Iliac crest vertical block grafts -placing outside or inside the bone contour: A cohort study

Objective and aim: Challenging defect configurations and dimensions arise from severe, localized vertical alveolar ridge defects caused by trauma or prior surgery. This study aims to analyze three-dimensional bone gain, assess marginal bone stability in such defect configurations, and evaluate the impact of grafting outside the bone contour on the overall outcome, with a focus on iliac crest block grafts as a valid treatment option.

Materials and methods: The prospective cohort study evaluated patients who required vertical block grafting due to localized bone defects in the maxilla or mandible and who had received iliac grafts. Three-dimensional bone gain was analyzed using cone beam computed tomography (CBCT) after 3 months of bone healing for each treated site and implant position. A comparison between bone grafts inside and outside the bone contour was conducted. Marginal bone stability was measured using intraoral radiographs during routine annual follow-up visits.

Results: Seventy patients with 89 treated sites were evaluated. After 3 months of graft healing, the mean vertical bone gain was 11.03 ± 3.54 mm, the mean horizontal bone gain was 7.18 ± 2.00 mm, and the mean graft length was 28.19 ± 11.01 mm. A total of 217 implants were placed in the augmented regions. On implant level, a mean vertical bone gain of 10.44 ± 3.44 mm and a mean horizontal bone gain of 6.54 ± 1.86 mm were measured. Over a 43-month observation period, mesial and distal marginal bone loss averaged 0.44 ± 0.92 mm and 0.49 ± 1.05 mm, respectively. Eight implants were diagnosed with periimplantitis, resulting in the loss of four implants, while no early implant losses were reported.

Conclusion: Within the limitations of this study, vertical bone grafts with iliac crest block grafts were found to be a dependable treatment option for dental implant placement, and placing block grafts outside the bone contour did not lead to inferior outcomes.