Background and aim: Leonardo da Vinci's face symmetry derives from 3 equal craniofacial segments: trichion-nasion (tn), which represents the superior third of the face, nasion-subnasal (ns) that is the medium third of the face, and subnasal-gnathion (sg) that is the length of the lower third of the face. It has been reported that adult subjects with celiac disease (CD) can be identified on the basis of a greater extension of the forehead in comparison to the medium third of the face, with a high tn/ns ratio. The aim of the present study was to investigate the correlation between facial asymmetry and CD in childhood and adulthood.
Methods: We studied 126 biopsy-proven patients with CD (76 children and 50 adults) and 102 healthy controls (43 children and 59 adults). Their faces were photographed; the pictures were edited using a software program to calculate the facial segments.
Results: The tn length was significantly different between adult celiac and adult controls (7.43 ± 1.46 cm vs 6.38 ± 1.73 cm, P = 0.001). The cutoff of 6.5 cm tn, derived from receiver operating characteristic curve analysis, identified 43 of 50 patients (sensitivity 86%), but 34 of 59 controls were positive (specificity 54.2%). The positive predictive value was 56%; however, the tn/ns ratio was not significantly different between celiacs and controls. Neither the tn length nor the tn/ns ratio in celiacs correlated to the time of gluten exposure.
Conclusions: Adults, but not children, with celiac disease show a forehead extension significantly greater than controls, but this test's specificity appears too low to be used in the screening of CD.