颅颌面硬组织测量分析是口腔正畸和正颌外科对牙颌颅面畸形进行正确诊断与治疗的前提。传统方法是利用正、侧位头颅定位片测量分析颅颌骨形态，但此方法因放大率和影像的重叠而影响准确性。７０年代随着CT的问世，因断层影像避免了相邻结构的重叠，并提高硬组织的清晰度，CT检 Craniofacial and hard tissue measurement analysis is the premise of correct diagnosis and treatment of dental and craniofacial deformities in orthodontics and orthognathic surgery. The traditional method is the use of positive and lateral skull positioning film measurement and analysis of cranial and mandible morphology, but this method due to the magnification and image overlap and affect the accuracy. In the 1970s, with the advent of CT, the overlapped adjacent structures were avoided due to tomographic images and the clarity of hard tissues was improved. CT