A comparative digital morphometric study of nasofrontal region in metopic and non-metopic cranial series

This study aimed to compare the nasofrontal region in metopic and non-metopic cranial series and to assess whether the persistent metopic suture is related to a specific morphology of this part of the cranium. For the purpose of the study, a total of 159 dry crania (control series n = 90 and metopic one n = 69) of contemporary adult males were scanned with a laser scanner. Digital morphometry was accomplished by recording the three-dimensional coordinates of eleven landmarks, 3 bilateral and 5 in the mid-sagittal plane, characterizing the nasofrontal region. Between these landmarks, 43 linear measurements were calculated as Euclidian distances and 25 triangles were constructed. The angles, areas and heights of these triangles were also computed. The results show that the metopic crania have a distinctive nasofrontal morphology as the significant differences are not in the forehead height, but mainly in its configuration and in the nasal bones dimensions. The metopic crania have significantly flattened glabella, broad interorbital distance and wider, shorter and less prominent nasal bones compared to the non-metopic ones.