치열궁내 공간 부조화와 진단적 평가에 관한 연구

정희교; 안광석

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치열궁내 공간 부조화와 진단적 평가에 관한 연구
A study of the arch length discrepancy and the diagnostic analysis

Korean Journal of Orthodontics 2004년 34권 1호 p.1 ~ 11

정희교, 안광석,

소속 상세정보

정희교 ( ) - 연세대학교 치과대학 교정학교실
안광석 ( ) - 연세대학교 치과대학 교정학교실

KMID : 0361920040340010001

Abstract

Predicting the arch length discrepancy by simply comparing the available arch perimeter with tooth materials is merely a 2-dimensional analysis of the teeth movement. However, the real teeth movement takes place 3-dimensionally and is affected by various factors such as, the arch form, the curve of Spee and the axis of the incisors.
The purpose of this study is to clarify the relationship between the decrease in the arch perimeter and the horizontal positional change of the incisors after extraction of the 1st bicuspids, for more analytic evaluation of the arch length discrepancy at pre-treatment model analysis stage. In addition to that to evaluate the effect of the curve of Spee, teeth axis to the basal plane, and the incisional crowding to the treatment outcome.
All patients were treated at the department of orthodontics, dental hospital, Yonsei university. Inclusion criteria for patients selection were as follows.

Angle classification I malocclusion with bialveolar protrusion Extraction of 4 1st bicuspids
No tooth anomaly or prosthesis No abnormal attrition
No ectopically erupted teeth
Angle classification I canine and molar relationship Less than 3mm of crowding

Model analysis of the above patients was performed and the following conclusions were obtained.

1. When the intercanine distance was maintained, the available space for the distal movement of the mandibular incisors
after the extraction of the 41st bicuspids was larger than the space provided by the extraction of the 4 1st bicuspids.
However the difference was less than 1mm. The more tapered the anterior arch form, the larger the difference.
2. Compared to the situation in which the intercanine distance was maintained, when the intercanine distance was
expanded to meet the width of the posterior teeth, the incisors could move about 3mm more distally.
3. The positional difference of the incisal tip was insignificant whether the central incisors were moved by tipping or bodily
movement
4. When the anterior crowding was solved without changing the intercanine distance, the larger the anterior arch length was, the more the anterior movement of the incisors.
5. When the curve of Spee was levelled, the increase in the arch perimeter was less than half of the deepest curve of Spee.