Angle Evaluation of Possible Routes that Can Be Used to Reach the Foramen Ovale in the Anterior Approach / Evaluación Angular de Posibles Rutas que se Pueden Utilizar para Alcanzar el Foramen Oval en el Abordaje Anterior

SUMMARY: For the treatment of trigeminal neuralgia, the foramen ovale is reached by entering the cheek with a needle. Thermocoagulation is performed with balloon compression, administration of alcohol or radiofrequency. Apart from the classical method, it is theoretically possible to reach the foramen ovale through the mouth with the anterior approach. In our study, it was aimed to examine horizontally and vertically the angular values that must be given to the needle to reach the foramen ovale in the anterior approach. Three landmark points were determined on both right and left sides of 25 dry skulls. A rod was inserted starting from these landmark points and passing through the center of the foramen ovale. The vertical and horizontal angular values of this bar were measured. For each foramen ovale, 3 vertical angles, 3 horizontal angles and 4 distance measurements were made. There was a significant difference between the right and left sides in terms of horizontal angular values. Average values of horizontal angles (in degrees); on the right, 7.29 for H1, 12.15 for H2, 32.29 for H3; 1.26 for H1, 9.46 for H2, and 30.56 for H3 on the left side (p<0.005). The angle value was measured as 0 or negative value in 5 (20 %) of the H1 angle measurements made on the right side and 14 (56 %) on the left side. The H2 angle value was found to be smaller than the H1 angle in the skull 2 (8 %) on the right and 3 (12 %) on the left. There was no difference between the right and left sides in terms of vertical angular values. A significant difference was found between the right and left sides in the D1, D2, D4 distances (p<0.005). Six important anatomical features affecting angular values were encountered.

Para el tratamiento de la neuralgia del trigémino, se alcanza el foramen oval introduciendo una aguja en la mejilla. La termocoagulación se realiza con compresión con balón, administración de alcohol o radiofrecuencia. Aparte del método clásico, en teoría es posible alcanzar el foramen oval a través de la cavidad oral mediante el abordaje anterior. En nuestro estudio se tuvo como objetivo examinar horizontal y verticalmente los valores angulares que se deben dar a la aguja para alcanzar el foramen oval en el abordaje anterior. Se determinaron tres puntos de referencia en los lados derecho e izquierdo de 25 cráneos secos. Se insertó una varilla comenzando desde estos puntos de referencia y pasando por el centro del foramen oval. Se midieron los valores angulares verticales y horizontales de esta barra. Para cada foramen oval se realizaron mediciones de 3 ángulos verticales, 3 ángulos horizontales y 4 distancias. Hubo una diferencia significativa entre los lados derecho e izquierdo en términos de valores angulares horizontales. Valores medios de ángulos horizontales (en grados); a la derecha, 7,29 para H1, 12,15 para H2, 32,29 para H3; 1,26 para H1, 9,46 para H2 y 30,56 para H3 en el lado izquierdo (p<0,005). El valor del ángulo se midió como 0 o valor negativo en 5 (20 %) de las mediciones del ángulo H1 realizadas en el lado derecho y 14 (56 %) en el lado izquierdo. Se encontró que el valor del ángulo H2 era menor que el ángulo H1 en el cráneo 2 (8 %) a la derecha y 3 (12 %) a la izquierda. No hubo diferencia entre los lados derecho e izquierdo en términos de valores angulares verticales. Se encontró diferencia significativa entre el lado derecho e izquierdo en las distancias D1, D2, D4 (p<0,005). Se encontraron seis características anatómicas importantes que afectan los valores angulares.

Crista Galli Morphometry and Morphology: An Anatomical, Radiological, and Machine Learning Application Study / Crista Galli Morfometría y Morfología: Un Estudio de Aplicación Anatómica, Radiológica y de Aprendizaje Automático

SUMMARY: The study purposed to examine the morphometry and morphology of crista galli in cone beam computed tomography (CBCT) and apply a new analysis, supervised Machine Learning techniques to find the answers to research questions "Can sex be determined with crista galli morphometric measurements?" or "How effective are the crista galli morphometric measurements in determining sex?". Crista galli dimensions including anteroposterior, superoinferior, and laterolateral were measured and carried out on 200 healthy adult subjects (98 females; 102 males) aged between 18-79 years. Also, crista galli was classified with two methods called morphological types and Keros classification. In this study, the Chi-square test, Student's t-test, and Oneway ANOVA were performed. Additionally, Machine Learning techniques were applied. The means of the CGH, CGW, and CGL were found as 14.96 mm; 3.96 mm, and 12.76 mm in males, respectively. The same values were as 13.54 mm; 3.51 mm and 11.59±1.61 mm in females, respectively. The CG morphometric measurements of males were higher than those of females. There was a significant difference between sexes in terms of morphological classification type. Also, when the sex assignment of JRip was analyzed, out of 102 male instances 62 of them were correctly predicted, and for 98 female instances, 70 of them were correctly predicted according to their CG measurements. The JRip found the following classification rule for the given dataset: "if CGH<=14.4 then sex is female, otherwise sex is male". The accuracy of this rule is not high, but it gives an idea about the relationship between CG measurements and sex. Although the issue that CG morphometric measurements can be used in sex determination is still controversial, it was concluded in the analysis that CG morphometric measurements can be used in sex determination. Also, Machine Learning Techniques give an idea about the relationship between CG measurements and sex.

