Adult Human Skulls Research Articles

Nonmetric Variants of Anatolian Crania: A Preliminary Study.

Analysis of nonmetric cranial variants has been essential for identifying the human population through osteologic analysis and genetic affinities. This study aimed to examine the nonmetric cranial variants to evaluate differences among sex and side correlations in Anatolian dry skulls. This study was carried out on 50 Anatolian adult dry human skulls (22 males, 28 females) with suitable features (nonfractured and/or with necessary features) out of a total of 97 dry skulls. After sex analysis, each skull was photographed from the norma frontalis, lateralis, inferior, and superior. Eleven nonmetrical cranial variants were investigated. The cranial variants and side incidences were analyzed to determine their sex differences and interside correlations. After the classification, traits were marked as "present" or "absent" on the charts. Some variants in female crania were seen more frequently than in males. Most of the variants such as the supraorbital notch, infraorbital and zygomaticofacial foramen, showed high correlations between the right and left sides. Overall, there were no statistically significant sex or side differences found in the Anatolian crania.

Incidence of Metopic Suture in Adult Human Crania in Uttar Pradesh

Introduction: Failure of ossification in the vertical direction between the two halves of the frontal bone is called a metopic suture; this suture is present in between the superciliary arch and tubers of the frontal bone so it is also called a median frontal suture. At birth, the frontal bone present is two half, in the 1st year they contact each other, and within the 7th to 8th year, they fused together. Sometimes, bones may not be fused completely and it becomes metopic fontanelle. Materials and Methods: The goal of the current study was to determine the prevalence of metopic suture in adult human skulls in Uttar Pradesh. One hundred and fifty macerated skulls of undetermined age and sex were used for this. The anatomical departments of Teerthankar Mahaveer Medical College and Research Center (Moradabad), King George Medical College (Lucknow), SRMS Institute of Medical Science (Bareilly), Govt. Medical College Kannauj, and Govt. Medical College Saharanpur provided these skulls. Results: This study has found the incidence of metopic sutures of about 12.90%. The two types of metopic sutures were found in this study, namely complete metopic suture 4.52% and incomplete metopic suture 8.38% in which found 0.64% "V" shape metopic suture. Conclusion: The morphological study of metopic sutures on adult crania is useful for anatomists, experts in forensic medicine, and neurologists for performing surgical procedures in this area.

Morphology of the groove of the inferior petrosal sinus: application to better understanding variations and surgery of the skull base.

Although adequate venous drainage from the cranium is imperative for maintaining normal intracranial pressure, the bony anatomy surrounding the inferior petrosal sinus and the potential for a compressive canal or tunnel has, to our knowledge, not been previously investigated. One hundred adult human skulls (200 sides) were observed and documented for the presence or absence of an inferior petrosal groove or canal. Measurements were made and a classification developed to help better understand their anatomy and discuss it in future reports. We identified an inferior petrosal sinus groove (IPSG) in the majority of specimens. The IPSG began anteriorly where the apex of the petrous part of the temporal bone articulated with the sphenoid part of the clivus, traveled posteriorly, in a slight medial to lateral course, primarily just medial to the petro-occipital fissure, and ended at the anteromedial aspect of the jugular foramen. When the IPSGs were grouped into five types. In type I specimens, no IPSG was identified (10.0%), in type II specimens, a partial IPSG was identified (6.5%), in type III specimens, a complete IPSG (80.0%) was identified, in type IV specimens, a partial IPS tunnel was identified (2.5%), and in type V specimens, a complete tunnel (1.0%) was identified. An improved knowledge of the bony pathways that the intracranial dural venous sinuses take as they exit the cranium is clinically useful. Radiological interpretation of such bony landmarks might improve patient diagnoses and surgically, such anatomy could decrease patient morbidity during approaches to the posterior cranial fossa.

