INCIDENCE, NUMBER AND LATERALITY OF EPIPTERIC BONES IN THE PTERION IN DRY HUMAN SKULLS OF SOUTH INDIA

Aim: To estimate and analyze the presence, number, incidence and laterality of epipteric bones in the region of pterion in dry human skulls of South India. Objective: To evaluate the relative frequency of occurrence, number and laterali epipteric bones of the pterion on examining dry human skulls and to analyze its variability in different populations. Background: The floor of the temporal fossa is formed by the frontal bone, parietal bone, greater wing of the sphenoid and the squamous part of the temporal bone. All four bones meet on each side at an H-shaped junction of sutures termed the ‘pterion’. Epipteric bones are small irregular bones developing at the site of pterion because of additional ossification centers. Its presence is important for anthropologists, radiologists and neurosurgeons. Reason: The number and incidence of epipteric anthropologists. The presence of epipteric bones provides fractures may be misinterpreted as epipteric bones on examining knowledge of epipteric bones are important to fix the neurosurgeons. the skull that is superiorly and by the frontal bone, parietal part of the fossa. All these junction of or epipteric at the site of According sutural bones most common [1]. There can be bone or Inca literature to the type of as well as in is available in different of pterion and important for Epiteric bones can cause weakness of the cranium and can help in extension of the fractures according to their locations. These bones also provide false impression of fractures or the fracture may be interpreted for epipteric bones especially in the region of pterion or asteroid either radiologically or clinically and may produce complications during burr hole surgeries.[3]. The incidence of epipteric bone is of extreme importance in anti-mortem cranial radiograph and forensic medicine as the presence of epipteric bones provides false impressions of fractures or fractures may be interpreted as epipteric bones. Although their occurre their presence may severe as a moderate marker for the identification of various anomalies and syndromes of the central nervous system and is relevant to anthropologists, neurosurgeons and radiologists to diagnose and manage it accordingly[4][5][6]. MATERIALS AND METHODS The study was conducted in the Department of Anatomy, Saveetha Dental College, Chennai. A total of 60 dry human skulls of unknown sex and without any gross abnormality were collected and evaluated. All skulls were serially numbered from 1 to 60. The skulls observed with naked eye. In each skull the presence, number, incidence and laterality i.e., present unilaterally or bilaterally and for the side of unilateral presence were observed, noted 6505, Impact Factor: SJIF: 5.995


INTRODUCTION
The temporal fossa is an important area of bounded inferiorly by the zygomatic arch, posteriorly by the temporal lines and anteriorly process of the zygomatic bone. The frontal bone, the greater wing of sphenoid and squamous temporal bone forms the floor of the temporal four bones meet on each side at an H-shaped sutures termed the 'pterion'. Epipteric bones ossicles are small irregular bones developing pterion because of additional ossification centers. to Bergman et al., (1) nearly 40% of skulls have in the vicinity of the lambdoid suture. The next is the epipteric bone found near the pterion another wormian bone called preinterparietal bone found at the lambda. Perusal of relevant reveals that major work on pterion is limited sutural patterns in pteric region in the primates several races of mankind. Very little literature regarding the study of epipteric bones populations. The knowledge of the variations its clinical anatomy, in Indian population are surgeons operating in the field [2]. These bones also provide false impression of fractures or the fracture may be interpreted for epipteric bones especially in the region of pterion or asteroid either radiologically or clinically and may produce complications during burr hole surgeries. [3]. The incidence of epipteric bone is of extreme importance in anti-mortem cranial radiograph and forensic medicine as the presence of epipteric bones provides false impressions of fractures or fractures may be interpreted as epipteric bones. Although their occurre their presence may severe as a moderate marker for the identification of various anomalies and syndromes of the central nervous system and is relevant to anthropologists, neurosurgeons and radiologists to diagnose and manage it accordingly [4][5] [6].

MATERIALS AND METHODS
The study was conducted in the Department of Anatomy, Saveetha Dental College, Chennai. A total of 60 dry human skulls of unknown sex and without any gross abnormality were collected and evaluated. All skulls were serially numbered from 1 to 60. The skulls observed with naked eye. In each skull the presence, number, incidence and laterality i.e., present unilaterally or bilaterally and for the side of unilateral presence were observed, noted

INCIDENCE, NUMBER AND LATERALITY OF EPIPTERIC BONES IN THE PTERION IN DRY HUMAN SKULLS OF SOUTH INDIA
To estimate and analyze the presence, number, incidence and laterality of epipteric bones in the region of pterion in dry human skulls of South India.
To evaluate the relative frequency of occurrence, number and laterality of epipteric bones of the pterion on examining dry human skulls and to analyze its variability The floor of the temporal fossa is formed by the frontal bone, parietal bone, greater wing of the sphenoid and the squamous part of the temporal bone. All four bones shaped junction of sutures termed the 'pterion'. Epipteric bones are small irregular bones developing at the site of pterion because of additional ossification centers. Its presence is important for anthropologists, radiologists and neurosurgeons.
bone are of much interest to provides false impression of fractures or examining cranial radiographs. The the site in burr hole surgeries for Epiteric bones can cause weakness of the cranium and can help in extension of the fractures according to their locations. bones also provide false impression of fractures or the fracture may be interpreted for epipteric bones especially in the region of pterion or asteroid either radiologically or clinically and may produce complications during burr hole cidence of epipteric bone is of extreme mortem cranial radiograph and forensic medicine as the presence of epipteric bones provides false impressions of fractures or fractures may be interpreted as epipteric bones. Although their occurrence is less frequent, their presence may severe as a moderate marker for the identification of various anomalies and syndromes of the central nervous system and is relevant to anthropologists, neurosurgeons and radiologists to diagnose and manage it

MATERIALS AND METHODS
The study was conducted in the Department of Anatomy, Saveetha Dental College, Chennai. A total of 60 dry human skulls of unknown sex and without any gross abnormality were collected and evaluated. All skulls were serially numbered from 1 to 60. The skulls were macroscopically observed with naked eye. In each skull the presence, number, incidence and laterality i.e., present unilaterally or bilaterally and for the side of unilateral presence were observed, noted

Research Article
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
International Journal of Current Advanced Research and photographed. The results obtained were a tabulated and represented in percentages.

