(A) study on the relationship of dental crowding to tooth size and apical base dimension

치의학과/석사[한글] 정상교합자(남자42명, 여자42명)와 치아밀집이 있는자(남자19명, 여자21명)의 석고모형에서, 치아크기. 치근단저 perimeter, 치근단저폭경을 측정하여, 통계적으로 분석 비교한 결과 다음과 같은 결론을 얻었다. 1. 치아크기는 치아밀집군이 정상교합자군에 비해 컸다. 2. 치아크기, 치근단저perimeter, 치근단저폭경은 남자가 여자보다 컸다. 3. 4전치크기의 치근단저 perimeter에 대한 비율의 평균값은, 상악에서 정상교합자군 0.42, 치아밀집군 0.45이고, 하악에서 정상교합자군 0.34, 치아밀집군 0.37이었다. 4. 4전치크기의 제 1대구치 부위에서의 치근단저폭경에 대한 비율의 평균값은, 상악에서 정상교합자군 0.52, 치아밀집군 0.55이고, 하악에서 정상교합자군 0.39, 치아밀집군 0.43이었다. [영문] This investigation was undertaken to examine the extent to which tooth size and apical base dimension each contribute to dental crowding. Two groups of dental casts were selected on the basis of dental crowding. One group, consisting of 84 pairs of dental casts (42 males and 42 females), exhibited no crowing. A second group, consisting of 40 paris of dental casts (19 males and 21 females), exhibited gross dental crowding (above 5 mm). Means and standard deviations of the two groups were used to compare these two groups. The results were as follows: 1. The crowded group was found to have larger tooth sizes than normal group. 2. Males have larger tooth size, apical base perimeter and apical base width than females. 3. As the mean value of ratio of collective diameters of four incisors to apical base perimeter, normal group has 0.42 and crowded group has 0.45 in maxilla. In mandible, normal group has 0.34 and crowded group has 0.37. 4. As the mean value of ratio of collective diameters of four incisors to apical base width at first molar area, normal group has 0.52 and crowded group has 0.55 in maxilla. In mandible, normal group has 0.39 and crowded group has 0.43.restrictio