Is dermis fat arthroplasty better than plain gap arthroplasty? A prospective randomised controlled trial.

The aim of the study was to compare interpositional arthroplasty using a dermis fat graft with gap arthroplasty in the management of ankylosis of the temporomandibular joint (TMJ). We organised a prospective randomised study of 22 patients who presented with ankylosis of the TMJ. They were randomised to be treated with either plain gap arthroplasty or dermis fat arthroplasty, and the predictor variable was the method of treatment. The primary outcome variables were mouth opening and pain on jaw exercises. Pain and interincisal opening were measured on day 5, day 14, at the end of one month, and at six months, one year, two years, and three years. There was a significant difference between the two groups on two occasions: postoperative day 5 (p=0.013) and at one year (p=0.018). The mean (SD) scores for mouth-opening were higher in the dermis fat group at all times (41.20 (4.69) mm compared with 39.50 (2.46) mm in gap arthroplasty at two years, and 41.40 (3.60) mm compared with 38.9 (2.02) mm at three years). The visual analogue pain scores were also lower in the dermis fat graft group. The groups showed similar results at the end of three years follow up, with no significant difference in mouth opening. We conclude therefore that the two techniques have similar outcomes in the management of ankylosis of the TMJ.