Epidemiological analysis of temporomandibular joint dislocation cases treated at the University of the Witwatersrand, Johannesburg

Abstract

Background: Temporomandibular joint (TMJ) dislocation is a rare and debilitating condition of the facial skeleton. The condition manifests itself in acute, recurrent or chronic forms, and with bilateral or unilateral expressions. The purpose of this study was to report on the epidemiological characteristics and management of patients with TMJ dislocation in our unit.

Methods: A retrospective analysis of the demographical and clinical risk factors of TMJ dislocations treated in the Maxillofacial and Oral Surgery Departments, from January 2015 to December 2019, at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) and Chris Hani Baragwaneth Academic Hospital (CHBAH), University of the Witwatersrand.

Results: There were 46 TMJ dislocation cases, with a bimodal age distribution with peaks at 20 to 25 and above-45-year-old age groups. Acute, chronic and recurrent dislocations were observed in 13 (28%), 9 (20%) and 24 (52%) patients, respectively. Yawning was the commonest cause of dislocation (28 cases, 61%), followed by trauma and spontaneity (both 6 cases, 13%). The type of TMJ dislocation was significantly associated with aetiology, frequency of TMJ dislocation, duration between dislocation and treatment, and type of treatment received (p<0.001). Manual reduction was frequently used to treat acute and recurring cases, whereas manual reduction with general anaesthesia was used to treat chronic cases.

Conclusion: Data provided by this retrospective study indicate that the majority of the TMJ dislocations are recurrent and are related to yawning. Most dislocations can be reduced manually under local anaesthesia however, the more prolonged the dislocation, the higher the need for reduction under general anaesthesia and surgical intervention.