垂直牙根斷裂是臨床上最難進行診斷及治療的病症之一，常建議拔除，而且成因眾說紛紜，所以也難以預防。本文根據文獻將可能造成的因素分為：1.根管治療後牙齒性質的改變2.柱(post)的影響3.擠針(spreader)的影響4.牙齒結構的完整性5.未接受過根管治療牙齒之垂直牙根斷裂等，逐項討論。希望透過系統性的回顧，讓臨床牙醫師了解垂直牙根斷裂的成因，進而能避免牙根斷裂的發生。

Vertical root fracture (VRF) occurring in oblique or longitudinal direction is one of the most complicated problem for general practitioner to do successful treatment. VRF usually result in extraction. It is difficult for the prevention of VRF due to its controversial etiology. The possible predisposing and iatrogenic etiologic factors of VRF are (1) the alteration of biomechanical property in root canal treated tooth; (2) the presence of the post in widening canal; (3) Cracks in the dentin created during lateral or vertical compaction of root filling material; (4) Loss of healthy/normal tooth structure as a result of caries, trauma, or canal enlargement; (5) other reason in non-endodontical1y treated teeth. The keynote of this review is introducing etiology of VRF to practitioners and reminding the possible risk during root canal therapy and post fabrication.