ABSTRACT
To evaluate the clinical results of reconstruction orbital defect with craniomaxillofacial implant. Three patients with orbital defect were treated with ten implants. The magnetic abutments were attached six months after one stage operation and the prostheses were fabricated. Within 11 to 47 months of follow up, all implants were stable with successful osseointegration. The prosthesis fit the orbital defects well. Reconstruction of orbital defect with craniomaxillofacial implant can be considered as a viable alternative treatment.
ABSTRACT
BACKGROUND:Alveolar distraction osteogenesis is an important method for treating alveolar bone atrophy, the osteogenesis process and biomechanics play a crucial role in the fol owing implantation and repair. At present, no related experimental studies are found. OBJECTIVE:To analyze the biomechanical and histological characteristics of alveolar distraction osteogenesis in a canine model. METHODS:Twelve adult mongrel canines received premolars extraction and alveoloplasty in mandible to establish an atrophy alveolar model. After 3 months, a segmental alveolar osteotomy was performed in the randomly selected unilateral atrophy alveolar and two intra-osseous distractors were placed. After a 7-days latency period, the alveolar ridge was augmented at a rate of 1.0 mm/d for 5 days. After a consolidation of 1, 2, and 3 months, the canines were sacrificed and the specimens of the distracted alveolar bone were harvested for clinical, radiographic, histological and biomechanical analysis. RESULTS AND CONCLUSION:The alveolar distractors obtained good healing with surrounding tissue. The atrophy alveolar bones were augmented for (4.80±0.50) mm and (5.12±0.47) mm by clinical and radiographic findings immediately after distraction, respectively. The bone trabeculae in the distracted chamber matured from 1 to 3 months of consolidation by histological analysis. The shearing force of alveolar distraction chamber increased from 1 to 3 months. After 3 months’ consolidation, the shearing force of distracted chamber was comparable to host bone. The histological and biomechanical property of distracted alveolar chamber is comparable to host bone after 3 months’ consolidation.
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Objective:To observe the effect of orbital implant shrink range on the stress distribution in bone-implant interface. Methods:The 3D finite element analysis of craniofacial and orbital implant models with the implant length of 3,4,6 and 10 mm,and with the shrink range of0.05,0.1 and 0.15 mm were established respectively.The stress in the bone-implant interface were calculat-ed and analyzed.Results:The stress increased with the increase of implant shrink range.The stress produced by the implant with 0.15 mm shrink range decreased.The stress of the implant of 10 mm was lower than that of other implants with the shrink range of 0.1 and 0.15 mm.Conclusion:The maximal implant shrink range of 0.1 mm in the model can meet the clinical requirements in orbital implant planning.
ABSTRACT
<p><b>OBJECTIVE</b>To assess the effects of 1-step method of changing the buccal position of the transported bone after distraction on early bone formation.</p><p><b>METHODS</b>The custom-made bidirectional distraction devices were used. Total of 8 adult mongrel dogs were procured. The bilaterally mandible premolars were extracted. After 1 month, the complete osteotomy was performed and the devices were placed. The gradual distraction was started after 1 week latency at the rate of 1 mm per day, total 6 mm in height was achieved. The 1-step method of changing the buccal position of the transported bone was performed the day after the vertical distraction period in one side of the animals, and the other side as the controlled side. All animals were killed after a 7 days consolidation. The vascular system was stained post mortem carbon ink perfusion to assess possible damages. Quantitative evaluations of bone density were performed with dual-energy X-ray absorptiometry (DEXA), analysis of the ratio of vascular square was conducted in a computer.</p><p><b>RESULTS</b>All animals tolerated the procedures well. After vertical distraction, the tested side can be moved 3 mm in buccal direction. DEXA examination showed that the density of the distracted bone was no statistical difference in both the tested and the controlled side. Vascular damage was not observed, and there was no statistical difference in the ratio of vascular square by analyzing the histological section in computer.</p><p><b>CONCLUSION</b>In some extent, 1-step method of changing the buccal position of the transported bone after distraction can mold the regenerate bone to correct the axial displacement, without endangering early callus formation and vascularization.</p>