Three-dimensional (3D) Changes of Condylar Position in Prognathic Mandible Corrected by Orthognathic Surgery

碩士 === 長庚大學 === 顱顏口腔醫學研究所 === 101 === Abstract Purpose: The purpose of this study was to assess alterations in three-dimensional (3D) position of condyles evaluated by cone-beam computed tomography (CBCT) images in the patients receiving LeFort I osteotomy and bilateral sagittal split mandibular ost...

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Bibliographic Details
Main Authors: I Ming Tsai, 蔡一民
Other Authors: C. S. Huang
Format: Others
Published: 2013
Online Access:http://ndltd.ncl.edu.tw/handle/71078133109546535420
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Summary:碩士 === 長庚大學 === 顱顏口腔醫學研究所 === 101 === Abstract Purpose: The purpose of this study was to assess alterations in three-dimensional (3D) position of condyles evaluated by cone-beam computed tomography (CBCT) images in the patients receiving LeFort I osteotomy and bilateral sagittal split mandibular osteotomy (BSSO). Subjects and Methods: CBCT scans were taken from 25 patients (12 male, 13 female, mean age= 20.9±3.53 years ) one week before and one month after orthognathic surgery. They were skeletal Class III malocclusion and underwent LeFort I osteotomy and BSSO. The CBCT images were standardized in the same head position and were measured the angles and distances of the condyles to surrounding anatomy structures. The Student paired t test was used to evaluate the difference of condylar position after the surgery. The preorperative and postoperative symptoms of temporomandible joint (TMJ) were also recorded. Results: In the axial view The right condyle went inward by 0.18±0.21mm and rotated inward by 1.11±1.0°. The left condyle went outward by 0.87±0.29mm and rotated outward by 0.75±0.86°. The intercondylar distance increased by 0.7±0.39mm. But, significant difference was only found in outward displacement of left condyle. In the sagittal view The right condyle went backward by 0.54±0.31mm and rotated backward by 3.58±0.81°. The left condyle went backward by 0.6±0.27mm and rotated backward by 3.66±1.15°. But, significant difference was found in backward displacement of left condyle and backward rotation of both condyles. In the coronal view The right condyle went inward by 0.43±0.43mm, and rotated inward by 2.85±0.66°. The left condyle went inward by0.14± 0.58mm and rotated inward by 1.76±0.76°. The intercondylar distance decreased by 0.3±0.97mm. But, significant difference was found in inward rotation of both condyles. Symptoms of TMJ were not found preoperatively and postoperatively. Conclusion: After surgery: In the axial view, the left condyle significantly went outward by 0.87±0.29mm. In the sagittal view, the right condyle significantly rotated backward by 3.58±0.81°. The left condyle went backward by 0.6±0.27mm and rotated backward by 3.66±1.15°. In coronal view, right and left condyles significantly rotated inward by 1.76±0.76° and 2.85±0.66°, respectively. In our study, the positional change of condyle occurred after surgery. Patient did not complain of TMJ symptoms before and after surgery. The changes of condylar position were within the range of self-adaptation.