Failures in ridge reconstruction with hydroxyapatite. Analysis of cases and methods for surgical revision

Misuse of hydroxyapatite for ridge reconstruction leads to problems in denture construction. The object of this article is to analyze cases that have failed to provide acceptable results and to discuss methods for surgical revision. The group under study was made of 30 patients treated originally in different centers (with one exception) with 34 attempts at ridge reconstruction for the 27 mandibular cases and 3 maxillary ones. Only two mandibular cases received a skin graft. Three major problems were identified: (1) improper location of hydroxyapatite over the vestibular instead of the lingual or palatal sides of the ridge (27 of 30 cases); (2) poorly defined ridge form (26 of 30 cases); and (3) submucosal hydroxyapatite extrusion (15 of 30 cases). Splints or binding agents did not prevent these complications. Mandibular revision was accomplished by adding hydroxyapatite over the old material and onto the lingual side of the ridge. At a second stage, the floor of the mouth was lowered. As the vestibule was extended, material in excess was removed before skin graft application. Maxillary revision involved material removal from the vestibular side to allow the lining mucosa of the vestibule to return to a normal position.