The Analysis Of The Direction Of Jaw Bone Growth In Skeletal Class ? Malocclusion

Objective Through the study and comparison of different types of population(different growth type and gender)in skeletal Class ? malocclusion,it is possible to understand the growth and development of jaw in different growing period,which is helpful for the diagnosis,prediction and treatment of orthodontic doctors.Methods 1.Sample selection: Selected from January 2011 to December 2018 to Tianjin Stomatological Hospital in the Department of Bone ? patients with 540 cases,of which men and women high angle,mean angle,low angle of 30 cases.According to the bone Age cervical CVM staging method,it was divided into three groups: Cvs1-2 was the prophase Group of growth and Development peak,Cvs3-4 was the peak period group of growth and Development,and Cvs5-6 was the late group of growth and development.All of them were photographed with skull orientation before orthodontic treatment.2.Through the viewbox4.0 software to the skull side plate for fixed-point,measurement,access to the jaw marker data analysis.3.Using SPSS 20.0 statistical software for data analysis.The data are expressed in mean and standard deviation.Two groups of independent sample T-Test were used to compare the three groups of different genders,different growth types and the same sex and the adjacent stages of growth,and the test marked level was p<0.05.Results1.Maxillary growth direction of skeletal class lll cases:Comparison of two groups in the early peak period and the late peak period: For different vertical bone types,the PP-FH angle and the C-axis angle increased.The change in angles of the PP-FH angle and the C-axis angle of the female group is greater than that of the male.For different vertical bone types,the PP-FH angle and the C-axis angle variation: high-angle group> mean-angle group> low-angle group.2.Mandible growth direction of skeletal class lll cases:Mean-angle group:Comparison of two groups in the early peak period and the late peak period: The male mandibular angle decreased,the SG/NM ratio increased,and the Y-axis angle decreased.The female MP-SN angle,the Y-axis angle and the O-plane angle decreased,the SG/NM ratio increased.The Y-axis angle,the SG/NM angle/ratio change: male> female.Low-angle group:Comparison of two groups in the early peak period and the late peak period: The male MP-FH angle,the MP-SN angle and the Y-axis angle decreased,the SG/NM ratio increased.The female MP-FH angle,the MP-SN angle,the Y-axis angle and the O-plane angle decreased,the SG/NM ratio increased.The MP-FH angle,the MP-SN angle,the Y-axis angle and the SG/NM angle/ratio change: male> female.At the stage of growth and development,early peak period,peak period and late peak period,regardless of male or female,the Y-axis angle increased first and then decreased,and the SG/NM ratio first decreased and then increased.The Y-axis angle and the SG/NM angle/ratio change: low-angle group> mean-angle group.High-angle group:Comparison of two groups in the early peak period and the late peak period: The male SG/NM ratio decreased,the Y-axis angle and the O-plane angle increased.The female MP-SN angle,the Y-axis angle and the O-plane angle increased,the SG/NM ratio decreased.The Y-axis angle,the O-plane angle and the SG/NM angle/ratio change: female> male.Conclusion:1.For skeletal class ?,regardless of male and female,with different vertical face types,the entire maxillary bone has a clockwise rotation tendency,and the clockwise rotation degree: high-angle group> mean-angle group> low-angle group.The overall degree of clockwise rotation of the female maxilla is more than the male.2.Regardless of gender,the low-angled and mean-angled mandible have a tendency of counterclockwise rotation in the overall direction during growth and development.The overall degree of counterclockwise rotation of the low-angled mandible is more than the mean-angled mandible.The overall degree of counterclockwise rotation of the male mandible is more than the female.The low-angle first rotates clockwise and rotates counterclockwise,finally,the overall trend is counterclockwise.3.The mandible in the high-angled mandible has a tendency of clockwise rotation;the trend of clockwise rotation of the female mandible is more than the male.