Comparison between direct clinical and digital photogrammetric measurements in patients with 22q11 microdeletion.

Thanks to recent advances in imaging and computing technology, photoanthropometry has become an increasingly helpful adjunct to obtain objective clinical evidence of morphologic abnormalities in patients with dysmorphic syndromes. The aim of this study was to evaluate measurements made using a new two-dimensional digital photogrammetry technique by comparison with direct clinical measurements. A total of 14 patients with 22q11 microdeletion were included in this study. There were seven females and seven males between 5 and 38 years of age. Sixteen direct clinical measurements were performed using a graduated anthropometric sliding caliper and angle meter. Photogrammetric measurements were made on digital photographs using a commercially available software package. After calibration to one in situ reference on frontal and profile views, photogrammetric measurements were compared to a total of 14 direct clinical measurements made in the same patients. Findings showed that photogrammetric measurements calibrated to an in situ reference were reliable especially on profile views. No statistical difference was found between 10 of the 14 measurements (P> 0.05) including eight of the nine measurements on profile views and two of the five measurements on frontal views. This study indicates that digital photogrammetry is a useful tool but there is still no reliable standard photographic measurement technique.