[Interstitial tubercle in Chinese and Japanese young adults]

A comparative study on the incidence of interstitial tubercle from standardized stone casts of 160 Chinese and 190 Japanese young adults,ages from 20-30.The following results were obtained:(1)No significant difference in the incidence of interstitial tubercle on maxillary first premolar between Chinese and Japanese groups(P>0.05),but on maxillary second premolar,Japanese is higher than Chinese(P<0.05).(2)The incidence of interstitial tubercle on maxillary first premolar is higher than second premolar in two groups(P<0.05).(3)The intestitial tubercle occurs in unilateral more frequently than in bilateral.The incidence of maxillary first premolar in mesial of occlusal is higher than in distal.No difference between mesial and distal on occlusal of maxillary second premolar in the Chinese group,and the incidence in mesial is higher than in distal in the Japanese group.