title: A clinical case report: interface analysis of a successful well-functioning transmandibular implant from a cadaver mandible.
abstract: Transmandibular implants (TMI) are indicated both for functional reconstruction of the severely atrophic mandible and when routine augmentation is unpredictable. This study investigates the interface of bone around a TMI, retrieved from the cadaver. The TMI had successfully functioned for 7 years. The mandible was immersed in 10% formaldehyde and sectioned into nine appropriate pieces. Samples were embedded in polymethylmethacrylate, and cut around the transosseous posts and cortical screws in both vertical and horizontal sections. Samples were analyzed at 400 MHz (nominal lateral resolution, 2.5 microm) using a UH3 Scanning Acoustic Microscope (Olympus, Tokyo, Japan). The middle of implant specimens 1-4 were cut to 50 microm, and stained by toluidine blue for light microscopy. Dental X-rays showed no bone resorption around any implant. On a 2-mm lateral scan, almost uniform interface space was seen between bone and implant surface in cortical screws. There are wider spaces around the transmandibular posts in the superior area. Histology revealed the small area of direct contact. There is bone marrow space in the interface, with no significant fibrous tissue. We interpret these results at the interface to be because of adaptation for stress distribution.
authors.affiliation: Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Japan. t-nomura@sf7.so-net.ne.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nomura
authors.forename: Evan
authors.initials: E
authors.lastname: Gold
authors.forename: Michael P
authors.initials: MP
authors.lastname: Powers
authors.forename: Susumu
authors.initials: S
authors.lastname: Shingaki
authors.forename: Chikara
authors.initials: C
authors.lastname: Saito
authors.forename: J Lawrence
authors.initials: JL
authors.lastname: Katz
mesh_terms: D000222:Adaptation, Physiological; D001853:Bone Marrow; D001862:Bone Resorption; D001863:Bone Screws; D002102:Cadaver; D005260:Female; D006801:Humans; D008341:Mandibular Prosthesis; D008422:Materials Testing; D008875:Middle Aged; D013314:Stress, Mechanical