International Journal of Applied and Basic Medical Research

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 9  |  Issue : 3  |  Page : 165--168

Incidence and medicolegal significance of wormian bones in human skulls in North India Region


Nisha Goyal1, Anil Garg2, Yogesh Kumar2,  
1 Department of Anatomy, Rama Medical College Hospital and Research Center, Hapur, Uttar Pradesh, India
2 Department of Forensic Medicine, BPS Government Medical College for Women, Khanpur Kalan, Gohana, Sonipat, Haryana, India

Correspondence Address:
Dr. Anil Garg
Associate Professor, Department of Forensic Medicine, BPS Government Medical College for Women, Khanapur Kalan, Gohana, Sonipat, Haryana
India

Abstract

Introduction: Wormian bones (Wbs) are small bones located in or near the sutures of the skull which are irregular in size, shape, and number. The present study is to look into the morphological details of such supernumerary bones of skull with regards to their incidence, number, and topography in skulls from the Haryana region. Materials and Methods: This observational study was carried out in the tertiary care hospital, in the region of Haryana and the total of 147 human skulls were examined during routine autopsy procedures with respect to sutures and topographic distribution of Wbs. The data were statistically analyzed. Results: In the present study, the overall incidence of Wbs was seen in 52 skulls (35.3%) with males having 23.8% and females having 11.5%. Conclusion: The knowledge of incidence and distribution of Wbs in the skull could be useful to radiologists, causality medical officers, and autopsy surgeons in successfully differentiating a skull fracture from normal suture with Wbs or exit gunshot wound from fractured small Wb and thus ruling out the possibilities of presence or absence of fractures due to physical abuse, brittle bones, and exit gunshot wounds. It is also helpful to neurosurgeons in timely diagnosis and management of diseases or fractures in relation to the Wbs.



How to cite this article:
Goyal N, Garg A, Kumar Y. Incidence and medicolegal significance of wormian bones in human skulls in North India Region.Int J App Basic Med Res 2019;9:165-168


How to cite this URL:
Goyal N, Garg A, Kumar Y. Incidence and medicolegal significance of wormian bones in human skulls in North India Region. Int J App Basic Med Res [serial online] 2019 [cited 2019 Oct 16 ];9:165-168
Available from: http://www.ijabmr.org/text.asp?2019/9/3/165/262483


Full Text



 Introduction



The identification of skeletal remains is a usual problem faced by the anthropologists and forensic experts. The human skull is composed of several bones that fused together after birth in addition to the regular center of ossification of the skull. Accessory bones appear along with the regular center of ossification of cranium.[1]

Wormian bones (Wbs)/supernumerary ossicles/sutural bones/intercalated bones/accidental bones/pterion ossicle or epipteric bone or flower's bone are small bones located in the cranium near the sutures of skull vault which are irregular in size, shape, and number. Normally, they are present in or near the suture or occupy fontanelles of neonatal skull and commonly present in man.[2],[3] The reasons of the development of Wbs is not been entirely known. Multiples theories have been suggested, but none of these has been universally accepted. Some authors believed that these bones are developed normally and genetically determined and other opined that they develop from external influences.[4],[5],[6]

A study reported that persons having Wbs are mostly showing cranial and central nervous system (CNS) disorder.[7] Wbs are also present in normal individuals and in various disorders, namely pycnodysostosis, osteogenesis imperfect, rickets, kinky hair, cleidocranial dysostosis, hypothyroidism and hypophosphatasia, otopalatodigital syndrome, primary acro-osteolysis, down syndrome represented by a mnemonic “PORKCHOPS.” Therefore, they help in diagnosis and treatment of affected children.[8]

The Wbs are also observed in fetus ultasonographical in the prenatal period. However, the prenatal period remained uneventful and also the growth of these newborns remain normal.[9] A study reported that singular bregmatic Wb may be a result of either biomechanical-induced development or definitive nonadaptive genetic change.[2] There is no relationship between stress during infancy on deformed or normal cranium and Wbs formation.[10] The Chinese population show the highest incidence (80%) of Wbs as compared to different population groups across the world.[11]

The aim of the current study is to report the incidence and topographical distribution of Wbs in the natives of Haryana region and to compare with the various population groups across the word. The morphological and clinical importance was emphasized with a relevant review of literature.

