关键词: 单侧唇裂, 鼻畸形, 三维重建, 有限元, 生物力学

Abstract: Objective To explore the cause and to reveal the biomechanical regularity of nasal deformation in patients with unilateral cleft lip through the biomechanical analysis on nasal deformation by finite element method, in order to establish a good biomechanical theoretical basis for treating nasal deformation of unilateral cleft lip. Methods From 2007 to 2009, 10 cases of unilateral cleft lip with nasal deformation were collected. All the cases were scanned by CT and MRI preoperatively, image data were collected and the three-dimensional nasal deformation were reconstructed by the software MIMICS. Then the finite element models of nasal deformation in unilateral cleft lip were established and the model's constraint conditions were defined for the biomechanical measurement and analysis of nasal deformation in unilateral cleft lip. Results The three-dimensional model of nasal deformation in unilateral cleft lip were reconstructed successfully. The biomechanical analysis showed that, under the static state, nasal deformation had a very small value of stress distribution. The value of the key stress points were as follows:nasal septum 0.009 35 ±0.002 MPa, the bottom of nasal columella 0.005 9 ±0.002 1 MPa, lateral feet of nasal alar 0.006 81±0.001 3 MPa;Under displacement load status, the deformed nasal had a large value of the stress distribution. The value of the key stress points were as follows:ipsilateral nasal columella 25.51 ±3.98 MPa, nasal septum 7.882 ±1.35 MPa, ipsilateral nasal alar 8.184 ±1.58 MPa. Conclusion Affected side of nasal columella is the key mechanical part to rectify deformed nose, and the following part is ipsilateral nasal alar; The stress concentration of nasal septum suggests that the rectification of nasal septum is very important, its rectification and fixation are perhaps the important contents of deformed nose rectification.

Key words: Unilateral cleft lip, Nasal deformation, Three-dimensional reconstruction, Finite element, Biomechanics