Dimensions Of Foramen Magnum Research Articles

Investigating the relationship between foramen magnum dimensions and cranial morphology in central Indian skulls

Investigating the relationship between foramen magnum dimensions and cranial morphology in central Indian skulls

Determination of Sexual Dimorphism from Foramen Magnum in an Eastern Indian Population

Human identification is an important arena of forensic investigation, it includes sex determination which becomes extremely difficult in fragmented skeletal remains. Skull dimensions are measured for the purpose of sexual dimorphism which vary in different populations. In this study, we attempted to analyse the measurements from adult human skulls and employ discriminant function to predict sex accurately. A manual vernier calliper was used to measure the antero-posterior (AP) diameter and transverse diameter of foramen magnum of 88 skulls (49 males, 39 females) from the collection housed at the department of Anatomy, RG KAR medical college and Calcutta medical college. The Wilk's lambda for the model is 0.795. The discriminant function equation is, Df= 3.342× (APdiameter of foramen magnum) +0.725× (Transverse diameter of foramen magnum) -13.641(constant). The cut-off point is 0.505. So above this value 0.505, the cases are male and below it, the cases are female. On comparing the measurements, we found that antero-posterior dimensions and transverse dimensions of foramen magnum were greater in males than females. Collectively, all the results indicate that dimensions of foramen magnum can be used as a moderate indicator for sex determination in regional populations.

The Correlation Between the Foramen Magnum Dimensions and the Main Craniometric Data of the Skull

The purpose of the study was to study the correlation between the length and width of the foramen magnum and the craniometric data of the skull. Methods. The research material consisted of 200 skulls. There were 20 skulls of adolescence age, I adulthood age 68, II adulthood age 72, and elderly age 40. In total, there were 86 male skulls and 114 female skulls. Foramen magnum length is measured as the mid-sagittal distance from the most anterior point on the foramen magnum to opisthion. Foramen magnum breadth is gauged between the lateral margins of the foramen magnum at the point of greatest lateral curvature. A non-parametric ρ-Spearman's rank correlation was used in the study. Results. A correlation between the foramen magnum length and foramen magnum breadth is identified (r=0.479, P<0.001).The foramen magnum length positively correlates with maximum cranial length, nasio-occipital length, bizygomatic breadth, basion-bregma height, cranial base length, basion-prosthion length, biauricular breadth, upper facial breadth, left and right orbital breadths, left and right orbital height, biorbital breadth, interorbital breadth, frontal chord, biasterionic breadth, bimaxillary breadth, and zygoorbitale breadth. The foramen magnum breadth positively correlates with maximum cranial length, nasio-occipital length, bizygomatic breadth, basion-bregma height, cranial base length, basion-prosthion length, maxilla-alveolar breadth, maxilla-alveolar length, biauricular breadth, upper facial breadth, nasal height, left and right orbital breadths, left and right orbital heights, biorbital breadth, frontal chord, parietal chord, bimaxillary breadth, and zygoorbitale breadth. Conclusion. The fact that the length and breadth of the foramen magnum positively correlate with many basic craniometric indicators allows us to regard the foramen itself, or rather, the structures limiting it, as quite stable.

Anatomical assessment of foramen magnum among the South Indian population – A CT scan comparative study

Background: Foramen magnum (FM) is the most prominent opening in the floor of the posterior cranial fossa. Occipital condyle (OC) protrusion into the FM alters the measurements and produces an impact on the surgical access. Diagnostic modalities such as computed tomography (CT) and magnetic resonance imaging scan made revolutionary changes in assessing the skull base. Aims and Objectives: The aim of our study is to measure the morphometric measurements of FM, OC and assess the shapes of the FM. Materials and Methods: An observational descriptive study on morphometric measurements of FM and OC is conducted in dry skulls and CT scan images. Area, index, and shapes of FM were calculated and tabulated. Relationship between the FM dimensions was statistically analyzed using student t-test (P < 0.05). Results: There was no significant difference of means (P > 0.05) between the FM and OC parameters with respect to dry skulls and CT measurements. The study results showed that CT is good in predicting the measurements of FM. Our results on shapes of FM showed highest occurrence of the hexagonal (28.57%) followed by diamond shape (22.8%) in dry skulls and CT images. On applying the kappa statistics, there was no agreement in shapes of FM between dry skulls and CT images. Conclusion: Our study hopes to provide extensive knowledge of FM and OC for the operative surgeons and aids in the reduction of iatrogenic complications.