En el estudio se propuso examinar la morfometría y la morfología de la crista galli del hueso etmoides usando tomografía computarizada de haz cónico (CBCT) y aplicar un nuevo análisis, técnicas de aprendizaje automático supervisado para encontrar las respuestas a las preguntas de investigación "¿Se puede determinar el sexo con mediciones morfométricas de la crista galli?" o "¿Qué tan efectivas son las medidas morfométricas de la crista galli para determinar el sexo?". Las dimensiones de la crista galli, incluidas los diámetros anteroposterior, superoinferior y laterolateral, se midieron y realizaron en 200 sujetos adultos sanos (98 mujeres; 102 hombres) con edades comprendidas entre los 18 y los 79 años. La crista galli se clasificó con dos métodos llamados tipos morfológicos y clasificación de Keros. En este estudio, se realizaron la prueba de Chicuadrado, la prueba t de Student y ANOVA de una vía. Adicionalmente, se aplicaron técnicas de Machine Learning. Las medias de CGH, CGW y CGL se encontraron en 14,96 mm; 3,96 mm y 12,76 mm en hombres, respectivamente. Los mismos valores fueron 13,54 mm; 3,51 mm y 11,59 ± 1,61 mm en mujeres, respectivamente. Las medidas morfométricas del CG de los hombress fueron más altas que las de las mujeres. Hubo una diferencia significativa entre sexos en cuanto al tipo de clasificación morfológica. Además, cuando se analizó la asignación de sexo de JRip, de 102 instancias masculinas, 62 de ellas se predijeron correctamente, y de 98 instancias femeninas, 70 de ellas se predijeron correctamente de acuerdo con las mediciones de CG. El JRip encontró la siguiente regla de clasificación para el conjunto de datos dado: "si CGH<=14.4, por tanto el sexo es femenino, de lo contrario, el sexo es masculino". La precisión de esta regla no es alta, pero da una idea de la relación entre las medidas del CG y el sexo. Aunque la pregunta si las medidas morfométricas CG se pueden usar en la determinación del sexo sigue aún siendo controvertida. Se concluyó en el análisis que las medidas morfométricas CG se pueden usar en la determinación del sexo. Además, las técnicas de aprendizaje automático dan una idea de la relación entre las medidas de CG y el sexo.

Topographic and Morphometric Study of the Foramen Spinosum of the Skull and Its Clinical Correlation.

Background and Objectives: The spinous foramen (FS) of the skull is an opening located in the greater wing of the sphenoid bone at the base of the skull, and it includes the middle meningeal vessels and the meningeal branch of the mandibular trigeminal nerve. The FS is commonly used as an anatomical landmark in neurosurgical procedures and neuroimaging of the middle cranial fossa because of its relationship with other cranial foramina and surrounding vascular and nervous structures. Thus, specific knowledge of its topography and possible anatomical variations is important regarding some surgical interventions and skull imaging. The aim of this study was to provide further details on the morphology of the FS of the skull by evaluating its topographic and morphometric relationships and correlating the findings with clinical practice. Materials and Methods: Thirty dried skulls of human skeletons from body donors from the collection of the Laboratory of Anatomical Microdissection at a medical school were used. The metric dimensions and variations of the FS and its relationship with adjacent bone structures were analyzed with an interface digital microscope. Results: The results showed the bilateral presence of the FS in all skulls; however, differences were observed in the shape, diameter, and topography in relation to the foramen ovale and the spine of the sphenoid. The FS was present in the greater wing of the sphenoid bone; however, in one skull, it was located in the lateral lamina of the pterygoid process. The FS was smaller than the foramen ovale. A round and oval FS shape was the most common (42.1% and 32.8% of the samples, respectively), followed by drop-shaped (12.5%) and irregular-shaped (12.5%) foramina. Conclusions: In conclusion, FS variations among individuals are common and must be considered by surgeons during skull base interventions in order to avoid accidents and postoperative complications.

Anatomical relationship of pterygoid process pneumatization and vidian canal.

INTRODUCTION: The vidian canal acts as landmark for the identification of the petrous carotid artery, especially during extended endoscopic endonasal approaches in cranial base surgeries. In order to localize the canal and to understand the relationship of pneumatization of pterygoid process to the type of vidian canal, this study was designed. OBJECTIVES: The objective was to describe the anatomical relationship of pneumatization of the pterygoid process with types of vidian canal. The length of vidian canal, relationship to medial plate of pterygoid process and relationship to the petrous part of internal carotid artery were evaluated. METHODS: Head computer tomography scans of 52 individuals for suspected paranasal pathology were studied. The degree of sphenoid sinus pneumatization, pterygoid process pneumatization and types of vidian canal (type 1, 2 and 3) were noted. The length of vidian canal, distance from the plane of medial pterygoid plate and relation of vidian canal to the junction of petrous and Gasserian (ascending) part of internal carotid artery was noted. RESULTS: 46 (92%) sphenoid sinuses were of the sellar variety. Out of 104 sides that were studied, 57 sides demonstrated a pneumatised pterygoid process and 47 were not pneumatised. In 49 sides (47.1%) the vidian canal was on the same plane as that of the medial pterygoid plate in the coronal section. The vidian canal partially protruded into the sphenoid sinus (type 2) was the most common type (50.9%), found both on right and left sides. There is a statistically significant association between the pterygoid process pneumatization and occurrence of type 2 and type 3 vidian canal configuration. The average length of the vidian canal was 16.16 ±â€¯1.8 mm. In 96 sides, the anterior end of vidian canal was inferolateral to petrous part of internal carotid artery in the coronal plane. CONCLUSION: Pneumatization of the pterygoid process indicates either type 2 or type 3 vidian canal configuration.

Incomplete petrosphenoidal foramen: morphological and morphometric analysis and the proposal of a classification study in Brazilian dry skulls / Foramen petrosfenoidal incompleto: análisis morfológico y morfométrico y propuesta de clasificación: estudio en cráneos secos brasileños

SUMMARY: The complete petrosphenoidal foramen, or canal, is an eventual and atavistic bony formation at the boundary between the posterior and middle cranial fossa, by occurrence of ossification of the superior petrosphenoidal ligament. This ligament ossification, which has important clinical and surgical significance, can be complete or incomplete, in variable degrees, and is associated with the passageway of neurovascular structures, such as the abducens nerve and the inferior petrosal sinus. This study, conducted with 175 dry skulls that belong to the University of São Paulo's collection (USP), São Paulo, Brazil, established criteria for a morphological classification of the incomplete petrosphenoid foramen in nine types. In addition, anatomical parameters were established for the morphometric determination of two diameters: the Oblique Diameter (ObDi) and the Maximum Transverse Diameter (MTD). Thus, of the 175 skulls, 146 (83.42 %) presented some of the incomplete forms of the petrosphenoid foramen, and 43 skulls (29.45 %), due to their conservation characteristics, were habilitated to the morphological study, in the classification and in the morphometry (the types I and II of our classification). The type II (incomplete foramen with bony projections of the petrosal tubercle, of the margin of the dorsum of the hypophyseal fossa or of the posterior clinoid process with a distance between them greater than 1mm) and type V (incomplete foramen with a bony projection only in one of the referential structures - posterior clinoid process) were the most common in this study (50 % of the 86 hemiskulls). Morphometry was attributed only to the types: I selar (incomplete foramen with bony projections from the petrosal tubercle and the margin of the dorsum of the hypophyseal fossa with a distance between them less than or equal to 1mm) and to the type II of this classification. The type I selar (9.3 % of the 43 skulls) resulted in an average of 3.25 mm of MTD and 4.63 mm, on average, of ObDi. The type II (25.58 % of the 43 skulls) showed, on average, 4.93 mm of MTD and 7.01 mm of ObDi.

