The role of pericranium grafts in the reduction of postoperative dehiscences and bone resorption after reconstruction of severely deficient edentulous ridges with autogenous onlay bone grafts

PURPOSE: To compare: (i) the incidence of soft tissue dehiscences; (ii) bone resorption before and after implant placement; and (iii) the survival and success rates of implants placed in two groups of patients with severe bone defects of the jaws reconstructed with autogenous onlay bone grafts alone (control group) or in association with autogenous pericranium coverage (study group). MATERIAL AND METHODS: Forty-four patients affected by severe atrophy of the alveolar ridges underwent bone reconstruction with vertical/tridimensional autogenous onlay grafts harvested from the calvarium or the mandibular ramus. In 23 patients (study group), grafts were covered with autogenous pericranium before suturing, while in 21 patients (control group) no coverage of the grafts before suturing was performed. After a 4-7 month waiting period, 199 implants were placed (105 in the study group, 94 in the control group) and 3-4 months afterward prosthetic rehabilitation was carried out. The mean follow-up after the start of prosthetic loading was 23.9 months (range: 12-48 months). RESULTS: The incidence of soft tissue dehiscences was 5,7% in the study group and 16% in the control group. The mean graft resorption before implant placement was 0.12 mm (SD ± 0.32) in the study group and 0.98 mm (SD ± 2.79) in the control group. The mean peri-implant bone resorption at the end of the follow-up period was 0.21 mm (SD ± 0.48) in the study group and 0.43 mm (SD ± 0.83) in the control group. The survival rate of implants was 99.1% in the study group and 100% in the control group, while success rate was 96.2% in the study group and 93.6% in the control group. CONCLUSIONS: The use of pericranium as an autogenous membrane for the coverage of onlay bone grafts seems to reduce the risk of soft tissue dehiscences after the reconstruction of atrophic edentulous ridges to reduce peri-implant bone resorption over time, while it seems to have no significant effect in reducing bone resorption in the reconstructed areas before implant placement.