skull with multiple sutural bones - a case report

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The sagittal suture was very wavy. There were no other notable abnormalities in the skull. DISCUSSION. Sutural bones are very commonly found in the skull.
Indian Journal of Medical Case Reports ISSN: 2319–3832(Online) An Online International Journal Available at http://www.cibtech.org/jcr.htm 2013 Vol.2 (3) July-September, pp.47-49/Kaur et al.

Case Report

SKULL WITH MULTIPLE SUTURAL BONES - A CASE REPORT Jeewandeep Kaur1, *Arvinder Pal Singh Batra2 and Anupma Mahajan3 1 Department of Physiology, BPS GMC for Women Khanpur Kalan Sonepat 2 Department of Anatomy, BPS GMC for Women Khanpur Kalan Sonepat 3 Department of Anatomy, SGRD Institute of Medical Sciences and Research, Sri Amritsar *Author for Correspondence ABSTRACT The sutural bones are unnamed bones commonly found at the level of lambda and lambdoid suture in a human skull. They vary from person to person in number and shape. It is important to know about these bones because they can mislead the diagnosis of fracture of skull bones. Knowledge of this variation is very important for forensic experts, anthropologists, radiologists, orthopedicians and neurosurgeons. We found one dry skull specimen with multiple skull bones at the level of lambda and lambdoid suture. Key Words: Skull, Wormian Bone, Lambdoid Suture, Variation INTRODUCTION The ‘sutural bones’or ‘Wormian bones’ are small, irregular bones found at the sutures and fontenellas 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 (Standring, 2008). The mechanism of formation of the wormian bones is not clearly known. Some say they are due to external influences (Hess, 1946; Bennett, 1965; Finkel, 1971). Other say they are due to normal developmental processes and are genetically determined (Murphy, 1956; El-Najjar and Dawson, 1977; Pal et al., 1986). 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. CASES A dry adult skull with a series of sutural bones in the lambdoid suture (Figure 1) was found in the Department of Anatomy, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar. The largest among them was at the lambda and the size of rest of the bones reduced progressively from lambda to asterion. They were irregular in shape. The sagittal suture was very wavy. There were no other notable abnormalities in the skull. DISCUSSION Sutural bones are very commonly found in the skull. Nearly 40% of skulls contain sutural bones in the vicinity of the lambdoid suture (Bergman et al., 1988). The next most common sutural bone is the epipteric bone found near the anterolateral fontanelle. The interparietal bone develops from three pairs of centers in membrane one pair for the lateral plates, one pair for the central piece and the third pair representing the pre-interparietals (Srivastava, 1977). Presence of sutural bones is almost invariably associated with abnormal development of the CNS and may serve as a useful marker for the early identification and treatment of the affected infant or child (Pryles and Khan, 1979). Jeanty et al., (2000) have reported the presence of wormian bones in four fetuses. But in these cases there were no associated anomalies. Tewari et al., (1982) studied 1500 skulls for the presence of sutural bones. They have found the pre interparietal bone in 6 (0.4%) cases. El-Najjar and Dawson (1977) are of the opinion that the occurrence of the wormian bones is controlled by the genetic factor. Significant sutural bones as against normal developmental variants were considered to be those more than 10 in number, measuring greater than 6 mm by 4 mm, and arranged in a general mosaic pattern. They were found in all the cases of osteogenesis imperfecta but not in the normal skulls (Cremin et al., 1982; Pal, 1987). Comparison of cranial capacity in skulls with and without sutural bones showed no significant

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Indian Journal of Medical Case Reports ISSN: 2319–3832(Online) An Online International Journal Available at http://www.cibtech.org/jcr.htm 2013 Vol.2 (3) July-September, pp.47-49/Kaur et al.

Case Report difference and this is interpreted as indicating that sutural bones are not formed secondary to stress (Malhotra et al., 1978). It has no morphological importance but it certainly has a morphogenetic bearing (Astley, 1971).

Figure 1: Showing multiple sutural bones at lambda and lambdoid suture Conclusion The sutural bones are important from clinical point of view. The presence of series of sutural bones like this may lead to problems in posterior approach to the cranial cavity. These bones might lead to confusions in reading the radiographs in the case of head injuries. The sutural bones may be mistaken for multiple fractures. REFERENCES Astley R (1971). Metaphyseal fractures in osteogenesis imperfecta. British Journal of Radiology 5 441443. Bennett KA (1965). The etiology and genetics of wormian bones. American Journal of Physical Anthropology 23(3) 255-260. Bergman RA, Afifi AK and Miyauchi R (1988). Skeletal systems: Cranium. In: Compendium of human anatomical variations. Baltimore, Urban and Schwarzenberg 197–205. Cremin B, Goodman H, Spranger J and Beighton P (1982). Wormian bones in osteogenesis imperfecta and other disorders. Skeletal Radiology 8(1) 35-38. El-Najjar M and Dawson GL (1977). The effect of artificial cranial deformation on the incidence of Wormian bones in the lambdoidal suture. American Journal of Physical Anthropology 46 155–160.

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Indian Journal of Medical Case Reports ISSN: 2319–3832(Online) An Online International Journal Available at http://www.cibtech.org/jcr.htm 2013 Vol.2 (3) July-September, pp.47-49/Kaur et al.

Case Report Finkel DJ (1971). Wormian bones — a study of environmental stress. American Journal of Physical Anthropology 35 278. Hess L (1946). Ossicula wormiana. Human Biology 18 61 - 80. Jeanty P, Silva SR and Turner C (2000). Prenatal diagnosis of wormian bones. Journal of Ultrasound in Medicine 19 863–869. Standring (2008). Gray's Anatomy. Williams PL, Warwick R, Dyson M, Bannister LH 40th edn, London Churchill Livingstone 418. Malhotra VK, Tewari PS, Pandey SN and Tewari SP (1978). Interparietal bone. Acta Anatomica (Basel) 101 94–96. Murphy T (1956). The pterion in the Australian aborigine. American Journal of Physical Anthropology 14 225–244. Pal GP, Bhagwat SS and Routal RV (1986). A study of sutural bones in Gujarati (Indian) crania 44(1) 67-76. Pal GP (1987). Variations of the interparietal bone in man. Journal of Anatomy 152 205–208. Pryles CV and Khan AJ (1979). Wormian bones. A marker of CNS abnormality? American Journal of Diseases of Children 133 380–382. Srivastava HC (1977). Development of ossification centers in the squamous portion of the occipital bone in man 124(3) 643-9. Tewari PS, Malhotra VK, Agarwal SK and Tewari SP (1982). Pre interparietal bone in man. Anatomischer Anzeiger 152 337–339.

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