汉族下颌第三磨牙牙尖与牙根的关系  

The relationship between the the cusps and roots of mandibalar third molar tooth of the Han nationality

作　　者：蔡月岚[1] 李萍 

机构地区：[1]北京复兴医院口腔科,100045

出　　处：《现代口腔医学杂志》1998年第1期51-53,共3页Journal of Modern Stomatology

摘　　要：本文对342颗下颌第三磨牙(牙合)面牙尖与牙根的关系以及阻生的临床类型与牙根数目之间的关系进行了探讨。结果表明:(牙合)面牙尖呈四型,分别是四尖型、五尖型、六尖型和八尖型。牙根呈三型,分别是融合根型、双根型和三根型。(牙合)面牙尖为四尖型,其融合根比例高达71.01％,五尖型融合根比例降为27.97％,双根比例升为61.91％。六尖型没有融合根,双根约占3/4(74.19％),三根约占1/4(25.81％)。八尖型都是三根。 阻生类型中水平位和颊向位融合根的比例大,分别为85.714％和56.43％。近中位、舌向位和垂直位则双根的比例高,分别为60.417％、58.334％和47.619％。以垂直位和远中位三根比例最高,分别为25.397％和25.0％,其余各类型中三根的比例均不足9％。This paper has studied the relationship between the cusps and roots and between the clinic impacted type and roots of 342 mandibular third molar tooth. The results are as follow: The cusp of the mandibular third molar tooth can be divided into 4 types,they are 4 cusps,5 cusps,6 cusps and 8cusps;The root of the mandibular third molar tooth can be divided into 3types they are 1 root,2 roots and 3 roots;The one root of the four cusps of the mandibular third molar tooth is the largest(71.01 % ). the two roots of the six cusps of the mandibular third molar tooth is more than five cusps(61.91 % ). 8 cusps type is three roots. The proportion of one root of horizontal impaction and buccoangular impaction separately is 85. 714% and 56.436% . The proportion of two roots of mesioangular impaction,linguoangular impaction and vertical impaction is 60.417% ,58.334% ,47.619% respectively. The proportion of three roots of vertical impaction and distoangular impaction is highest, it separately reach 25. 397% and 25. 0% . The proportion of three roots of rest types is less than 9% .

关 键 词：汉族 磨牙 牙尖 牙根 下颌第三磨牙 

分 类 号：R78[医药卫生—口腔医学] R322.41[医药卫生—临床医学]