Pterion types in Anatolian adult skulls Rev Arg de Anat Clin; 2019, 11 (1): 8-17 ___________________________________________________________________________________________ Original Communications PTERION TYPES AND MORPHOMETRY IN MIDDLE AND SOUTH ANATOLIAN ADULT SKULLS Kaan Cimen, Ilhan Otag, Mehmet Cimen Department of Anatomy, Faculty of Medicine, Cumhuriyet University, Sivas, Turkey ABSTRACT en 4 tipos de la siguiente manera: Esfenoparietal, frontotemporal, epiptérico y estrellado. El pterion Pterion is an irregular H letter shaped sutural representa: la rama anterior de la arteria meníngea confluence in the temporal fossa formed by frontal, media, la arteria cerebral media, el área motora del parietal bones, great wing of sphenoid bone and habla de Broca, la ínsula y el vástago del surco temporal squama. Pterion is classified in 4 types as cerebral lateral. Esta unión del pterión se ha utilizado follows: sphenoparietal, frontotemporal, epipteric and como un hito extracraneal común para los cirujanos en stellate. The pterion represents: anterior branch of the enfoques microquirúrgicos y quirúrgicos relacionados middle meningeal artery, middle cerebral artery, con patologías importantes de esta región. En el Broca’s motor speech area, insula and stem of the presente estudio, nuestro objetivo es determinar los lateral cerebral sulcus. This pterion junction has been tipos de pterion, estimar las distancias entre el pterión used as a common extra-cranial landmark for surgeons y algunos puntos de referencia especiales para in microsurgical and surgical approaches pertaining to contribuir a la literatura relacionada mediante la important pathologies of this region. In the present comparación de los datos con otros estudios que se study, our aim was to determine pterion types, to centran en diversas poblaciones. Los tipos de pterión estimate distances between pterion and some special identificados por observación y mediciones fueron landmarks by which means to contribute to the related tomados por un calibrador a Vernier de acero. Este literature by comparing the data with other studies estudio se realizó con 75 cráneos adultos (ambos focusing on various populations. Pterion types identified lados 150 pterion). Los cráneos se clasifican en by observation and measurements were taken by steel función del género como: 47 hombres y 28 mujeres. Vernier caliper. This study was conducted with 75 adult Los tipos de pterion observados en ambos sexos se skulls (both sides 150 pterion). Skulls were classified clasifican en: tipo esfenoparietal 82% (84,04% en with regard to gender as: 47 male and 28 female. hombres, 78,57% en mujeres), tipo frontotemporal Pterion types observed in both genders were classified 4,66% (5,31% en hombres, 3,57% en mujeres), tipo as: sphenoparietal type 82% (84.04% in male, 78.57% epiptérico 10,66% (8,51% en hombres, 14,28% en in female), frontotemporal type 4.66% (5.31% in male, mujeres) y tipo estrellado 2,66% (2,12% en hombres, 3.57% in female), epipteric type 10.66% (8.51% in 3,57% en mujeres). Estos hallazgos serán útiles para male, 14.28% in female) and stellate type 2.66% los clínicos, antropólogos y médicos forenses. (2.12% in male, 3.57% in female). These findings will be usefull for clinicians, anthropologists and forensics. Palabras clave: pterion; morfometría; cráneo; anatomía; morfología. Key words: Pterion; morphometry; human skull; human anatomy; morphology. _________________________________________________ RESUMEN * Correspondence to: Kaan Cimen. El pterion es una confluencia sutural con forma de [email protected] letra H irregular en la fosa temporal formada por los huesos frontales, parietales, el ala mayor del hueso Received: 18 October, 2018. Revised: 5 November, 2018. esfenoides y la escama temporal. Pterion se clasifica Accepted: 21 November, 2018. 8 www.anatclinar.com.ar Pterion types in Anatolian adult skulls Rev Arg de Anat Clin; 2019, 11 (1): 8-17 ___________________________________________________________________________________________ INTRODUCTION ramus anterior, ascendens and posterior branches. Pterion corresponds to the fontanella Pterion is usually characterized by an H letter anterolateralis (sphenoidalis) in the newborn shape sutural structure formed by frontal, cranium that disappeares 3 months after birth parietal, temporal and greater wing of sphenoid (Moore, 1992). Pterion is crucial intraoperative bones on temporal fossa. Four pterion types field in surgical approaches. In neurosurgery, were classified as: sphenoparietal, fronto- pterional approaches are used in such various temporal, epipteric and stellate by Murphy interventions and treatments as removal of (1956). complicated tumors, medial cerebral artery, The center of the pterion is located approximately internal carotid artery and traumatic optic 3.5 - 4 cm above arcus zygomaticus and 3 - 3.5 neuropathy (Mori et al., 2007). This pterion cm behind the suture frontozygomaticus. In junction has been used as a common extra- practice, the pterion is located two finger widths cranial landmark for surgeons