Variations and Classification of Bony Septations of the Jugular Foramen: An Anatomic and Histologic Study With Application to Imaging and Surgery of the Skull Base

Approaches to the jugular foramen can be challenging. Adding to this difficulty is the potential for a bony septation to occur in the foramen thus subdividing its contents. Although such bony septations in the jugular foramen are known, the anatomic details of these structures have not been studied well. Therefore, the present anatomic study was performed. One hundred adult human skulls (200 sides) underwent evaluation for the presence or absence of a bony septation within the jugular foramen. The source, morphology, and size were all documented. A classification scheme was developed to better describe the varied types of morphology of the jugular foramen bony septa. Select bony septations were submitted to histologic analysis using hematoxylin and eosin and Masson's trichrome. Bony bridges were found on 8.5% of sides. These were bilateral in 3% of skulls. Eight (47%) were incomplete (type I). Nine sides (53%) were found to have completely articulated bony bridges (type II) and these had articulation between the bony processes as either touching (type IIa), joint-like (type IIb), or completely fused (type IIc) morphologies. Multiple septa were observed on 2.5% of sides and these were classified as type III septa. Histologically, both incomplete and complete septa were found to be composed of normal bone tissue. Our study found significant variations regarding the bony septa of the jugular foramen. Knowledge of this anatomy can be useful for preoperative planning and intraoperative navigation with approaches to the skull base that target pathology of the jugular foramen.

Morphometric and Morphological Variants of Pterion with its Clinical Importance in South Indian Population

Background: Pterion is a critical neuroanatomical landmark in various neurosurgical approaches, including for the placement of burr holes. In addition, it also holds significance from radiological, anthropological, and forensic point of view. Thus, we undertook the current study to investigate the prevalence of different morphological types of pterion along with their morphometric parameters from adjacent bony landmarks in the south Indian population. Methodology: A total of 64 adult dry human skulls of unknown gender and age were included for the study. All skulls were grossly normal. The types of pterions were classified on both sides based on Murphy's classification. The vertical linear distance from the center of the pterion to the zygomatic arch (PZ) and to the anterior border of the frontozygomatic suture (PF) was measured with a digital vernier caliper. Data were statistically analyzed. Results: All four varieties of pterion were noticed. The sphenoparietal variety was found as most predominant bilaterally (81%), followed by epipteric (12.5%) stellate (3.9%) and frontotemporal (2.39%). One of the epipteric varieties consists of an unusually large ossicle. Pterion was typically located 3.59 ± 0.43cm behind the fronto zygomatic suture and 3.71 ± 0.34 cm above the zygomatic arch. Conclusion: The sphenoparietal variant of pterion was predominant on both sides, followed by epipteric variety.

Morphometric study of nasal bones and piriform apertures in human skulls

The piriform aperture (PA) is the skeletal aperture located in the middle part of the face. There are many variations in morphometric measurements of nasal bones, piriform apertures and their shapes in different population. Objective of present study was to study morphological and morphometric features of nasal bone and piriform aperture. Adult human skulls available from collection of dried skulls were used for study purpose. Skull bones of unknown age and sex were obtained. Height, width of nasal bone, height, upper and lower width of piriform aperture, shapes of nasal bone and piriform aperture were observed. Height, upper width and lower width of piriform aperture were greater in male as compared to female. This difference was not statistically significant for upper width of piriform aperture (p=0.49) and for lower width of piriform aperture (p= 0.65) while the difference in height of piriform aperture was statistically significant. (p <0.0001).Differences in Height and width of nasal bone were not statistically significant among male and female nasal bones. Most common shape of nasal bone observed was Type A followed by Type B and C. Most common shape of piriform aperture was triangular to oval (50.00) in both the gender. Majority finding of the present study are in concordance with Indian population studies while significant differences have been noted in comparison to the morphometric measurements of Turkish, Korean, Brazilian and Anatolian population. These variations might be because of differences in ethnicity.

