The effects of steel and titanium mandibular reconstruction plates on photon and electron beams

Abstract

The use of metal plates, designed to be screwed into the bone in reconstruction of composite mandibular defects is an accepted and widely used procedure in oral cancer therapy (Castillo et al, 1988; Sindet-Pedersen, 1988). Many of these patients must receive post-surgical radiotherapy in the course of their treatment because of possible residual microscopic disease. The effects of radiation on tissue-metal interfaces have been studied for photon (Dutreix & Bernard, 1966; Gibbs et al, 1976; Hudson et al, 1984) and electron beams (Weatherburn et al, 1975; Khan et al, 1976; Gagnon & Cundiff, 1980; Klevenhagen et al, 1982). They have been found to result in an enhancement of the dose to the tissue in the immediate vicinity of the interface on the side facing the beam. A search through the literature has revealed limited studies on the effects of radiation beams on metal mandibular implants of the oral cavity (Castillo et al, 1988; Scher et al, 1988). These investigations were confined to stainless steel and vitallium plates irradiated with 6 MV photons. In the last few years, titanium reconstruction plates have become available and are growing in popularity because of the increased strength relative to the thickness of the plate, greater tissue compatibility and easier adaptation to the bony fragments.