An inference modeling of human visual judgement of sagittal jaw-base relationships based on cephalometry: Part I

When there appears to be a contradiction between a cephalometric tracing an d what is seen, the clinician tends to place more reliance on the appearanc e of the face in profile than on a formal cephalometric evaluation of the s agittal jaw relationship. With this in mind, we derived a multiple regressi on model with cephalometric variables to explain the visual influences that affect the subjective classification of sagittal jaw relationships made by experienced orthodontists, The regression model that showed the highest co efficient of determination, 0.90, was constructed from a linear combination of the angle ANB, the anteroposterior position of Gnathion, the SN length, and the mandibular body length. The performance reliability of the inferen ce system has been tested for 175 female adult cases and will be reported i n Part II of this article.