MORPHOLOGICAL STUDY OF JUGULAR FORAMEN IN HUMAN ADULT NEUROCRANIUM

AIM: To evaluate bilateral morphological features of the Jugular Foramen in human adult skulls. Material and methods: Study was conducted in 50 crania(unknown sex) of Indian origin. Morphological features of the Jugular foramen studied in detail like likeDome (presence/ absence),Septa(presence/ absence) & Type of septa (complete/ incomplete) were noted and are the values are compared with the earlier literature. OBSERVATIONS & RESULTS: Morphology of the jugular foramen is observed for Dome (presence/ absence),Septa(presence/ absence) & Type of septa (complete/ incomplete).Mean Dimensions for the right side (APD, MLD& AREA) were 11.8+ 2.03mm,15.7+2.42mm, 141.45+41.18mm and the left side were 11.3+ 1.85mm,13.72+ 2.31mm ,120.41+36.24mm respectively CONCLUSION:. In depth knowledge on morphological features of the jugular foramen could assist the neurosurgeons and the radiologists

A rare anatomical variation in foramen of Vesalius: A useful guide for maxillofacial surgeons

Background: Foramen of vesalius is an inconstant foramen that gives passage to an emissary vein that connects pterygoid venous plexus with cavernous sinus. It lies in the anteromedial side of the foramen ovale. Foramen ovale allows the passage for the mandibular branch of trigeminal nerve, the main site for the trigeminal rhizotomy. The presence and description of anatomical variations about the foramen of Vesalius is important during the surgical procedure on the trigeminal nerve which may injure the emissary vein in the foramen leading to intracranial bleeding. Objectives: The aim of the present study is to report the presence and to enlighten the anatomical variations of foramen vesalius which may serve as a guideline for surgeons. Methods: The study was conducted on 100 dry adult human skulls collected from the department of anatomy at Panimalar medical college hospital & research institute Chennai. The skulls were viewed both extracranially and intracranially to identify the presence of foramen of vesalius. The presence and variation of the foramen was noted and discussed. Result: A total of about 200 sides of 100 skulls were studied. Among them 20% of the skull showed presence of foramen of Vesalius bilaterally, 25% unilaterally and one particular skull showed doubled opening on the left side with the presence of a bony septum. This is a rare variation which was less documented in the literature. Conclusion: The knowledge of variations in foramen of Vesalius may help the surgeons for safer planning and execution of the trigeminal rhizotomy technique.

Morphometric Dimensions of Superior Orbital Fissure: A Cross-sectional Study

Introduction: Superior Orbital Fissure (SOF) is located between the roof and lateral wall of the orbit. SOF exhibits complex anatomy because of abundant neurovascular structures running through or near it and it connects the orbit with cranial cavity. Variant anatomy, in terms of morphology of SOF is well documented in literature, but data regarding morphometrical study of SOF is limited. Aim: To provide a baseline data on morphometry of SOF. Materials and Methods: A cross-sectional study was conducted from April 2010 to September 2010, on 60 SOF in 30 dry adult human skulls of unknown age and sex collected from Government Medical College, Amritsar, Punjab, India. A Vernier caliper with least count of 0.02 mm, a large scale with least count of 1 mm, a divider and probes were used to measure maximum anteroposterior and transverse diameters of parts of SOF, and distance from spina-rectalis to anterior and posterior end of SOF. Data was collected on right and left-sides and mean with standard deviation and range of measurements and p-value were calculated. Results: A total of 60 SOFs were analysed from 30 adult human skulls. Maximum anteroposterior diameter of inferomedial part was 6.335±1.56 mm on right-side and 5.81±1.34 mm on left- side. Maximum transverse diameter of inferomedial part was 5.82±1.69 mm on right-side and 5.19±2.04 mm on left-side. Maximum anteroposterior diameter of superolateral part was 10.59±2.48 mm and 11.32±2.09 mm on right and left-side, respectively. Maximum transverse diameter of superolateral part was 3.57±0.82 mm and 3.68±1.23 mm. Distance of spina-rectalis from anterior end was 8.37±2.42 mm and 8.03±2.59 mm on right and left-sides. Distance of spina-rectalis from posterior end was 9.39±2.59 mm and 10.62±3.41 mm. Conclusion: Mean of different diameters on right and left-side were compared to each other and it was found, that, there was no statistically significant difference.

