头颈部癌放射治疗后的一个严重的并发症是放射性骨坏死,可发生在治疗后的数月或数年。头颈区放射的副作用,可以改变口腔的健康状况,从而使牙齿组织龋蚀。放射治疗后口腔的早期表现为涎液质与量的减少,进而出现牙颈部过敏及迅速脱钙,发生牙冠自龈缘以上崩溃。有些作者曾报导放射治疗后涎液的PH值偏向于酸性,照射野内 A serious complication after radiotherapy for head and neck cancer is radiation osteonecrosis, which can occur months or years after treatment. Head and neck radiation side effects, can change the health status of the mouth, so that the dental caries. Early oral cavity after radiotherapy for the salivary fluid and the amount of reduction, followed by dental neck allergy and rapid decalcification, the occurrence of the crown from the gingival margin collapse. Some authors have reported that salivary fluid PH value after radiation therapy tends to acidic, irradiation field