Measurement And Study Of Dental Model On Normal Occlusion In Changchun Children

ObjectiveTo develop a computer assisted CT(computed tomography) scanning system for 3D dental cast measurement. It was designed to determine consistency of dental arch measurements using spiral CT volume rendering by computer systems and sliding caliper, and evaluated the precision and accuracy of 3D rendered images.On the other side, this study is aim to establish the norms of dental model on normal occlusion in Han race of Changchun Children in mixed dentition, to reveal the characteristics of dental model, compare with different sexual,different areas and different racial population and provide the reference for diagnoses in orthodontics.Materials and MethodsThe study population consisted of 20 cases of normal occlusion dental model that were examined with spiral CT. The archived CT data were transferred to a workstation,and 3D- CT volume rendered images were generated using computer graphics tools. Linear measurements, respectively by display tools and sliding caliper. The consistency between the two measurements was analyzed by Paired t test. The precision and accuracy of 3D rendered images measurements was calculated. These dental casts were scanned and measured to test the reliability of the system, contrasting with manual measurement.120 cases of normal occlusion dental model of Han race of Changchun Children in mixed dentition (60 males and 60 females)were selected.The width and length of the dental arch,the basal arch width and length were measured. Correlation analyses of some norms were calculated.The measurements were analyzed with statistic methods and compared with that of different groups. Results1.The results demonstrated no statistically significant difference between 3D-CT scanning and manual measurement( P > 0.05) .2.The norms of dental model on normal occlusion in Changchun Children in mixed dentition are established.Conclusion1. There was significant consistency between spiral CT measurement and manual measurement for linear distance. The system is a valuable computer assisted system for clinical diagnosis and treatment of malocclusion.2.The norms of dental model on normal occlusion in Changchun Children in mixed dentition are established.3. There was significant difference between different sexual,different areas and different racial population.4.Statistically significant correlations between the width and length of the dental arch, the basal arch width and length could be established.5.There were certain basic rules of dental arch and bone growth in normal occlusion in Changchun Children in mixed dentition.