ANATOMICAL VARIATIONS OF THE PARIETAL FORAMEN AND ITS RELATIONS TO THE CALVARIAL LANDMARKS: A CROSS-SECTIONAL CADAVERIC STUDY.

The aim: Estimate the prevalence of the parietal foramen in the adult human skulls of Ukrainian origin, and study its morphology and relationships to main anatomical landmarks of the skull. Materials and methods: A cross-sectional observational study of PF was conducted with 42 random cadaveric adult human skull roofs (calvaria) collected from the laboratory and museum of Human Anatomy Department, Kharkiv National Medical University, Ukraine. The patency and the length of the PF canal were determined, and PF external/internal diameters and the distance to the calvarial landmarks from PF were measured using the caliper. Mean and standard deviation were calculated to compare with the existing data. Results: In the present study 85.7% (n = 36) of the calvaria had the PF, 54.8% (n = 23) had bilateral location of PF, 30.9% (n = 13) had unilateral presence of PF (right side: 23.8%, n=10 and left side: 7.1%, n=3), and 14.3 % (n = 6) demonstrated bilateral absence of PF. Conclusions: An anatomical variation in parietal foramen is not uncommon, and the differences can be based on multiple factors like geography and race. It is important to have detailed information on anatomical variations in different population groups to facilitate surgical and radiological interventions.

Jugular Foramen of Adult Human Skull and its Clinical Significance in Population of Eastern India: A Cross-sectional Study

Introduction: Jugular foramen is a complex irregular bony canal located at the base of the skull between the condylar part of occipital bone and petrous part of temporal bone. It allows passage of important nervous and vascular structures. These are ninth, tenth, eleventh cranial nerves, sigmoid sinus continued as the superior bulb of internal jugular vein and inferior petrosal sinus, meningeal branches of the ascending pharyngeal and occipital arteries. Jugular fossa has a septum and a dome. The dome lodges the superior bulb of internal jugular vein. The septum divides the foramen into two compartment, antero- medial and postero-lateral. There is a wide variation in shape, size and septation of jugular foramen in different regions of globe which have been studied by different authors in different periods of time. Many tumours may arise in this region causing compression of the vital structures passing through it. Surgery is the treatment of choice in these cases. Successful neuro surgeries involving this region require detailed knowledge about the anatomical variation of the jugular foramen. Aim: To study and compare the morphology of jugular foramen, its various dimensions, shape, size and septation which is related to the size of internal jugular vein. Materials and Methods: A cross-sectional descriptive study was carried out on 85 adult dry human skulls, collected from the Anatomy Department as well as from the first year Bachelor of Medicine and Bachelor of Surgery (MBBS) students of different Medical colleges of West Bengal from September 2020 to June 2021. Presence of septa were observed and anteroposterior (AP), mediolateral diameter (ML diameter) were measured by using vernier caliper. Then the area was calculated. Data collected were compiled in tabular form. They were analysed by using Statistical Package for Social Sciences (SPSS) statistics version 20.0 and paired t-test and chi-square tests were applied. Results: In the total 85 skulls studied, the area of jugular foramen was larger on right side in 91.76% and on left side in 8.24% of skull. The AP diameter was less than the ML diameter and areas in all cases. But both the diameters were significantly (p-value<0.001) larger on right side than the left. Complete septation was present in right side of 34 foramina and in left side of 17 foramina. Partial or incomplete septation was present on right side of 51 foramina and left side of 68 foramina. Conclusion: The study revealed variation in shape, size and septation in different skulls and also bilateral variation in same skull. It has immense value to radiologists, Ear Nose Throat (ENT) surgeons, neuro-surgeons and radiologists who deal with the diagnosis and management of space occupying lesions surrounding the jugular foramen.

