- 期刊
台灣華人三牙根的下顎第一大臼齒之X光齒槽骨喪失量
Radiographic Bone Loss on Mandibular First Molars with Three Roots in Taiwan Chinese
摘要
恆牙的下顎第一大臼齒通常有兩個牙根，當發生三個牙根的情況時，對於牙周治療會因為多一個根叉而增加治療的困難度及影響預後。而對於下顎第一大臼齒三個牙根與牙周病的關係，則尚未有學者研究發表。本文的目的是探討：l)下顎三牙根大臼齒與X光牙周附連喪失量的相關性；2)下顎三牙根第一大臼齒根叉病變的發生率。本研究樣本為收集來自1999年1月至2001年12月間，在教學醫院牙周病科接受診療而拍攝之符合標準平行法的常規全口X光片(full mouth radiographs)，分別記錄病患基本資料，包括性別、年齡等，並進行其根尖X光片之影像數位化水平量化。研究中牙周疾病的嚴重程度以X光齒槽骨累積喪失量(cumulative radiographic alveolar bone loss, CRABL)與X光齒槽骨喪失年平均量(yearly radiographic alveolar bone loss, YRABL)表現。研究結果顯示1)以三牙根之第一大臼齒遠心根之年平均齒槽骨喪失量而言，慢性牙周炎組明顯大於牙周健康組。(2)下顎三牙根第一大臼齒有63.9%的根叉病變發生，遠心面根叉病變多於頰舌面。結論顯示下顎三牙根第一大臼齒多了一個遠心舌面根叉(disto-lingual root furcation)，或許不是造成牙周病的主要因素，但當遠心面齒槽骨破壞到達遠心根叉區時，三個牙根的下顎第一大臼齒遠心根叉病變有較大的X光齒槽骨喪失量。此外，下顎三牙根第一大臼齒根叉病變的發生率高達63.9%。
並列摘要
Most mandibular molars have two roots. When a three-rooted mandibular first molar trait is present, the difficulty of treatment is increased due to an additional furcation area that may affect the prognosis. The relationship between the three-rooted mandibular first molars and the periodontal disease is unclear. The purpose of the present study was to retrospectively evaluate radiographic periodontal attachment loss on the three-rooted mandibular first molars. The study samples were collected from the department of Periodontology of medical centers, from 1999 January to 2001 December. The documented patients' basic data included gender, age, and full mouth radiographs that fit the standard paralleling techniques, and were examined for digital radiographic evaluation. The severity of periodontitis was expressed with cumulative radiographic alveolar bone loss (CRABL) and yearly radiographic alveolar bone loss (YRABL). Results of this study indicated that there was more yearly radiographic alveolar bone loss of the three-rooted mandibular first molars in the chronic periodontitis patients than in the periodontally healthy patients. Higher prevalence rate (63.9%) of the distal furcation involvement was found than mesial furcation involvement in three-rooted mandibular first molars. In conclusion, the additional third root appeared to increase the destructive process of alveolar bone at the distal furcation of mandibular first molar. The three-rooted mandibular first molars may be a cofactor in the progression of periodontal disease.