3D Measurements And Comparisons Of Facial Images Of Chinese Han Male And Female Adults With Angle Class Ⅰ And Class Ⅱ Occlusion

The development of orthodontics and the improvement of people’s living standards have brought about an orthodontic philosophy revolution,which shifted from conventional good occlusion acquisition to the present oral and maxillofacial coordination.Therefore,soft tissue is becoming more and more imoportant in both orthodontic clinical practice and scientific research,inspiring researchers to invent quantities of three-dimensional scanning devices and measuring methods,which in turn boost the.development of orthodontics both in clinical practice and scientific research.At present,researches on soft tissue mainly focuses on the comparison of different races,sexes,developmental stages and comparative analysis before and after treatment.However,little research on the three-dimensional features of adult maxillofacial regions in China has been reported.Ⅰn order to explore three-dimensional facial characteristics of Chinese Han adults and clarify the influence of occlusions on facial contour to popularize soft tissue concept in orthodontic treatment,this paper adopted advanced facial 3dMD digital imaging system to acquire images of 103 Chinese Han nationality adults with Angle Class Ⅰ or Ⅱ occlusion.Measurements and comparisons were carried out between male and female adults with Angle Class Ⅰ occlusion,between male and female adults with Angle Class Ⅱ malocclusion,between male adults with Angle Class Ⅰ and Angle Class Ⅱ occlusions,and between female adults with Angle Class Ⅰ and Angle Class Ⅱ occlusions.Skull posterioranterior and lateral hard tissue cephalograms of Angle Class Ⅰ subjects were acquired to get comparisons of soft and hard tissues of male adults with class Ⅰ occlusion and female adults with Class Ⅰ occlusion,respectively.The study can be divided into the following 5 parts: Part Ⅰ 3D measurements and comparisons of facial soft tissue of Chinese Han male and female adults with Angle Class Ⅰ occlusion Objective:To establish 3-dimensional facial soft tissue reference values of Chinese Han nationality adults with Angle Class Ⅰ occlusion and explore the facial morphology differences between genders.Methods: 3dMD images from 30 males,32 females of Han nationality with Angle Class Ⅰ occlusion,aging from 18-35 were analyzed and compared between males and females on 25 linear distances,8 angular measurements and 17 linear distance ratios.Results: Linear distances concerning the width and height of facial and organic contours revealed larger in males,while the ratio of facial height to width revealed larger in females;the nasofrontal angle and nasal prominence angle were both smaller but nasofacial angle were larger in males than in females.Conclusion: The facial and organic contours revealed larger in males than in females.Males had wide-elliptical face while females had thin-elliptical one.The nose of males revealed more prominent compared with females.Values acquired in this study could serve as clinical reference.Part Ⅱ 3D measurements and comparisons of facial soft tissue of Chinese Han male and female adults with Angle Class Ⅱ malocclusion Objective:To explore 3-dimensional facial soft tissue morphology differences between male and female adults of Han nationality with Angle Class Ⅱ malocclusion.Methods: 3dMD images from 15 males,26 females of Han nationality with Angle Class Ⅱ malocclusion,aging from 18-35 were analyzed and compared between males and females on 25 linear distances,8 angular measurements and 17 linear distance ratios.Results: Linear distances concerning the width and height of facial and organic contours revealed larger in males,while the ratio of facial height to width revealed no statistical significance between males and females;the nasofrontal angle and nasal prominence angle were both smaller in males than in females.Conclusion: The facial and organic contours revealed larger in males than in females.Face conour of males and females were similar in shape.The nose of males revealed more prominent compared with females.Part Ⅲ 3D measurements and comparisons of facial soft tissue of Chinese Han male adults with Angle Class Ⅰ occlusion or Angle Class Ⅱ malocclusion Objective:To explore the impacts of different occlusions of male adults with Han nationality on the facial contours.Methods: 3dMD images from 45 males,including 30 with Angle Class Ⅰ occlusion and 15 with Angle Class Ⅱ malocclusion,aging from 18-35 were analyzed and compared on 25 linear distances,8 angular measurements and 17 linear distance ratios.Results: The lip prominence angle and the width of palpebral fissure and oral fissure were larger in Angle Class Ⅰ occlusion group than in Angle Class Ⅱ malocclusion group,while other measurements revealed no statistical significance between groups.Conclusion: Males of Han nationality had narrower eyes and mouths and more prominent lip in Angle Class Ⅱ malocclusion individuals than Angle Class Ⅰ occlusion ones while facial contours and nose shape and magnitude were not affected by occlusions.Part Ⅳ 3D measurements and comparisons of facial soft tissue of Chinese Han female adults with Angle Class Ⅰ occlusion or Angle Class Ⅱ malocclusion Objective:To explore the impacts of different occlusions of female adults with Han nationality on the facial contours.Methods: 3dMD images from 58 males,including 32 with Angle Class Ⅰ occlusion and 26 with Angle Class Ⅱ malocclusion,aging from 18-35 were analyzed and compared on 25 linear distances,8 angular measurements and 17 linear distance ratios.Results: Apart from tiny differences on the width of philtrum and the ratio of facial height to width,there was no other significant difference found between groups.Conclusion: Females of Han nationality had similiar facial and organic contours between Angle Class Ⅰ and Ⅱ occlusions.