ObjectiveTo establish a model of three-dimensional (3-D) cephalometric analysis to study dentomaxillofacial deformities. MethodsBetween January 2012 and October 2013,15 patients with dentomaxillofacial deformities were treated using 3-D cephalometric analysis in orthognathic surgery plan.There were 7 males and 8 females with an average age of 23.6 years (range,17-37 years),including 4 cases of mandibular protrusion with maxillary deficiency,4 cases of maxillary protrusion with mandibular deficiency,2 cases of long face syndrome,and 5 cases of facial asymmetry.CT images were reconstructed by Mimics software.The anatomical landmarks were located,the reference planes and analysis planes were defined and the 3-D coordinate was established.The distance and degree between landmarks and analysis planes which defined in the measure project were measured. ResultsBased on the 3-D CT quantitative analysis methods,cephalometric analysis project was defined in the 3-D coordinate.3-D cephalometric analysis provided a convenient and precise method for the clinical measurement of dentomaxillofacial morphology,and reduce the time in preoperation analysis. ConclusionThe model of 3-D CT cephalometric analysis can provide precise information in the diagnosis and treatment planning of orthognathic surgery.