Adult Dry Skulls Research Articles

Morphometry of the Foramen Ovale in Adult Human Skulls from a Clinical Perspective.

The foramen ovale is present in the posterior part of the greater wing of sphenoid. A trauma or space-occupying lesion in this area would result in clinical manifestations due to compression of the structures passing through it. This study was undertaken because of the clinical significance of the foramen ovale in radiological and neurological procedures. The aim is to study the morphometry of the foramen ovale and its bilateral variations. Fifty adult dry human skulls of unknown age and sex were studied. The shape of the foramen ovale (FO), presence of accessory foramina or abnormal bony outgrowths, if any, were noted. Maximum length and width of FO were measured. The foramen ovale was present bilaterally in all 50 skulls. Accessory foramen was present in 17 (34%) and 13 (26%) skulls on the right and left side, respectively. Bony out growths were present in 9 (18%) and 15 (30%) skulls on the right and the left side, respectively. Understanding the exact topography, morphometry and variations of the FO is required to enable the clinician to correctly interpret radiographs and help in planning the surgical procedures. The findings presented here should be taken into account when neurological procedures of the middle cranial fossa are performed.

Canalis basilaris medianus: An anatomical study

BackgroundThe clivus, a key skull base structure for neurosurgeons due to its proximity to brainstem areas, is formed by the fusion of two bones. A rare variation, the canalis basilaris medianus (CBM) or clival canal, can exist within the occipital bone. The clivus has a rich venous network, and the CBM's presence might be linked to veins or embryonic structures. Understanding the CBM is valuable for interpreting clival fractures and during neurosurgery. This study aimed to determine the frequency and morphometric parameters of the CBM. Material and methodsFifty-nine dry adult skulls were selected for the investigation. Morphometric measures included establishing the diameters of the internal and external foramina of the CBM, the length of the canal, and its distance from the foramen magnum (FM), jugular tubercles, and lateral margins of the basilar part of the occipital bone. ResultsOut of the 59 skulls investigated, only a single specimen contained the CBM. Thus, the frequency of canal presence in our sample was 0.59 %. The internal foramen of the CBM was located on the internal surface of the clivus, 4.03 mm anteriorly to the FM with a diameter of 2.84 mm. Further, the canal passed through the clivus and had its external foramen on the external surface of the clivus at 0.11 mm above the pharyngeal tubercle and its distance from the FM was 9.19 mm. The length of the CBM was established at 8.16 mm. ConclusionThe CBM is a rare variation of the basilar part of the occipital bone. Therefore, the possibility of the existence of this variation should be considered when analyzing CT and MRI images to avoid misinterpretation of their results and during surgical interventions in this area.

Morphological and Morphometric Study of the Pterion – A Cadaveric Study in Sri Lanka

Introduction: Pterion is an important landmark as its relation to the anterior branch of middle meningeal artery, Broca’s motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal as it provides access to vital structures such as sylvian fissure, circle of Willis, optic nerve, para-sellar regions, middle meningeal vessels and cavernous sinus. Approach through pterion is mostly used to treat lesions of anterior and middle cranial fossa. Pterion ossicle or Epipteric bone are sometimes mistaken as a fracture at this point.Objective: The aim is to study the types of pterions and measure the distance from various bony landmarks on skull to the midpoint of pterion.Methods: Specific measurements were taken, and type of the pterion recorded by two independent investigators in the Frankfurt plane on both sides of 37 adult dry skulls of unknown age, gender and race, without calvaria which were prepared for academic purposes, none of which showed any obvious pathology or trauma. The skulls with broken lateral walls were excluded. The linear distance from the center of the pterion to four anatomical landmarks were measured using a Vernier caliper with an accuracy of 0.1 mm.Results: The sphenoparietal type of pterion was the most common (83.8% left, 81.1% right), followed by the frontotemporal (8.1% left, 13.5% right), and epipteric (8.1% left, 2.7% right) types and the stellate type was the least commonly observed (2.7% left side only). The distances on the left and right sides respectively from the center of the pterion to the frontozygomatic suture were 3.60 ± 0.57 cm and 3.68 ± 0.50 cm, to the zygomatic arch 3.76 ± 0.39 cm and 4.03 ± 0.40 cm, to the tip of the mastoid process 7.96 ± 0.58 cm and 8.16 ± 0.61 cm, and to the topmost part of the external auditory meatus 5.42 ± 0.34 cm and 5.53 ± 0.35 cm.Conclusions: This knowledge is essential in surgical approaches and interventions via the pterion, especially for neurosurgeons while drilling a burr hole at the pterion to prevent orbital penetration due to an anterior drilling and an ineffective access for instrumentation due to a posterior drilling. It will also be helpful for surgeons, radiologists, anthropologists, forensic pathologists in their diagnosis and treatment.