Sexual Dimorphism and Clinical Importance of Posterior Condylar Canal

Background: The posterior condylar canal (PCC) and its associated emissary vein are important anatomical landmarks for juxta-condylar approach and extreme lateral approach for exposing lesions in the region lateral to the foramen magnum. The study aimed to provide a complete gender-based assessment of the morphological characteristics of PCC in an adult central Indian population. Methodology: The study was conducted on 130 dry adult central Indian human skulls of known sex (81 males, 49 females). The presence of PCC on both sides, their patency, variations, and site of internal opening in relation to important anatomical landmarks, i.e., sigmoid sulcus, jugular foramen, and foramen magnum were assessed. Results: The PCC and probe patency were statistically more common bilaterally than unilateral. Females showed statistically significant higher incidence of bilateral PCC and bilateral probe patency than males. Three morphological variations in PCC were found, i.e., double condylar canal, septation, and spur. They showed no significant gender differences. In both sexes, bilateral intrasinus was the most common type of internal opening of PCC. Internal opening into jugular foramen, foramen magnum, and retro sinus was significantly more unilaterally than bilateral. Significant gender differences in unilateral intrasinus and unilateral retro sinus type of internal opening were noted. Conclusion: This study gives knowledge about the comparison of various morphological variations of PCC in both sexes of an adult central Indian population, and its clinical impact on the surgeries of this region.

Morphometry of the Crania and the Cranial Capacity in Dry Human Skull Bones- A Descriptive Analytical Study

Introduction: The crania constitute the skull bones that are held together by sutures which determines the brain size and an individual's mental ability. The present study would help the forensic anthropologist differentiate sex and predict brain development by measuring the cranial capacity of an unknown skull. Aim: To determine the cranial morphometry and the endocranial capacity in dry human skull bones. Materials and Methods: This descriptive analytical study included 100 adult male and female dry human skull bones, procured from the Department of Anatomy, AMC&H (Annapoorana Medical College & Hospitals), Salem, Tamil Nadu, India, from July 2021 to December 2021.The linear parameters like cranial length, breadth were measured using a Spreading caliper, and cranial height was measured using an anthropometric rod. The cranial volume was measured by direct and calculated methods. Using Statistical Package for Social Sciences (SPSS) software version 25.0, the data obtained were analysed and a descriptive statistical analysis was done. The significance of parameters of male and female skulls was compared using the unpaired student ‘t’ test and Pearson’s correlation test. Results: The cranial length, cranial capacity, and cephalic index showed statistically significant (p<0.05) differences between male and female skulls. The mean cranial length in male and female skulls were 174.11±7.07 mm, 168.84±9.36 mm, respectively, whereas the mean cranial breadth were 131.61±7.52 mm, 130.14±8.99 mm, respectively and the mean cranial height were found to be 126.53±6.59 mm, 125.12±8.17 mm, respectively. Using the direct method, the mean cranial capacity in male and female skulls was 1246.67±116.60 cc, 1191.63±83.23 cc, respectively. The mean cranial capacity in male and female skulls was found to be 1300.91±112.35 cc and 1245.51±79.93 cc, respectively obtained using the calculated method. Conclusion: The cranial capacity in the male skulls was significantly greater than the female skulls. This knowledge would help the anthropologists and forensic experts to use the anthropological examination in medico-legal cases to determine the sex, stature, and cranial capacity to expose the growth and development of the brain of an unknown individual.

Mastoid Canals and Grooves in Human Skulls: A Dry Bone Study

Background: The mastoid canals and mastoid grooves are formed within the mastoid part of temporal bones of skull, these are present on the external surface of mastoid region, anterior to the occipitomastoid suture, behind and parallel to the petrosquamous suture and anteroinferior to the asterion. The study was conducted to observe the incidence of mastoid canals and grooves in dry adult human skulls.Methods: Total of 120 dry adult human skulls consisting of 80 male & 40 female were examined to determine the incidence of mastoid canals and grooves. The mastoid parts of both sides were examined for the presence of mastoid canals and grooves. Then length of mastoid canals was measured.Conclusion: Out of the total of 120 skulls, mastoid canals were observed in 8.75% of skulls. The incidence of mastoid canals was 10% in females and 8.12% in males. The incidence of mastoid grooves was 10.42% of total skulls. It was 11.88 % in male skulls and in female skulls, it was 7.55%. The knowledge of mastoid canals and grooves of the temporal bones is very useful to the neurosurgeons and ENT surgeons while doing surgery to avoid severe bleeding.

