The Study Of Three-Dimensional Technique In Three-Dimensional Measurement Of Hemifacial Microsomia Facial Soft Tissue And The Ear Reconstruction In The Patients Of Microtia Syndrome

The First PartThe Three-Dimensional Measurement and Preliminary Analysis of the Symmetry of Cranial Soft Tissue of the Patients of The Hemifacial Microsomia Patients with MicrotiaObjective:To obtain the CT scanning data and reconstruct digital model of the cranial soft tissue of the patients of the hemifacial microsomia patients with microtia by three-dimensional CT scanning technique. To measure and analyze the symmetry of cranial soft tissue preliminarily. To provide theoretical proof of cranial soft tissue in the patients with hemifacial microsomia patients.Methods:A total of 30 cases of patients of the hemifacial microsomia patients with microtia who underwent auricular reconstruction between 2008 and 2010 were chosed. After obtainning the data and reconstructing digital skull model of the patients, we selected 28 mark points in the digital model to measure and analyzed the symmetry of cranial soft tissue preliminarily. The measurement data contained:1. the measurement of space distance.2.The measurement of radian.3. The measurement of angle.4. The measurement of area.5. The measurement of volume. The data were analyzed by SPSS 13.0Result:1. In all the mark points, the items with significant statistics difference were:the space distance from alae nas point to X axis and to Y axis, the cheek point to X axis,Y axis and to Z axis; gonial angle point to X axis,Y axis and to Z axis;tragion point to X axis.2. In the arc length:all the arc length which were measured had significant statistics difference.3. In the angle which was measured, the second, the fifth and the sixth had significant statistics difference.4. In all the area measured,, the items had significant statistics difference were: the area of mandibular area, zygomatic region, and mental region.5. In all the area measured, the items with significant statistics difference were:the area of mandibular area, zygomatic region and mental region. 5. In all the volume measured, the items with significant statistics difference were:the volume of mandibular area, zygomatic region, mental region and temperal region. Conclusion:1. The asymmetric deformity of cranial soft tissue in the hemifacial microsomia with microtia was multi-aspect deformity.2. Except for microtia, the deformity of mandibular area was the principal appearance and the key of the treatment.3. The degree of deformity of the angulus oculi lateral is and alae nas were fairly light, and the most severe deformity existed in the tragion point and mandible point.4.The deformity of temporal region has direct relationship with the f ibracation and location of ear framework.The Second PartThe Application of the Three-Dimensional skull Mould in the choice of the auricular framework location in the reconstruction of the external earObjective:To probe the application of the three-dimensional skull mould in the choice of the auricular framework location in the reconstruction of the external ear. To compare the two groups with or without using the three-dimensional skull mould in the choice of the auricular framework's location in the ear reconstruction.Methods:We selected 20 cases of patients of hemifacial microsomia with unilateral microtia who underwent auricular reconstruction between 2008 and 2010. Three-dimensional CT scanning technique and rapid prototyping technology were used to manufacture three-dimensional skull mould of the patient before the operation.40 cases of patients were followed up. Two groups of the shape and symmetry of the reconstructed auricle were compared by 4 surgeons, and two groups of the cranioauricular angle were compared also. The data were analyzed by SPSS 13.0 and Pearson'X2 test.Result:1. The patients using the three-dimensional skull mould were compared with those without using skull mould in the shape and symmetry of the reconstructed auricle and it showed significant difference statistically (P= 0.0424, P<0.05).2. The patients using the three-dimensional skull mould were compared with those without using the skull mould in the cranioauricular angle of the reconstructed auricle and it showed no significant difference statistically (P=0.799, P>0.05).Conclusion:Three-dimensional skull mould has clinical value in the ear reconstruction. It was technical improvement in the ear econstruction.The third PartFinite element modeling study of the reconstructed ear in patients with microtiaobjective:The purpose of this research is to create 3D finite element model of reconstructed ear, To create a system for predicting the reconstructed ear deformation. To investigate a more effective method for ear sugery.Material and methods:Finite Element modeling study of one patient of the hemifacial microsomia patient with microtia was carried out after CT scanning and reconstruction of the ear. Development of 3D finite element model of the ear boundary conditions were set and the mesh was manually made by using tetrahedrons on the basis of 3 CAD models of skin, and cartilage framework. Finite element model of the reconstructed ear was then developed by means of ANSYS software package. Surgical simulation and prediction of reconstructed deformation resulting from different skin retraction rates in the future.The different time points were chosen to evaluate the ear deformation by means of ANSYS soft warepackage. The reconstructed ear was evaluated at different time points.Result:There were 52566 elements and 84787 nodes in the reconstructed ear. Finite element model of the ear reflected the biomechanical features in some respect. Results were outputed in form of medical images. The most apparent tissue displacement was superior helix of the renconstructed ear, followed with scaphoid fossa. And tragus is the least affected.Conclusion:This paper addressed to create a digital model of the reconstructed ear on the bas is of finite element method. The post-operation ear deformation could be predicted.The paper focused on the prediction of reconstructed ear deformation resulting from the skin tissue retraction.