Recording sagittal condylar angles using a mandibular facebow.

Abstract

The aim of this study was to determine the average sagittal condylar inclination angles of dentate subjects using a mandibular facebow with pencil tracing styli, to relate these angles to values assigned to articulators, and to assess the repeatability accuracy of drawing a tangent to a traced curve. The right and left sagittal condylar inclination angles of 103 subjects were recorded using a mandibular facebow with pencil tracing styli which marked a graph card during protrusive excursions. Tangents to the tracings were measured with a protractor allowing assessment of reproducibility. The mean left and right sagittal condylar inclination angles were 32 degrees and 31.5 degrees, respectively, with no significant differences (P= 0.609). Individual right and left measurements within each group showed significant differences (P = 0.0000). The mean of the tangents drawn through three sagittal condylar angle tracings by 10 operators was 33.3 degrees, and the mean of 10 tangents drawn through the same three tracings by one of the authors was 32.9 degrees, with no significant difference (P = 0.634). The average sagittal condylar inclination angles found in this study are in agreement with those reported in the literature. In fixed sagittal condylar angle articulators 30 degrees appear to be an appropriate setting. The reproducibility of this method of recording sagittal condylar inclination angles was found to be accurate for the individual operator and between operators.