Evaluate The Effect Of Different Measurement Methods And Different Sagittal And Vertical Skeletal Types On Facial Soft Tissue Thickness

Part Ⅰ Assessment of two-dimensional versus three-dimensional measurement comparison analysis in facial soft tissue thickness studies.Objective The purpose of this study was to use different methods to measure facial soft tissue thickness(FSTT)to provide methodological and data support for the facial reconstruction of the Han population in the northern part of China.Methods In this study,craniofacial thin spiral Computed Tomography images of 195 Han adults(104 males and 91 females)in the northern region were collected for three-dimensional(3D)reconstruction and preliminary selection of 38 cranial landmarks.The FSTT was measured in three-dimensions in all subjects,and 50 of them were randomly selected for two-dimensional measurements.To compare whether there were significant differences between the two methods of measurement and the effects of different gender,age and BMI on FSTT were analyzed.Results Matched samples t-test showed that the correlation between the data measured by both methods was greater than 0.7,with significantly differences at 30 of the landmarks.Multivariate analysis of variance(MANOVA)showed significantly different between 6 and 33 landmarks by gender and by BMI,respectively.Only 4landmarks showed significantly differences between age groups.Conclusion Different measurement methods affect FSTT measurements.FSTT in northern Han Chinese adults is more influenced by gender and BMI,but less affected by age.Part Ⅱ Assessment of the effect of different sagittal and vertical facial patterns on the thickness of adult facial soft tissueObjective Three-dimensional images reconstructed with thin spiral CT were applied to measure and evaluate the effects of different sagittal and vertical bone facet types on facial soft tissue thickness in Chinese adults.Methods Retrospectively collected and analyzed craniofacial thin spiral CT images of unrelated healthy Han adults.To exclude the effects of age and BMI,104 subjects(45 males and 59 females)aged 18-35 years with a BMI of 18.5-23.5 were selected for 3D reconstruction and classified into sagittal and vertical degrees according to the ANB angle and MP-FH angle measured by cephalometrics.The soft tissue thickness corresponding to the 10 marker points based on the skull was measured,and the effect of different sagittal and vertical bone facial types on the soft tissue thickness of the adult face was analyzed separately for men and women.Results One-way ANOVA results showed that the overall means of 5 marker points showed statistical significance in different Sagittal facial patterns in females,and no statistical significance was shown in the overall means of each sagittal facial patterns in males.the overall means of 4 marker points showed statistical significance in different vertical facial patterns in females.In males,only 1 marker point showed a statistically significant overall mean.Conclusion The sagittal and vertical facial patterns affect the magnitude of facial soft tissue thickness in specific areas in men and women,and skeletal facial patterns in women cause a wider range of soft tissue thickness differences than in men.The results of this study help forensic physicians to use more anatomical features that have an impact on facial soft tissue thickness in their practice for more accurate craniofacial reconstruction.