A prospective comparative study of the alveolar bone resorption after teeth extraction was achieved in a series of 79 patients in order to analyze macroscopically the possible consequences of radiotherapy and chemotherapy on the toothless edges. After quarterly coronal and sagittal X-rays for two years, this study enhances quite a similar vertical resorption for the radiation and chemotherapy-treated patients as well as for the witness patients. The alveolar bone resorption progression also appears unaltered by anti cancerous treatments. In both cases, a resorption stabilisation can be clearly seen after 6 months according to dental extractions. The vertical alveolar bone resorption is more important in incisor and canine regions. The anti cancerous treatments may not have significant disastrous consequences as far as available bone amount is concerned, on a post prosthetic restoration.