Sagittal images of bilateral lateral pterygoid muscles with the mandible seated at intercuspal position with and without biting, and at mouth-open-position were taken respectively.

• 结果：3组受试者的翼外肌上下头均表现为在大开口时缩短增粗的收缩影像，在牙尖交错位闭口和紧咬时的舒张影像。