Abstract: Objective　To evaluate the clinical effect and absorption rule of alveolar ridge reconstructed by autologous bone blocks and deproteinized bovine bone covered by absorbable membrane with outer oblique line or chin as a donor site, and to provide references for clinical operation. Methods A total of 10 patients who were diagnosed with severe alveolar ridge defects by cone beam CT and needed bone augmentation before implant insertion were selected during the period from July 2018 to September 2019. Guided bone regeneration was carried out with mandibula external oblique line or chin as a donor site. Complications were recorded postoperatively. CBCT was taken pre-operation, immediately post-operation and before implant insertion. The width of the top, middle and base of the alveolar ridge were measured. Data were analyzed by SPSS 23.0. Results All of the 10 patients successfully underwent the operation of bone harvesting and grafting. There was no discomfort such as dizziness or headache and no local numbness or abnormal feeling in 2 cases of chin osteotomy postoperatively. One patient (2 sites) underwent bone graft exposure. The exposure rate was 9.52%, and the other sites healed uneventfully before the implant placement. The actual bone increment at the top, middle and base of alveolar ridge were 3.93 ± 1.80mm, 3.90 ± 1.60mm and 2.89 ± 1.43mm, respectively. The increment effect was obvious. The ratio of incremental bone resorption was 28.0 (28.26) %, 17.1 (22.35) % and 10 (18.9) %, respectively. There was a significant difference in bone resorption rate among the three groups (P < 0.05). There was a significant difference in absorptivity between the top of alveolar ridge and the base of alveolar ridge (P < 0.05). There was no significant difference in the absorption rate among the other groups (P > 0.05). Conclusion The absorption rate at the top of alveolar ridge is significantly higher than the base when guided bone regeneration is carried out by oral autogenous bone blocks combined with deproteinized bovine bone matrix, suggesting that we should pay more attention to increase the bone volume at the top of alveolar ridge in clinical operation.

Key words: Bone augmentation, Bio-oss, Quantitative analysis, Cone beam CT