A STUDY ON THE PATTERN OF THE ROOT RESORPTION FOLLOWING MAXILLARY INCISOR RETRATION

상악 전치부 견인시 치근 흡수 발생 양상에 관한 연구

This study was carried out in order to find out the pattern of the root resorption following maxillary incisor retraction after maxillary 1st bicuspid extration in maxillary protrusion patients. For this study, thirty two patient who received orthodontic treatment were chosen. The results were as follows; 1. Of the total 192 teeth, 61 teeth(31.77%) showed no apical root loss, 64 teeth(33.33%) fell into the class "slight", 46 teeth(23.96%) fell into the class "moderate". Only 21 teeth(10.94%) were classified as "excessive". 2. No correlation was noted between the amount of apical root loss and the types of tooth movement of the maxillary central incisors. 3. The patients who were treated with standard brackets had more changes in tooth axis and less movement of root apexes, but the patients with straight brackets had less changes in tooth axis and more movement of root apexes. 4. Comparing the degree of root resorption between bracket types, patients who had used standard brackets showed more apical root loss than patients who had used straight brackets. 5. The most frequent degree of root resorption observed in standard bracket patients was second degree, followed by first degree and third degree. The most frequent degree of root resorption observed in straight bracket patients was zero degree, followed by first, second degree and third degree.

본 연구는 상악 전돌증을 보이는 환자에게서 상악 제 1 소구치를 발치한 후 견인시 bracket 종류에 따른 치근흡수 차이, 이동양상에 따른 치근 흡수 차이, 각 치아간에 따른 전치부의 치근 흡수 정도를 연구하기 위해 단국 대학교 부속 치과 병원 교정과에 내원한 남녀 환자 32명을 대상으로 연구하여 다음과 같은 결과를 얻었다. 1. 상악 전치 후방 견인시 치근 흡수를 보이지 않는 것은 31.77%, 약간의 흡수는 33.33%, 치근의 1/4이하 흡수는 23.96%, 1/4이상은 10.94%를 보였다. 2. Apical tipping, lingually bodily movement, ant-post apical displacement 의 세가지 이동 양상은, 치근 흡수와의 상관 관계에 유의한 차이를 보이지 않았다. 3. Standard br.을 사용한 환자는 많은 치축 변화를 보이고 치근첨의 이동은 적었으나, straight br.을 사용한 환자는 적은 치축 변화를 보이고 치근첨의 이동량은 많았다. 4. Standard br.과 straight br.의 치근흡수에서 standard br.을 사용한 환자가 더 많은 치근 흡수를 보였다. 5. Standard br.을 사용시 치근 흡수정도는 2>1>3=0순을 보이고, straight br.을 사용시에는 0>1>2>3으로 나타났다.