The main aim of this study is to compare the gap arthroplasty with interpositional gap arthroplasty for the management of TMJ ankylosis.A prospective randomized multicenter clinical trial had been performed, on 60 patients diagnosed with TMJ ankylosis from August 2005 to June 2015. Patients were equally divided into two groups: Group I patients were treated with gap arthroplasty, while patients in Group II were treated with interpositional arthroplasty.The mean age in Group I was 27.9 years and in Group II was 25.6 years. Trauma was the common etiological factor in both the groups. The mean postoperative mouth opening after 1 month, 6 months and 24 months was found to better in Group II. Open bite after 24 months was present in six patients in Group I and in one case in Group II. Permanent facial nerve palsy was present in one patient in both the groups. Frey's syndrome was present in one patient from Group I and none from Group II. Reoccurrence occurred in eight cases from Group I (26.6%) and none from Group II.This study concluded that interpositional arthroplasty is better than gap arthroplasty in terms of mouth opening and reankylosis.