RELIABILITY OF MEASUREMENTS FROM CEPHALOGRAMS AT THE BURLINGTON ORTHODONTIC RESEARCH CENTRE

¹ Burlington Orthodontic Research Centre, and Department of Zoology, University of Toronto; and Division of Medical Statistics, Ontario Department of Health, and Faculty of Dentistry, University of Toronto.

Today much emphasis is being placed on the use of cephalometric analysis as a means of clarifying problems of growth and development of the skeleton. The present study has attempted to define the efficiency and reliability of this method for studying anatomic variations. The method was to compute the error variances involved in the radiographic and tracing technic with data derived from duplicate radiograms and duplicate tracings of 15 3-year-old children. The results showed that, as applied by the present investigators, the technical process is highly refined and that no practical improvement is needed. It was found that by far the greatest source of distribution variation is due to the real difference between children and that from the point of view of economical production of data for creating norms and permitting comparisons, the best experimental procedure is to use a sufficient number of children rather than to attempt to reduce technical error further by duplicating measurements.