Evaluation of Correlation between Some Intra and Extra Cranial Horizontal Cephalometric Parameters

Introduction: Intra-cranial references plans used in cephalometry analysis are not considered as stable points and therefore their validity is low; however they are widely used. The purpose of conducting this study is to investigate correlation rate of a number of horizontal parameters of extra-cranial with common Horizontal analyses. Methods: In this descriptive and periodic study, lateral cephalometric radiography in NHP position for 46 patients (24 women and 22 men) in range of 22- 28 years old was prepared; all graphs were prepared by a person using the same device; then after tracing, correlation coefficient was achieved between TH/AB and TH-wist, wylie, wits, TH-wits McNamara, Schwartz, APP-BPP, and Downs. Results: The highest rate of correlation was observed between TH-wits linear parameters and angular parameters of AB/TH (r=0.975) which was statistically significant. ANB parameter had low correlation with Wylie analysis (r=+0.365) that was definitely significant. ANB angular parameters with other horizontal dimension parameters showed the highest correlation with Downs analysis (r=-0.870) and linear parameter APP-BPP (r=+0.730) which were statistically significant too. Conclusions: In this study the highest correlation coefficient was shown between TH/AB and TH-wits, ANB and Downs, Downs and wits, ANB and APP-BPP respectively.