The Morphologicalanalysis Of Pterion In North Indian Population

Pterion is defined as an H-shaped small circular area formed by the junction of four bones: Frontal, Parietal, Temporal and Sphenoid on Norma lateralis of the skull. A 35 dry adult human skulls of unknown sex without any gross pathology or abnormalitywere taken for the study. Sphenoparietal was the commonest type of pterion observed on both the sides. Second most common type of pterion found in our study was stellate type. Stellate type of pterion was present only on right side of skull. The accomplishments of this study contribute to anatomical variations of the pterion, which are of interest to anthropologists, forensic pathologists and surgeons. This topic of study deserves further investigation in other populations from different geographical areas.

Classification and incidence of pterion patterns of Thai skulls / Clasificación e incidencia de los patrones de pterion en cráneos de Tailandia

SUMMARY: The pterion, a landmark for neurosurgery, is the weakest part of the skull owing to relatively thin bone. Variant patterns of pterion can confuse the clinicians during diagnosis of the lateral skull fractures in emergency situations. Thedifferent pterion types of many races have been reported but not of Thais. In this study; therefore, we investigated the incidence of sutural pterion patterns on of Thai skulls. The infratemporal fossa of 110 sides from 55 dried skulls identified as Thais were observed and classified for individual pterion types. The results showed that the pterion patterns can be classified into 4 types; spheno-parietal (87.27 %), fronto-temporal (4.55 %), uni-epipteric (6.36 %), and multi-epipteric (1.82 %) types. It was found that the spheno-parietal type was dominant in males (61.81 %) than in females (25.45 %). The majority of the skulls showed bilateral symmetry (85.45 %) in all types and the unilateral ones were far less (14.55 %). In bilateral pterion incidence, the spheno-parietal type was approximately 93.61 % while the uni-epipteric type was not found. Moreover, the bilateral multi-epipteric type was found only in one female skull (2.13 %). These findings will be useful for the radiologists and the neurosurgeons concerning lateral skull fractures in emergency diagnosis.

RESUMEN: El pterion es un punto de referencia para la neurocirugía, y es la parte más débil del cráneo debido a estar conformado por hueso relativamente delgado. Los diversos patrones de pterion pueden confundir a los clínicos durante el diagnóstico de fracturas laterales de cráneo en situaciones de emergencia. Con excepción de los tailandeses, diferentes tipos de pterion se han reportado en muchas razas. hemos investigado la incidencia de diversos patrones de pterion en cráneos de Tailandia. Analizamos 110 fosas infratemporales, correspondientes a 55 cráneos secos del Noreste de Tailandia y se clasificaron de acuerdo al tipo de pterion. Los resultados mostraron que el pterion puede clasificarse en 4 tipos: esfeno-parietal (87,27 %), fronto-temporal (4,55 %), epiptérico (3,63 %) y multi-epiptérico (1,81 %). Se encontró que el tipo esfeno-parietal tuvo mayor incidencia en hombres (61,81 %) que en mujeres (25,45 %). Además, la incidencia de simetría bilateral (85,45 %) fue mayor que la unilateral (14,55 %). A nivel bilateral, el tipo esfeno-parietal fue de 93,61 %, mientras que el tipo epiptérico no se observó. Por otra parte, el tipo multiepiptérico fue encontrado bilateralmente en un solo cráneo femenino (2,13 %). Esta incidencia puede ser utilizada como un conocimiento básico para los radiólogos tailandeses sobre las fracturas laterales del cráneo en un diagnóstico de emergencia.

Morphological Study on Shapes of Pterion.

Background: Pterion is defined as an H-shaped small circular area formed by the junction of four bones: frontal, parietal, temporal and sphenoid on norma lateralis of the skull, 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 optic nerve, orbit, sphenoidal ridge and for the anterior circulation aneurysm and tumors, because of its clinical importance we focused our present study on morphology of shape of pterion. Materials and Methods: A total of 500 pterions were examined from 250 adult dry skulls. The present study was undertaken in adult south Indian skulls from different regions of south India, from different medical colleges. We have observed different shapes of pterion like sphenoparietal frontotemporal, stellate and epipteric. Results: The sutural morphology of the pterion and asterion is important in surgical approaches to the cranial fossae. 250 human skulls of known gender (148 male, 102 female) were examined on both sides. Four types of pterion were observed – sphenoparietal 72.8%, frontotemporal 16.4%, stellate 8.8% and epipteric 2%. Conclusion: The pterion is points of sutural confluence seen in the norma lateralis of the skull. The patterns of formation exhibit population based variations. The sutural morphology of the pterion is important in surgical approaches to the cranial fossae. These findings may helpful in surgical approaches and interventions via the pterion.

