以錐狀束電腦斷層掃描輔助多重性牙根外吸收下顎大臼齒之診斷及治療：病例報告

Diagnosis and Treatment of a Multifactorial External Root Resorption Assisted with Cone-beam Computed Tomography: Case Report

根尖外吸收（apical root resorption）及齒頸部外吸收（external cervical resorption）均屬牙根外吸收（external root resorption）。根尖外吸收多因根尖發炎所致，造成根管治療清創及充填的困擾。齒頸部外吸收是臨床上少見的病變，治療方式的選擇與病灶嚴重程度有關。本病例報告為曾根管治療的右下第一大臼齒，放射學檢查於近心鄰接面及遠心鄰接面各發現一處齒頸部外吸收、近心外吸收處與根管有交通情形、及遠心根尖外吸收。應用錐狀射束電腦斷層掃描（cone beam computed tomography）輔助診斷，經根管重新治療，合併牙周翻瓣手術並修補齒頸部外吸收及穿孔，遠心牙根根管以三氧礦化聚合物（mineral trioxide aggregate）填補，經一年追蹤，癒後良好。藉此病例，討論牙根外吸收之疾病分類、診斷、治療方式及復形材料選擇、治療計畫擬定及預後，作為治療參考。

Root resorption is segmented into internal and external resorption. Based on the location of the resorptive defect, external root resorption can be further categorized as cervical, lateral surface, and apical resorption. Apical resorption often results from apical or periapical inflammation, which interfere with root canal procedures, such as determination of working length, debridement for apical tissue, and hermetic sealing of apical root canals. External cervical resorption is a clinically uncommon external root resorption lesion. The advent of three-dimensional imaging has provided numerous benefits to endodontic practice and leads to greater three-dimensional geometric accuracy than conventional radiography in diagnosing and managing resorptive lesions. Within this case, we observed a complicated etiology, diagnosis and classification of the external root resorption, as well as different treatment options. Meanwhile, this case report herein demonstrates how cone beam computed tomography can be used to make a definite diagnosis and a comprehensive treatment plan for a lower right first molar with multifactorial external root resorption. The postoperative one-year follow-up examination revealed a favorable outcome.