PURPOSE: This is to evaulate the efficacy of orthognathic surgical aids to imporve the painful TMJ in Class II open-bite deformites. CASES: Four patients who had been sufferred from temporo-mandibular disorders with open-bite retrognathic deformities underwent orthognathic surgeries. The presurgical orthodontic treatment and conservative management for temporomandibular disorders could not be continued due to progressive pain loading on TMJs and muscle tenderness. Bilateral ramus oseotomy with semirigid internal fixation were followed for 2 years by radiologic changes including MRI, bone scan, clinical examination of jaw opening. pain(VAS) and occlusal changes. RESULTS: Open-bite deformites with painful TMJ showed DJD findings without reduction of disc and hot spots on bone scans. The surgeries helped pain reduction to VAS 0.5 from 8.0 and improved jaw opening to 45 mm. Hot spots of TMJ were decreased or disappeared in one year. There were no signs or evidence of openbite-recurrence. CONCLUSION: In the standpoint of sequential management of TMD, the orthognathic surgery is a good option and modality to treat the class II openbite deformities with temporomandibular disorders with temporomandibular disorders which are not respond to conservative management during orthodontic treatment.