Deep overbite components in Angle Class II division I Malocclusion

• Main Authors: Cheng-Tsung Huang, 黃丞聰
• Other Authors: Hwai-Jen Fong
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/78154286248451654692

碩士 === 國立陽明大學 === 臨床牙醫學研究所 === 93 === Excessive deep overbite is frequently encountered in patients with Angle Class II division I malocclusion. Deep overbite not only influence esthetics, periodontal health but also increase the complexity of orthodontic treatment because it combines horizontal and vertical problems. Instability and relapse of treatment result may also occur. Most deep bite problems will not self-correct and may result from different etiology. Therefore, successful treatment of deep overbite should be based on correct differential diagnosis. The purpose of this study was to find out the skeletal and dental components of deep overbite in Angle class II Division 1 patients by comparing deep overbite patients with those with normal overbite patients. Lateral cephalograms of thirty-seven adults with deep overbite and thirty-six controls were collected and skeletal and dental characteristics were studied and analyzed by independent t-test. The results showed that compared to deep overbite group,our control group presented larger the sum of saddle angle, articular angle, gonial angle, more retruded pogonion, larger SN-MP, PP-MP, lower gonial angle, smaller PFH/AFH ratio, larger U1-PP (angle), U1-NA(angle), U1-NA (distance) and L1-Apog, but smaller interincisal angle. U1m-L1m and U1m-L1m/U1PP-L1MP ratio were also larger. Deep overbite group showed larger U1-PP/LAFH, L1-BS plane, and curve of spee. Our results suggested that deep bite problems in class II division 1 patients are associated with supereruption of upper and lower incisors.Therefore, deep bite problems could be resolved by intruding incisors. Furthermore, class II division 1 deep bite patients also presented hyperdivergent skeletal pattern and increased anterior facial height. Therefore,extrusion of posterior teeth or large amount increase anterior facial height may also worsen the anterior-posterior discrepancy.