A STUDY OF UPPER AND LOWER INCISOR POSITION IN NORMAL OCCLUSION

정상교합자의 상하악절치 위치에 관한 연구

This study was attempted to individualize upper and lower incisor position appropriate to individual characteristic dento-facial pattern. Lateral cephalometric radiographs of 75 Korean adults with normal occlusion and good facial profile whose ages were over 17 years were traced, digitized, and statistically analysed. The results of this study were as follows; 1. All cephalometric measurements of incise. position and dento-facial pattern for normal occlusion showed wide range of variation. 2. There were no significant differences of incisor position between males and females. 3. Lower incisor position was highly correlated with ANB, N-A-Pog and SN/Mand. pl. angle and upper incisor position, with ANB, N-A-Pog and SN/Occ. pl. angle. 4. Multiple regression equations were established to individualize incisor position appropriate to individual characteristic dento-facial pattern. ANB and N-A-Pog angle were selected as the significant guiding variables affecting upper and lower incisor position. 5. Lower incisor position such as $\bar{1}$ to SN, $\bar{1}$ to occlusal plane and $\bar{1}$ to NPog(mm) and upper incisor position such as $\underline{1}$ to SN, $\underline{1}$ to palatal plane, $\underline{1}$ to NA, $\underline{1}$ to NA (mm) and $\underline{1}$ to NPog(mm) could highly predicted from the variables of dento-facial pattern.