Morphometric study of pterion in dry human skull bones of nigerians / Estudio morfométrico del pterion en huesos del cráneo humano secos de nigerianos

The pterion is an important landmark on the side of the skull as it overlies both the anterior branch of the middle meningeal artery and the lateral cerebral fissure intracranially. The study was carried out to determine the pterion types and define its distances to some neighboring structures in dry human skulls of Southern Nigerians. The study comprised 50 dry human skulls of unknown sex and age obtained from selected Nigerian Universities. Sutural patterns of the pterion on both sides of each skull based on the description of Murphy (1956), were observed and recorded. Distances of the pterion to neighboring structures were also measured using digital vernial caliper. Data obtained were subjected to statistical analysis using descriptive statistics and chi-square contingency table with the aid of the statistical package for social sciences (SPSS) version 16. P<0.05 is considered statistically significant. Results showed that the most common type of Pterion in Nigerian skulls was sphenoparietal. There was no significant association between side of the head and pterion type. The mean distance of the pterion to the frontozygomatic suture was 31.56±2.47 mm taking both side together, (left side = 31.08±2.24 mm; right side = 32.06±2.62 mm). The mean distance of the pterion to the midpoint of the zygomatic arch was 39.87±3.16 mm taking both sides together (left side = 39.52±3.32 mm; right side = 40.22±2.98 mm). The mean distance of the pterion to the glabella was 77.51±4.08 mm taking both side together (left side = 76.74±4.27 mm; right side = 78.27±3.77 mm). This will be useful in Surgery, Anthropology and for assessing the location of the pterion in incomplete archeological remains or forensic materials.

El pterion es un importante marcador del lado del cráneo, ya que se superpone a la rama anterior de la arteria meníngea media y a la cisura cerebral lateral por vía intracraneal. El estudio se realizó para determinar el tipo de pterion y definir las distancias con algunas estructuras cercanas, en cráneos humanos secos de nigerianos del Sur. Se utilizaron 50 cráneos humanos sin información de sexo y edad, obtenidos de Universidades. Fueron observados y registrados los patrones suturales del pterion en ambos lados de cada cráneo, basados en la descripción de Murphy en 1956. También se midieron las distancias del pterion hacia estructuras cercanas utilizando un cáliper digital. Los datos obtenidos fueron sometidos a análisis estadístico mediante estadística descriptiva y prueba de chi cuadrado con el programa estadístico SPSS versión 16. Un valor P<0,05 se consideró significativo. El tipo más común de pterion en cráneos de Nigeria fue esfenoparietal. No hubo asociación significativa entre el lado del cráneo y el tipo pterion. La distancia media del pterion a la sutura frontocigomática fue 31,56±2,47 mm (al lado izquierdo = 31,08±2,24 mm, al derecho = 32,06±2,62 mm). La distancia media del pterion hasta el punto medio del arco cigomático fue 39,87±3,16 mm (al lado izquierdo = 39,52±3,32 mm; al derecho = 40,22±2,98 mm). La distancia media del pterion a la glabela fue 77,51±4,08 mm (al lado izquierdo = 76,74±4,27 mm, al derecho = 78,27±3,77 mm). Esta información es útil para la cirugía y antropología, así como también en la evaluación de la ubicación del pterion en restos arqueológicos incompletos o material forense.

Study of pterion and incidence of epipteric bones in dry human skulls of Gujarat.

Background: Pterion is present in floor of temporal fossa which is a meeting point of four bones, frontal and parietal bone superiorly and the greater wing of sphenoid and squamous temporal bone inferiorly. It is ‘H-shaped’ in most of the skulls. The most common variation is in its shape and presence of epipteric bone. Aim : To report the various types of pterion and incidence of epipteric bones in the human skulls and to compare with other racial groups from previous study. Methods: The present study was conducted using 311 dry, grossly normal human skulls from sources in Gujarat. Different types of pterion and the presence of epipteric bones were observed. Results: In the present study sphenoparietal variety of pterion was predominant and the incidence of epipteric bone was 11.73%. Conclusion: Knowledge of the presence of epipteric bones are important to prevent complications during burr hole surgery and to prevent misdiagnosis of fracture skull at the site of pterion.