in microsurgical above the arcus zygomaticus and a thumb-width and surgical approaches pertaining to important behind the processus frontalis of os zygomaticus pathologies of this region (Urzi et al., 2003). In (Moore, 1992). Pterion has a different morphol- the present study, our aim was to determine ogy because of meeting point of skull base, pterion types, to estimate distances between calvaria and facial skeleton (Urzi et al., 2003). pterion and some special landmarks by which Pterion also forms the base of temporal fossa. means to contribute to the related literature by Pterion is known as the Sylvian point. This is the comparing the data with other studies focusing point where the sulcus lateralis is divided into on various populations. Figure 1: (A) sphenoparietal type of pterion, (B) frontotemporal type of pterion, (C) epipteric type of pterion, (D) stellate type of pterion. 9 www.anatclinar.com.ar Pterion types in Anatolian adult skulls Rev Arg de Anat Clin; 2019, 11 (1): 8-17 ___________________________________________________________________________________________ Figure 2: Showing distances of pterion to some special landmarks. P: Pterion, SFZ: Posterior Aspect of Sutura Frontozygomaticus, AZ: Midpoint of the Arcus Zygomaticus, OML: Posterior Edge of the Orbita Margo Lateralis, PM: Inferior Pole of the Processus Mastoideus, MAE: Upper Edge of the Meatus Acusticus Externus, G: Glabella, I: Inion, A: Asterion. MATERIAL AND METHOD the frontotemporal type: frontal and temporal In the present study, 75 (both side 150 pterions) bones are directly in contact (Fig. 1b). In the adult skulls, which have shown non-trauma, were epipteric type, the presence of sutural bones is examined. Examined skulls were obtained from located between sphenoid and parietal bones the laboratories: Anthropology Department of the (Fig. 1c). In the stellate type: frontal, temporal, Faculty of Letter and Anatomy Department of the sphenoid and parietal bones meet at same Faculty of Medicine of Cumhuriyet University and junction point (Fig. 1d). Anatomy Department of the Faculty of Medicine, Distance parameters were taken as: between Erciyes University. Morphometrical mesurements pterion center (P) and posterior aspect of sutura were taken by steel Vernier caliper and outer frontozygomaticus (SFZ), midpoint of the arcus diameter compass. zygomaticus (AZ), posterior edge of the orbita This study was done by determining the sutural margo lateralis (OML), inferior pole of the patterns of the pterion on both sides of each skull processus mastoideus (PM), upper edge of the based on the description of Murphy (Fig. 1a, 1b, meatus acusticus externus (MAE), glabella (G), 1c, 1d). In the sphenoparietal type: sphenoid and inion (I), asterion (A). Also distance between parietal bones are directly in contact (Fig. 1a). In glabella (G) and inion (I) was measured (Fig. 2). 10 www.anatclinar.com.ar Pterion types in Anatolian adult skulls Rev Arg de Anat Clin; 2019, 11 (1): 8-17 ___________________________________________________________________________________________ The data obtained from our study were loaded on parameters in the evaluation of the data. ANOVA the SPSS (Ver: 22.0) program, and the t-test was was used in the comparison of the pterion types used in independent subjects to compare the and the error level was taken as 0.05. Figure 3: Arrows indicate that: (A) sphenoparietal type of pterion on female skull, (B) frontotemporal type of pterion on male skull, (C) epipteric type of pterion on female skull, (D) stellate type of pterion on male skull. RESULTS Mean distance between pterion and arcus zygomaticus was measured as 36.5±6.6 mm, In classifying pterion types; sphenoparietal type 35.5±5.9 mm in male and female skulls (Table 2) was the most dominant one with 79 sides respectively and totally 36.1±6.4 mm (Table 3). (84.04%), 44 sides (78.57%) in male and female Mean distance between pterion and orbita margo skulls respectively and totally 123 sides (82%) lateralis was measured as 38.0±6.9 mm, (Fig. 3a, b, c, d) (Table 1). 35.7±6.6 mm in male and female skulls (Table 2) Mean distance between pterion and sutura respectively and totally 37.2±6.9 mm (Table 3). frontozygomaticus was measured as 32.8±4.8 Mean distance between pterion and processus mm, 31.6±4.4 mm in male and female skulls mastoideus was measured as 82.6±5.1 mm, (Table 2) respectively and totally 32.4±4.7 mm 76.2±6.0 mm in male and female skulls (Table 2) (Table 3). respectively and totally 80.2±6.3 mm (Table 3). 11 www.anatclinar.com.ar Pterion types in Anatolian adult skulls Rev Arg de Anat Clin; 2019, 11 (1): 8-17 ___________________________________________________________________________________________ Male Female Both Sides (Regardless gender) Right Left Both % Right Left Both % Right Left % Side Side Sphenoparietal 41 38 79 84.04 23 21 44 78.57 64 59 82 Frontotemporal 2 3 5 5.31 1 1 2 3.57 3 4 4.66 Epipteric 3 5 8 8.51 3 5 8 14.28 6 10 10.66 Stellate 1 1 2 2.12 1 1 2 3.57 2 2 2.66 Table 1: Frequency and distribution of the pterion types in terms of gender and side.