Evaluation of Varied Forms of Constant Metopic Suture in Adult Dried Skulls of South India

Persistence of frontal suture separating the two frontal bones in the adults is called metopism and the suture is called metopic suture. The fusion of metopic suture starts at around 18 months after birth and is completed by 8-9 years of age. As the metopic suture fuses, the two frontal bones become single which is seen normally in adult skulls. Constant metopic suture may be seen as complete or incomplete forms in some adult skulls. This feature of variant anatomy of the skulls seems to be increasingly on rise in the present era. Knowledge of this variant anatomy could be of paramount importance in certain fields like Forensic medicine where this could form a feature of identification. Complete metopism is rare in adult skulls where the metopic suture extends upto bregma- the point at which sagittal and coronal sutures meet. Incomplete metopic sutures exhibit different forms like shapes of ‘V’, ‘H’, ‘Y’, or ‘U’ that may be misinterpreted as hairline fractures in radiological findings. Incomplete metopism is usually seen at glabella, the bony prominence at the root of the nose. The present study aims at the presence of metopism in the adult skulls from South India in various forms. 180 adult skulls ranging from 40-65 years of age group from the department of Anatomy were studied for the presence of metopic suture. Their shapes and measurements were tabulated. The results were compared with those of other studies. 103 skulls were found to have no metopic suture, 9 skulls showed complete metopic suture extending from glabella up to bregma, 18 skulls revealed ‘V’ shaped, 14 skulls manifested to have ‘H’ shape, 16 skulls were discovered to have linear metopic suture in the midline, 7 ‘Y’ shape, 11 had inverted ‘U’ shaped metopic suture, 2 skulls showed ‘U’ shaped metopic suture with extension on to the right. These values strikingly show that the prevalence of metopism is on the rise. To conclude, 42.5 % of skulls revealed the presence of metopic suture in various forms and 57.2% showed no metopism.