RESUMO
PURPOSE: This study aims to evaluate the clinical outcomes of using demineralized freeze-dried allogeneic bone blocks (DFDABB) combined with the periosteal vertical mattress suture (PVMS) technique for the reconstruction of severe horizontal alveolar bone deficiencies in the maxilla. METHOD: In continuous horizontal maxillary defects cases, bone augmentation was performed using DFDABB and deproteinized bovine bone matrix (DBBM) filling the interstice. Subsequently, a resorbable collagen membrane was carefully placed over the graft surface, and both the membrane and bone graft were firmly secured using the periosteal vertical mattress suture technique (PVMS). Linear changes were assessed through superimposed cone-beam computed tomography (CBCT) scans obtained before the operation and after a healing period of 6-10 months. RESULTS: A total of 7 female patients with ten bone blocks and 13 implants were included in this study. One of the wounds was slightly ruptured postoperatively without infection, and all implants showed successful osseointegration. The average alveolar ridge width at a point 5 mm below the crest was 4.52 ± 2.03 mm before bone graft and 9.79 ± 1.57 mm after implantation, with an average increase of 5.26 ± 1.97 mm. Similarly, at a point 10 mm below the crest, the pre-graft alveolar ridge width measured 7.23 ± 3.60 mm, and post-implantation, it expanded to 11.81 ± 2.90 mm, showing an average gain of 4.58 ± 2.01 mm. CONCLUSION: This case series demonstrates the successful application of DFDABB combined with the PVMS technique to achieve adequate bone width for implantation at severe continuous horizontal bone deficiency of the maxilla. DFDABB with the PVMS technique resulted in superior horizontal bone gain during maxillary bone augmentation with horizontal continuity deficiency. However, further studies are necessary to validate these findings.
RESUMO
BACKGROUND: Clinical scenarios frequently present challenges when patients exhibit asymmetrical mandibular atrophy. The dilemma arises: should we adhere to the conventional All-on-4 technique, or should we contemplate placing vertically oriented implants on the side with sufficient bone mass? This study aims to employ three-dimensional finite element analysis to simulate and explore the biomechanical advantages of each approach. METHODS: A finite element model, derived from computed tomography (CT) data, was utilized to simulate the nonhomogeneous features of the mandible. Three configurations-All-on-4, All-on-5-v and All-on-5-o were studied. Vertical and oblique forces of 200 N were applied unilaterally, and vertical force of 100 N was applied anteriorly to simulate different masticatory mechanisms. The maximum von Mises stresses on the implant and framework were recorded, as well as the maximum equivalent strain in the peri-implant bone. RESULTS: The maximum stress values for all designs were located at the neck of the distal implant, and the maximum strains in the bone tissue were located around the distal implant. The All-on-5-o and All-on-5-v models exhibited reduced stresses and strains compared to All-on-4, highlighting the potential benefits of the additional implant. There were no considerable differences in stresses and strains between the All-on-5-o and All-on-5-v groups. CONCLUSIONS: With the presence of adequate bone volume on one side and severe atrophy of the contralateral bone, while the "All-on-4 concept" is a viable approach, vertical implant placement optimizes the transfer of forces between components and tissues.
