第一恒磨牙髓室底解剖形态的观察

The Morpholegical Observation of the PulP Chamber Floors of 100 First Molar Teeth

将100枚离体第一恒磨牙切断牙冠,观察髓室底形态并测量其厚度。结果:髓底外形可归纳为四型:中凹型(43%)、平坦型(38%)、中凸型(7%)与钙化闭塞型(12%)。髓室底厚度上颌第一磨牙平均为2.96mm,下颌第一磨牙平均为2.80mm,左右侧磨牙相似,本资料可供临床诊断与治疗参考。

An observation was made on 100 floor surfaces of pulp chamber of first molars.There were four types—convexity(7%),concavity(43%),plain form(38%)and obstructed by overcalcification on the surface(12%).Generally,the upper first molar root was divided into two buccal parts and one lingual part,and each canal having one orifice.The lower first molar root was divided intomesial root canal and distal root canal.The orifices of all canals have three forms.These funnel(33.1%),flat(50.1%)and calcifing(16.8%).Partial crifice of root canals were cross-communicated and connected by shallow grooves or notchs and their propor tions were38/50 in the upper qinst molar,32/50 in the lower first molar The average measurements of thickness of pulp chamber floor being2.96mm in upper first molar ane 2.80mm in the lower first molar,These observation showed that the shape of floor of pulp chamber,the form of root canals orifices,the rule of distribution of root canal and the thickness of the pulp chamber floor were helpful in the clinicai diagnosis and treatment.