Navigating the Intersection Between the Orbit and the Skull Base: The "Mirror" McCarty Keyhole During Transorbital Approach: An Anatomic Study With Surgical Implications.

McCarty keyhole (MCK) is the most important entry point during orbitocranial and cranio-orbital approaches; nevertheless, its anatomic coordinates have never been detailedly described from transorbital perspective. To provide the spatial coordinates for intraorbital projection of the "mirror" MCK by using the well-established main anatomic-surgical bony landmarks met along transorbital corridor. MCK was identified in 15 adult dry skulls (30 sides) on exocranial surface of pterional region based on the well-defined external bony landmarks: on the frontosphenoid suture, 5 to 6 mm behind the joining point (JP) of frontozygomatic suture (FZS), frontosphenoid suture (FSS), and sphenozygomatic suture (SZS). A 1-mm burr hole was performed and progressively enlarged to identify the intracranial and intraorbital compartments. Exit site of the intraorbital part of burr hole was referenced to the FZS on the orbital rim, the superior orbital fissure, and the inferior orbital fissure and to the JP of FZS, FSS, and SZS. To electronically validate the results, 3-dimensional photorealistic and interactive models were reconstructed with photogrammetry. Finally, for a further validation, McCarty mirror keyhole was also exposed, based on results achieved, through endoscopic transorbital approach in 10 head specimens (20 sides). Intraorbital projection of MCK was identified on the FSS on intraorbital surface, 1.5 ± 0.5 mm posterior to JP, 11.5 ± 1.1 mm posterior to the FZS on orbital rim following the suture, 13.0 ± 1.2 mm from most anterior end of superior orbital fissure, 15.5 ± 1.4 mm from the most anterior end of the inferior orbital fissure in vertical line, on measurements under direct macroscopic visualization (mean ± SD). These values were electronically confirmed on the photogrammetric models with mean difference within 1 mm. To be aware of exact position of intraorbital projection of MCK during an early stage of transorbital approaches provides several surgical, clinical, and aesthetic advantages.

Sex determination from foramen magnum parameters in Thai cadaveric donor

The foramen magnum (FM) occupies a well-protected position, making it particularly intriguing for forensic research. The necessity for methods to estimate sex from cranial fragments becomes evident when only a partial skull is available for identification. The objective of this study was to assess sex differences in anthropometric measurements, including the length of the foramen magnum (FML), width of the foramen magnum (FMW), foramen magnum area (FMA), and circumference, with the aim of developing a binary logistic regression model in Thai cadaveric donors. Sixty adult dry skulls underwent both intraclass and interclass correlation analyses. Subsequently, 240 adult dry skulls of known sex (120 males and 120 females) were meticulously measured and analyzed to determine the optimal threshold for sex determination. Morphometric analysis of the FM was carried out using vernier calipers, and the area of the FM was precisely calculated. The FML, FMW, FMA, and circumference were all found to be significantly larger in males than in females. Furthermore, FM circumference exhibited an AUC (Area Under the Curve) value of 0.908, signifying it as an excellent parameter for sex discrimination. Lastly, binary logistic regression was executed. Significant sex differences in FM circumference were consistently observed, demonstrating an accuracy of 81.62% when validated in 120 dry skulls.

Mastoid Emissary Foramina in Dry Skulls: Its Morphometry, Topography, and Associated Clinical Implications.