RESUMEN: El foramen o canal petroesfenoidal completo es una formación ósea eventual y atávica en el límite entre las fosas craneal posterior y media, por osificación del ligamento petroesfenoidal superior. Esta osificación del ligamento, que tiene un importante significado clínico y quirúrgico, puede ser completa o incompleta, en grados variables, y está asociada al paso de estructuras neurovasculares, como el nervio abducente y el seno petroso inferior. Este estudio se realizó en 175 cráneos secos pertenecientes a la colección de la Universidad de São Paulo (USP), São Paulo, Brasil. Se establecieron criterios para una clasificación morfológica del foramen petrosfenoidal incompleto en nueve tipos. Además, se establecieron parámetros anatómicos para la determinación morfométrica de dos diámetros: el Diámetro Oblicuo (ObDi) y el Diámetro Transversal Máximo (MTD). Así, de los 175 cráneos, 146 (83,42 %) presentaron alguna de las formas incompletas del foramen petrosfenoidal, y 43 cráneos (29,45 %), por sus características de conservación, fueron habilitados para el estudio morfológico, en la clasificación y en la morfometría (los tipos I y II de nuestra clasificación). El Tipo II (foramen incompleto con proyecciones óseas del tubérculo petroso, del margen del dorso de la fosa hipofisaria o del proceso clinoides posterior con una distancia entre ellos mayor de 1 mm) y el Tipo V (foramen incompleto con proyección ósea solamente en una de las estructuras referenciales - proceso clinoides posterior) fueron los más comunes en este estudio (50 % de los 86 hemiscráneos). La morfometría se atribuyó únicamente al Tipo I selar (foramen incompleto con proyecciones óseas desde el tubérculo petroso y el margen del dorso de la fosa hipofisaria con una distancia entre ellos menor o igual a 1mm) y al Tipo II de esta clasificación. El Tipo I selar (9,3 % de los 43 cráneos) resultó en un promedio de 3,25 mm de MTD y 4,63 mm, en promedio, de ObDi. El Tipo II (25,58 % de los 43 cráneos) mostró, en promedio, 4,93 mm de MTD y 7,01 mm de ObDi.

Morphometric analyses of the caroticoclinoid and interclinoid foramina: a study in Brazilian dry skulls / Análisis morfométricos del foramen caroticoclinoideo e interclinoideo: un estudio en cráneos secos brasileños

SUMMARY: The caroticoclinoid (CF) and the interclinoid (IF) foramina are variant formations of the middle cranial fossa, which result from idiopathic and possibly atavistic ossifications of the caroticoclinoid and interclinoid ligaments, respectively. Topographically, these foramina are intimately associated, to varying degrees, depending on their conformations, with the neurovascular elements of the paraclinoid region and have important clinical and surgical significance. Thus, this study, conducted from 38 dry skulls belonging to the shared collection of the Federal University of Juiz de Fora, Governador Valadares campus, revealed 11 skulls (28.95 %) with one of the two complete formations - the caroticoclinoid or the interclinoid, and in 6 skulls the caroticoclinoid foramen occurred uni or bilaterally. As a result, 50 % of these skulls presented the CF exclusively on the right (or 62.5 % of the total number of variant foramina), with an average transverse diameter of 4.91 mm and 5.8 mm AP (anteroposterior) diameter and an average area of 22.5 mm2. Concerning the IF, the findings occurred in 5 skulls with variable distributions between the clinoid processes and lateralities. The average length of the bone bridges in the IF was 7.7 mm. In conclusion, detailed anatomical knowledge of the caroticoclinoid and the interclinoid foramina is fundamental to the practice of neurosurgical procedures, since they have intimate relationships at a location of high structural complexity.

RESUMEN: El foramen caroticoclinoideo (FC) y el foramen interclinoideo (IC) son formaciones variables de la fosa craneal media, que resultan de osificaciones idiopáticas y posiblemente atávicas de los ligamentos caroticoclinoideo e interclinoideo, respectivamente. Estos forámenes están íntimamente asociados topográficamente en diversos grados, dependiendo de sus conformaciones, con los elementos neurovasculares de la región paraclinoidea y tienen importancia clínica y quirúrgica. Así, este estudio, realizado a partir de 38 cráneos secos pertenecientes a la colección compartida de la Universidad Federal de Juiz de Fora, campus Governador Valadares, reveló 11 cráneos (28,95 %) con una de las dos formaciones completas: el FC o el IC, y en 6 cráneos el FC se presentó uni o bilateralmente. Como resultado, el 50 % de estos cráneos presentaba el FC exclusivamente a la derecha (o el 62,5 % del total de forámenes variantes), con un diámetro transversal medio de 4,91 mm y un diámetro anteroposterior medio de 5,8 mm y un área promedio de 22,5 mm2. En cuanto a la FI, los hallazgos se presentaban en 5 cráneos con distribuciones variables entre los procesos clinoides y lateralidades. La longitud media de los puentes óseos en el FI fue de 7,7 mm. En conclusión, el conocimiento anatómico detallado de los forámenes caroticoclinoideo e interclinoideo resulta fundamental para la práctica de procedimientos neuroquirúrgicos, ya que presentan relaciones íntimas en un lugar de alta complejidad estructural.

