Objective:To study the gender characteristics and changes with aging of the length of upper lips and the width of angulus oris in Shandong to provide effective basis for treating and prognosis of prosthodontics and orthodontics. Methods:852 subjects with normal occlusion from Shandong were selected randomly. They were divided into 3 groups ac-cording to ages(18 ~ 36 years old,37 ~ 55 years old,56 ~ 74 years old)and the number of male and female in each group was 142 . These subjects,face were recorded and the images were measured in order to analysis among the groups. Results:The length of upper lips and the width of angulous oris were significantly different among the groups(P < 0. 01);the width of angulous oris was significantly different between the male and female in the same group(P < 0. 01);the length of upper lips was statistically different between the male and the female among the groups(P < 0. 05);there is positively correlated between age and all measurement items and the average value was increased with age. Conclusion:The relationship be-tween all measurement items and age is positively correlated,the length of upper lips and the width of angulous oris in-creased with age and there were gender differences at the same age.

As the medical student on the long road to learn stomatology,the anatomy physiology and microstructure of teeth were not only stepping stones to the oral world,but also our essential basis to do further clinical work.In the process of inquiry-based learning,personally collecting teeth,analyzing their characteristics,preparing and observing the tooth grind-ing,could inspire our interest as well as guide us to learn imperceptibly.