The purpose of this retrospective clinical study was to determine the efficacy of allogeneic bone for secondary alveolar cleft osteoplasty. Twenty-four patients with unilateral cleft lip and palate treated with allogeneic bone grafts were examined by a surgeon, orthodontist, and prosthodontist 20 to 47 months after surgery. Radiographic and clinical examination of the periodontal status of the teeth adjacent to the cleft and their antimeres were compared for differences with Student's t test and the Wilcoxon test. Radiographs indicated complete bone bridging in 21 patients. Two of the remaining three patients had a 1-mm radiolucent gap in the cleft site. The third patient had a 6-mm-wide radiolucency and recurrence of an oronasal fistula which was regrafted with autogenous bone. No statistically significant differences between the cleft and noncleft tooth antimeres were found for plaque, gingivitis, bleeding, sulcus depth, or level of attachment. A statistically significant difference in the amount of attached gingiva was found between the cleft and noncleft tooth antimeres. Nine patients with missing lateral incisor teeth avoided prosthetic replacement by orthodontic movement of the canine tooth into the grafted edentulous space. In those cases where the maxillary canine was unerupted at the time of the surgery, eruption into the graft occurred. Stability of the maxillary segments was sufficient to allow prosthodontic restoration with a fixed partial denture in those cases where it was indicated.