350例上颌前磨牙Interstitial结节发生率的调查

上颌第一、第二前磨牙咬Ｈｅ面上，颊侧副沟与横副沟间边缘嵴肥厚呈结节状称Ｉｎｔｅｒｓｔｉｔｉａｌ结节。作者对中，日两所医科大学生Ｉｎｔｅｒｓｔｉｔｉａｌ结节的发生情况作了调查，结果如下：（１）上颌第一前磨牙Ｉｎｔｅｒｓｔｉｔｉａｌ结节发生率在中日无差异，上颌第二前磨牙日方组发生率高于中方组；（２）Ｉｎｔｅｒｓｔｉｔｉａｌ结节在上颌第一前磨牙发生率显著高于上颌第二前磨牙；（３）单侧发生多于双侧；（４）

Interstitial tubercle in Chinese and Japanese young adults

A comparative study on the incidence of interstitial tubercle from standardizedstone casts of 160 Chinese and 190 Janpanese young adults,ages from 20-30. The followingresults were obtained: 1)No significant difference in the incidence of interstitial tubercle onmaxillary first premolar between Chinese and Japanese groups (P> 0. 05), but on maxillarysecond premolar, Japanese is higher than Chinese (P<0. 05) . 2)The incidence of interstitialtubercle on maxillary first premolar is higher than second premolar in two groups (P<0. 05).3 )The intestinal tubercle occurs in unilateral more frequently than in bilateral. 4)The inci-dence of maxillary first premolar in mesial of occlusal is higher than in distal. 5)No differencebetween mesial and distal on occlusal of maxillary second premolar in the Chinese group, andthe incidence in mesial is higher than in disal in the Japanese group.