The Incidence of Atlanto-Occipitalization and Additional Foramina Present in The Dry Skulls of Nepalese Population

Introduction: Atlanto-occipitalization(AOZ) is one of the congenital anomalies related to craniovertebral synostosis. The clear understanding of its anatomical features and cranial foraminal variants plays a critical role in finding the possible coping mechanism with its pathogenesis such as segmental instability or neurologic deficits.
 Objective: This study aimed to investigate the incidence of occipitalization of Atlas and related variant foramina, as the baseline awareness of these conditions among the Nepalese population is yet to be documented.
 Methodology: A retrospective study was performed for the total 86 dry skulls available in the department of Anatomy in Katmandu University of Medical Sciences, Institute of Medical Science, and B.P. Koirala Institute of Health Sciences. The skulls were examined thoroughly to evidence the occurrence of cranio-vertebral variations.
 Result: Out of 86 human adult skulls, 2 cases (2.32 %) were found with partial AOZ presenting posterior spina bifida close to the midline. Sphenoidal emissary foramen (SEF) was also observed in 17 skulls (19.76 %), an additional foramen lying anteromedial to the foramen ovale. Moreover, one of the skulls (1.16 %) was found with the presence of pterygospinous bar creating an additional foramen ‘foramen of Civinini’ in the lateral pterygoid plate of the sphenoid bone.
 Conclusion: The incidence of AOZ and pterygospinous bar seems to be quite low as compared to the cases of SEF. However, the knowledge of such variations and the presence of additional foramina carry great significance for orthopedists and neurosurgeons to have prognostic implications and an accurate surgical approach.

Image Quality Optimization of Dental Panoramic Tomogram and Lateral Cephalogram: A Pilot Study on Human Skull

Purpose: The purpose of this study was to investigate the effects of varying scanning parameters of DPT and LC on diagnostic performance and quality of the images. Materials and Methods: Clinical evaluations of image quality were performed using an adult human skull with permanent dentition. Dental panoramic tomogram (DPT) and lateral cephalogram (LC) images were obtained using two different radiographic machines Instrumentarium 300OP taken at Sungai Buloh (SB) and Sirona Orthophos 3D taken at Puncak Perdana (PP) by varying tube voltages. Two orthodontic residents assessed images based on overall quality using a five-point rating scale and diagnostic performance by detection of anatomical landmarks. The correlations between radiation doses and diagnostic value of the images were analyzed using Pearson’s Correlation Test. Univariate analysis was calculated for the evaluation for image quality. Intra-class Correlation Coefficient (ICC) was used to test for intra-rater and inter-rater reliability. Results: Both modalities taken at both centers showed negative correlation between dosage and detection of anatomical landmarks except for LC SB. All images were rated at least with median of 3= more than adequately presented regardless of the radiation dosage except for DPT PP (median 5= inadequately presented). Conclusion: Lower dosage parameters should be used when taking DPT and LC as images appeared darker, lower in quality and less anatomical landmarks can be detected at higher scanning parameter.

