The relationship of the glenoid fossa to the functional occlusal plane

The geometric relationship of the functional occlusal plane to the center o f the glenoid fossa, as seen in the sagittal view, is described for males a nd females from age 7 through 25 years. This relationship is fully describe d by the distance from the geometric center of the glenoid fossa perpendicu lar to the functional occlusal plane (L, in millimeters) and its angulation (theta, in degrees) relative to a constructed Frankfort horizontal (SN-7 d egrees). Regression formulas with 95% confidence levels are described for L and theta for both genders combined. The differences between genders were found to be statistically insignificant. No correlation was found between t hese dimensions relative to the presence of temporomandibular joint dysfunc tion symptoms. A statistically significant difference in both L and theta w as found in males who exhibited a Class III relationship compared with male s exhibiting a Class II relationship.