A review of surgical procedures designed to increase the functional height of the resorbed alveolar ridge.
By raising the alveolar ridge, relatively or absolutely, in partially or totally edentulous patients, preprosthetic surgery makes possible an improvement in the bed for the denture. Raising the height of the ridge, relatively, by deepening the sulci surrounding the jaw, can be achieved by vestibuloplasty and grafts to the floor of the mouth. However, for these procedures it is essential that there still be sufficient bone (at least 20 mm in the mandible). Long term observations show that the main problem is a reduction in the vestibular depth initially obtained by surgery. The most durable results follow vestibuloplasties with free skin or mucosal grafts, the latter being preferred. If resorption or atrophy is far advanced the jaw bone has to be reconstructed, so that an absolute increase in the ridge height is the aim. This is secured by onlay grafting, preferably of autologous bone, or inlay grafting (sandwich technique: horizontal osteotomy with bone interposition). In the lower jaw there is also the possibility of 'displacement grafting' (visor osteotomy: vertical osteotomy and visor-like displacement) and grafting to the lower border in cases of extreme mandibular atrophy. In the long term onlay grafts show a high degree of resorption; in appropriate circumstances, the results of the other methods are encouraging. A feature common to all procedures is a greater or lesser functional disturbance of the mental nerve.