Measurement accuracy of the mandibular kinesiograph--a computerized study.

Today's high-technology electronic and computer techniques have been applied to the long-standing problem of tracking mandibular movement and skeletal relation in research and diagnosis of mandibular function/dysfunction. The measurement established that within an area known as "clinical space" where most diagnostic data is derived, the linearity and quantitative accuracy ranged from error of 0 mm at intercuspation to 0.5 mm at worst error. This order of accuracy provides data that is qualitatively and quantitatively useful for research and diagnosis without the need for further correction. Computer processing further reduces the worst anywhere within the clinical space to 0.1 mm. Geometric skewing of the trace patterns that occur while taking data at mouth openings beyond clinical space (though not pronounced enough to affect the qualitative usefulness of the data) is readily corrected by computer processing. A microcomputer attached to the K5-R corrects the skew in real-time so that the data are displayed to an accuracy within 1.5% of exact values or a worst-case error less than 0.5 mm for a 30 mm vertical opening. When tested against a computer-controlled electronic measuring system, the accuracy and linearity parameters of the trace patterns confirmed the validity of the MKG recordings as precise representations of mandibular movement at the incisor point.