Pathogenesis of Ankylosis and Re-Ankylosis: The Story

Abstract

Ankylosis is the Greek for “stiff joint”. The term “ankylosis of the temporomandibular joint” (TMJ) refers to bony or fibrous adhesion of the anatomical components of the joint and their ensuing loss of function. A progressive reduction in jaw movement is the main clinical presentation. TMJ ankylosis not only affects mouth opening but also the normal growth pattern of the mandible. Outcome of surgery for TMJ ankylosis is unpredictable. The type of ankylosis and patient age should be evaluated when planning surgery. Care in the choice of surgical technique and of interposition material and subsequent meticulous attention to long-term physiotherapy are considered essential to achieve a satisfactory result. Iatrogenic causes of ankylosis may arise from cytotoxic medication, repeated TMJ surgery and irradiation. Repeated TMJ surgery emerged as a dilemma largely confined to Western countries following the introduction of the concept of internal derangement and disk displacement which acted as the catalyst for unmitigated surgical intervention in TMJ disorders during the 1970s and 1980s.1 While there have been many publications regarding the condition and its treatment, very little as been written about its pathogenesis. Due to the difficulty of operation to release the ankylosis and the high incidence in the recurrence rate, surgical treatment of bony ankylosis is still a considerable challenge for maxillofacial surgeons. Understanding the story of pathogenesis of the ankylosis and re-ankylosis might help in improving the outcome of the surgical treatment.2