Quantifying the outcome of surgical treatment of temporomandibular joint ankylosis: A systematic review and meta-analysis

Introduction: Temporomandibular joint ankylosis results in restricted mouth opening due to a fibrous or bony (non-neoplastic) union of the mandibular head to the glenoid fossa. Early surgical treatment is recommended, but the ideal surgical technique is debated. Our objective was to quantify the effect of different surgical interventions on maximal (interincisal) mouth opening.

Methods: The systematic literature search (1960-2015) was based on PubMed, Web of Science and the Cochrane Library. Pooled mean differences and 95% confidence intervals between pre-operative and post-operative maximal mouth opening (in mm) were calculated with random-effects meta-analyses. The surgical interventions were grouped according to increasing complexity: gap arthroplasty, interposition arthroplasty and reconstruction arthroplasty.

Results: Thirty-eight articles were identified (1993-2015), including 1215 patients who underwent operations; 84% of the cases were caused by trauma, and 8% by infection. Gap arthroplasty (n=463), interposition arthroplasty (n=409) and reconstruction arthroplasty (n=293) resulted in improved maximal mouth opening of 26.2 mm (95% CI, 24.1-28.2), 26.7 mm (95% CI, 24.6-28.8) and 30.6 mm (95% CI, 28.7-32.5), respectively, and 28.7 mm overall (95% CI, 26.7-29.2). The mean pooled post-operative maximal mouth opening ranged between 33.0 and 36.1 mm.

Conclusions: The maximal mouth opening improved most after reconstruction arthroplasty, and least after gap arthroplasty. However, the post-operative maximal mouth opening was similar for all techniques.