Objective: This study was conducted to develop a cephalometric standard in natural head position (NHP) for adult patients. Methods: A total of 40 subjects (20 male & 20 female) were selected under the following criteria: uncontributory medical history, Mexican for at least two previous generations, age in between 18-32 years, Angle Class I occlusion with no crowding, all permanent teeth presented and erupted (except third molars), without previous orthodontic treatment and facial
harmony. Head films were taken in NHP and a fluid level device was used to validate the accuracy of the procedure. After which, the true horizontal was traced and 26 cephalometric measurements (12 linear & 14 angular) were evaluated in each radiograph. Descriptive statistics including the mean, standard deviations and range, as well as Student’s t-test with significance predetermined at p < 0.05 were calculated. Results: A wiggle-gram in NHP was made to simplify the cephalometric diagnosis. There were significant differences regarding to the head position between sexes. Although variations of the intercranial reference lines were found in both S-N and FH, the discrepancy was bigger in S-N line. Conclusions: The findings of this study suggest that true horizontal could be a stable reference line for cephalometric analysis. The wiggle-gram in NHP for adult patients can be recommended for orthodontic diagnosis.
(Rev Esp Ortod. 2008;38(1):025-031)