Mastoid emissary foramen transmitting mastoid emissary vein connects the posterior auricular vein with the sigmoid sinus. This foramen and so the mastoid emissary vein varies in prevalence, number, size and location, knowledge of which is essential for carrying out uneventful surgeries, especially retrosigmoid, mastoidectomy, and skull base surgeries. There is a paucity of literature on this foramen in the Indian context, so the study was done. The purpose of the study is to elaborate on the prevalence, number, size, and location of mastoid foramen in dry adult skulls. The study was conducted in the Department of Anatomy using 90 dry skulls of unknown age and sex, and prevalence, number, size, and location in these skulls were noted. The mastoid foramen was detected in 27.8% of skulls, with an incidence of 31.1% and 12.2% on right and left sides of skulls, respectively. The number of foramina ranged between 1 and 4. The mean diameter of this foramen was 0.9mm, and the most frequent location was mastoid process. The detailed morphology and morphometry of mastoid foramen are of utmost use to neurosurgeons, ENT surgeons, radiologists, and vascular surgeons as it transmits mastoid emissary vein and meningeal branch of the occipital artery, which may be injured during various surgical procedures involving mastoid region and skull base causing catastrophic hemorrhage. In addition to this, mastoid emissary vein may be the source of thrombus, causing thrombus of sigmoid sinus creating helm of neurological complications.

Study of Topography of Stylomastoid Foramen With Respect to Nearby Landmarks to Carry Out Facial Nerve Block With Minimum Complications.

Nadbath facial nerve block is the most common procedure to anesthetize the facial nerve at stylomastoid foramen in intraocular surgeries, but it is associated with complications. Also, this foramen exhibits ethnic and racial variations with regard to its location. There is scanty literature describing the topographical location of this foramen. So, the study is carried out. The purpose of the study is to describe the topography of stylomastoid foramen from the surrounding landmarks so that Nadbath facial nerve block can be performed with minimum complications. The study was conducted using 80 adult dry skulls of unknown age and sex, and the distance of this foramen was measured from the tip, upper end, and lower end of the anterior border of the mastoid process and jugular foramen. The statistical analysis consisting of mean, SD, median, range mode, and t test was calculated. Mean distances of stylomastoid foramen from the upper end, the lower end of anterior border and tip of mastoid process and jugular foramen on right side were 1.5±0.16, 1.02±0.09, 0.84±0.09, and 0.49±0.06cm and those on left side were 1.5±0.16, 1.02±0.09, 0.84±0.09, and 0.5±0.06cm, respectively. The mode of these distances was 1.5, 1, 0.8, and 0.5, both on the right and left sides. The topographic information about stylomastoid foramen given in this study is useful to anesthetists to carry out Nadbath facial nerve block successfully with minimum complications.

Variation of Wormian and Inca Bones in Adult Skulls

Objective: Irregular and abnormal small additional bones called Wormian bones can be encountered between the skull bones. This study aimed to investigate the incidence, topographical distribution, morphology, and interrelationship of the Wormian and Inca bones in Central Anatolia Region dry adult skulls. Methods: In the study, 119 adult skulls were examined. The location and frequency of additional bones (Wormian) in the sutures in the cranium were determined. Skulls with Inca bones were identified. The Inca bones were typified in accordance with the literature and their dimensions in the transverse and sagittal axis were measured with a digital caliper. Results: Wormian bone was present in 33 of 119 adult skulls (27.7%). Of the 33 bones, 22 were detected in the male (66.66%) and 11 female (33.34%) skulls. The locations of the Wormian bones in the order of decreasing incidence were the lambdoid suture (16.0%, 19/119), pterion (16.0%, 19/119), lambda (7.6%, 9/119), asterion (2.5%, 3/119), and bregma (1.7%, 2/119). Nine Inca bones were found in the lambdoid region (27.3%, 9/33). Six of these bones (66.7%) were in the male skull. We found that two of these bones were incomplete lateral asymmetric, two were complete symmetric bipartite, two were incomplete asymmetric bipartite and three were incomplete median type. We found that 13 (10.9%) of the skulls in the study had metopic sutures and 0.8% had craniosynostosis. When the craniums with metopic suture were evaluated, it was found that 8 of them (61.5%) had additional bone. 50% of the Wormian bones were found in the lambdoid suture. Conclusion: It has been found that the incidence of Wormian bone increases with suture variations. It was determined that the frequency of Inca bone variation may vary depending on regional differences.