Study of anatomical variations of pterion in Karnataka population

The Pterion is a point of sutural confluence formed by frontal, parietal, temporal and sphenoid bones. Center of pterion is located 4cms above the midpoint of zygomatic arch and 3.5cms behind the fronto-zygomatic suture. Pterion is a reference landmark for many regions of the brain. Knowledge of various types of pterion is important in neurosurgeries as pterion keyhole approach has several advantages over traditional craniotomy; it has got radiological significance in interpretation of radiographs; in forensic medicine, it has been used for estimation of age and stature; and types of pterion has racial variations, hence it has got anthropological significance. Hence, the present study was taken to assess various types of pterion in South Indian adult human skulls. To classify the types of pterion based on Murphy’s classification and compare the right and left sides.The study was conducted on 100 adult dry human skulls collected from Kempegowda Institute of Medical Sciences & Research center, Bangalore. The various types of pterion were noted. All the readings were tabulated and subjected to analysis. All measurements and frequencies of the data were tabulated. The mean, standard deviation for each of the measurements were assessed. Statistical software SPSS version 16 was used. Right and left side were compared using One-Way ANOVA (Analysis of Variance). Various types of pterion were observed. Spheno-parietal was the most predominant (78%) type, followed by epipteric (16%), stellate (4%) and fronto-temporal (2%).: The results of the present study can be utilized by neurosurgeons, radiologists, anthropologists and forensic experts. The findings can be used in future for comparing various types of pterion from a different population, race or species altogether.

Positions and Types of Pterion in Adult Human Skulls: A Preliminary Study.

A trauma to the skull in the area of the pterion usually causes rupture of the middle meningeal artery leading to life- threatening epidural hematoma. The objective of the study is to assess the prevalence of different types of pterion and to determine its location using valuable bony landmarks. On 90 dry adult human skulls of unknown sex, age and nationality the distance of different landmarks from pterion was measured using stainless steel sliding Vernier caliper. The data were analyzed using SPSS version-20 and an independent t-test analysis was implemented. A value of P< 0.05 was considered as statistically significant. A higher occurrence of sphenoparietal type of pterion with the absence of frontotemporal type was noted. About 23% and 77% of the suture types are found to be unilateral and bilateral, respectively. There was a statistically significant difference between right and left sides of the skull in distances from the center of pterion to frontozygomatic suture, root of zygomatic arch, inion and in central thickness pterion. This study showed that the most prevalent type of pterion is sphenoparietal, and revealed asymmetry in the distances from center of pterion to frontozygomatic suture, root of zygomatic arch and inion, and its central thickness. Such findings could offer worthy information about the type and location of pterion, which could be relevant to anatomists, neurosurgeons, forensic medicine specialist and anthropologists.

Prevalence and Distribution of Pterion in Adult Dry Human Skull and its Clinical Importance

Prevalence and Distribution of Pterion in Adult Dry Human Skull and its Clinical Importance

Operative Anatomy of the Skull Base: 3D Exploration with a Highly Detailed Interactive Atlas.

Objective We evaluated the usefulness of a three-dimensional (3D) interactive atlas to illustrate and teach surgical skull base anatomy in a clinical setting. Study Design A highly detailed atlas of the adult human skull base was created from multiple high-resolution magnetic resonance imaging (MRI) and computed tomography (CT) scans of a healthy Caucasian male. It includes the parcellated and labeled bony skull base, intra- and extracranial vasculature, cranial nerves, cerebrum, cerebellum, and brainstem. We are reporting retrospectively on our experiences with employing the atlas for the simulation and teaching of neurosurgical approaches and concepts in a clinical setting. Setting The study was conducted at the University Hospital Mainz, Germany, and Hirslanden Hospital, Zürich, Switzerland. Participants Medical students and neurosurgical residents participated in this study. Results Handling the layered graphical user interface of the atlas requires some training; however, navigating the detailed 3D content from intraoperative perspectives led to quick comprehension of anatomical relationships that are otherwise difficult to perceive. Students and residents appreciated the collaborative learning effect when working with the atlas on large projected screens and markedly improved their anatomical knowledge after interacting with the software. Conclusion The skull base atlas provides an effective way to study essential surgical anatomy and to teach operative strategies in this complex region. Interactive 3D computer graphical environments are highly suitable for conveying complex anatomy and to train and review surgical concepts. They remain underutilized in clinical practice.