2차원 방사선 규격사진에서 하악골 상행지 고경의 보정분석에 관한 3차원 CT 영상 연구

Correction of mandibular ramus height with frontal and lateral ramal inclinations in cephalograms and its effects on diagnostic accuracy of asymmetry

  • 황현식 (전남대학교 치과대학 치의학연구소 및 치과교정학교실) ;
  • 김형민 (전남대학교 치과대학 치의학연구소 및 치과교정학교실) ;
  • 이기헌 (전남대학교 치과대학 치의학연구소 및 치과교정학교실) ;
  • 임회정 (전남대학교 치과대학 치의학연구소 및 치과교정학교실)
  • Hwang, Hyeon-Shik (Department of Orthodontics, School of Dentistry and Dental Science Research Institute, Chonnam National University) ;
  • Kim, Hyung-Min (Department of Orthodontics, School of Dentistry and Dental Science Research Institute, Chonnam National University) ;
  • Lee, Ki-Heon (Department of Orthodontics, School of Dentistry and Dental Science Research Institute, Chonnam National University) ;
  • Lim, Hoi-Jeong (Department of Orthodontics, School of Dentistry and Dental Science Research Institute, Chonnam National University)
  • 발행 : 2007.10.31

초록

안면비대칭 환자의 진단 및 치료계획 수립 시 하악골 상행지 고경의 좌우 차이를 정확히 판정하는 것이 필요하다. 본 연구는 2차원 방사선사진에서 정면 상행지경사도 및 측면 상행지경사도를 이용하여 하악골 상행지 고경을 보정하는 방법이 비대칭 판정에 도움이 되는지 알아보고자 시행되었다. 이부 편위가 있는 안면비대칭자 40명을 대상으로 정모두부방사선규격사진을 촬영하고 좌우 각각의 하악골 상행지 고경을 측정하는 한편 정모 및 측모 방사선사진에서 계측된 정면 상행지 경사도 및 측면 상행지 경사도를 이용하여 상행지 고경을 3차원적 개념으로 보정한 후, 실제 3차원 영상에서의 비대칭 판정 결과와 비교 분석을 시행하였다. 측정결과, 정면 및 측면 상행지 경사도는 이부 편위측에 비하여 반대측에서 크게 나타났으며 보정 후 상행지 고경의 좌우 차이는 증가하는 양상을 나타내었다. 보정 전 그리고 보정 후 각각에서 상행지 고경의 좌우비대칭 여부를 판정한 후, 3차원 영상에서의 판정을 기준으로 하여 보정에 따른 sensitivity, specificity 그리고 accuracy 변화를 살펴본 결과, specificity는 44%에서 22%로 감소하였으나 sensitivity는 74%에서 94%로 증가하는 것으로 나타났다. 아울러 accuracy가 보정 전 68%에서 보정 후 78%로 증가하는 것으로 나타나 정면 및 측면 상행지 경사도를 이용하여 상행지 고경을 3차원적 개념으로 보정할 경우, 이는 보다 정확한 비대칭 판정에 유용함을 보여주었다.

Defining right and left side differences in mandibular ramus height is one of the key elements in the diagnosis of facial asymmetry. The purpose of the present study was to evaluate the effect of correction of ramus height with frontal and lateral ramal inclinations (FRI and LRI) in 2-dimensional cephalograms and observe how this affects the diagnostic accuracy of asymmetry. Methods: Frontal and lateral cephalograms were obtained in 40 individuals with chin deviation. FRI and LRI were measured on each side and ramus height measurement was corrected with these inclinations using Pythagorean's theorem. The results of diagnosis before and after correction on cephalograms were compared with the results in 3D CT images. Results: Both FRI and LRI showed greater values in the contralateral side than in the chin-deviated side and these contributed to an increase in the right and left side ramus height differences. After comparison of diagnostic results before and after correction on cephalograms with the results on 3D CT images, the sensitivity increased significantly (from 74 to 94 %) whereas the specificity decreased (from 44 to 22 %). Overall accuracy increased from 68 to 78 % with the correction using FRI and LRI. Conclusions: The results of the present study indicate that correction of ramus height with FRI and LRI is useful for an accurate diagnosis of facial asymmetry on frontal cephalograms.

키워드

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