Local radiation dose, fixation, and non-union of mandibulotomies

Background. Non-union of mandibulotomies is a serious complication but risk factors are unclear. No data are available on the effect of the specific d ose of irradiation at the osteotomy site. Methods. Forty-eight patients (36 men, 12 women, median age 58 years) under going a mandibulotomy and postoperative radiotherapy were enrolled in the s tudy. Twenty-five had wire and 23 had plate osteosyntheses. Five patients h ad a non-union and three had minor complications. The distribution of the r adiation dose and the specific dose at the mandibulotomy site were calculat ed. Parametric tests and logistic regression were used for analysis. Results: Non-union was not related to a specific dose of irradiation at the osteotomy site. Also, no effect could be attributed to type of fixation. Conclusions: There is no evidence for a single factor, radiation. or fixati on type, that contributes to a non-union. We recommend a careful surgical t echnique. (C) 1999 John Wiley & Sons, Inc.