RESUMO
<p><b>OBJECTIVE</b>To study the coordination of facial soft tissue in Angle's Class I, II1, III malocclusion, providing reference for the clinical practice.</p><p><b>METHODS</b>60 lateral cephalometric radiographs of three classes of Angle's malocclusion were included. 13 measurements were analyzed by SPSS 10.0.</p><p><b>RESULTS</b>Protrusion of the upper and lower lips increased in Angle's II1 comparing with Angle's I and protrusion of the upper lip was larger than the lower lip, no difference was found in the facial convexity. Increase of upper lip inclination and underdevelopment of maxillary in Angle's III comparing with Angle's I. No significant different was found in the form of lower lip, soft tissue facial angle and Z angle. Comparing Angle's II1 with Angle's III, every measurements were significantly different except upper lip inclination, nasolabial angle, representing the formation mechanism of malocclusion.</p><p><b>CONCLUSION</b>Some differences were found in form and position of lip in three classes of Angle's malocclusion. However, the deformity was not obvious in Angle's II1 and Angle's III because of compensation mechanism. Nasolabial angle only reflected change of upper lip, but could not reflect characters of facial profile.</p>
Assuntos
Humanos , Cefalometria , Face , Lábio , Má Oclusão , PatologiaRESUMO
Objective To evaluate the methods of surgical treatment for tumors of brain stem and their curative effects. Methods: 25 cases of tumors of brain stem were analysed retrospectively. Results: There were 18 cases of astrocytomas, 2 cases of cavernous angioma, 1 cases of hemangioblastoma, 1 cases of dermoid cyst, 1 cases of syringopontia, 1 cases of inflammatory granuloma accompanied with hecrosis and 1 cases of AVM of brain stem in 25 cases. Four patients died after operation. Conclusion: Extrinsic tumors of brain stem could be resected totally or subtotally, resulting in good outcome.
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Objective:To analyze the perpendicular force on each tooth produced by the reverse-curve arch wires of various angles and depths using the method of 3-D finite element (3-D FEM) analysis. Methods:3-D FEM models of lower teeth, periodontal ligaments and alveolar bone as well as the 0.46 mm?0.64 mm inch stainless steel reverse-curve arch wires with different angles and depths were developed with the ANSYS finite element software, and the displacements of deformation of the reverse-curve arch wires were established on the models. Results:A ideal 3-D FEM was construct,including 2 709 elements and 1 969 nodes. The depth and angle of the reverse-curve arch wires produced obvious effect on the force exerted to teeth, and they could alter both the strength and the direction of the force. The force was mainly loaded on the canines, the second premolars and the molars, while less loaded on the incisors. Affected by the reverse-curve arch wires, the perpendicular force on the incisors were brought intrusively and on the molars were brought intrusively and distal upright; however, the canines and the bicuspids, in the perpendicular direction, moved along with the transformation of the angle and depth of the reverse-curve arch wires. When the angle of reverse-curve arch wires was fixed, the intrusive force on the incisors and molars was increased along with the increase of depth of the reverse-curve arch wires. Perpendicularly, the canines underwent a process from extrusion to intrusion, while the bicuspids were from intrusion to extrusion. When the depth of reverse-curve arch wires was fixed, the intrusive force on the incisors and molars was increased along with the increase of angle of the reverse-curve arch wires. The canines underwent a process from intrusion to extrusion.Conclusion:The variation of the angle and depth of the reverse-curve arch wires may produce evident effect on the force exerted to teeth.