Computed tomographic study of bone availability for facial prosthesis-bearing endosteal implants.

In a computed tomographic study, 56 patients with facial defects were examined to assess the availability of bone for extraoral Brånemark implants (3 or 4 mm long, 3.75 mm diameter) to bear facial prostheses. Bone depths were determined in the auriculotemporal (2-8 mm), infraorbital (0-10 mm), lateroorbital (8-14 mm), supraorbital (1-14 mm) and medioorbital (1-6 mm) areas as well as at the base of the nasal skeleton (1-5 mm). The low values for the supraorbital and infraorbital areas were determined at the points closest to the frontal- and maxillary sinuses, respectively. Implantation in these areas would be permissible only under certain conditions. The very thin osseous structures of the nasal region also present problems for implants. In the auriculotemporal region, the bone width is always sufficient, but at the orbital margin it can vary from 3 to 8 mm. The three-year success rates for implant survival were found to be 100% and 85.8% respectively for auricular and orbital defects. No serious skin complications were seen. Six patients (10.7%) required secondary corrective surgery in a total of 13 implant areas.