Anatomical variations and morphometric study of pterion in a Thai population associated with clinical implications / Variaciones anatómicas y estudio morfométrico del pterion en una población tailandesa asociada con implicaciones clínicas

SUMMARY: The objective of this study was to consider the type of variation and to estimate the landmarks for localizing the pterion. One hundred twenty Thai dry skulls were selected randomly from the Forensic Osteology Research Center, Faculty of Medicine, Chiang Mai University. The distances of the parameters were measured via Vernier caliper. The sphenoparietal type is the most dominant in the Thai population with 88.75 %. In the male, the distance of the midglabella to the pterion was 9.94?0.64 mm The distance of the frontozygomatic suture to the pterion was 35.41?4.38 mm The distance of the zygomatic arch to the pterion was 39.39?4.69 mm and the distance of the mastoid process tip to the pterion was 86.88?4.44 mm In the female, the distance of the midglabella to the pterion was 9.27?0.63 mm The distance of the frontozygomatic suture to the pterion was 33.08?4.12 mm The distance of the zygomatic arch to the pterion was 33.08?4.12 mm and the distance of the mastoid process tip to the pterion was 83.62?5.16 mm. The pterion approach is the most popular method for neurosurgical procedures, and it provides anatomical variations in the pattern. The sphenoparietal type of pterion is the most common form and the stellate type of pterion is the least common form in Thai skulls. Sex influences the location of the pterion. These findings will be of importance to predict the pterion type in Thai skull and estimate the localization of pterion by using a bony landmark. Knowledge of the precise location of the pterion is an important landmark in the neurosurgical approach.

RESUMEN: El objetivo de este estudio fue considerar el tipo de variación del pterion y estimar los puntos de referencia para localizarlo. Se seleccionaron al azar 120 cráneos secos de individuos tailandeses del Centro de Investigación de Osteología Forense de la Facultad de Medicina de la Universidad de Chiang Mai. Las distancias de los parámetros se midieron mediante un caliper Vernier. El tipo esfenoparietal es el más dominante en la población tailandesa con 88,75 %. En el hombre, la distancia de la glabella al pterion fue de 9,94 ? 0,64 mm. La distancia de la sutura frontocigomática fue de 35,41 ? 4,38 mm La distancia del arco cigomático fue de 39,39 ? 4,69 mm y la distancia del ápice del proceso mastoideo al pterion fue de 86,88 ? 4,44 mm. En la mujer, la distancia de la glabella al pterion fue de 9,27 ? 0,63 mm. La distancia de la sutura frontocigomática al pterion fue de 33,08 ? 4,12 mm. La distancia del arco cigomático al pterion fue de 33,08 ? 4,12 mm y la distancia del ápice proceso mastoideo al pterion fue de 83,62 ? 5,16 mm. El abordaje del pterion es el método más utilizado para procedimientos neuroquirúrgicos y proporciona variaciones anatómicas en el patrón. El tipo esfenoparietal del pterion es la forma más común y el tipo estrellado del pterion es la forma menos común en los cráneos tailandeses. El sexo influye en la ubicación del pterion. Estos hallazgos serán importantes para predecir el tipo de pterion del cráneo en tailandeses y a la vez estimar su localización mediante el uso de un punto de referencia óseo. El conocimiento de la ubicación precisa del pterion es un hito impor- tante en el abordaje neuroquirúrgico.

The pterygospinous foramen (Civinini) and the pterygoalar (crotaphitico-buccinatorius): laboratory findings / El foramen pterigoespinoso (Civinini) y el pterigoalar (crotafítico-buccinatorius): hallazgos de laboratorio

SUMMARY: The Pterygospinous foramen and pterygoalar foramen (crotaphitico-buccinatorius) are variant and atavic formations of the skull base and arise respectively from complete or incomplete idiopathic ossifications of the pterygospinous and pterygoalar ligaments. By proximity with areas of relevance for diagnosis and surgery, such as access pathways to the parapharyngeal and retropharyngeal spaces, it is necessary to be aware of these conditions due to the difficulties generated in surgical maneuvers and the promotion of compressive syndromes of mandibular nerve branches. This study was conducted on 45 samples of dry skulls and disarticulated sphenoid bones belonging to the collection of the Federal University of Juiz de Fora, Governador Valadares campus, Minas Gerais, Brazil. Our results indicated a total incidence of complete and incomplete pterygospinous and pterygoalar foramen (crotaphitico- buccinatorius) in 15, 5 % (7 skulls), with a higher incidence for the incomplete form of pterygospinous foramen (Civinini foramen) in 4 skulls (8.8 %), with 3 presenting unilaterally and 3 presenting bilaterally. The pterygoalar foramen (crotaphitico-buccinatorius or Hyrtl) was noted bilaterally in 1 of the skulls (2.2 %). The pterygospinous foramen and pterygoalar foramen are important findings, sometimes incidental, of an area of great anatomical expressiveness and pathological occurrences, besides the indispensable and unclear studies of phylogenetic order.

RESUMEN: El foramen pterigoespinoso y el foramen pterigoalar (crotafítico-buccinatorius) son formaciones variantes y atávicas de la base del cráneo y surgen respectivamente de osificaciones idiopáticas completas o incompletas, de los ligamentos pterigoespinoso y pterigoalar. Debido a la proximidad con áreas de relevancia para el diagnóstico y la cirugía, como las vías de acceso a los espacios parafaríngeo y retrofaríngeo, es necesario conocer estas condiciones por las dificultades que se generan en las maniobras quirúrgicas. Este estudio se realizó en 45 muestras de cráneos secos y huesos esfenoides desarticulados pertenecientes a la colección de la Universidad Federal de Juiz de Fora, campus Governador Valadares, Minas Gerais, Brasil. Nuestros resultados indicaron una incidencia total de foramen pterigoespinoso y pterigoalar completo e incompleto (crotafítico-buccinatorius) en el 15,5 % (7 cráneos), con una mayor incidencia de la forma incompleta de foramen pterigoespinoso (agujero de Civinini) en 4 cráneos (8,8 %), con 3 de presentación unilateral y 3 de presentación bilateral. El foramen pterigoalar (crotaphitico-buccinatorius o Hyrtl) se observó bilateralmente en 1 de los cráneos (2,2 %). El foramen pterigoespinoso y pterigoalar son hallazgos importantes, a veces incidentales, de un área de gran expresividad anatómica y ocurrencias patológicas, además de los estudios indispensables y poco claros de orden filogenético.

