Patients with end stage degenerative, rheumatoid and ankylotic disease of the TMJ can be successfully managed with total prosthetic replacement. There is little understanding of the factors responsible for dislocation of the joint replacement and how to manage this complication. This prospective audit looks at the risk factors and management of 11 cases within a case series of 102 patients. 102 patients (86 females) underwent total prosthetic replacement of the TMJ (5 Biomet, 97 TMJ Concepts) between March 2004 and January 2013. 11 (10.8%) had on-table dislocation managed with 1 week of light intermaxillary elastic traction. One patient developed a dislocation managed with elastics for 4 weeks and botulinum injection into the medial pterygoid for dystonia. The incidence of dislocation was significantly greater in patients who had coronoidectomy (3/10, 30%) compared with those who did not (7/92, 7.6%). There was an increased prevalence of dislocation in those patients who did not have coronoidectomy but had closure of anterior open bite (2/18, 11.1%) compared with those who did not (6/74, 8.1%). Joint dislocation seems to occur when there is loss of vertical joint stability due to either loss or reduction in length of the temporalis control.