The transmandibular implant: from progressive bone loss to controlled bone growth.
OBJECTIVE
In a prospective study, 146 consecutive transmandibular implant (TMI) patients were treated according to revised surgical and prosthetic protocols to induce and control bone growth. Revisions included 1) placement of transosseous posts and cortical screws between the mental foramina so that two threads extended beyond the alveolar crest of the mandible without protruding through the mucosa and 2) fabrication of an implant-borne prosthesis that rested on the retromolar pads with a gap of 2 mm between the denture base and the mucosal tissues in the saddle areas.


METHODS
Measurements of the height of the mandible were made using a digital millimeter calliper and panoramic radiographs, with the enlargement calculated for each radiograph. The follow-up period ranged from 18 to 51 months.


RESULTS
Bone growth was present in 131 of the 146 patients whereas the bone resorption was arrested in the remaining patients. Increase in bony apposition varied from 9 mm in patients with severe mandibular atrophy to 2 mm in patients with mild atrophy.


CONCLUSIONS
The revised surgical and prosthetic protocols for TMI insertion and rehabilitation are advocated to prevent further alveolar resorption and to promote bone growth in patients with mandibular atrophy.
Powers
M P
MP
Department of Oral and Maxillofacial Surgery, Case Western Reserve University, Cleveland, OH 44106-4905.
Bosker
H
H
Van Pelt
H
H
Dunbar
N
N
D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000503:physiopathology / Q000601:surgery; D001284:Atrophy; D001846:Bone Development / Q000502:physiology*; D001860:Bone Plates; D016723:Bone Remodeling / Q000502:physiology; D001862:Bone Resorption / Q000503:physiopathology* / Q000601:surgery; D001863:Bone Screws; D003758:Dental Implantation, Endosseous; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008336:Mandibular Diseases / Q000503:physiopathology* / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D011862:Radiography, Panoramic