Purpose: To present clinical outcomes of alveolar ridge augmentation using in situ autogenous block bone and to compare the outcomes with previous studies.

Materials and methods: The medical records of patients with a severe horizontal bone defect in a partially edentulous alveolar ridge (width < 3.5 mm), who received bone augmentation using in situ autogenous block bone, were retrospectively reviewed. After a 6-month or longer healing period, the augmentation effect was examined before implant placement. Cone beam computed tomography (CBCT) was performed before and after surgeries. The alveolar width of the bone grafts was measured on the CBCT images.

Results: A total of 16 patients (22 grafts) were included. Graft exposure was seen in three grafts, which were classified as failed cases. The augmentation volume at implant placement in the failed cases was significantly lower than that of the successful cases. There were no significant differences in augmentation between anterior maxillary and mandibular implant sites.

Conclusion: Autogenous bone grafting using in situ block bone is an effective and reliable approach for horizontal bone augmentation in the mandible and anterior maxilla that eliminates second donor site morbidity. Complete release of the buccal flap and tension-free suture is the key to avoiding wound dehiscence and ensuring the effectiveness of bone augmentation.