| Project/Area Number |
12470410
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
OKUDA Kouichi Hokkaido Univ., Dent. Hosp., Inst., 歯学部・附属病院, 助手 (10204124)
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| Co-Investigator(Kenkyū-buntansha) |
AITA Hideki Hokkaido Univ., Dent., Inst., 大学院・歯学研究科, 助手 (10301011)
YORIMOTO Takumi Hokkaido Univ., Dent. Hosp., Inst., 歯学部・附属病院, 助手 (60292033)
UEDA Yasuo Hokkaido Univ., Dent.,Lect., 大学院・歯学研究科, 講師 (30241342)
SATOH Yoshiaki Hokkaido Univ., Dent. Hosp., Lect., 歯学部・附属病院, 講師 (00250465)
YAMAGICHI Hiro-o Hokkaido Univ., Dent., Inst., 大学院・歯学研究科, 助手 (10239907)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥14,000,000 (Direct Cost: ¥14,000,000)
Fiscal Year 2001: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2000: ¥11,100,000 (Direct Cost: ¥11,100,000)
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| Keywords | jaw deformity / improve function / Orthognathic surgery / rapid prototyping / soft tissue model / 顎変形庄 / 三次元医療画像 / チームアプローチ / アーチファクト / 外科矯正 |
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| Research Abstract |
1. Objective
Orthognathic surgery has been widely performed to improve function and esthetics of patients suffering from jaw deformity. We have applied rapid prototyping (RP) technology to fabricate 3-dimensional cranio-facial bone models from 3D-CT data and the models have been used for presurgical simulation. However, post-operative relapse usually takes place due to tension from distorted soft tissues and muscles. Therefore, the purpose of this study was to fabricate simulation models including soft tissue in order to evaluate soft tissue change before and after surgery.
2. Materials and Methods
The masseter was modelled because masticatory muscles, especially the masseter, are supposed to have strong influence on postoperative relapse. Among patients underwent sagittal split or vertical ramus osteotomy, those who met the following criteria were included as subjects ; 1)no maxillary surgery or limited blow the zygomatic and nasal bones, 2)Preoperative CT taken after growth period was over and postoperative CT taken within 6 months after surgery are available. The masseter data was extracted from each CT slice. The long axis of the masseter was defined as a regression line of the center of gravity of the masseter on each slice. The change of the masseter muscle angluation was evaluated by the angle between the reference axes before and after the surgery.
3.Results
The long axis of the masseter muscles tended to tilt slightly to the posterior direction after surgery. However, if the technical errors regarding the scanning angle and the reference axes determination are taken into account, it can be concluded that the distortion of the masseter muscles, was minimal. The method used in this study would be inaccurate when the difference between the CT scanning angles taken pre and postoperatively was large. Therefore, in order to evaluate soft tissue changes more accurately, it may be necessary to strictly standardize pre and postoperative CT scanning conditions.
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