Natural head position recording on frontal skull radiographs.

This paper sets out to evaluate the variability and reproducibility of frontal head position in healthy young adults. Two posteroanterior skull radiographs of 22 dental students and 2 frontal photographs of these and 24 other students, taken at a 1-week interval, were analyzed with regard to head position and cervical spine inclination. Head position varied in the range of +/- 5 degrees with regard to the vertical. The cervical spine was more often inclined to the right than to the left. The reproducibility of the head position with regard to the craniovertical angle was 1.15 degrees and that of the craniocervical and cervicohorizontal angles 0.93 degrees and 1.45 degrees, respectively. Any deviation in the frontal head position tended to be spontaneously corrected on looking in a mirror. It is concluded that the frontal head position is slightly more accurately reproducible than the sagittal head position. The use of a mirror in front of the patient when recording the frontal natural head position is not to be recommended.