Root Resorption in Maxillary Central Incisors during Active Orthodontic Treatment-A Radiographic Study-
| Project/Area Number |
63570938
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
外科・放射線系歯学
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| Research Institution | Hiroshima University |
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Principal Investigator |
WADA Takuro Hiroshima University, School of Dentistry, Department of Dentomaxillofacial Radiology, Professor, 歯学部, 教授 (10028756)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Kazue Hiroshima University, School of Dentistry, Department of Orthodonitics, Research, 歯学部, 助手 (10034208)
SUEI Yoshikazu Hiroshima University, School of Dentistry, Department of Dentomaxillofacial Radi, 歯学部, 助手 (10206378)
TOMITA Shinichi Hiroshima University, School of Dentistry, Department of Dentomaxillofacial Radi, 歯学部, 助手 (60172186)
古木 良彦 広島大学, 歯学部附属病院, 助手 (50165479)
小川 正晃 広島大学, 歯学部, 助手 (70144847)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Orthodontic / Root Resorption / Incisors / 規格撮影 / 歯牙移動 / 口内法X線規格撮影法 |
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| Research Abstract |
The purpose of this study was to investigate whether it is possible to detect an early radiographic changes of root resorption in upper incisors during active orthodontic treatment. A newly occlusal technique for measurement of tooth length combined with lateral cephalogram was developed. Although experimental study with 10 dry skulls showed a good results to measure tooth lengths, clinical use for measurement of tooth length in patients was not satisfactory. The cause of failure in measurement was that a geometric factor, patients' open bite, ill-defined incisor edge, and so on were combined. The measurement of the thickness of periodontal space and lamina dura showed a good correlation with the observation of the occlusal radiograms.
Out of registered 120 volunteer patients in this study, 36 patients were quit because of some reasons(e. g. . non-cooperation of the patients or orthodontists after registration, or the patients with cleft palate, occurrence of tumor). Forty-four patients were still in active orthodontic treatment. Subsequent 40 patients were analyzed this time. The duration for active orthodontic treatment was 3 to 31 months, mean 20 months. The radiograms were taken every 3 months during active orthodontic treatment. The final radiograms were taken at one month before or after starting the retention. The root resorption was clearly occurred in 26 patients(65%)and suspected in 6 patients(15%). The first detection of root resorption was from 3 months to one year or more. In the severe resorption cases, the timing of the first detection of root resorption was very early in the first radiogram. It is important for orthodontists to know that the early detection of root resorption sucgests the high risk of root resorption. Also the changes of lamina dura and periodontal space were different between root resorption patients and non-resorption patients. We will report about this point after this project is finalized.
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Report
(4 results)
Research Products
(3 results)
