Efficacy of bone ring grafts for the reconstruction of alveolar ridge deficiencies: a systematic review. Part II: animal trials.

Background: Bone ring (BR) grafts have been introduced to reconstruct alveolar ridge defects with simultaneous implant placement, but their clinical effectiveness remains undetermined. The aim of the current systematic review was to critically appraise evidence from animal studies regarding the effectiveness of BR grafts in alveolar ridge reconstruction and their variations under different surgical protocols. Methods: Electronic retrieval of six databases (MEDLINE, Embase, Cochrane Library, ScienceDirect, Web of Science, and Scopus) and citation search until 11 October 2023, for animal studies on bone augmentation employing BR grafts. The outcome variables were total bone area (BA), bone volume (BV), bone-implant contact (BIC), and histology. The protocol was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and prospectively registered with PROSPERO (CRD42023453949). Results: Ten studies were included in the qualitative analysis according to the screening criteria. Two studies demonstrated favorable bone remodeling and osseointegration of the BR with both the implant and pristine bone. A comparative study between autogenous BRs and allogenic BRs reported a higher percentage of BA and BIC at 4 months of healing, but conflicting data were observed at 8 months. Another study indicated a significant advantage of autogenous BRs over bovine and biphasic ceramic BRs in terms of BA and BIC after 5 weeks. Three studies found that using collagen membranes did not significantly affect BA, BV, or BIC when used simultaneously with autogenous BRs during implant placement. Two studies evaluated one-stage and two-stage implant placement in conjunction with BR grafts, revealing similar levels of BA, BV, and BIC except for differences in total treatment time. Furthermore, one study found that the use of mucogingival junction incision and split-thickness flap significantly reduced the incidence of wound dehiscence compared with conventional incision and flap. Conclusions: Vertical bone augmentation surgery utilizing BR grafts with one-stage implant placement yielded histological and histomorphometric outcomes comparable to those achieved with two-stage implant placement or the additional application of collagen membrane.

HIMS-Net: Horizontal-vertical interaction and multiple side-outputs network for cyst segmentation in jaw images.

Jaw cysts are mainly caused by abnormal tooth development, chronic oral inflammation, or jaw damage, which may lead to facial swelling, deformity, tooth loss, and other symptoms. Due to the diversity and complexity of cyst images, deep-learning algorithms still face many difficulties and challenges. In response to these problems, we present a horizontal-vertical interaction and multiple side-outputs network for cyst segmentation in jaw images. First, the horizontal-vertical interaction mechanism facilitates complex communication paths in the vertical and horizontal dimensions, and it has the ability to capture a wide range of context dependencies. Second, the feature-fused unit is introduced to adjust the network's receptive field, which enhances the ability of acquiring multi-scale context information. Third, the multiple side-outputs strategy intelligently combines feature maps to generate more accurate and detailed change maps. Finally, experiments were carried out on the self-established jaw cyst dataset and compared with different specialist physicians to evaluate its clinical usability. The research results indicate that the Matthews correlation coefficient (Mcc), Dice, and Jaccard of HIMS-Net were 93.61, 93.66 and 88.10% respectively, which may contribute to rapid and accurate diagnosis in clinical practice.

Efficacy of bone ring grafts for the reconstruction of alveolar ridge deficiencies: A systematic review. Part I: Clinical trials.

BACKGROUND: Bone ring (BR) grafts have been introduced to reconstruct alveolar ridge defects with simultaneous implant placement, but its clinical effectiveness remains undetermined. This systematic review aimed to comprehensively investigate BR grafts in diverse scenarios of ridge defect with simultaneous or staged implant placement. METHODS: Electronic retrieval of MEDLINE, Embase, Cochrane Library(CENTRAL), Web of Science, Scopus, and citation search until August 3, 2023, was used to identify relevant clinical articles that utilized BR grafts for ridge defect reconstruction. The quality of evidence in the studies reviewed was assessed with the Joanna Briggs Institute Critical Appraisal tool. The protocol was registered in Prospective Register of Systematic Reviews (CRD42023453943). RESULTS: Fourteen studies with 251 BRs were identified, of which 8 studies were for alveolar ridge augmentation, 4 studies were for extraction socket augmentation, and 2 studies were for sinus floor elevation. Reported sources of BRs included autografts, allografts, and xenografts. The follow-up period ranged from 4 months to 4.7 years. Regarding the primary outcomes, the utilization of BR grafts demonstrated favorable bone gain along with acceptable graft absorption and marginal bone loss. Regarding the secondary outcomes, satisfactory bone mineral density and implant stability were confirmed, accompanied by a recorded incidence of postoperative complications (20 cases) and an implant failure rate of 5.58%. CONCLUSIONS: BR grafting with simultaneous or staged implant insertion is an effective approach for reconstructing alveolar ridge deficiencies. The BR grafts demonstrate favorable bone remodeling and osteointegration with the alveolar bone and implant; however, its success may be compromised by complications. Future studies should further investigate the clinical efficacy of BR grafting comparing to other bone augmentation techniques in diverse scenarios.