The objectives of the study were to evaluate the outcome of Gap arthroplasty and Interpositional arthroplasty in terms of mouth opening for management of TMJ ankylosis. This Quasi experimental study was carried out in Oral & Maxillofacial Surgical unit, Khyber College of Dentistry, Peshawar from May 2006 to August 2007. Sixty patients of TMJ ankylosis seeking treatment for the first time, irres...