하악중절치 위치에 관한 두부방사선계측학적 연구

A ROENTGENOCEPHALOMETRIC STUDY ON THE POSITION OF THE LOWER CENTRAL INCISOR

By observing the correlationships between the characteristics of the facial pattern and the methods of establishing the position of the lower central incisor to the five reference lines on the lateral roentgenocephalograms, the author tried to find the most useful method of them, the criteria of which were the independence of a variation according to facial patterns, the close relationships with soft tissue and lip balance, and the simple and consistent usefulness in clinical practice. The subject consisted of forty normal occlusions, forty class II div I malocclusions, forty class III malocclusions, ten treated claas II div 1 cases and ten treated class III cases, all were in 14-17 yrs of age. The findings of this study are as follows: 1. The position of the lower central incisor to EP, OP, MP and NB showed variations according to ANB, FMA, facial convexity and Holdaway angle. 2. The position of the lower central incise. to AP line (A-Pog) was not co..elated with ANB, FMA, facial convexity and Holdaway angle, so it can be used consistently, regardlesss of the facial pattern. 9. The lineal position of the incisal edge of the lower central incisor to AP line has a profound influence on harmonious soft tissue and lip balance.