Morphology of the pterion in Serbian population / Morfología del pterion en población serbia

The pterion is a topographic point on the lateral aspect of the skull where frontal, sphenoid, parietal and temporal bones form the H or K shaped suture. This is an important surgical point for the lesions in anterior and middle cranial fossa. This study was performed on 50 dry skulls from Serbian adult individuals from Department of Anatomy, Faculty of Medicine in Novi Sad. The type of the pterion on both sides of each skull was determined and they are calcified in four types (sphenoparietal, frontotemporal, stellate and epipteric). The distance between the center of the pterion and defined anthropological landmarks were measured using the ImageJ software. Sphenoparietal type is predominant with 86 % in right side and 88 % in left side. In male skulls, the distance from the right pterion to the frontozygomatic suture is 39.89±3.85 mm and 39.67±4.61 mm from the left pterion to the frontozygomatic suture. In female skulls the distance is 37.38±6.38 mm on the right and 35.94±6.46 mm on the left. The shape and the localization of the pterion are important because it is an anatomical landmark and should be used in neurosurgery, traumatology and ophthalmology.

El pterion es un punto topográfico en la cara lateral del cráneo donde los huesos frontales, esfenoides, parietales y temporales forman la sutura en forma de H o K. Este es un punto quirúrgico importante para las lesiones en la fosa craneal anterior y media. Este estudio se realizó en 50 cráneos secos de adultos serbios del Departamento de Anatomía de la Facultad de Medicina de Novi Sad. Se determinó el tipo de pterión en ambos lados de cada cráneo y se calcifican en cuatro tipos (esfenoparietal, frontotemporal, estrellado y epipterico). La distancia entre el centro del pterion y los puntos de referencia antropológicos definidos se midió utilizando el software ImageJ. El tipo esfenoparietal es predominante con 86 % en el lado derecho y 88 % en el lado izquierdo. En los cráneos masculinos, la distancia desde el pterion derecho hasta la sutura frontocigomática es 39,89 ± 3,85 mm y 39,67 ± 4,61 mm desde el pterion izquierdo hasta la sutura frontocigomática. En los cráneos femeninos, la distancia es 37,38 ± 6,38 mm a la derecha y 35,94 ± 6,46 mm a la izquierda. La forma y la localización del pterion son importantes debido a que es un indicador anatómico y debe usarse en neurocirugía, traumatología y oftalmología.

Where does the cranial base flexion take place in humans?

The modern human has the most flexed cranial base among all living animals. The flexure allowed a larger cranial volume to accommodate a greater brain. Spheno-occipitalis synchondrosis (SOS) has been largely responsible for cranial base flexion, between the sphenoid and the Pars basilaris of the occipital bone. The objective of this work is to evaluate the real place of skull base flexure. Analysis based on 50 magnetic resonance imaging from normal adult subjects were used to evaluate normal place for cranial base angulation (CBA). The vertex of the cranial base angle in all individuals occurred intrinsically in the sphenoid bone. In humans, cranial base flexure had a specific pre-chordal origin, rather than in the transition between pre-chordal and chordal plates and occurred in the inner sphenoidal bone.

The sphenoidal emissary foramen and the emissary vein: Anatomy and clinical relevance.

Although the sphenoidal emissary foramen (SEF) and its content are anatomically and clinically relevant, accurate description of them in the modern literature is lacking. This study aimed to examine and describe the SEF and its content (the sphenoidal emissary vein [SEV]). We analyzed 1,000 computed tomography (CT) images, 170 dry skulls, 50 formalin-fixed specimens, and three specimens (heads) following guidelines proposed by Dr. Albert L. Rhoton Jr. MD for latex injection. SEV morphology was determined by histological staining and electron microscopy. The SEF was observed in 46.8% of the CTs studied (25.4% bilateral and 21.4% unilateral), and 45.2% of the dry skulls (18.8% bilateral and 26.4% unilateral). In 9.5% of CTs and 21.1% of dry skulls there was a blind channel in the external surface of the cranial base; since there was no communication with the cranial cavity, it was not considered as the SEF. During the dissections, the SEF was found in seven individuals. In three of them, the SEV was an alternative route for venous drainage of the venous plexus of the foramen ovale. Its walls were composed of collagen fibers and its endothelium contained rhomboid cells resembling those commonly found in the superior sagittal sinus. The presence of the SEF and SEV can anatomically explain the spread of certain cranial base pathologies from or toward Meckel's cave or the cavernous sinus, and should be taken into account during procedures in the middle cranial fossa, percutaneous approaches, odontological procedures, and treatment of dural arteriovenous fistulas. Clin. Anat., 33:767-781, 2020. © 2019 Wiley Periodicals, Inc.

Morphological and morphometric characterization of the "sphenoidal tubercle" / Caracterización morfológica y morfométrica del tubérculo esfenoidal

The sphenoidal tubercle is a bone elevation located in the anterior edge of the infratemporal crest of the sphenoid greater wing, where the temporal and lateral pterygoid muscles have their origin. This bone accident presents varied morphology so its description and denomination are a topic of discussion. 60 dry skulls obtained from the morphology laboratory of the Biomedical Basic Sciences Department of the University of Talca were used for a morphological and morphometric analysis of the sphenoidal tubercle including its morphology, diameters (anteroposterior, transverse and vertical) and the distance to the grooves for the maxillary artery and maxillary nerve. Sphenoidal tubercle had a prevalence of 98.4 % of all dry skulls analyzed with a bilateral presentation in the 76.6 % of the cases. According to its different forms of presentation established by Cáceres et al., (2016) the pyramidal form was the most frequent with a 25.7 %. The average diameters were of 4.12 mm anteroposterior, 5.50 mm transverse and 3.89 mm vertical. The average distance to the grooves of the maxillary artery and maxillary nerve were 9.04 mm and 7.6 mm, respectively. Sphenoidal tubercle is a constant bone accident with a variated morphology and measures. Due to its anatomical relations with important neurovascular elements such as the maxillary artery and the maxillary nerve, it may be used as a reference point for surgical access to the infratemporal fossa. From this analysis we establish that the denomination of "infratemporal process" is more accurate, because the development of this bone accident is from muscular traction performed by the lateral pterygoid muscle and the deep portion of the temporal muscle causing great variations in its morphology, probably due to external and functional parameters or even influenced by the biotype.

