Effects of postoperative radiotherapy for temporomandibular joint ankylosis after gap arthroplasty: An animal study using sheep

PurposeThe aim of the present study was to examine the effects of postoperative irradiation on reducing heterotopic bone formation after gap arthroplasty release of temporomandibular joint ankylosis.Materials and methodsFive sheep underwent induction of right temporomandibular joint ankylosis. After 3 months, the ankylosis was released by gap arthroplasty. At 24 hours after the release, they received a single radiation dose of 10 Gy. All sheep were sacrificed at 3 months after gap arthroplasty release. The body weight, jaw opening amount, and radiographs were measured at key intervals, with histologic assessment after death. The findings were compared with those in a control group treated with gap arthroplasty without irradiation.ResultsThe clinical measurements, radiographs, and histologic findings all revealed less evidence of reankylosis in the irradiated sheep.ConclusionThe results of the present study have shown that a single radiation dose at 24 hours after gap arthroplasty for temporomandibular joint ankylosis inhibits heterotopic ossification.Makoto Takaishi, Kenichi Kurita, Yuko Hatano, Hiroaki Matsuura, Martin Borg and N. Alastair Gos