Department of Conservative Dentistry, Yonsei University, Seoul, Korea.
J Endod. 2011 May;37(5):711-4. doi: 10.1016/j.joen.2011.01.015. Epub 2011 Mar 3.
Endodontic infection or physical trauma of a developing tooth might lead to unusual situation for root development.
Two cases are presented. Both cases involved immature mandibular second premolars with infected pulps. In the first case, the tooth was treated by apexification, whereas revascularization procedures were performed in the second case. Interestingly, a separated root tip was observed with the main root at the initial presentation of case 2.
At recall after apexification, a separate root tip was observed apically to the main root end, and root development continued in case 1. In the second case, the separate root displayed continuing root formation, but the main root did not gain root thickness or length.
These cases revealed that Hertwig's epithelial root sheath and stem cells from the apical papilla can be separated from the main tooth structure by an external force or iatrogenic factors and thereafter produce a separate root tip.
牙髓感染或发育中牙齿的物理创伤可能导致牙根发育异常。
报告 2 例病例。这两例均为感染牙髓的未成熟下颌第二前磨牙。第一例采用根尖诱导成形术治疗，第二例采用了血运重建术。有趣的是，第二例在初始就诊时观察到一个与主根分离的根尖。
根尖诱导成形术后复查时，在主根根尖上方观察到一个单独的根尖，第一例继续进行了牙根发育。第二例中，分离的根尖继续形成，但主根没有增加厚度或长度。
这些病例表明，Hertwig 上皮根鞘和根尖乳头的干细胞可以被外力或医源性因素从主牙结构中分离出来，并随后形成一个单独的根尖。
