OBJECTIVES: To construct three-dimensional (3D) horizontal reference planes based on visual pathway and to determine their stability and reliability by analyzing the structural patterns of normal and dysmorphology for 3D craniofacial analysis.
SETTING AND SAMPLE POPULATION: Thirty-six subjects with maxillofacial dysmorphology and malocclusion, and eight normal controls. MATERIALS AND METHODS POPULATION: On the 3D computed tomographic images of the subjects, the visual pathway-based planes, including the orbital axis plane (OAP), visual axis plane (VAP), and the optical axis plane (OpAP), were constructed and evaluated.
RESULTS: The OAP, but not the VAP and OpAP, showed the ideal relationship between the midsagittal and posterior maxillary plane, and properly described the different patterns of maxillofacial dysmorphology with craniofacial plane 1 of Delaire's analysis and the occlusal plane.
CONCLUSIONS: The proposed visual pathway-related horizontal reference planes, and in particular the OAP, seem to correctly express the visual axis and the position of the head in natural head position and can be used as a horizontal reference plane for the 3D analysis of craniofacial dysmorphology and anthropology.