정상교합자의 crown angulation에 관한 연구

Abstract

[한글]

최근에는 Straight-wire appliance의 여러 가지 장점으로 인하여 많은 임상가들이 Straight-wire appliance를 선호하는 경향이 증가 되고있다.

이에 저자는 Straight-wire appliance의 기초자료와 second-order bend의 양을 설정하기 위하여 정상교합자 50명의 석고모형에서 crown angulation을 측정하여 분석한 결과 다음과 같은 결론을 얻었다.

1. 상악 중절치는 4°, 상악 측절치는 7°,상악 중절치와 측절치는 0°의 crown angulation을 가진다.

2. 상악 견치는 8°,하악 견치는 2°,crown angulation을 가진다.

3. 상악 제 1,2소구치와 하악 제2소구치는 4°, 하악 제1소구치는 1°의 crown angulation을 가진다.

4. 상악 제1대구치는 3°,상악 제2단구치는 0°,하악 제1단구치는 5°,하악 제2단구치는 8°의 crown angulation을 가진다.

5. 하악 치아에서는 제1소구치에서 후방 치아로 가면서 점차 crown angulation이 증가되는 경향을 보였다.

6. 상악에서는 한 치아의 crown angulation이 크며 인접치아들의 crown angulation도 큰 수치를 보였다.

7. 하악에서는 측절치의 crown angulation이 크며 견치의 crown angulation도 크고, 제1소구치의 crown angulation이 크며 제2대구치의 crown angulation도 큰 수치를 보였다.

[영문]

The purpose of this study was to collect the inpormation of the straight-wire appliance and to determine the amount of second-order bends in clinical orthodontics.

The author analysed the study model of 50 individuals with normal occlusion and reaults were obtained as follows.

1. The crown angulation was 4 degree in upper cental incisor, 7 degree in upper lateral incisor,and 0 degree in lower central incisor and lateral incisor.

2. The crown angulation was 8 degree in upper cuspid and 2 degree in lower cuspid.

3. The crown angulations were 4 degree in upper first bicuspid, upper second bicuspid and lower second bicuspid and 1 degree in lower first bicuspid.

4. The crown angulation was 3 degree in upper first molar, 0 degree in upper second molar, 5 degree in lower first molar and 8 degree in lower second molar.

5. The crown angulations in lower arch were progressively increased from first premolar to second molar.

6. In upper arch, as the crown angulation of one tooth was increased, those of adjacent teeth were in creased, too.

7. In the case of lower arch,

the crown angualtion of cuspid was increased as that of lateral incisor was increased, the crown angulation of second premolar was increased, and similarity the crown angulation of second molar was increased as that of first molar was increased.