El tubérculo esfenoidal es una elevación ósea ubicada en el extremo anterior de la cresta infratemporal del ala mayor del hueso esfenoides, donde presta inserción al músculo temporal y pterigoideo lateral. Presenta morfología variada, por lo que su descripción y denominación resultan motivo de discusión. 60 cráneos secos obtenidos del Laboratorio de Morfología del Departamento de Ciencias Básicas Biomédicas de la Universidad de Talca, fueron utilizados para realizar un análisis morfológico y morfométrico del tubérculo esfenoidal evaluando forma, diámetros (anteroposterior, laterolateral y vertical) y distancia con el surco de la arteria y nervio maxilar. El tubérculo esfenoidal tuvo una prevalencia del 98,4 % del total de cráneos analizados, presentándose bilateralmente en el 76,6 % de los casos. De acuerdo a las diferentes formas de presentación establecidas por Cáceres et al (2016) la forma piramidal fue la más frecuente con un 25,7 %. Los diámetros promedio fueron de 4,12 mm anteroposterior, 5,50 mm laterolateral y 3,89 mm vertical. Las distancias promedio con el surco de la arteria y nervio maxilar fueron de 9,04 mm y 7,6mm, respectivamente. El tubérculo esfenoidal es un accidente óseo constante de morfología y dimensiones variadas. Debido a sus relaciones con elementos vasculares de importancia, tales como la arteria y nervio maxilar, podría ser utilizado como elemento de referencia para el acceso quirúrgico a la fosa infratemporal. A partir de su análisis planteamos que su denominación como "proceso infratemporal" sería más apropiado, debido a que se desarrollaría a partir de la tracción muscular ejercida por el musculo pterigoideo lateral y la porción profunda del músculo temporal, ocasionando variaciones notables en su morfología, probablemente debido a factores externos y funcionales o incluso influenciada por el biotipo.

Tomographic and anatomical study of the orbit and nasolacrimal duct in capybaras (Hydrochoerus hydrochaeris-Linnaeus, 1766).

The objective of this study was to describe the reference values of cranial measurements of capybaras, correlating the ocular orbit with the nasolacrimal duct. The documentation of its results can contribute to standardizing characteristics of anatomical normality and favouring the correct diagnosis and treatment of changes. The capybara carcasses, maintained by freezing, were distributed in two groups (G) designated GA (n = 12) adult animals (A) and GY (n = 13) for young animals (Y). All subjects underwent dacryocystography examination by computed tomography (CT) and cranial measurements. Descriptive analyses of cranial and nasolacrimal duct measurements and statistical analysis of the Pearson correlation with the variable weight were performed. In GA, there was no correlation between the nasolacrimal and cranial duct measurements. However, in the GY, a correlation was verified with facial length (r = .6233), facial width (r = .5771), cranial height (r = .6981), cranial length (r = .7116), total right length (r = .7517) and left length (r = .7999). Thus, in the young animals, cranial length measurements were strongly correlated with nasolacrimal duct lengths. However, this biological behaviour was not observed in adults, demonstrating stability in development. The capybara's ocular orbit was found to be circular and incomplete, with developed zygomatic process of the maxilla. CT dacryocystography is indicated to evaluate the nasolacrimal canal pathway in capybaras, emphasizing the importance of normal anatomical study to aid in treating animals affected by diseases.

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.

The sphenoid sinus, foramen rotundum and vidian canal: a radiological study of anatomical relationships / Seio esfenoidal, forame redondo e canal pterigoideo: estudo radiológico das relações anatômicas

Abstract Introduction: The sphenoid sinus is an important structure in ventral skull base surgeries that is surrounded by several vital anatomical structures including the internal carotid arteries, optic nerve and cranial nerves inside the cavernous sinus. In addition, the foramen rotundum is a small canal deeply situated in the base of the skull, which represents the way for exit of the maxillary nerve. Understanding of the sphenoid bone anatomical relationships is central to the expanded endonasal approaches to the skull base. Objective: To record and analyze the measurement indexes of the sphenoid sinus and foramen rotundum in the coronal plane of normal computer tomography scans. Methods: Patients underwent paranasal sinuses computer tomography scan from June 2014 to November 2015 were retrospectively entered this cross-sectional study. We obtained several morphometric measurements from both the right and left sides using computer software. We also classified foramen rotundum and vidian canal types and determined position of the foramen rotundum regarding to base of lateral pterygoid plate. Results: One-hundred patients with the mean age of 38.56 ± 18.51 years entered this study. Mean bilateral FR distances were 38.48 ± 3.87 mm. Average right and left FRs distances to midline were 19.00 ± 2.07 and 19.34 ± 2.17 mm, respectively (p = 0.03). Twenty-eight cases (28%) had type I vidian canal, 48% and 24% had type II and III vidian canals, respectively. Four patients (4%) had type I rotundum foramen, 28% and 44% had type IIa and IIb, respectively and 24% had type III rotundum foramen. The position of foramen rotundums regarding to the base of lateral pterygoid plate was online in 50% of cases, medially placed in 47% and laterally placed in 3% of cases. Conclusion: The results of this study can be used to provide a better anatomical understanding of the area, which is necessary for endoscopic skull base surgeons.

