patients (8 males and 12 females), aged from 17 to 34 years with an average age of 21.2 years and diagnosed as condylar hyperplasia, were selected after condylectomy high site. Straightwire appliance or invisible appliance was used for the orthodontic treatment. Mini-implants were used to intrude upper posteriors on the affected side. The function of TMJ before surgery, after surgery, and after orthodontic treatment was compared. CBCT, cephalometric film, and Tc99m_MDP SPECT were used to measure the change of joint space specifically. Results: Significant differences were found in TMJ space (including anterior space, posterior space, and superior space) of affected side and normal side after surgery and after orthodontic treatment, whereas no significant difference was found before surgery. Conclusion: Orthodontic treatment with condylectomy high site can improve the facial deformity and malocclusion induced by CH. TMD could also be improved. The condyle will return back to the normal condition in joint fossa after orthodontic treatment and the stability is promising.

Key words: Condylar hyperplasia, Surgery treatment, Orthodontic treatment, Joint space, Mini-implant