安氏Ⅲ类错雅合和下颌前突很久以前就被认为是一种严重的面部畸形 ,对口腔功能和颜面美观有较严重的影响。在2 0世纪早期 ,人们就对安氏Ⅲ类错雅合进行了广泛的研究。Ｘ线头影测量技术为错雅合的研究提供了一种有力的手段。近几十年 ,利用计算机辅助Ｘ线摄影术又进一步对安氏Ⅲ Class III malocclusion and mandibular protrusion have long been considered a serious facial deformity and have a more serious effect on oral function and facial appearance. In the early 1900s, extensive research was conducted on the Class III malocclusion. X-cephalometry techniques provide a powerful tool for the study of Fallacy. In recent decades, the use of computer-aided radiography and further on the Angle Ⅲ