Relationship between CO-CR discrepancy and facial skeletal type

Cho, Jin Young; Lee, Young Jun; Park, Young Guk; Chung, Kyu Rhim

Abstract

The present study was performed to prove the relationship between CO-CR discrepancy and facial skeletal type. In this study, 242 subjects were randomly selected and devided into 9 groups(devided into class I, Il, 111 by ANB and each one devided into dolicho-, brachy mesofacial skeleton by Ricketts' vertical index). Lateral cephalometric radiographs with the mandible in centric occlusion were taken and measured and CO and CR bites were registered on all subjects. Diagnostic casts were mounted on Panadent articulator using an estimated face-bow and centric relation bite registration. The amount and direction of CO-CR discrepancy present was recorded using a Condylar Position Indicator(CPI) and a centric occlusion wax bite registration. CPI measurements and cephalometric measurements were statistically analyzed. The finding of this study can be summerized as follows: 1. There is little correlation between right and left sides for magnitude or direction. of CO-CR discrepancies. The correlation between the magnitude of CO-CR discrepancy of left A-P and right A-P is higher than that of left S-I and right S-I. 2. Correlation of Class H malocclusion group was higher than that of the other groups between the magnitude of CO-CR discrepancy of left CPI and right CPL 3. There is no difference between the pattern of CO-CR discrepancy of 9 malocclusion groups. 4. There is very little, if any, correlation between Skeletofacial measurements and CO-CR discrepancy. 5. In Class II brachyfacial skeleton and Class IIl mesofacial skeleton there was Lateral cephalometric measurements by that we predict CPI measurements was detected. That was overbite, overjet, upper gonial angle, lower gonial angle, saddle angle, articular angle, convexity of point A, ANS-Me/Na-Me, PCBL/I3H, Posterior FH/anterior FR