- 期刊
分析二維牙根吸收與三維牙周支持喪失程度之關聯性
Analyze the Relationship between Two-Dimensional Root Resorption and Three-Dimensional Periodontal Support Loss
摘要
研究目的：利用微型斷層掃描下顎小臼齒並利用影像檔案模擬分析牙根解剖型態，藉以探討二維牙根吸收程度與三維牙周支持喪失程度之關聯性及臨床價值。材料與方法：37顆完整無明顯缺損的下顎單牙根小臼齒，利用微型斷層掃描樣本並轉換為三維成像，從牙根尖以每5%牙根長度間隔依序測量至一半牙根長度之二維數據，計算分析其對應之三維牙根表面積和體積變化量及百分比。結果：本研究總共掃描了37顆下顎小臼齒，平均牙根長為14.100 mm，平均牙根總表面積為203.039 mm2，牙根總體積226.550 mm3，每5%的平均牙根長為0.705 mm，若依矯正定義之嚴重牙根吸收達1/3牙根長度時，平均喪失長度為4.7mm，牙根表面積喪失占總表面積約17%，牙根體積喪失佔總體積約14%。迴歸分析指出牙根表面積與體積喪失量比例隨牙根吸收長度比例呈曲線狀增加（顯著值<.001）。結論：利用微型斷層掃描技術分析下顎小臼齒牙根及模擬牙根吸收後之變化，縱使嚴重根尖吸收達二維1/3牙根長度，三維牙根表面積喪失僅佔17%。儘管嚴重的牙根吸收通常不會影響牙齒的功能，但對於年長、有牙周病或牙根較短的患者來說，或許可能需要重新評估其診斷的分級和預後，因此牙周預防還是有其重要性。
並列摘要
The purpose was using micro computed tomography to scan the mandibular premolars and using image files to simulate and analyze the root anatomy, in order to investigate the relationship between two-dimensional root resorption and three-dimensional periodontal support loss and its clinical value. Materials and Methods: 37 intact single-root mandibular premolars are scanned by micro computed tomography technology and converted into 3D imaging. Measure 2D data from the apex to half of the root length at intervals of every 5% of the root length, and calculate 3D data of the remaining root surface area and root volume amount and percentage. Results: A total of 37 mandibular premolars were scanned in this study. The average root length was 14.100 mm, the total root surface area was 203.039 mm2, and the total root volume was 226.550 mm3. The average per 5% of the root length was 0.705 mm. When severe root resorption reached 1/3 of the root length, the average loss of length was 4.7 mm, the loss of root surface area was about 17%, and the loss of root volume was about 14%. Regression analysis indicated that the percentage of the loss of root surface area and root volume increased curvilinearly with the percentage of the length of root resorption (P <.001). Conclusion: The use of micro computed tomography technology can accurately simulate and analyze the root resorption of mandibular premolars. Even if severe resorption reaches two-dimensional 1/3 of the root length, the loss of three-dimensional root surface area only accounts for 17%. Although severe root resorption usually doesn't affect the function, for elderly, patients with periodontal disease or short roots, the grade of diagnosis and prognosis may need to be reassessed. Therefore, periodontal prevention is still important.