Buccal Exostosis and Excessive Undercuts
more common in the maxilla than the mandible. ent of implants in the future. For this reason the A local anesthetic should ‘ .nfiltrated around the area i~trasptal alveoplasty s~?uld reduce the thickness of the requiring bony Tprlion. For mandibular buccal exostoridge In an ~mount sufficient only to reduce or eliminate sis, infpp; r alveolar b’cks may also be required to anes- ~ndelrcutsd In areas .where a plan to place endos~ etize bony areas. A crestal incision extends 1.0 to 1.5 em Imp ants oes not exist. ey.ond each end of the area requm. n.g contour, an d a, full-thickness ucoperiosteal flap is ‘reflected to expose the areas of bony exostosis. If adequate exposure cannotbe obtained, vertical-releasing incisions are necessary toprovide access and prevent trauma to the soft tissue flap.
If the areas of irregularity are small, recontouring with a bone file may be all that is required; larger areas may necessitate use of, a rongeur or rotary instrument (Fig. 13-11). After completion of the bone recontouring, soft
tissue is readapted, and visual inspection and palpation ensure that no irregularities or bony undercuts exist. Interrupted or continuous suturing techniques are used to close the soft tissue incision, and the sutures are
removed in approximately 7 days. Denture impressions can be made 4 weeks postoperatively. Although extremely large areas of bony exostosis generalIy require removal, small undercut areas are often best treated by being filled with either autogenous or allogeneic bone material. Such a situation might occur in the anterior maxilla or mandible, where removal of the bony buccal protuberance results in a narrowed crest in the alveolar
ridge area and a less desirable area of support for the denture, as well as an area that may resorb more rapidly: . Local anesthetic infiltration is generally sufficient’ when filling in buccal undercut areas. After a vertical incision is made in the anterior maxillary or mandibular areas, a small periosteal elevator is used to create a subperiosteal tunnel extending the length of the area to be filled in with bone graft (Fig. 13-12). Sutures are removed at 7 days postoperativelyr and denture impressions can be
taken 3 to 4 weeks after surgery. Another technique that may be used to correct contour defects involves open exposure of the area to be grafted, placement of graft material, and the use of a membrane covering .over the grafted tissue to facilitate guided bone regeneration (also discussed in Chapter 14).