| Objective: In this study,cone-beam computed tomography(CBCT)-synthesized cephalograms were used to measure the craniofacial hard tissue landmarks of adults with normal occlusion in Hebei area,and line distance and angle were abstained.The relationship between occlusal vertical dimension(OVD)and these measuring parameters was analyzed to provide guidance and basis for clinical prediction and determination of OVD.Methods: The study sample consisted of 114 participants in Hebei area who were patients in Hospital of Stomatology Hebei Medical University,46 males with an average age of 31 and 68 females with an average age of 30.Criteria for case selection include: 1)complete dentition(except third molars);2)adults or growing development has ended;3)basically symmetrical maxillofacial;4)lateral coordination;5)without a history of temporomandibular joint diseases(TMD).Exclusion criteria: 1)diagnosed with periodontitis;2)orthodontic,orthognathic surgery,cleft lip and palate treatment history;3)systemic disease.CBCT data was output to Dolphin Imaging 11.9 software in DICOM format.The software was used to measure and analyze 14 hard tissue landmarks.The 21 measurements were obtained by measuring the linear distances and angles.The data in each group was measured three times at 10 day intervals and then averaged.All of the data was analyzed by SPSS 21.0 statistical software.Intra-observer correlation coefficient(ICC)was used to test the reliability of measuring items.The normality of all data were tested,and the statistics were descripted via mean(? X)and standard deviation(SD).Independent sample t test or Wilcoxon rank sum test were used to compare the differences betweengenders.Pearson correlation analysis or Spearman correlation analysis were performed on the data.And linear regression analysis was used to obtain the regression equation.Results:1.There were significant differences in all line distance measurements between males and females(P ? 0.05),and all line distance measurements were higher in males than those in females.There was no significant difference in angle measurements in gender distribution(P?0.05).2.The distance between anterior nasal spine and menton(ANS-Me)has correlations with 11 line distance measurements(P ? 0.05),among which distance between sella and nasion(S-N),distance between porion and orbitale(Po-Or),distance between nasion and anterior nasal spine(N-ANS),distance between anterior nasal spine and posterior nasal spine(ANS-PNS),distance between nasion and left orbitale(N-Or L),distance between left orbitale and anterior nasal spine(Or L-ANS),distance between right articulare and menton(Ar R-Me),distance between left articulare and menton(Ar L-Me),distance between right gonion and menton(Go R-Me),distance between left gonion and menton(Go L-Me),distance between right orbitale and left orbitale(Or R-Or L).Taking ANS-Me as the corresponding variable(Y)and 11 above line distance measurements as independent variables(X),the corresponding linear regression equations were obtained.3.The facial lower surface angle(LA)had significant linear correlation with the facial centre angle(CA)and mandibular angle(GA)(P?0.01).The corresponding linear regression equations among which LA and CA,GA respectively were obtained.Conclusions:1.All line distance measurements of normal occlusion people in Hebei region has significant difference in gender distribution,and all line distance measurements were higher in males than those in females,but there is no significant difference in all angle measurements.2.ANS-Me has significant correlations with S-N?Po-Or?N-ANS ?ANS-PNS?N-Or L?Or L-ANS?Ar R-Me?Ar L-Me?Go R-Me?Go L-Me?Or R-Or L of normal occlusion people in Hebei area,and these line distance measurements can be defined as the references for clinically determining occlusal vertical dimension.3.LA has significant linear correlation with CA and GA of normal occlusion people in Hebei area,CA and GA can be used as clinical references in order to measure occlusal vertical dimension and improve the accuracy of determination occlusal vertical dimension. |
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