title: Microradiographic study of retrieved craniofacial osseointegrated implants.
abstract: In this study 18 screw-shaped extraoral osseointegrated implants retrieved from 10 patients were analyzed. The reasons for retrieval were: unexplained pain (n = 4); inability to cope with the implants (n = 2); fracture of the central screw (n = 2); skin penetration problems (n = 1), and trauma (n = 1). Retrieved implants were trephined with a border of surrounding bone, fixed, embedded in epon plastic, ground and processed for microradiography. The study group comprised 6 males and 4 females with a mean age of 53.4 (range 9-81) years. All implants were clinically stable at the time of removal, and the mean osseointegration time was 3 (range 1-5) years. Six implants were removed from the temporal bone, 5 from the frontal bone, and 7 from the maxilla. By microradiography, it was found that all retrieved implants were surrounded by a lamellar type of bone with haversian systems, vascular channels, osteocyte lacunae, and in some specimens regeneration and resorption areas. Bone metal contact was estimated to vary between 27 and 83%. Bone metal contact was lower in the frontal bone compared to the temporal bone or maxilla, and was further reduced after preoperative irradiation. Longer osseointegration time increased bone metal contact, as did increased age up to 60 years. It is concluded that extraoral osseointegrated implants in humans may integrate morphologically as well as clinically. By microradiography it was possible to define bone metal contact in the region of implant installation.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Göteborg University, Sweden. gosta-granstrom@orlss.gu.se
authors.forename: G
authors.initials: G
authors.lastname: Granström
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005624:Frontal Bone / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D009998:Ossicular Prosthesis; D019736:Prostheses and Implants / Q000009:adverse effects*; D013701:Temporal Bone / Q000601:surgery; D013997:Time Factors