Incidence of metopism in the Lebanese population

Abstract

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.

Association between frontal sinus development and persistent metopic suture

“…There are publications suggesting the persistent metopic suture was associated with the absence of frontal sinus; however, none of them are based on a scientific work or explanation [2,6]. Since the plain X-ray exams are not as sensitive as the CT and MRI studies, correct results from the investigations related to skull anatomy can be obtained from the CT and MRI scans, or from the autopsy material and cadavers only.…”

“…Results acquired from the material consisting of X-rays are prone to misinterpretation arising either from the erroneous evaluation of the radiograms or their insufficient resolution. Baaten et al [2] declared that the absence of frontal sinus was found in 7 of the 8 cases of metopism in a study they carried out on 968 skull X-rays. In that study they also admit that some irrelevant results to the literature they obtained could be due to the use of X-rays rather than cadavers.…”

Morphological Variation and Occurrence of Persistent Metopic Suture in Indian Population

“…There are divergences in the different studies regarding the time of closure of the metopic suture. Metopic suture starts fusing at the age of two years and may have completely fused by the age of seven 9,10 years. Bademci G et al reported that the time of physiological closure of these sutures varies from birth to 8 years of age, the widely accepted closing 11 period has been approximated at 2 years of age.…”

“…Although the persistant metopic suture is rare anatomical variant, it must be included in the differential diagnosis of a suspected skull fracture particularly of the frontal bone. 9 Baaten et al reported that the incomplete metopicsutures are difficult to identify on the X rays and may be mistaken for the vertical fractures close to the central line. Neurosurgeons have to be aware of the suture configurations to avoid confusion and unwanted dangerous offence in cranial surgery.…”

Incidence of Metopism in Adult Thai Skulls

“…Therefore the knowledge of the metopism incidence in different races is important and should be considered before diagnosis of frontal bone fractures. Previously, the incidence of metopic suture has been reported in many populations such as Scottish (Bryce, 1915), Australian (Bryce), Mongolian (Bryce), European (Bryce), Nigerian (Ajmani et al, 1983), Nepalese (Bilodi et al, 2004) Lebanese (Baaten et al, 2003), Brazilian (Castilho et al, 2006), Indian (Murlimanju et al, 2011), Turkish (Bilgin et al, 2013), and West Anatolian (Aksu et al, 2014). Recently, there is no report of this incidence from Thai population.…”