Résumé
BACKGROUND:Three-dimensional finite element has been widely used in the oral cavity field, but little is reported on the three-dimensional finite element reconstruction of the mandibular body using titanium plate. OBJECTIVE:To study the biomechanical characteristics of reconstructing the mandibular body using titanium plate. METHODS:We established a three-dimensional finite element model of mandibular body defect undergoing reconstruction using bicortical titanium screws and titanium plate. Under the simulated normal occlusion state, a 200 N vertical load was added to the central fossa of the occlusal surface of the right mandible first molar. Then, stress distribution and maximum displacement of the mandible, titanium screw, and titanium plate were analyzed. RESULTS AND CONCLUSION:Under the simulated normal occlusion state, mandible stress was concentrated in the mandibular body and mandibular branch, especial y in the anterior and posterior edges of the mandibular branch and the lower edge of the mandible. The stress in the posterior edge of the mandible was lower than that in the anterior edge of the mandible, and moreover, the contact site between the titanium plate and the mandible also presented a concentration of stress. The maximum stress of the bicortical titanium screws appeared near the screw cap, and the stress was also concentrated at the contact site between the titanium screw and the titanium plate. The maximum stress of the titanium screw at the ascending branch of the mandible was higher than that of the titanium screw at the anterior end of the defect. For the titanium plate, the stress was mainly concentrated at the fixed site of the titanium screws;the peak stress of the anterior and posterior edges of the titanium plate was found at the contact site between the anterior end of mandibular defect and the titanium stress as wel as between the ascending branch of the mandible and the titanium screw. After mandibular body reconstruction using the titanium plate, a displacement was likely to occur at the contact site between the anterior end of mandibular defect and the titanium plate. In conclusion, these findings indicate that mandibular body reconstruction using bicortical titanium screws and titanium plate is relatively stable, but the titanium plate fixed at the anterior part of the mandibular angle is prone to breakage.
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The nasal deformity secondary to cleft lip of 1 0 patients was repaired with lateral segment of partial costal cartilage harvested by a self-made special knife.6 to 30-month follow-up showed that nasal alar morphology of all patients was improved.No any complications happened at donor site.
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Objective To introduce experiences with non-elongated cheiloplasty and rectangular mucomuscular complex flaps of double vermilion for repairing bilateral cleft lips. Methods 29 patients (20 males and 9 females) with bilateral cleft lips underwent operations of non-elongated cheiloplasty and rectangular mucomuscular complex flaps of double vermilion. There were 15 bilateral complete cleft lips, 11 bilateral incomplete cleft lips and 3 bilateral mixed cleft lips. The deformity of white lips was reconstructed with traditional non-elongated cheiloplasty. When repairing the vermilion, the rectangular mucomuscular complex flaps which included mucous membrane of vermilion and part of orbicularis oris in double vermilion were designed, and vermilion of fore lip was incised along boundary of wet lip and dry lip. Then rectangular mucomuscular complex flaps of double vermilion were rotated downward and inward to be sewn with fore lip. At the step, the end of orbicularis otis should be sewn widely and fitly in order to form a normal annular structure. Results The wounds of all the patients were healed at one stage. The height and width of patients' upper lips were proper and the center tubercles of the upper lips were obvious. No whistling deformity appeared. Conclusion The method for repairing bilateral cleft lips is simple and reliable. Less tissues could be excised and the satisfactory form and function of nose and lip could be achieved. It is worthy to be applied in clinical practice.
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0.05),that of AR 84.21% and 50.00% (P0.05). Conclusions: The pathogenesis of SS salivary glands appears to be linked to decrease or loss of topical action of androgens.Sex hormones act on epithelial cells of salivary glands through corresponding receptors.
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Objective:To investigate the expression of apoptosis-associated genes bcl-2, bax, fas and fasL in salivary tissue with Sjgrens syndrom(SS). Methods:Bcl-2, Bax, Fas and FasL in salivary tissue from 16 patients with SS and 10 normal controls were detected by SP immunohistochemical staining.Results:Expression of Bcl-2 was significantly decreased(P