Analyzing Foramen Ovale Morphometrically in Adult Dry Skulls of Nigerian-Based Population

Introduction: The foramen ovale is one of the major foramina on the greater wing of the sphenoid that is used for advanced surgical therapeutic and diagnostic procedures pertaining to the middle cranial fossa. The study was aimed at determining the length and width of foramen ovale in a Nigerian population. Materials and Methods: Seven dehydrated adult skulls, all the same gender, were acquired from the anatomy departments of Achievers University in Owo and Delta State University in Abraka, Nigeria. The length and the width of the foramen ovale were measured using digital sliding calipers. The paired sample t-test was used for the analysis. Results: The mean length of the foramen ovale was 0.611±0.21cm on the right side, and 0.42±0.12cm on the left side. The mean width was 0.5±0.15cm on the right side, and 0.43±0.12cm on the left side. Conclusion: Understanding the dimensions of the foramen ovale vary is crucial for neurosurgery during invasive surgical procedures like percutaneous trigeminal rhizotomy, as well as for biopsying Meckel cave lesions and cavernous sinus tumors.

Prevalence, Number and Localization of Wormian Bones in Anatolian Adult Dry Skulls

Aim: The locations of the Wormian bones (WBs) are critical knowledge for physicians, anatomists, forensic scientists, and anthropologists. The purpose of the study is to identify the number and location of WBs in the Anatolian population.
 Material and Methods: The study included 29 adult skulls from anatomy departments at two universities in Türkiye. The skulls' gender and age were unknown. The prevalence, quantity, and location of WBs were assessed. 
 Results: The greatest number of WBs (mean 1.79) were found in the lambdoid suture, which was followed by the coronal suture (0.43). Among the fontanelles, the Asterion had the highest number of WBs (0.42).
 Conclusion: According to our findings, the Lambdoid suture has the highest number of WBs. There is still a great deal of mystery around the causes of the occurrence and localization of WBs. Radiologists, neurosurgeons, forensic scientists, anatomists, and anthropologists must conduct more research in this area.

Clinical anatomy of the spina musculi recti lateralis: A frequently overlooked variation of the greater wing of the sphenoid

BackgroundThe spina musculi recti lateralis (SMRL) is often visible along the lateral rim of the superior orbital fissure (SOF). Aim of this study is to characterize SMRL morphology and topography relative to known bony landmarks. MethodsOrbits from 291 adult dry skulls and from 60 CT scans were analyzed to measure the distance between the SMRL and the SOF or the inferior orbital fissures (IOF) as well as its height, width and orientation. Processes other than SMRLs were also recorded. Fetal skulls were observed for comparison with adult samples. ResultsForty-one per cent of orbits on dry skulls and 43.3% by CT showed an SMRL. Additional 32.9% of orbits on dry skulls had processes with a different shape. On average, SMRL were orientated almost along the transverse plane and showed implant bases as wide as 141.9° or as narrow as 36.8°. SMRLs were close to the infero-posterior angle of the orbital plate of the sphenoid, 1.21 ± 0.84 mm in front of the SOF, 5.8 ± 1.9 mm above the IOF and 12 ± 2.3 mm from the anterior end of the SOF. They were 1.58 ± 0.64 mm high and did not show any age or sex-related prevalence. By CT, the SMRL appeared as the insertion site for the lateral rectus, tendinous ring and, sometimes, inferior rectus. ConclusionsThe SMRL is a process of the sphenoidal orbital plate rather than of the SOF. It is also a reliable landmark for the insertion of the tendinous ring and lateral rectus. Orbital surgeons should be aware of this common variant of the orbital apex.

Wormian Bones: Prevalence, Topography, and Implications.

