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

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. 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. 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. 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.