In spite of all the attempts that have been made so far to bring about an absolute augmentation of the mandible, this procedure remains more or less at the experimental stage. The greatest difficulty in the known techniques is that the transplanted bone is resorbed to a great extent in a relatively short time. In the last 2 years at our department we have developed a new technique in which the resorption has up to now been minimal. Bone is no longer transplanted subperiosteally on the alveolar process, but the resorbed mandible is split into cranial and caudal portions from the region of the left 3rd molar to the region of the right 3rd molar, and between these two fragments the bone transplant is placed. In this way the resorption after 2 years is practically nil and, moreover, the patient can wear a normal prothesis.