Resumo Introdução: O seio esfenoidal (SE) é uma estrutura importante em cirurgias da base do crânio, que está cercada por várias estruturas anatômicas vitais, como as artérias carótidas internas, o nervo óptico e os nervos cranianos no interior do seio cavernoso. Além disso, o forame redondo (FR) é um pequeno canal profundamente situado na base do crânio, que representa a forma de saída do nervo maxilar. Compreender as relações anatômicas do osso esfenoidal é fundamental para as abordagens endonasais expandidas da base do crânio. Objetivo: Registrar e analisar os índices de medição do SE e FR no plano coronal de exames normais de tomografia computadorizada (TC). Método: Os pacientes que foram submetidos a TC dos seios paranasais (SPN) de junho de 2014 a novembro 2015 foram retrospectivamente incluídos neste estudo transversal. Obtivemos várias medidas morfométricas de ambos os lados, direito e esquerdo, com o uso do software de computador. Também classificamos os tipos de FR e canal pterigoideo (CP) e determinamos a posição do FR em relação à base da placa pterigoide lateral. Resultados: Cem pacientes com a média de 38,56 ± 18,51 anos foram incluídos neste estudo. As distâncias médias bilaterais de FR foram de 38,48 ± 3,87 mm. As distâncias médias direita e esquerda dos FR até a linha média foram de 19,00 ± 2,07 e 19,34 ± 2,17 mm, respectivamente (p = 0,03). Vinte e oito casos (28%) tinham canal pterigoideo do tipo I, 48% e 24% canais pterigoideos de tipo II e III, respectivamente. Quatro pacientes (4%) tinham forame redondo do tipo I, 28% e 44% do tipo II-a e II-b, respectivamente, e 24% forame redondo do tipo III. A posição dos FR em relação à base da placa pterigoide lateral era em linha em 50% dos casos, medialmente posicionados em 47% e lateralmente posicionados em 3% dos casos. Conclusão: Os resultados deste estudo podem ser usados para promover uma melhor compreensão anatômica da área, necessária para cirurgias endoscópicas da base do crânio.

The sphenoid sinus, foramen rotundum and vidian canal: a radiological study of anatomical relationships.

INTRODUCTION: The sphenoid sinus is an important structure in ventral skull base surgeries that is surrounded by several vital anatomical structures including the internal carotid arteries, optic nerve and cranial nerves inside the cavernous sinus. In addition, the foramen rotundum is a small canal deeply situated in the base of the skull, which represents the way for exit of the maxillary nerve. Understanding of the sphenoid bone anatomical relationships is central to the expanded endonasal approaches to the skull base. OBJECTIVE: To record and analyze the measurement indexes of the sphenoid sinus and foramen rotundum in the coronal plane of normal computer tomography scans. METHODS: Patients underwent paranasal sinuses computer tomography scan from June 2014 to November 2015 were retrospectively entered this cross-sectional study. We obtained several morphometric measurements from both the right and left sides using computer software. We also classified foramen rotundum and vidian canal types and determined position of the foramen rotundum regarding to base of lateral pterygoid plate. RESULTS: One-hundred patients with the mean age of 38.56±18.51 years entered this study. Mean bilateral FR distances were 38.48±3.87mm. Average right and left FRs distances to midline were 19.00±2.07 and 19.34±2.17mm, respectively (p=0.03). Twenty-eight cases (28%) had type I vidian canal, 48% and 24% had type II and III vidian canals, respectively. Four patients (4%) had type I rotundum foramen, 28% and 44% had type IIa and IIb, respectively and 24% had type III rotundum foramen. The position of foramen rotundums regarding to the base of lateral pterygoid plate was online in 50% of cases, medially placed in 47% and laterally placed in 3% of cases. CONCLUSION: The results of this study can be used to provide a better anatomical understanding of the area, which is necessary for endoscopic skull base surgeons.

Volumetric study of sphenoid sinuses: anatomical analysis in helical computed tomography.

PURPOSE: The sphenoid sinus is the most inaccessible part of the face, being inside the sphenoid bone and closely related to numerous vital neural and vascular structures. The objective of this study was to analyze and evaluate the variation of anatomy and the volume of the sphenoid sinus using helical computed tomography and medical imaging software. MATERIALS AND METHODS: A total of 47 helical CT scans of sinuses of male and female individuals aged 18-86 years were selected. The images were formatted using ITK-SNAP software, consisting of three steps: (1) segmentation; (2) volumetric analysis and (3) 3D reconstruction. The sphenoid sinuses were also classified according to Hammer, i.e., in conchal, pre-sellar, sellar and post-sellar types. A single investigator, who is specialist in dental radiology and was trained and calibrated, performed the volume and image analysis. After 15 days, the segmentations were repeated. RESULTS: The Dunn's multiple comparison test revealed significant differences in the volume rankings between the right and left sides (P = 0.0002), with the post-sellar type presenting the greatest volume on the right side compared to pre-sellar and sellar types. In the left sphenoid sinuses, the post-sellar type showed the greatest volume. The Lin's correlation coefficient showed excellent reproducibility values. CONCLUSIONS: According to the applied methodology, it was found that the volume of the sphenoid sinus was influenced by neither age nor gender (P > 0.005). There was difference in the volumes of sphenoid sinus on the right and left sides and in the anatomical classification.

A morphological study of the dorsum sellae in human skull / Estudio morfológico del dorsum sellae en el cráneo humano

Anatomical variations in the shape and dimension of the dorsum sellae and posterior clinoid process are common. Most textbooks describe its shape as a median rectangular plate, a square plate, or a transverse ledge on a slope behind the sella turcica (hypophyseal fossa). This work aims to study the dorsum sellae of human skull. One hundred and twenty five dried adult human skulls, irrespective of age, were used for the study. Detailed features of the dorsum sellae were noted and classified into five types: crest like, thin plate, frail quadrilateral plate, heavy square plate, thick elongated plate. Fusion of the posterior and middle clinoid processes in one (unilateral) and all the clinoid processes (anterior, middle, and posterior) in three skulls (unilateral in one, bilateral in two) were also noticed. Findings are discussed in the light of the literature.

Son frecuentes las variaciones anatómicas de la forma y dimensión de dorsum sellae y de los procesos clinoides posteriores. La mayoría de los textos describen su forma como una placa rectangular mediana, una placa cuadrada, o un plano transversal en una pendiente detrás de la sella turcica (fosa hipofisaria). Este trabajo tiene como objetivo estudiar el dorsum sellae en cráneo humano. Para el estudio se utilizaron 125 cráneos humanos adultos secos, de diferentes edades. Se observaron características detalladas de dorsum sellae y se clasificaron en cinco tipos: cresta, al igual que la placa delgada, lámina cuadrilátera, placa cuadrada gruesa, placa alargada gruesa. En tres cráneos se observó fusión de la parte posterior y los procesos clinoides intermedios (unilateral) y los procesos clinoides (anterior, medio y posterior) (unilateral en uno de ellos, bilateral en dos). Los resultados se discuten en consideracion de la literatura.

