Metopism: a Study of the Persistent Metopic Suture

Metopism, the persistence of the metopic suture in adulthood, is a clinically significant radiographic finding. In addition to masquerading as a fracture of the frontal bone, a persistent metopic suture may be associated with other clinically significant anatomical variations including frontal sinus abnormalities. Several geographically and craniofacially distinct populations have yet to be assessed for the prevalence of metopism. This study aimed to determine the prevalence of metopic sutures in adult crania of diverse populations among which scant research exists. A total of 505 adult crania were examined for the presence of a metopic suture. A total of 13 (2.57%) demonstrated metopism. Among subpopulations, metopism was present in 8.06% (5:62) of European crania, 15.38% (2:13) of East Asian crania, 2.20% (2:91) of Egyptian crania, and 2.86% (1:35) of Bengali crania. Metopism was also found in 1 Chilean, Roman, and Tchuktchi cranium, respectively. Metopism was not seen in crania from individuals of African (non-Egyptian) descent (0:62), Peruvians (0:144), Malayans (0:23), or Mexicans (0:23). Among sexes, metopism was present in 3.77% (8:212) of females and 1.79% (5:279) of males. The prevalence of metopism differs between populations and sexes. The results of this study provide anthropological, developmental, and clinical insight with regard to metopism.