RESUMO
Objective:To study the related factors of landmarks identification repeatability in the computer monitoring. Methods:Totally 30 lateral cephalograms were selected at random, and the landmarks were identified by 2 orthodontists with the computer monitor twice. The data were obtained and the differences were analyzed. Results:There were differences in inter-operator and intra-operator in their coordination. The operators were similar to each other within a certain range. There were significant differences between the data of the abscissas and ordinate in some landmarks. Conclusion:The repeatability of identified landmarks is closely related to the location of the landmarks, the landmarks identification by human eyes and the quality of the X-rays.
RESUMO
Objective:To establish the normal value of McNamara cephalometric analysis in Chongqing adolescents with normal occlusion and to obtain its regression models. Methods:Fifty five Chongqing adolescents with normal occlusion (male 27 and female 28)were taken lateral cephalograms. McNamara analysis was conducted and the correlation analysis was carried out.Results: There were significant differences in the normal values of McNamara analysis between male and female Chongqing adolescents, namely the effective maxillary length, effective mandibular length, lower anterior facial height and A Np line. There were no significant differences in Pog Np line, upper incisor to point A vertical,lower incisor to A P line.There were correlations between the effective maxillary length and effective mandibular length, effective mandibular length and lower anterior facial height, A Np line and Pog Np line, respectively.When effective mandibular length was fixed,lower anterior facial height and Pog Np line was correlated.The regression models were obtained.Conclusion:There is correlation between the linear measurements of the cephalometrics values.