RESULT
Epipteric bones were noted in 11 out of 60 skulls. Out of 11 skulls, 10 skulls showed epipteric bone on one side (unilateral) and remaining 1 skull showed epipteric bone o both sides (bilateral). Among the unilateral skulls epipteric bone occurrence was more common on the right side than on the left side. The epipteric bones which are present occurred as 2 fragments in 1 skull and in the rest it was present as 1 fragmented bone. The Incidence, Laterality and Side of unilateral presence are given in Table 1     Epipteric bones were noted in 11 out of 60 skulls. Out of 11 skulls, 10 skulls showed epipteric bone on one side (unilateral) and remaining 1 skull showed epipteric bone on both sides (bilateral). Among the unilateral skulls epipteric bone occurrence was more common on the right side than on the left side. The epipteric bones which are present occurred as 2 fragments in 1 skull and in the rest it was present as 1 bone. The Incidence, Laterality and Side of unilateral presence are given in Table 1

DISCUSSION
Various hypotheses have been put existence of epipteric bones. The most appropriate hypothesis was put forward by Ranke in 1898 [7]]. He was of the view that the postero-superior border of the greater wing of sphenoid has got a separate centre of ossification. This c fuses with the greater wing of the sphenoid during the 4 month of the intrauterine life. In case, it fails to unite with the greater wing, it results in an epipteric bone. Here the incidence of epipteric bones is 11 out of 60 skulls out of which 10 was unilateral and 1 was bilateral and among the unilateral skulls epipteric bone occurrence was more common on the right than on the left side.
Pterion junction has been used as a common extra landmark for surgeons in microsurgical and surgical approaches towards important pathologies of this region. Pterion is an important landmark for anterior branch of middle meningeal artery, Broca's motor speech area to the left, insula, the lateral cerebral fissure, for the pathologies of optic nerve, orbit, sphenoidal ridge and for the anterior circulation aneurysm and tumors. Because of its clinical importance the present study was focussed on presence, number and laterality of epipteric bones on pterion. Thus its presence is important for anthropologists, neurosurgeons.

CONCLUSION
To conclude, the occurrence and laterality of epipteric bone in human skulls is variable in different populations. Identification of the occurrence of epipteric bones at the site of pterion and its variations are important for neurosurgeons, radiologists and anthropologists. As incidence of epipteric bone is variable, further studies will be required on different populations. The number and incidence of epipteric bones are of much interest to Anthropologists.
The presence of epipteric bone provides false impression of fractures or fractures may be misinterpreted as epipteric bones on examining cranial radiographs for Radiologists. The knowledge of epipteric bones are important to fix the site in burr hole surgeries and other related surgeries in the region of pterion for Neurosurgeons. The occurrence and laterality of epipteric bone in human skulls is variable in different population and the knowledge about their presence, throws light upon the anatomico sutural/epipteric bones in the cranium.

3200, April 2017
Various hypotheses have been put forward to justify the existence of epipteric bones. The most appropriate hypothesis was put forward by Ranke in 1898 [7]]. He was of the view superior border of the greater wing of sphenoid has got a separate centre of ossification. This center fuses with the greater wing of the sphenoid during the 4 th month of the intrauterine life. In case, it fails to unite with the greater wing, it results in an epipteric bone. Here the incidence of epipteric bones is 11 out of 60 skulls out of was unilateral and 1 was bilateral and among the unilateral skulls epipteric bone occurrence was more common on the right than on the left side.
Pterion junction has been used as a common extra-cranial landmark for surgeons in microsurgical and surgical approaches towards important pathologies of this region. Pterion is an important landmark for anterior branch of middle meningeal artery, Broca's motor speech area to the left, insula, the lateral cerebral fissure, for the pathologies of , sphenoidal ridge and for the anterior circulation aneurysm and tumors. Because of its clinical importance the present study was focussed on presence, number and laterality of epipteric bones on pterion. Thus its presence is important for anthropologists, radiologists and To conclude, the occurrence and laterality of epipteric bone in human skulls is variable in different populations. Identification of the occurrence of epipteric bones at the site re important for neurosurgeons, radiologists and anthropologists. As incidence of epipteric bone is variable, further studies will be required on different populations. The number and incidence of epipteric bones are of much interest to Anthropologists.
The presence of epipteric bone provides false impression of fractures or fractures may be misinterpreted as epipteric bones on examining cranial radiographs for Radiologists. The knowledge of epipteric bones are important to fix the site rr hole surgeries and other related surgeries in the region of pterion for Neurosurgeons. The occurrence and laterality of epipteric bone in human skulls is variable in different population and the knowledge about their presence, throws omico-clinical significance of sutural/epipteric bones in the cranium.