固定斜面导板治疗骨性下颌后缩髁突形态及位置变化的核磁共振研究

目的探讨应用固定斜面导板引导下颌向前骨矫形作用髁突形态及位置变化的核磁共振(MRI)表现。方法13例骨性安氏II类错下颌后缩患者,经固定斜面导板进行Ⅰ期矫治,分别在治疗前、治疗开始、治疗中、治疗后拍摄双侧TMJ的MRI片进行描绘和测量。结果13例患者MRI片上均可见到髁突后上部发生改建,有新骨形成的表现;治疗前后髁突在关节窝中位置无明显变化。结论固定斜面导板导下颌向前刺激髁突产生适应性改建,矫治结束后髁突在关节窝内的位置不受矫治器的影响。

Study of changes of condylar morphology and position by MRI with fixed inclined bite-plate therapy in mandibule-retrusion patients

Objective To study the changes of condylar morphology and position in the mandibule-retrusion patients during fixed inclined bite-plate treatment.Methods The subjects were 13 consecutive Class II osseous malocclusions with mandibular retrusion treated with fixed inclined-bite.From each subject,four MRI images of TMJ were obtained and evaluated:before treatment,at the beginning of treatment,during treatment and after treatment.Results MRI-signs of condylar remodeling were observed at the posterior-superior border in all 13 subjects treated with fixed inclined-bite.Condylar-fossa relationship changes were unconspicuous before and after treatment.Conclusion Condylar remodeling seems to contribute significantly to the increase in mandibular growth resulting from fixed inclined bite-plate treatment,while condylar-fossa relationship has no remarkable changes.