Quantifying the Impact of Surgical Treatment on Temporo-Mandibular Joint Ankylosis: a Systematic Review and Meta-analysis

INTRODUCTION: Temporo-mandibular joint ankylosis (TMJA) results in a restricted mouth-opening due to fibrous or bony (non-neoplastic) union of the mandibular head to glenoid fossa. TMJA causes speech disorders, oral hygiene and breathing problems, and disturbances of facial and mandibular growth in children. Early surgical treatment is recommended, but the ideal surgical technique is still debated. The objective of this study is to assess and quantify the effect on maximal mouth-opening of the different surgical interventions reported in the literature.

METHODS :The systematic literature search (1960-2013) was based on PubMed, Web of Science and Cochrane. A random-effects meta-analysis was performed to analyse the pooled mean difference between pre-and postoperative maximal interincisal mouth-opening (in millimetres, presented with 95% confidence intervals). The surgical interventions were grouped according to increasing complexity: gap arthroplasty (GA), interposition arthroplasty (IA) and reconstruction arthroplasty (RA). IA and RA were performed with autogenous (auto-) or allogenous (allo-) materials.

RESULTS : Thirty-eight articles were identified (1993-2013), including 787 operated patients (50% male, 20% bilateral). Mean age of onset varied between 5-18 years, with on average 9 years (±5.2y) delay of treatment; 81% was caused by trauma and 11% by infection. GA (n=140), auto-IA (n=311), allo-IA (n=79), auto-RA (n=217) and allo-RA (n=37) resulted in an improvement in mouth-opening of respectively 25.2 (CI 21.5-29.02), 26.7 (CI 24.8-28.7), 23.3 (CI 18.5-28.1), 28.5 (CI 26.4-30.6) and 29.9 (CI 25.1-34.6) mm, or a pooled average of 26.9 (CI 25.6-28.2) mm. However, the mean pooled postoperative mouth-opening was similar in all groups (33.7-35.3 mm). The mean difference was similar in children and adults, respectively 27.3 (CI 24.3-30.3) and 26.2 (CI 20.6-31.8) mm. Complication and recurrence rates could not be compared.  

CONCLUSIONS : Improvement of mouth-opening was largest after RA, and smallest after GA. However, the post-operative mouth-opening was similar for all techniques.