A comparative study of variation of the pterion of human skulls from 13th and 20th century Anatolia / Un estudio comparativo de la variación del pterion en cráneos humanos de los siglos 13 y 20 de Anatolia

The pterion is a commonly used anthropologic and neurosurgical landmark defined as the junction of the sphenoid, temporal, parietal and frontal bones. It is commonly classified into four types based on sutural pattern: sphenoparietal, in which the sphenoid and parietal bones are in direct contact; frontotemporal, in which the frontal and temporal bones are in direct contact; stellate, in which all four bones come into contact at a point; and epipteric, in which a small sutural bone is found between the parietal bone and the greater wing of the sphenoid bone. In the present study, 44 Anatolian skulls from two different eras, Byzantine (13th century) and contemporary (20th century), were investigated for morphology and location of the pterion. Sphenoparietal was the most common form, comprising 87.5 percent and 89.2 percent in the Byzantine and contemporary groups, respectively. The frequencies of the epipteric type of pterion were 6.25 percent and 3.6 percent in the Byzantine and contemporary groups, respectively. Measurements of the location of the pterion were made by using stainless steel calipers and Scion Image software. There were no significant differences in digital and manual measurements between the right and left sides of the skulls in both groups. However, the distance from the pterion to the inion was significantly greater in the manual measurements compared to the digital measurements. Anatomical variations of the pterion, which are of interest to anthropologists, forensic pathologists and surgeons, deserve further investigation in other populations from different geographical areas.

El pterion es un punto comúnmente usado como punto de referencia antropológico y neuroquirúrgico, correspondiendo a la unión de los huesos esfenoides, temporal, parietal y frontal. Generalmente es clasificado en 4 tipos basado en padrones suturales: esfenoparietal, en el cual los huesos esfenoides y parietal están directamente en contacto; frontotemporal, en el cual el frontal y el temporal se encuentran en contacto directo; estrellado, en el cual los cuatro huesos mencionados se contactan directamente en un punto y epiptérico, en el cual un pequeño hueso sutural se encuentra entre el hueso parietal y el ala mayor del esfenoides. En el presente estudio, investigamos la morfología y la localización del pterion en 44 cráneos Anatolian de diferentes épocas, Bizantina (Siglo XIII) y contemporánea (Siglo XX). La forma más común que se encontró fue la Esfenoparietal, con un 87,5 por ciento para los del grupo Bizantino y 89,2 por ciento para los de la era contemporánea. La frecuencia del tipo epiptérico fue de 6,25 por ciento y 3,6 por ciento, respectivamente. Se realizaron medidas de la posición del pterion utilizando un caliper y un software de imágenes. No hubo diferencias estadísticamente significativas en las mediciones manuales y digitales entre los lados derecho e izquierdo de los cráneos de ambos grupos. Sin embargo, la distancia desde el pterion al inion fue significativamente mayor en las medidas manuales comparadas con las digitales. Las variaciones anatómicas del pterion, las cuales son de interés para antropólogos, patólogos forenses y cirujanos, son un tema de investigación a desarrollar en otras poblaciones de diferentes áreas geográficas.

Morphological Analysis of the Pterion in Korean / 체질인류학회지

The morphology and location of the pterion was investigated in total of 149 Korean skulls (298 pteria). The most common form of the pterion was a sphenoparietal articulation in the incidence of 76.5%. The most common location of the pterion was in an area which covers 5 mm from the supraorbital horizontal line parallel to Frankfurt line and the incidence was 81.8%. The metric location of the pterion was on 36.9 +/-3.8 mm above the upper margin of the zygomatic arch and 26.8 +/-4.5 mm behind the posterior margin of the frontozygomatic suture. The average length of the pterion was 12.2 +/-4.4 mm. The most common form of the epipteric bone was a single bone which articulated with the frontal, parietal, temporal and sphenoid bone, and the incidence was 40.3%. The most common location of the epipteric bone was in an area which covers 5 mm from the supraorbital horizontal line parallel to Frankfurt line and the incidence was 45.2%. Morphological analysis of the pterion, when combined with some other non -metric and metric variants, may become useful physical anthropologic tools for the identification of the Korean skull.