Wormian bones also known as sutural bones are asymmetrical and shapeless bones occurring in cranial sutures and fontanelle of the skull. Their incidence is reported to vary in population. The exact etiology is debatable, but their formation is under the control of both genetic and environmental factors and has great anthropological and clinical implications related to the cranium. Due to high clinical relevance of Wormian bones, the study was carried out. The aim of the study is to expound the incidence and topography of Wormian bones along with clinical significance in dry adult skulls of Indian origin. The study was conducted in the Department of Anatomy using 200 complete adult dry skulls of unknown age and sex. All the sutures in the skull were inspected for the presence of Wormian bones. The Wormian bones were classified into 10 categories, and associated implications were brought out. The Wormian bones were photographed, and details were compared with the available literature. The Wormian bones were observed in 190 (380 sides) skulls with 186 on the right side and 108 on the left side. The predominance site of sutural bone was lambdoid suture followed by sagittal suture. The least common site of Wormian bone was lambda. The detailed information of precise topography, frequency, and number of Wormian bones is of utmost use for surgeons performing surgery on the skull, anthropologists for identifying races, and forensic scientists for investigating child abuse cases.

Morphology and Morphometry of the Asterion in the South African sample within KwaZulu-Natal

IntroductionThe asterion is a meeting point formed by the union of the lambdoid, parieto-mastoid and occipito-mastoid sutures. It is the most common landmark in surgery due to its close relation to the transverse-sigmoid sinus junction. Population-specific differences were noted when determining the position of the asterion using external bony landmarks. Therefore, this study aimed to determine the anatomical position of the asterion in relation to external bony landmarks, and to determine the morphology of the asterion within the South African sample of KwaZulu-Natal. Materials and methodsThirty-six dry adult skulls were obtained from the Department of Clinical Anatomy, University of KwaZulu-Natal. The morphology of the asterion was classified according to Morales Avalos et al. (2011). While, the morphometry regarding the position of the asterion were measured in accordance with Akkaşoğlu et al. (2019) methodology. ResultsType I asterion was observed in 18 (25.0%) of the cases and Type II presented in the majority of the cases with a prevalence of 75.0%. The distances from the asterion to the respective external bony landmarks were found to have no differences with regard to laterality (p > 0.05). The South African sample of KwaZulu-Natal was found to have majority of Type II present. The measurements from the asterion to the external bony landmarks were found to be very similar to an African based population. ConclusionThis study may enhance the existing body of knowledge regarding the morphology and morphometry of the asterion, which may lead to improved outcomes when analysing radiographs and for neuro-surgery.

Morphometric Study of Supra-meatal Triangle and Mastoid process in the Adult dry Skulls

Introduction: This study was done with an objective to do a craniometric study of supra meatal triangle and mastoid process to explore the variations as a determinant to sex. Methodology: A total of 47 skull bones formed our study sample which comprised of 31 males and 16 females Six landmarks were identifi ed on each side of the skulland measurements were taken using Digital Vernier caliper with precision of 0.01. Observations and Results: The area of supra-meatal triangle in male was 134.68± 21.69 mm3 on the right side and 134.17± 16.98 mm3 on the left side. In females the area of supra-meatal triangle was 114.82± 21.99 mm3 on right side and 122.46± 24.05 mm3 on the left side. In male skulls, the length, breadth and width of the mastoid process on the right side was 23.56 ± 2.88, 19.81 ± 2.49 and 11.46 ± 2.51 mm and the left side measurements were 23.33 ± 2.17, 18.93 ± 1.91 and 10.84 ± 2.39mm respectively. In females the length, breath and width of mastoid were 23.03 ± 2.94, 18.87 ± 2.42 and 10.03 ± 2.32 mm on right side and 22.06 ± 1.99, 17.85± 2.22 and 9.43 ± 1.89 mm in left side respectively. conclusion: In this present study the supra meatal triangle and all measurements of mastoid process were greater in males with the mastoid breadth and width showed statistically signifi cant values. The fi ndings can be applied to unknown skull samples or bone fragmentsand can provide insight to future studies of forensic anthropologists and ENT surgeons.

Morphological Study of Stylomastoid Foramen at the Base of Skull and its Role in Facial Nerve Palsy.

