Early volumetric changes after vertical augmentation of the atrophic posterior mandible with interpositional block graft versus onlay bone graft: A retrospective radiological study.

The research aimed to compare the outcomes of two different bone grafting techniques used to augment the height of the posterior mandible, revealing that in both techniques, there were similar bone volume changes and successful dental implant placement, with no significant difference in the success rate.

Research Methods and Participants

• This retrospective study focused on 20 subjects split into two groups. In the inlay group, an interpositional equine cancellous bone block was inserted into the patient’s alveolar ridge, whereas the onlay group received an autogenous bone block placed on their alveolar ridge.
• The bone volumes were measured using computed tomography at baseline (before surgery) and four months after surgery.

Results and Findings

• The research showed an average vertical height increase of 6.0 mm in the inlay group and 7.4 mm in the onlay group after surgery.
• There was no significant difference recorded between the two groups concerning the volume loss of the grafted bone or decrease in vertical bone height at the surgery site during healing.
• Some postoperative complications were noted — two cases including one wound dehiscence and a mandibular fracture in the inlay group, and three cases of wound dehiscence in the onlay group.
• A total of 80 dental implants were successfully placed in the augmented areas. The inlay group received 46 implants with a peri-implant marginal bone loss of 0.8 mm, and the onlay group had 34 implants with a peri-implant marginal bone loss of 1.3 mm.

Conclusions

• The results indicated a similar pattern of volumetric bone remodeling in both the inlay xenogeneic grafts and the onlay autogenous bone groups.
• Although the success rate of implanted autogenous onlay blocks was slightly lower (82.4%) compared to the inlay group (93.8%), the difference was not statistically significant.