An Investigation Of The Craniofacial Morphology Of Early Permanent And Permanent Dentition Females With Class â…  Malocclusion In ZhengZhou

ObjectiveTo investigate the craniofacial morphology discrepancies between early permanent and permanent dentition groups of Class I females in ZhengZhou with cephalometrics ,and to compare the mean values of these two groups with that of the normal occlusion groups respectively, to obtain the craniofacial characteristics,malocclusion mechanism and development rule of Class I females for guilding the clinical practice.Materials and MethodsThe sample consisted of 81 cephalograms of untreated females of Han Nationality in Zhengzhou with Class I malocclusion, early permanent 40(11-16years),permanent dentition 41 (19-43years). The winceph8.0 cephalometric software and eleven kinds of cephalometric analysis methods were used in this smdy,including Northwestern,Tweed,Wylie,Downs,Steiner,Ricketts,Wits,Bjork,Burstone,Holdaway and the Comprehensive analysis of Beijing University. Every measurement was compared with that of the normal occlusion ones respectively.Results1 .Compared with early permanent dentition, there were 5 angular measurements and 4 linear measurements of permanent dentition group were larger,and 2 angular measurements. 2 linear measurements smaller.2. Compared with normal occlusion,the mean values which were smallerr than those of the normal occlusions are SNA,SNB,SND Angles,facial angle and the length of SL. But the items which were greater than those of the normal occlusion are the length of Co-S,the length of SE,the convexity of the upper central incisors,Y axis,the angle of the mandible plane to SN plane,the angle of the lower central incisors to occlusal plane.These findings showed that the local females with Class I malocclusion had backward maxilla and mandible position.Their growth style was backward and downward with bigger vertical development and smaller saggital development,the position of mandible were clockwise rotated; the depth and height of Craniofacial skeleton have increased;In addition,the upper and lower central incisors were more labial inclined.The soft tissue survey results indicated that such malocclusion had backward nose and chin position,protruded upper and lower lips;no statistically significant differences were found in the rations between the linear measurements.Conclusions1. Compared with early permanent dentition,the permanent dentition females with Class I malocclusion of Zhengzhou showed larger craniofacial height and depth as well as anti-clockwise rotated mandibles.2. Compared with normal occlusion, the depth and height of Craniofacial skeleton in Class I have increased ; .And the females possess Class II profile morphological characteristics own to the vertical growth style and clockwise rotated mandible.