Cephalometric Study Of Hard Tissue Feature On Sagittal Plane With Normal Occlusion Of Han College Studentds In Liaoning

ObjectiveTo establish the average value of each index of their sagittal hard tissue by surveying and analysing to the cephalometric of the sagittal hard tissue with normal occlusion of Han college students in Liaoning. And then campare with the average value of hard tissue index of Han people with normal occlusion in the same age group in other areas of the country and reveal the structural features of teeth, jaws, craniums and faces of the vicinal college students with normal occlusion, which can provide guide for clinical cases and researches.MethodsPick out 102 eligible objects of study strictly by the means of carrying out a questionnaire survey and an oral examination to the Liaoning Han college students from the three universities in Jinzhou, including 49 boys and 53 girls. This test will have a comprehensive analysis to the 18 easy positioning and higher clinical value measurement items elected from the classical analysis methods (Steiner, Downs, Ricketts, McNamara and Wits etc.). In order to get the average value and the standard deviation of each trace distance as well as angle in sagittal hard tissue, we will take lateral cephalometric X-ray films for the objects of study after fixing the positions strictly according to the standardized conditions and choose points, pictures and measurements to the shooting X-ray films in manual ways during the test. And then analyse and campare to the data with SPSS17.0. Results1.Get the average value of each index of the sagittal hard tissue in the Liaoning Han college students with normal occlusion. There is no statistical significance of other indexs between the differences of the male and female(P>0.05) except two ones which male's are smaller than female's on SN-GoGn Angle (P<0.05) and male's are larger than female's on L1-MP (P<0.05).2. Campared with Shijiazhuang Han people with normal occlusion in the same age group, there is highly significant statistical difference on L1-MPand U1-NA Distance in male group(P<0.01)and significant statistical difference on L1-NB Angle(P<0.05). Thereinto, L1-MP, L1-NB Angle are larger in Liaoning; U1-NA Distance is smaller there. There is highly significant statistical difference on SNA,SNB and U1-L1 Angle(P<0.01)in female group. Their average values are all larger in Liaoning.3.Campared with Shandong Han people with normal occlusion in the same age group, there is highly significant statistical difference on ANB,NPg-FH,U1-L1 Angle, L1-MP,NA-PA in male group (P<0.01)and significant statistical difference on ANB,NP-FH,U1-L1 Angle,L1-Mp and NA-PgA in female group (P<0.01). The result is the average values in other groups are larger in Liaoning except U1-L1 Angle in female group, which is smaller.4.Campared with Guangdong Han people with normal occlusion relation in the same age group, there are significant average differences on SNA,NP-Fh and NA-PA in male group (P<0.01, P<0.05 of the former two) and SNA and NA-PA in female group(P<0.01). The result is the average values in other groups are smaller in Liaoning except NP-FH in male group, which is larger.Conclusions1. Females'chins of the under jaws are a little more behind and the lower central incisors lean to tongues carepared with mandibular planes in the Liaoning Han college students with normal occlusion.2. Women's silhouettes are a little more prominent in Liaoning than Shijiazhuang Han women's with normal occlusion in the same age group, but there is no obvious difference among men's.3. People's silhouettes are more prominent in Liaoning than in Shandong Han individual with normal occlusion in the same age group, but they are all straight face types.4. Campared with Guangdong Han individual with normal occlusion in the same age group, Liaoning people's silhouettes are more straight.The above analyses confirm again that there are sexual and regional differences on the cephalometric of the sagittal hard tissue. So we must take people's features with normal occlusion of the same nation and local areas as reference during the process of diagnosis and treatment. Besides, we must give suggest to the clinicians that in the project and design of correction treatment, they have to make appropriate correction on the basis of the normal value of the patients'locations in order to get a more satisfactory clinical result.