 Materials and Methods



During a routine autopsy procedure, a total number of 147 skulls of Haryana population were examined. These skulls were cleaned properly for the overlying scalp layers, including the periosteum covering, and meticulously observed for the presence of Wbs. The skulls with injury or fracture were not included in the current study. The following parameters were evaluated in the present study:

Percentage of skulls where Wbs were presentIncidence of Wbs with respect to sutures in the skullTopographic distribution of Wbs in the skull.

The data were tabulated, analyzed and compared with earlier studies. The interparietal and preinterparietal bones which were seen at the lambda region were not considered as Wbs.

 Results



In the present study, the overall incidence of Wbs was seen in 52 skulls (35.3%), with males having 23.8% and females having 11.5% [Table 1] and the highest number of Wbs is observed along the lambdoid suture [Table 2]. The data are statistically analyzed and Chi-square test is applied to the incidence of Wbs in male with respect to females [Table 1]. The P value obtained is 0.802 which is insignificant. Thus, we can conclude that there is no association of the presence of Wbs in males to the females.{Table 1}{Table 2}

 Discussion



In the present study, maximum Wbs are observed along the lambdoid suture similar to previous studies [Table 2]. The P value obtained is 0.802 which is insignificant (>0.05%). Thus, we can say that there is no association between incidences of Wbs in males to the females. The incidence of Wbs in our study is 35.3% as compared to different population groups within India and in world, i.e., 7% to 77% [Table 3].{Table 3}

Considerable genetic variations have also been documented among population groups residing in different regions of India.[21] A study from south India studied 78 skulls and noticed Wbs in 57 (73.1%), which is significantly higher as compared to the present study.[12]

A Malaysian study also reported the occurrence of Wbs in the coronal, squamosal, and sagittal sutures in 6 out of 25 dried human skulls.[13] A study from Vidarbha region, India, reported 34.22% incidence of Wbs. Among them, in the male skulls incidence rate is 39.13%, whereas in female, it is 21.87% and the most common site for the occurrence of Wbs is the lambdoid suture.[14]

A retrospective French study on 605 CT brain scans from normal child population excluding constitutional bone diseases cases, had found Wbs in 53% of population, two to three Wbs were found in 43%. The maximum incidence of Wbs is seen along with lambdoid suture.[15] The Turkey-based study examined 300 skulls and found 9% having Wb, with maximum incidence at lambdoid.[16] In another study in West Anatolian Population on 150 skulls, rate of skulls with Wbs were found as 59.3%. The left lambdoid suture was having maximum rates of suture having Wbs as 40.7%.[17]

In another study from India's eastern region on 120 unknown adult skulls found the incidence of Wbs being 45%. The maximum incidence of Wbs was also observed in lambdoid suture.[18] A similar study in Greek revealed 124 skulls (74.7%) having Wbs out of total 166 skulls, with no difference of gender and age.[19] In Nigeria based study, 22 skulls were examined, with incidence of Wbs in 45.46% and maximum incidence in lambdoid suture.[20] The orifices due to small Wbs may sometimes be medico-legally misinterpreted as gunshot wound or vice versa.[22]

