Analysis And Compare Of Crown Form And Gingival Shape Of Upper Anterior Teeth In Young China-Zhuang And Young Viet Nam-Kinh Population

Objective: Measuring the crown of maxillary anterior teeth and gingival parameters in young China-Zhuang and VietNam-Kinh population,to classify the shape of maxillary anterior teeth,to evaluate ratio of distribution in each ethnic and,to compare two ethnic's crown and gingival features.In order to provide quantitated reference data in crown of the anterior teeth and gingival morphology in adolescence of China-Zhuang and VietNam-Kinh.Methods: 200 maxillary models of young students of China Zhuang and Vietnam Kinh were colleted with silicone impression material.All subjects were in the range of 20-25 years old.The ratio of width and lenght of the crown(CW/CL),gingival angle(GA),gingival embrassure angle(GEA),proximal contact area proportion(PCAP)were measured by Digital Calipers(accuaccy of 0.01 mm).Using cluster analysis method the samples were categoried into three groups according to the crown form including square.ovoid,tapered.The data were statistically analyzed by SPSS 20.0 solfware.Results: 1.The parameters of CW/CL,GA,GEA,PCAP of maxillary anterior tooth segment in China Zhuang and Vietnam Kinh were obtained.2.The ratio of crown forms in China Zhuang square(35%)Ovoid(44%)Tapered(21%);in Vietnam Kinh Square(26%)Ovoid(50%)Tapered(24%).3.There is nosignificant difference in CW/CL of maxillary central incisor between two ethnics.4.The means of GA,GEA,PCAP in Vietnam Kinh group are greater than China Zhuang group(P<0.001).Conclusion:.The distribution ‘s ratio of crown forms between China Zhuang and Vietnam Kinh have no significant differences.In the comparison of tooth form in the same group in different ethnic,the measurements of GA,GEA,PCAP in Vietnam Kinh are greater than China Zhuang.