Cephalometric Study On Li And Han Adults With Normal Occlusion In Hainan Using Ricketts Analysis

Objective: To establish the average range of Ricketts analysis methods for Li and Han adults with normal occlusion in Hainan and to conduct a comparative study of ethnic and gender differences,to fill the gaps in the measurement data of cephalometric analysis methods in Hainan,to supplement the measurement data of Ricketts analysis methods for ethnic minorities in China,and to provide data support for orthodontic and orthognathic treatment in Hainan.Method:A total of 101 normal adults with individual normal occlusion who met the experimental requirements were selected from the college students in Hainan:24 males and 26 females of Li nationality;25 males and 26 females of Han nationality.Lateral cephalometric radiographs were taken under natural head position.Uceph cephalometric software was used to fix the point and measure three times to take the average value.SPSS 23.0 software was used for statistical analysis.The measured data were expressed as mean±standard deviation((?)±s).The indicators between ethnicity and gender were compared and analyzed by t test.P<0.05 indicated that the difference was statistically significant.Result:The mean range of Ricketts analysis of Li and Han adults with normal occlusion in Hainan was obtained.The ethnic differences of MP-NPog,FH-MP and Dc-Xi-Pm in Ricketts analysis were statistically significant(P<0.05).The MP-NPog and Dc-Xi-Pm of Li adults in Hainan area were larger than those of Han adults in Hainan,and the FH-MP was smaller than that of Han adults in Hainan area.There was no significant difference in other measurement indexes(P>0.05).The ANS-Em,NBa-Pt Gn and N-CC in the Ricketts analysis of Li adults with normal occlusion in Hainan was statistically different in gender(P<0.05).The ANS-Em and N-CC of Li males in Hainan are larger than those of females,and the NBa-Pt Gn is smaller than that of females.There was no significant difference in other measurement indexes(P>0.05).The Xi-Pm in the Ricketts analysis of Han adults with normal occlusion in Hainan was statistically different in gender(P<0.05).The Xi-Pm in the Ricketts analysis of Han adults with normal occlusion in Hainan was statistically different in gender(P<0.05),and the male was larger than the female.There was no significant difference in other measurement indexes(P>0.05).Conclusion:This study established the average range of Ricketts analysis for Li and Han adults with normal occlusion in Hainan,which can be used for case diagnosis,scheme design and prognosis analysis of orthodontic and orthognathic surgery for Li and Han adults in Hainan.There are ethnic differences in the tissue structure of dentognathic craniofacial between Li and Han adults in Hainan.The chin position of Li adults in Hainan is closer to the front,the mandibular plane is lower,the lower face height is shorter and the face type is short.The dental craniofacial tissue structures of Li and Han nationalities in Hainan have gender differences.The upper lip length,mandibular development and anterior skull length of Li males in Hainan are larger than those of Li females.The Li female faces are shorter.The mandibular development of Han males in Hainan is larger than that of Han females in Hainan.Therefore,ethnic and gender differences should be considered in case diagnosis,etiology analysis and program design of orthodontic and orthognathic surgery.