Human skull with complete metopic suture and multiple sutural bones at lambdoid suture – a case report

Introduction Frontal bone of the skull develops in two halves during the fetal life separated by the metopic suture. The suture normally disappears soon after the birth [1]. The persistent complete metopic suture extending from the nasion to bregma is called metopism [2]. Lambda represent the meeting point of the sagittal and lambdoid suture. It represents the site of posterior median fontanel in the fetal life. It obliterates by the age of 2 to 3 months. The ‘sutural bones’ or ‘Wormian bones’ are small, irregular bones found at the sutures and fontanels of the skull. Whenever the wormian bones are present they are either two or three but they are present in large numbers in case of hydrocephalic skulls [1]. The mechanism of formation of the wormian bones is not clearly known. Some say they are due to external influences [3]. Other say they are due to normal developmental processes and are genetically determined [4]. They are commonly found in relation to the frontal and occipital bones. It is important to know about these bones because they can mislead in the diagnosis of fracture of skull bones in medicolegal cases.