Incidence of metopism in the Lebanese population.

This study was carried out on 968 skull X-rays to determine the incidence of the metopic suture in the Lebanese population. Complete and incomplete metopism was present in 0.82% and 0.93% of cases, respectively, leading to an overall incidence of 1.75%. In both categories, the incidence was relatively higher in males (1.84%) than in females (1.62%). Persons living in rural areas had a higher incidence of complete and incomplete metopism compared to persons living in urban areas, with ratios of 4:1 and 4:2, respectively. Other findings included an absence of frontal sinuses in all but one skull with complete metopism, accessory ossicles in the majority of cases of complete metopism (7/8), and hydrocephalus in one case. Medical records did not reveal any other associated diseases or abnormalities. Despite the low incidence of metopic suture in the Lebanese population, in X-ray diagnosis of fractures of the frontal bone, metopic suture must not be ruled out.