The facial nerve emerges out of skull through the stylomastoid foramen located between styloid process and mastoid process. Unilateral paralysis of facial nerve is known as Bell's palsy and is reported to be caused most frequently by herpes simplex virus. The herpes infection is comparatively common but Bell's palsy is not very common. So, other causes of Bell's palsy like variation in morphological forms of stylomastoid cannot be ruled. There is paucity of literature elucidating morphological shapes of this foramen and correlating these forms of foramen with Bell's palsy. Hence the study was carried out. The aim of this study is to expound varied forms of stylomastoid foramen and to bring out clinical implications. The study was conducted in the department of anatomy using undamaged 70 adult dry human skulls of unknown age and sex. The morphological shapes were observed, interpretated and compared with available literature and their clinical implications were brought out. Most common shapes observed were round and oval followed by square shapes. Round shaped foramina were observed in 40 skulls on right sides constituting 57.1% and in 36 skulls on left side constituting 51.4%. While oval shapes were found in 16 skulls on right side (22.6%) and in 12 skulls on left side (17.1%). Rare variants of the foramen include triangular, serrated and closely applied to styloid process. The rare morphological forms were mostly observed to be unilateral in occurrence. Unilateral Bell's palsy is common, so, the rare morphological forms might be responsible for Bell's palsy.

Metopism: Its Prevalence and Morphometry in Adult Nigerian Dry Skulls

Background: Metopic suture also known as the frontal, interfrontal, or median frontal suture is formed in the midline at the meeting of the two halves of the frontal bone. Normally it gets obliterated by early childhood, but in some cases, it persists and is described as metopism. This study is aimed at investigating metopism prevalence in dry Nigerian skull. 
 Methods: This study was conducted on ninety-six (65 males and 31 females) adult Nigerian dry skulls from 5 selected Universities in the Southern part of Nigeria. Metopic suture (metopism) was considered to be complete when it continued uninterruptedly from the nasion to the bregma and incomplete when it was not present over its entire length. The incomplete metopic sutures were further classified into shapes.
 Results: Metopism was observed in 31 skulls (32.3%) of which 22 (21.9%) were males and 9 (9.4%) were females. Complete metopic suture was found in only 1 skull (1.04%) and incomplete metopic suture was seen in 30 skulls (31.25%). Among the incomplete ones, linear shape metopic suture was the most common in 16 skulls (16.67%). 7 (7.29%) were V-shaped metopic suture and another 7 (7.29%) were double-type metopic suture. Prevelence of metopic suture was slightly higher in males than in females. However, there was no statistical level of association with respect to sexual dimorphism.
 Conclusion: The prevalence and morphometry of metopism in the 96 adult Nigerian skulls studied, revealed complete metopism to be 1.04% with a length of 127.0mm as against incomplete metopism of 31.25% making a total prevalence of 32.29%. The prevalence of metopic suture was slightly higher in males than in females with the linear metopic suture occurring the most. Sexual dimorphism with respect to incomplete metopism types and shapes revealed no association This study is important for radiologists and neurosurgeons in diagnosis of frontal bone fractures and during surgical intervention including frontal craniotomy.

Granular Foveolae in the Groove of the Sigmoid Sinus: An Anatomical Study.

Background Granular foveolae in the groove of the sigmoid sinus have rarely been reported in the literature compared to numerous published reports on the granular foveolae near the superior sagittal sinus and its sulcus on the internal aspect of the calvaria. The present study was performed to better elucidate their prevalence and locations. Materials and methods One hundred and ten adult dry skulls (220 sides) were analyzed for the presence of granular foveolae within the groove of the sigmoid sinus. The exact position of the foveolae was documented, and the diameter of the granular foveola wasmeasured. Results Granular foveolae were found in the groove of the sigmoid sinus on 3.6% of the sides.These were at or within a mean of 1.3 cm inferior to the transverse-sigmoid junction. When a mastoid foramen was noted in the groove, it was always located inferior to the granular foveolae when present. The mean diameters of the granular foveolae of the left groove of the sigmoid sinus were 2.8 mm and 4 mm for the right grooves. The mean depth of the granular foveolae in the left groove of the sigmoid sinus was 2.7 mm and 3.5 mm for the right grooves.Granular foveolae were statistically larger and deeper on the right versus left sides (p<0.05). Conclusions Granular foveolae of the groove of the sigmoid sinus were identified most commonly on the right sides and 3.6% onall sides. If identified on medical imaging, these uncommon structures at the skull base should be considered normal anatomical variations.

