Study on the correlation parameters of Class II malocclusion in child tooth dentition early stage by using 3D technique

OBJECTIVE: To record the dentition, jaw and facial growth and development of children with class II malocclusion at the age of 7-8 years old in the early dental transitional stage with 3D technology and to provide the study basis for the growth and development parameters of normal children and children with class II malocclusion. METHODS: Twenty-four children who were suffering class-II malocclusion in the early dental transitional stage and received treatment between July 2016 and July 2017 in our hospital were selected as the study group, and 20 healthy children were selected as the control group in the same period. SIRONA CEREC dentition scanning, 3D reconstruction of the lower mandible and 3d MD face scanning were performed on the children. Relevant data were recorded and compared. RESULTS: The dentition scanning results suggested that the study group had significantly larger anterior overbite and anterior overjet and smaller width of the upper arch than the control group; there was a significant difference between the two groups (P<0.05). The 3D reconstruction of the lower mandible suggested that the study group had smaller Go angle and SNB angle and shorter ANS-Me distance, Go-Me distance and N-Me distance compared to the control group; the differences had statistical significance (P<0.05). The face scanning results demonstrated that the nasolabial angle and facial convexity angle of the study group were significantly larger than those in the control group, and the difference was statistically significant (P<0.05). CONCLUSION: The dentition scanning results suggested that the study group had significantly larger anterior overbite and anterior overjet and smaller width of the upper arch than the control group; there was a significant difference between the two groups (P<0.05). The 3D reconstruction of the lower mandible suggested that the study group had smaller Go angle and SNB angle and shorter ANS-Me distance, Go-Me distance and N-Me distance compared to the control group; the differences had statistical significance (P<0.05). The face scanning results demonstrated that the nasolabial angle and facial convexity angle of the study group were significantly larger than those in the control group, and the difference was statistically significant (P<0.05).