본 연구는 openbite을 나타내는 환자의 구강내 증상을 분류하여 원인 및 재발 가능성에 대한 특성을 파악하고자 교정치료를 완료한 성인 여자 앵글씨 Ⅰ급 부정 교합을 나타내는 자를 대상으로 실시하였다. 두부방사선규격사진을 촬영하고, 투사도를 작성하여, BjÖrk, Ricketts분석법 및 일부 추가적인 계측방법을 사용하여 계측하고, 전체 대상을 교합평면의 특성에 따라, 즉, 상악 제 1대구치의 근심협측 교두정과 상악 중절치 절단연을 연결하고, 이때 상악 제 1소구치의 변연융선보다 상방에 교합평면이 존재하면 제1군, 하방에 존재하면 제2군으로 정하고 분류하였다. 이렇게 분류된 각 군은 각 군내 특성파악, 군간특성파악, 치료전후 및 functional oral volume에 대한 분석이 행해졌고, 다음과 같은 골격 형태를 보였다. 1. 군간의 골격 형태 비교에서 제 1,2군 모두 hyperdivergent한 골격형태를 보이고 있다. 그러나, 제 2군이 제 1군에 비해 하악골의 발육이 적고, articular angle이 작아 전방 위치되는 경향이 있다. 2. 치료 전후의 치열분석에서 제 1군의 상악치열은 전하방에서 전상방으로, 제 2군은 전상방에서 전하방으로 변화되었고, 하악치열은 제 1,2군 모두 전상방으로 변화되었다. 3. functional space에 대한 분석에서, 제 2군의 구개평면이 더욱 후하방으로 처져 있으므로 더욱 강한 골격적 openblte 경향을 보인다. 이상의 결과에서 상악 교합평면이 편평한 군은 굴곡을 보이는 군에 비해 비록 외견상 나타난 골격형태는 같더라도 내부 골격형태에서는 더욱 강한 openbite 특성을 나타내고 있다.
It is the purpose of this study to characterize oral symptoms and to comprehend the cause and the relapse possibility of patients with open bite. This case study examines the orthodontic treatment of a group of female patients with open bite and Angle’s Class I malocclusion. A cephalograph of the patient was taken and tracing of the radiograph was completed. In addition to BjÖrk and Ricketts analysis, additional measurements of specific areas were taken. The occlusal plane was determined by drawing a line connecting the mesiobuccal cusp tip of the maxillary first molar and the incisal edge of the maxillary central incisors. Patients were divided into two groups depending on the relationship between the marginal ridge of the maxillary first premolar and the drawn line. Those patients with marginal ridges above the occlusal plane were placed into Group 1, while Group 2 subjects exhibited marginal ridges lower than the occlusal plane. The common characteristics within each group and the characteristic differences between each group both prior to and after orthodontic treatment were examined, and finally, the functional oral volume of each patient was analyzed. The results of the case study were as follows: 1. An examination of the skeletal relationship and anatomical form for both Group 1 and 2 showed that all subjects exhibited hyperdivergent skeletal forms, but Group 2 subjects generally demonstrated underdevelopment of the mandible and a smaller articular angle, resulting in an anterior positioning tendency of the mandible. 2. An analysis of the maxillary arches of Group 1 subjects prior to and after orthodontic treatment showed that the antero-inferior direction had changed to an antero-superior directional tendency, while the maxillary arches of the Group 2 patients showed a trend from an antero-superior direction to an antero-inferior relationship. The mandibular arches in both groups showed a change to an antero-superior direction. 3. Functional space analysis showed that Group 2 patients exhibited a greater tendency of having palatal planes that drop in a postero-inferior direction, resulting in a more severe open bite than their Group 1 counterparts. The results of this case study show that although patients belonging to either Group 1 or 2 exhibited few external differences in the appearance of open bite, an examination of the dental and skeletal relationships by analyzing patient cephalographs showed that patients presenting with flat maxillary occlusal planes exhibited more severe open bite relationships than patients with curved occlusal planes.