하악 치열궁에서 제 3대구치 맹출상태에 따른 밀집에 관한 연구

Abstract

[한글]

하악 제 3 대구치가 하악 치열궁의 late crowding에 영향을 미치는 지에 대해 많은 학자들이 연구를 해 왔으나 아직도 그 영향에 관해서는 분명히 밝혀지지 않은 상태이다. 한편 하악 제3대구치는 매복, 맹출, 선천적으로 결손된 경우에 따라 치열궁의 크기 및 치아

의 크기와 상관관계를 갖는다는 연구결과도 보고되고 있다.

본 연구는 하악 제 3 대구치의 상태에 따른 3가지 경우에서 하악 치열궁의 밀집의 양을 비교하고 제 3 대구치의 상태와의 상관관계를 알아보고자 시행되었다. 정상적인 악골관계를 가지며 연세대학교에 재학중인 140명의 성인 남녀를 대상으로 하였고 하악 제 3 대구치의 상태에 따라 선천적 결손군, 맹출군, 매복군으로 나누어 치아의 크기, 치열궁의 크기, 밀집의 양에 관해 3군간의 차이를 비교하여 본 결과 다음과 같은 결론을 얻었다.

1. 치아의 크기 비교시 결손군과 맹출군 사이에는 모든 계측치에서 통계적 유의차가 없었고 매복군은 결손군에 비해 중절치를 제외한 모든 치아의 치관폭경과 치관폭경총화, 절치 치관폭경총화가 컸으며 또한 맹출군에 비해서는 중절치, 견치, 제 2 소구치의 치관폭경과 치관폭경총화, 절치 치관폭경총화가 컸다(p<0.05).

2. 치열광의 크기 비교시 3군 간 비교에서는 모든 계측치에서 통계적 유의차가 없었고 2군 간미교에서는 대구치간폭경에서만 결손군이 매복군보다 크게 나타났다(p<0.05).

3. 밀집의 양의 비교시 전체 밀집의 양에 있어서는 각 군 간의 비교에서 모두 통계적 유의차를 보여 매복군, 맹출군, 절손군의 순서로 크게 나타났고 절치부 밀집의 양에 있어서는 결손군과 맹출군 간에는 통계적 유의차가 없었고 매복군이 나머지 2군보다 유의성 있게 큰 것으로 나타났다(p<0.05).

A COMPARATIVE STUDY ON CROWDING ACCORDING TO THE STATUS OF THE THIRD MOLARS IN

MANDIBULAR ARCH

Joo-Hun Song, D.D.S.

Department of Dental Science, Graduate school, Yonsei University

(Directed by Professor Young-Kyu Ryu, D.D,S., Ph.D.)

It has been generally believed that the impaction or eruption of mandibular third

molars has significant correlations with the growth of the mandible, size of

mandibular arch and size of teeth. The purpose of this study was to examine if

there is any correlation between the status of eruption of mandibular third molars

and the amount of mandibular crowding. The effect of missing of third molars to

mandibular crowding was studied as well.

140 adult students of Yonsei University were selected and divided into three

groups according to the status of mandibular third molars, congenital missing

group, eruption group and impaction group. The tooth size, dimensions of the

mandibular dental arch, and the amount of crowding were measured arid compared.

Results were as follows :

1. There was no statistically significant difference in tooth size between the

missing group and the eruption group(p<0.05). Impaction group showed larger total

tooth material, incisal tooth material, and individual tooth size except central

incisors compared to missing group (p<0.05). Impaction group showed larger total

tooth material, incisal tooth material compared to eruption group as well(p<0.05).

When individual tooth size was compared, impaction group had larger central

incisors, canines, and second premolars than eruption group(p<0.05).

2. Missing group showed larder intermolar width than impaction group and it was

statistically significant(p<0.05).

3. When compared the amount of total crowding, impaction group showed the largest

amount of crowding, then eruption group, and missing group showed the least amount

of crowding respectively(p<0.05). There was no statistically significant difference

between missing group and eruption group in the amount of incisal crowding(p<0.05).

Impaction group showed the largest amount of incisal crowding among all three

groups(p<0.05).

[영문]

It has been generally believed that the impaction or eruption of mandibular third molars has significant correlations with the growth of the mandible, size of mandibular arch and size of teeth. The purpose of this study was to examine if there is any correlation between the status of eruption of mandibular third molars and the amount of mandibular crowding. The effect of missing of third molars to mandibular crowding was studied as well.

140 adult students of Yonsei University were selected and divided into three groups according to the status of mandibular third molars, congenital missing group, eruption group and impaction group. The tooth size, dimensions of the mandibular dental arch, and the amount of crowding were measured arid compared.

Results were as follows :

1. There was no statistically significant difference in tooth size between the missing group and the eruption group(p<0.05). Impaction group showed larger total tooth material, incisal tooth material, and individual tooth size except central incisors compared to missing group (p<0.05). Impaction group showed larger total tooth material, incisal tooth material compared to eruption group as well(p<0.05).

When individual tooth size was compared, impaction group had larger central incisors, canines, and second premolars than eruption group(p<0.05).

2. Missing group showed larder intermolar width than impaction group and it was statistically significant(p<0.05).

3. When compared the amount of total crowding, impaction group showed the largest amount of crowding, then eruption group, and missing group showed the least amount of crowding respectively(p<0.05). There was no statistically significant difference between missing group and eruption group in the amount of incisal crowding(p<0.05).

Impaction group showed the largest amount of incisal crowding among all three groups(p<0.05).