儿童安氏Ⅲ类错是儿童口腔常见疾病之一 ,不仅影响美观 ,而且影响功能 ,引起口颌系统的功能紊乱。国内外学者对错与肌肉功能有无内在联系进行了大量研究 ,认为错可以使颌面部相关肌肉发生功能变化。这种功能变化可以通过肌电图技术检测出来。肌电图 (ｅｌｅｃｔｒｏｍｙ Children Class III malocclusion is one of the most common oral diseases in children, which not only affects the appearance, but also affects the function and causes the disorder of the oral jaw system. Scholars at home and abroad have made a great deal of researches on whether there is an internal connection between the wrong  and muscle function, and believe that the wrong  can change the function of the related maxillofacial muscles. This functional change can be detected by electromyography. Electromyography