The Characteristic Of Craniofacial Growth In Untreated Class â…  Malocclusion

Class I malocclusion has the highest proportion in different types Angle’sclassification of malocclusion. The incidence of deciduous, mixed and earlier permanentdentition period are51.7%,50.25%and52.83%. The craniofacial growth andmalocclusion occurrence, development and prognosis are interacted and mutuallyrestricted. The stage of skeletal maturation should be evaluated to improve the correctdiagnosis and treatment plan. There are so many methods to study the craniofacialgrowth, such as longitudinal method and cross-sectional method. The longitudinal studyis always used to observe the skeletal maturation, but it is difficult to collect data andhardly to apply them. In recent years, more and more scholars focus on cross-sectionalmethod, and it can collect a lot of data in a short time, which used the large sample tostudy. Analysis on the craniofacial growth of the untreated patients with Class Imalocclusion through CVM method has not been reported in China.Objective: The purpose of this study was to investigate the characteristics of craniofacial growth in untreated Class I malocclusion subjects by cross-sectional study.Material and Methods: The sample consisted of909subjects with Class I malocclusion,who were divided to six groups according to their gender and CVM. The craniofacialgrowth were be measured by their cephalograms. The data were analyzed by SPSS18.0.Results:1. All groups exhibited larger SNA angle, SNB angle and SND angle, but the change wasnot statistically significant.2. Males: ANS-Ptm’ and ANS-PNS increased significant in CS1-CS2and CS3-CS4.(P<0.05).3. Females: ANS-Ptm’, ANS-PNS and S-N increased significantly in CS1-CS4（P<0.05）.4. Males: Co-Go,Go-Gn,Co-Gn increased significantly in CS1-CS2and CS3-CS4.5. Females: Co-Go and Co-Gn also increased significantly in CS1-CS2and CS3-CS4.Go-Gn increased graduatly from CS1to CS4.6. Both males and females,N-ME,N-ANS and ANS-Me showed significant increasesfrom CS1to CS4,but after CS4, they grew slowly in female groups. SL, SE, MPA, Yaxis angle, OP-FH reduced obvious in CS3-CS4.Conclusion:There are some differences between male and female patients withmaxillary growth, which in males the peak of growth increased from CS1-CS2andCS3-CS4and in females continued growth until the CS4. The growth of mandibule hadgreatest growth in CS1-CS2and CS3-CS4in both males and females. Go-Gn continuedgrowth from CS1to CS4. ANS-Me grew earlier. Because the posterior facial heightincreased faster than ANS-Me, the mandibular plane angle decreased.