Long-term results of secondary alveolar bone grafting using a technique to harvest pure calvarial cancellous bone: Evaluation based on plain radiography and computed tomography.

ABSTRACT

BACKGROUND: We introduce a method to extract the maximum amount of cancellous bone from the calvarium and analyze the outcomes using plain radiography and computed tomography. METHODS: We retrospectively analyzed the medical records of patients who underwent secondary alveolar bone grafts using a maximal harvesting technique for calvarial cancellous bone. Bone survival was determined based on Enemark's grading system using plain radiographs. Alveolar thickness and height were analyzed by computed tomography and compared with radiographic measurements. RESULTS: Our study enrolled 27 patients, 22 unilateral and 5 bilateral, for a total of 32 alveolar clefts. The mean age at surgery was 9.04 ± 0.41 years (range 6-12 years). Donor sites were successfully recovered without complications, such as hematomas, seromas, infections, or tears in the dura mater. The mean follow-up duration for obtaining plain radiographs was 6.90 ± 0.61 years (range 2.0-18.50 years). The mean follow-up duration for computed tomography was 6.51 ± 0.99 years (range 2.0-14.83 years). A canine tooth erupted in 30 cases. Success (Enemark's grades I or II) was achieved in 26 cases. Alveolar height was strongly correlated with the Enemark scale results (γ = 0.878, p < 0.001), but alveolar thickness was not correlated (γ = 0.4575, p = 0.08). CONCLUSION: Our cancellous bone harvesting technique resulted in successful graft survival without serious complications, including dural or brain injuries. Although the ilium is widely accepted as the optimal donor site for secondary alveolar bone grafting, the calvarium could be an alternative donor site that results in equivalent outcomes.