Surgical anatomy of hypoglossal canal for various skull base surgeries

PurposeAnatomical knowledge of the hypoglossal canal is very important in relation to drilling of occipital condyle, jugular tubercle etc. So, this study was conducted to identify various morphometric and morphological features of the hypoglossal canal and its distance from adjacent structures relative to stable and reliable anatomic landmarks.MethodsThe study was performed on 142 hypoglossal canals of 71 adult human dry skulls. The parameters measured were the transverse, vertical diameter, depth of the hypoglossal canal. The distances from the hypoglossal canal to the foramen magnum, occipital condyle and jugular foramen were also noted. In addition, the different locations of the hypoglossal canal orifices in relation to the occipital condyle were assessed. The different shapes and types of the hypoglossal canal were also noted.ResultsThere was significant difference (p < 0.05) in measurements taken on the right and left sides in males and females. The intracranial orifice of hypoglossal canal was present in middle 1/3rd in 100% of occipital condyle for both genders. The extracranial orifice of the hypoglossal canal was found to be in the anterior 1/3rd in 99% and 93.7% for male and female, respectively. Simple hypoglossal canal with no traces of partition was found to be more in males and females. The most common shape noted was oval both in males and females (71.8% and 68.7% respectively).ConclusionThe results of the dimensions of the hypoglossal canal and its distance from other bony landmarks will be helpful for neurosurgeons to plan which surgical approaches should be undertaken while doing various surgeries in posterior cranial fossa.

Morphometry and morphological analysis of carotico-clinoid foramen: an anatomical study with clinical implications.

The dural fold between anterior and middle clinoid processes on mineralisation leads to the formation of caroticoclinoid foramen (CCF). Different morphology of this foramen presents with different clinical features. The present study reports the frequency of CCF in the population of Bihar, while providing an account of assimilated information from previous literature regarding the association of caroticoclinoid ligament ossification with age and human genetics. The study was conducted on 100 adult dry human skulls of unknown age and sex, and 50 lateral view radiographs of the head. Of the 100 dry skull bones, 9 presented with different forms of CCF. Bilateral complete foramina were noticed in 2 (2%) skull bones, while the incomplete foramina were observed bilaterally in 3 (3%) and unilaterally in 4 (4%) skulls. The lateral view radiograph data (n = 50) presented with a bilateral foramen in one subject and unilateral complete CCF in two different subjects. On measurements of the diameters of the complete CCF the mean values observed were 4.06 mm and 4.51 mm on the right side, while that on the left side were 5.15 mm and 4.14 mm. For the incomplete foramina, the mean values for the vertical diameter were 4.48 mm on the right and 4.19 mm on the left side, respectively. The frequency of CCF in the present study population of Bihar was much lesser than that of previously studied populations. However, the variation in frequency of different morphological types of CCF was observed to be the same across populations. The variations in CCF's metric data could help in predicting the morphological changes it causes to the clinoidal segment of the internal carotid artery, as well as in distinguishing its varieties.

MORPHOMETRIC ANALYSIS OF ETHMOIDAL FORAMEN IN ADULT DRY INDIAN SKULL

Ethmoid bone is located in the anterior part of the base of the cranium between the orbits. The medial orbital wall separates the content of the orbit from the ethmoidal air sinuses. The anatomical landmarks of orbital cavities are very much important during orbital surgeries which includes surgery of anterior cranial fossa and endonasal microsurgeries of ethmoidal region. On this medial orbital wall, the anterior and the posterior ethmoidal foramina are located along the frontoethmoidal suture and more anteriorly to the optic canal and these are very much important in orbital surgeries. This prospective observational study was undertaken to study the morphology of Ethmoidal foramen in adult dry Indian skull and to study the clinical implications of ethmoid foramen. A total 50 dry adult skulls were measured for the ethmoidal foramen. It was reported that the mean of posterior ethmoidal canal right and left was 2.09±0.75mm and 2.31±0.132mm respectively. The study concluded that to ensure the safety of surgical procedures to be performed among ethmoid foramen it is very important to measure the various landmarks; as the anatomical variations can cause problems and leads to surgery related complications.