並列摘要
Severely atrophic alveolar ridge of the mandible has long been a difficult problem for the dentists. When the atrophy is of a degree that defies the attempts to reconstruct with conventional or even endosseous implant denture techniques, mandibular subperiosteal implant is helpful for restoring the functions of mastication and speech. Five cases of mandibular subperiosteal implant denture were collected in this report. Two-stage surgery under general anesthesia was empolyed for installing the implant. At the first stage, direct bone impression was performed with special attention to recording the detail of important anatomic landmarks. One week later, the custom-make cobalt-chromium implant was inserted and screw-fixed to the mandibular ridge in another operation. Four posts were designed on the framework in the bilateral canine and first molar areas for future support of the denture. The prosthetic phase began about one month after the implantation. Overdenture-type prosthesis was constructed in acrylic resin, 4 cobalt-chromium caps were embedded in the tissue side to fit the intraoral posts of the subperiosteal implant. Observation periods for these 5 cases were 1 to more than 2 years. Generally, the patients found improvement in denture stability as compared with the mandibular prosthesis made before the implantation. Paresthesia or anesthesia of the lower lip and intraoral exposure of the metal framework were the most common complications encountered. Avoiding injury to the mental nerves during the operations and high-level oral hygiene care are necessary for preventing such complications.