通常认为:牙齿(牙合)面易患龋齿是由于表面窝沟的存在。但目前,作者证明龋齿发生主要是在牙齿萌出时期,因为此时口腔环境更有利于菌斑聚集,而沟窝形态差异并不影响龋齿发生率。但此差异与龋齿的组织学特点及菌斑结构、菌斑内微生物代谢活力间有一定关系。 材料和方法 作者以22名18～20岁患者的萌出时间少于18个月,并无异常病变的第三磨牙作为标本。依据萌出时间分为3组:A组小于3月(7个),B组3～12月(8个),C组12～18月(7个),每个牙都进行常规包埋,磨制,作成两张颊舌向磨片,依据结构角度分为裂隙形(2～25°),沟形(25～75°)。龋齿发展程度可 Generally believed that: dental (occlusal) face susceptible to dental caries is due to the presence of surface pit. However, at present, the authors show that dental caries mainly occur during tooth eruption, because the oral environment is more conducive to plaque accumulation, and the differences in the shape of the groove do not affect the incidence of dental caries. However, this difference is closely related to the histological features of dental caries and the plaque structure and the metabolic activity of the microorganisms in the plaque. MATERIALS AND METHODS The authors examined the eruption time of 22 patients aged 18-20 years with eruption time of less than 18 months and no abnormal molars. According to the eruption time is divided into 3 groups: A group of less than 3 months (7), B group 3 to December (8), C group of 12 to 18 months (7), each tooth were routine embedding, grinding System, made of two cheek tongue to the mill, according to the structural angle is divided into fissure (2 ~ 25 °), ditch (25 ~ 75 °). Degree of dental caries development