Several studies examined the effect of age on overlapping lists of discrete cranial traits evaluated on a presence/absence basis, including, for example, mandibular tori, metopism
, and parietal notch bone (Berry 1975; Corruccini 1974; Perizonius 1979).
Although an incidence about skull morphology like the metopism
, a rare variant suture persistence, in Northeastern Thais has been previously documented (Khamanarong et al., 2015), there is no later report about classification of pterion formation in our population.
DISCUSSION: In the present study metopism or metopic suture was found in 3% cases.
According to Baaten, et al (6) people who live in rural area have a high incidence of metopism compared to people living urban area, with ratio 4: 1 to 4: 2.
The metopism is a rare variant suture present on the adult frontal bone because it fails to fuse in early childhood.
Therefore the knowledge of the metopism incidence in different races is important and should be considered before diagnosis of frontal bone fractures.
Sometimes when it fails to ossify and persists as a complete suture extending from bregma to nasion, it is called metopism.
The incidences of metopism vary among population of different regions and different races as reported by various workers.
SUMMARY: The metopic suture is found between the frontal bone tubers, there being divergences concerning the precise time of its closure, varying from the first to tenth year of life, and it can persist until adult age (metopism).
It was observed the occurrence of metopism in 7.04% (05/71) of the studied skulls, of which 80% (4/5) were female and only 20% (1/5) male.