牛牙样牙文献综述

Taurodontism: a literature review

牛牙样牙(taurodontism)为一种少见的牙体畸形,Hertwig上皮根鞘未能在适当的水平内折或者断裂延迟是牛牙样牙发生的重要原因,但其发病机制尚不完全清楚。以牙髓腔冠根向膨大、髓室底及根分叉向根方移位、而釉牙骨质界没有明显收缩为特征。牛牙样牙最常见于恒磨牙中,但这种改变也可见于乳牙,可在单侧或双侧以及任何牙齿或象限中看到,可单独发生,亦可伴有其他综合征同时存在。通常无明显临床症状,大多数通过拍摄X线片得以发现。该文对牛牙样牙的病因、临床表现和放射学特征,各种综合征的关系以及这种牙齿的牙科治疗进行综述,以满足对其诊断和治疗的迫切需求。

Taurodontism is a rare tooth deformity, a change in tooth shape caused by the failure of Hertwig’s epithelial sheath diaphragm or the delay of fracture at the proper horizontal level. However, its pathogenesis has not been fully understood. An enlarged pulp chamber, apical displacement of the pulpal floor and bifurcation or trifurcation of the root,and no constriction at the level of the cemento-enamel junction are the characteristic features. Although permanent molar teeth are most commonly affected, this change can also be seen in both the permanent and deciduous dentition, unilaterally or bilaterally, and in any combination of teeth or quadrants. Whilst it appears most frequently as an isolated anomaly, its association with several syndromes has also been reported. Usually no obvious clinical symptoms appear, most of which are found by the X-ray film. This article reviews the etiology, clinical and radiological features of the taurodontism, the relationship between various syndromes, and the dental treatment of such teeth to meet the urgent need for diagnosis and treatment.