Mandibular residual ridge reduction (RRR) after Edlan flap vestibuloplasty, buccal mucosal graft, and split skin graft vestibuloplasty was measured on lateral cephalometric radiographs obtained 1, 3, 6, 12 and 24 months postsurgery in 50 patients. The ridge reduction was most severe during the immediate postoperative period. The different operation methods did not give rise to significant variations in the reduction pattern, neither did the sex of the patient appear to be an important factor. The temporary increase of mandibular resorption after vestibuloplasty surgery is of a magnitude comparable to the average RRR during 1 year in full denture wearers with a long denture experience.