Intra- and interexaminer variability in head posture recorded by dental auxiliaries

Determination of the natural head position is essential in the esthetic assessment of the facial profile and could be of value in prediction of facial developmental trends. Recording of head posture has previously been performed in university clinics under experimental conditions. The purpose of the present study was to examine the reliability of a method that dental auxiliaries could use for routine recording of the natural head posture in children in an orthodontic clinic. The material comprised thirty orthodontic patients 6 to 15 years of age and recorded on two occasions 1 to 35 days apart. The auxiliary staff consisted of three different operators. The duplicate cephalometric head films were analyzed separately for the groups of patients recorded by each of the three operators. The data were also divided into one group recorded by the same operator and another group recorded by different operators at the first and the second occasions. No systematic difference between the first and the second recordings was found for the patients examined by each of the three operators or for the groups examined by the same or by different operators. The error of the method for the whole group was 2.3 degrees for the position of the head in relation to the true vertical (NSL/VER), 3.1 degrees for the cervical inclination (OPT/HOR), and 3.4 degrees for the craniocervical angulation (NSL/OPT). The method was found to yield sufficient reproducibility and is suggested to be of clinical value in the study of head posture in relation to orthodontic treatment.