하악골 비대칭에 관한 임상 및 방사선학적 연구

Retrospective clinical & radiologic study on mandibular asymmetry

The purpose of this study was to compare Obwegeser classification with Bruce & Hayward classification in patients who had mandibular asymmetry in terms of clinical applicability, advantage, disadvantage and to study most frequent site of causing asymmetry under the concept of independent growth unit. Also, age distribution according to onset time, and its clinical correlation, reliability of bone scanning in condylar hyperplasia were studied. The primary sample consisted of 13 males and 26 females who complained of facial asymmetry, and showed clinically apparent mandibular asymmetry, and had never been involved in patholgical condition. According to clinical, radiological characteristics, 39 patients were re-classified using Obwegeser classification and Bruce & Hayward classification. Panoramic view, frontal cephalogram, submentovertex view of each patient were traced on tracing paper using 0.5mm pencil. Specific landmarks on each side were measured and compared, thus morphologic asymmetry and spatial relationship of maxilla, mandibular each unit on the basis of skull base were analyzed. When measurements showed discrepancy of more 2mm on each side, presence of asymmetry was judged. The results of the study were as follows: 1. Obwegeser classification could describe more details of asymmetric aspect in condylar hyperplasia, but showed less objectivity due to complex subdivision. 2. When 39 cases were analyzed by three-dimensional analysis including concept of independent growth unit, cases associated with condylar unit were most frequent, amounting to 32 cases(82%). 3. According to onset time, cases could be classified into growth-onset group and post-growth onset group and mandibular condyle has potential for post-maturity growth. 4. According to radiological view, hyperplastic condyles and necks could be classified into 4 groups.