 Conclusion



In the current study, we observed an incidence rate of 35.57% Wbs in North Indians skulls, which is comparable with previous studies, and thus, the present study also confirmed that Wbs are not so uncommon. Furthermore, the incidence of Wbs is more frequent at the lambdoid suture which is in correlation with the studies done by previous authors. The nonsignificant P value also indicates that there is no association of the incidence of Wbs and gender. The present study also comes across Wbs in coronal and sagittal suture which shows that the Wbs are also present in these sutures in addition to lambdoid suture [Figure 1], [Figure 2], [Figure 3], [Figure 4]. The knowledge of sutural bones, their incidence and features are helpful for the treating doctors to arrive at an early diagnosis and timely management of disorders associated with it. The knowledge of Wbs in the skull is also helpful to radiologists, causality medical officers and autopsy surgeons in successfully differentiating a skull fracture from normal suture with Wbs and thus ruling out the possibilities of presence or absence of fractures due to physical abuse and brittle bones.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Small Wbs at various sutures may fall during putrefaction and thus gives appearance of entry or exit gunshot wound. Thus its knowledge is important for labelling a small bony skull defect as due to gunshot wound or fall of small Wbs in the cranial cavity. Sometimes, the Wbs looks like fractures and may confuse the radiologist or surgeon. Sometimes, fractures at these sites may be misdiagnosed as normal Wbs and thus timely treatment for the fracture is not given. This results in fatal health complications and legal implications for the concerned doctors.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Krogman WM. The Human Skeleton in Forensic Medicine. 3rd ed. Springfield: Charles C Thomas; 1978. p. 3-10.
2Barberini F, Bruner E, Cartolari R, Franchitto G, Heyn R, Ricci F, et al. An unusually-wide human bregmatic wormian bone: Anatomy, tomographic description, and possible significance. Surg Radiol Anat 2008;30:683-7.
3Srivastava HC. Ossification of the membranous portion of the squamous part of the occipital bone in man. J Anat 1992;180(Pt 2):219-24.
4Hess L. Ossicula wormiana. Hum Biol 1946;18:61-80.
5Murphy T. The pterion in the Australian aborigine. Am J Phys Anthropol 1956;14:225-44.
6Pal GP. Variations of the interparietal bone in man. J Anat 1987;152:205-8.
7Pryles CV, Khan AJ. Wormian bones. A marker of CNS abnormality? Am J Dis Child 1979;133:380-2.
8Wormian Bones. Available from: https://en.wikipedia.org/wiki/Wormian_bones. [Last updated on 2018 Nov 27; Last accessed on 2019 Jan 09].
9Jeanty P, Silva SR, Turner C. Prenatal diagnosis of wormian bones. J Ultrasound Med 2000;19:863-9.
10Wilczak CA, Ousley SD. Test of the relationship between sutural ossicles and cultural cranial deformation: Results from Hawikuh, New Mexico. Am J Phys Anthropol 2009;139:483-93.
11Brothwell DR. The use of non-metrical characters of the skull in differentiating populations. Dtsch Ges Anthropol 1959;6:103-9.
12Murlimanju BV, Prabhu LV, Ashraf CM, Kumar CG, Rai R, Maheshwari C. Morphological and topographical study of Wormian bones in cadaver dry skulls. J Morphol Sci 2011;28:176-9.
13Khan AA, Asari MA, Hassan A. Unusual presence of wormian (sutural) bones in human skulls. Folia Morphol (Warsz) 2011;70:291-4.
14Walulkar S, Ksheersagar D, Walulkar M. The study of wormian bones in human skulls in Vidarbha region. Panacea J Med Sci 2012;2:18-21.
15Marti B, Sirinelli D, Maurin L, Carpentier E. Wormian bones in a general paediatric population. Diagn Interv Imaging 2013;94:428-32.
16Govsa F, Ozer MA, Bayraktaroglu S, Aktas EO. Anatomoradiological identification of intrasutural bones for importance of cranial fracture. Turk Neurosurg 2014;24:357-62.
17Cirpan S, Aksu F, Mas N. The incidence and topographic distribution of sutures including wormian bones in human skulls. J Craniofac Surg 2015;26:1687-90.
18Ghosh SK, Biswas S, Sharma S, Chakraborty S. An anatomical study of wormian bones from the eastern part of India: Is genetic influence a primary determinant of their morphogenesis? Anat Sci Int 2017;92:373-82.
19Natsis K, Piagkou M, Lazaridis N, Anastasopoulos N, Nousios G, Piagkos G, et al. Incidence, number and topography of wormian bones in Greek adult dry skulls. Folia Morphol (Warsz) 2019;78:359-70.
20Uchewa OO, Egwu OA, Egwu AJ, Nwajagu GI. Incidence of wormian bones in the dried skull of Nigerian males. Int J Anat Var 2018;11:32-4.
21Balgir RS. Regional and genetic variations among the Hindu Gujjars of Northwestern India. Int J Anthropol 1992;7:35-41.
22Machado MP, Simões MP, Gamba TO, Flores IL, Haiter Neto F, Durão CH, et al. A wormian bone, mimicking an entry gunshot wound of the skull, in an anthropological specimen. J Forensic Sci 2016;61:855-7.