Igarashi Yuriko, Yoshida Satoru, Kanazawa Eisaku
Department of Anatomy I, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-Nishi, Matudo-Shi, Chiba, 271-8587, Japan.
Odontology. 2017 Oct;105(4):443-452. doi: 10.1007/s10266-017-0300-y. Epub 2017 Mar 8.
Non-carious cervical lesions (NCCLs) were examined in 6541 extracted human teeth and classified based on the morphology of the lesions. As a result, NCCLs were found on 38.7% of teeth (41.6% on maxillary teeth and 36.0% on mandibular teeth), and were most frequent on canines and first premolars. According to the new method of classification, the morphology of NCCLs was classified both by the surface contour (SC) and by the cross-sectional contour (CC). Three types of NCCLs appeared to be dominant. The causes of these NCCLs were discussed based on their morphologies, positions where these NCCLs were frequently found, and the results of previous studies. NCCLs with a horizontal oval SC and a round CC (Type I), which were frequent on the labial surfaces of maxillary canines and buccal surfaces of maxillary first premolars, may be associated with wear by friction and chemical degradation. NCCLs with a vertical oval SC and a round CC (Type II), which were frequent on the lingual surfaces of mandibular incisors and canines, might be mainly related to chemical degradation. NCCLs with a horizontal oval SC and a wedge shape CC (Type III), which were extensively found on the buccal surfaces of maxillary premolars, had formed most probably due to wear by friction and microstructural loss by stress. This new method can classify the morphology of NCCLs more precisely and deduce the mechanisms of the formation of NCCLs more clearly than former methods.
在6541颗拔除的人牙中检查了非龋性颈部病变（NCCLs），并根据病变形态进行分类。结果发现，38.7%的牙齿存在NCCLs（上颌牙为41.6%，下颌牙为36.0%），且在犬齿和第一前磨牙上最为常见。根据新的分类方法，NCCLs的形态通过表面轮廓（SC）和横截面轮廓（CC）进行分类。三种类型的NCCLs似乎占主导地位。基于这些NCCLs的形态、常见位置以及先前研究的结果，对其成因进行了讨论。在上颌犬齿唇面和上颌第一前磨牙颊面常见的具有水平椭圆形SC和圆形CC的NCCLs（I型），可能与摩擦磨损和化学降解有关。在下颌切牙和犬齿舌面常见的具有垂直椭圆形SC和圆形CC的NCCLs（II型），可能主要与化学降解有关。在上颌前磨牙颊面广泛发现的具有水平椭圆形SC和楔形CC的NCCLs（III型），很可能是由于摩擦磨损和应力导致的微观结构损失而形成的。与以前的方法相比，这种新方法能够更精确地对NCCLs的形态进行分类，并更清晰地推断NCCLs的形成机制。