Foramen venosum: prevalence, patency and correlation with cephalic index / Foramen venoso: prevalencia, permeabilidad y correlación con el índice cefálico

The foramen venosum (FV) is an anatomical structure situated at the base of the skull, generally posteromedial to the foramen rotundum and anteromedial to the foramen ovale. Its prevalence and patency may be related to the shape of the skull. The objective of this study was to verify the prevalence and patency of the FV and its association with the different skull types. Overall, 143 dry skulls were screened. Of these, 84 were considered to be in an adequate state of conservation and were included in the analysis, which was conducted through a cross-sectional view of the skullcap. The transverse (T) and anteroposterior (AP) diameters of the skull were evaluated by pachymetry and the skull type was classified according to the cephalic index (CI) (CI = T/AP x 100). The presence and patency of the FV were evaluated. Overall, 25 % of the skulls were dolichocephalic, 21.4 % sub-dolichocephalic, 26.2 % mesaticephalic, 16.7 % sub-brachycephalic and 10.7 % brachycephalic. Overall, the FV was found in 41.6 % of the skulls (n=35), with this prevalence being greater in the mesaticephalic skulls (50 %; n=11). Patency was 25 % (n=21). A positive correlation was found between the CI and the presence of the FV in dolichocephalic skulls (on the right-hand side only) and in sub-brachycephalic skulls (bilaterally). In conclusion, the prevalence of the FV was considerable in the sample analyzed and was directly associated with the CI in dolichocephalic and sub-brachycephalic skulls.

El foramen venoso (FV) es una estructura anatómica situada en la base del cráneo, en general, posteromedial al foramen redondo y anteromedial al foramen oval. Su prevalencia y permeabilidad pueden estar relacionados con la forma del cráneo. El objetivo de este estudio fue verificar la prevalencia y permeabilidad del FV y su asociación con los diferentes tipos de cráneo. Se estudiaron 143 cráneos secos. De éstos, 84 fueron considerados en estado adecuado de conservación y se incluyeron en el análisis, realizado mediante la visualización de una sección transversal del cráneo. Los diámetros transversal (T) y anteroposterior (AP) del cráneo se evaluaron mediante paquimetría y el tipo de cráneo se clasificó de acuerdo con el índice cefálico (IC) (IC = T/AP x 100). Se evaluó también la presencia y permeabilidad del FV. El análisis mostró que 25 % de los cráneos eran dolicocefálicos, 21,4 % subdolicocéfalicos, 26,2 % mesaticéfalos, 16,7 % sub-braquicéfalos y 10,7 % de braquicéfalos. El FV se encontró en 41,6 % de los cráneos (n=35), con prevalencia mayor en los cráneos mesaticéfalos (50 %, n=11). La permeabilidad fue del 25 % (n=21). Se encontró una correlación positiva entre el IC y la presencia del FV en cráneos dolicocéfalicos (sólo en el lado derecho) y en sub-braquicéfalos (bilateral). En conclusión, la prevalencia del FV fue considerable en la muestra analizada y se asocia directamente con el IC en cráneos dolicocéfalicos y sub-braquicéfalos.

Pre-operative measurement of the morphometry and angles of the anterior clinoid process (ACP) for aneurysm surgery / Medición preoperatoria de la morfometría y los ángulos del proceso clinoide anterior (PCA) para la cirugía de aneurisma

The anterior clinoid process (ACP) is proximal to vital structures, such as the optic nerve, internal carotid artery and ophthalmic artery; therefore, study of its anatomy is important in guiding and defining surgery. We studied the anatomical structure of the ACP, including the angle formed by the apex of the ACP triangle, and its orientation, to provide information for easier and safer surgery. The measurement was performed on the axial planes of 242 cranial computerized tomography (CT) scans and 27 adult Turkish skulls of both sexes. The length of the ACP, width of the ACP at its base, the angle formed by the apical angle of the ACP triangle and the orientation of the ACP defined according to the sagittal midline were examined. In the Turkish skulls, the length and width of the ACP were similar to previous studies. Our study was the first to measure the angle and orientation of the ACP. The mean angle was 39.67±12.64 (16.6-89.5) and 135 posterior (55 %) and 107 medial (45 %) orientations. Surgical complications can be avoided by pre-operative radiological planning using axial CT scans and by determining whether the morphology is Type 2 (long, narrow, acute-angled), which requires total resection.

El proceso clinoide anterior (PCA) está próximo a estructuras vitales, como el nervio óptico, la arteria carótida interna y la arteria oftálmica, por tanto el estudio de su anatomía es importante en la orientación y la definición de la cirugía de base de cráneo. Se estudió la estructura anatómica de la PCA, incluyendo el ángulo formado por el vértice del triángulo PCA, y su orientación, para proporcionar información para una cirugía más fácil y más segura. La medición se realizó en los planos axiales de 242 exploraciones craneales de tomografía computarizada (TC) y 27 cráneos de individuos adultos turcos de ambos sexos. Se examinó la longitud del PCA, el ancho del PCA en su base, el ángulo formado por el ángulo apical del triángulo PCA y la orientación del PCA definido de acuerdo con la línea mediana sagital. En cráneos turcos, la longitud y el ancho del PCA fueron similares a estudios anteriores. Nuestro estudio fue el primero en medir el ángulo y la orientación del PCA. El ángulo promedio fue de 39,67 ± 12,64 (16,6 a 89,5) y, la orientación fue posterior en 135 cráneos (55 %) y medial en 107 cráneos (45 %). Las complicaciones quirúrgicas pueden evitarse mediante la planificación radiológica preoperatoria através de cortes axiales de tomografía computarizada y determinando si la morfología del PCA es de tipo 2 (larga, estrecha y aguda en ángulo recto), lo que requiere la resección total.