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 Branemark(R) implants (3 or 4 mm long, 3.75 mm diameter) to bear facial prostheses . Bone depths were determined in the auriculotemporal (2-8 mm), infrao rbital (0-10 mm) lateroorbital (8-14 mm), supraorbital (1-14 mm) and m edioorbital (1-6 mm) areas as well as at the base of the nasal skeleto n (1-5 mm). The low values for the supraorbital and infraorbital areas were determined at the points closest to the frontal- and maxillary s inuses, respectively. Implantation in these areas would be permissible only under certain conditions. The very thin osseous structures of th e nasal region also present problems for implants. In the auriculotemp oral region, the bone width is always sufficient, but at the orbital m argin it can vary from 3 to 8 mm. The three-year success rates for imp lant survival were found to be 100% and 85.8% respectively for auricul ar and orbital defects. No serious skin complications were seen. Six p atients (10.7%) required secondary corrective surgery in a total of 13 implant areas.