Evaluation of Foramen Magnum for Sex Determination among the Population of Dakshina Kannada District: A Retrospective CBCT Study.

This study aims to evaluate the accuracy rate of foramen magnum dimensions in determining sex among the South Indian population using discriminant functional analysis. An observational study in which CBCT images from 200 full field of view (FOV) scans were analysed. The dimensions of the foramen magnum were measured. Intra- and interobserver reliability were calculated. Independent t-tests were used to compare the various parameters between sexes. Stepwise discriminant function analysis was used to determine sex. A total of 200 CBCT scans were included in the study. The mean age (±SD) was 25.66 (±7.11) years among males and 24.64 (±5.12) years among females. The measurements and the circumference of the foramen magnum were significantly (p < 0.001) greater in males than in females. The univariate analysis of foramen magnum measurements reached an accuracy rate of 73.5% in sex determination. The discriminant function analysis combining the foramen magnum measurements and circumference yielded an overall predictability rate of 66.5% for determining sex. Taking into account the predictability rate of sex based on foramen measurement in the present population, it can be concluded that its applicability should be limited to cases associated with fragmentary skull bases.

Metopic skull with occipitalisation of the atlas.

In this study we report a combination of anatomic variations in the neurocranium of an adult male skull. The skull is scanned using an industrial μCT system Nikon XT H 225. The cranial vault shows a persistent metopic suture, a remnant from the mendosal suture and supernumerary bones. Cranial base inspection reveals atlas occipitalisation (AO), basilar kyphosis, unusually shaped dorsum sellae and bilateral interclinoid bridging. AO is extensive without signs of atlantooccipital articulation. The anterior and posterior arches of the atlas and the right transverse process are fussed to the occipital bone above. The complete fusion of the posterior arch causes a formation of bone canals for the vertebral arteries passage into the cranium. AO in this case is not related to a reduction of the foramen magnum dimensions and clivus length.

Osteometry of Foramen Magnum by Using Post-Mortem Computed Tomography (PMCT) for Discriminant Analysis of Sex and Population Affinity among Malaysian Population

Osteometry of the foramen magnum was assessed for discriminant function analysis of biological sex estimation and population affinity estimation based on post-mortem computed tomography (PMCT) images in this Malaysian population-based study. This retrospective cross-sectional study was performed using convenient sampling of PMCT skull images originating from 300 Malaysian adults. Linear dimensions of the foramen magnum transverse diameter (FMTD) and anterior-posterior diameter (FMAPD) were measured. Statistical analyses were performed via independent t-test, ANOVA, univariate and multivariate analyses concurrently with discriminant function analyses. There were significant differences in FMTD and FMAPD between males and females within respective population affinities. The foramen magnum dimensions of males were comparably larger than females. There were relatively significant differences in FMTD and generally sufficient significant differences in FMAPD among population affinities. The osteometry of foramen magnum dimensions of Chinese were generally larger than Malays and Indians. Discussion and Conclusion: Foramen magnum dimensions had a stronger discriminant function in biological sex estimation with 60% accuracy as compared to population affinity estimation with only 40.7% accuracy. FMTD and FMAPD are the potential sex discriminators among the Malaysian population particularly if other indicators are not available for evaluation.

Magnificent Harmony in Morphometric Measurements of Orbita and Foramen Magnum

The foramen magnum (FM) is the key component of the craniovertebral junction, which connects the brain stem and medulla spinalis and is closely related to vital structures. FM dimensions are of great clinical importance. Considering the similarity in shape between FM and orbita, we thought that there might be a relationship between the lengths (sagittal diameter) and widths (transverse diameter) of these structures. Since it is not possible to reach FM directly, we set up our hypothesis as can we calculate the foramen magnum dimensions from orbital measurements before proceeding to costly tests. We also investigated this harmony in the skulls we used in the study. In the study, 21 dried skull bones from the Turkish population were used. FM and right Orbital length and width measurements were made. Precision digital caliper was used for measurements. Statistical validity and reliability analyzes were performed to prove the agreement between the measurements. We found that the length of the orbit and FM in the sagittal plane is close to each other, with 34.74±2.11 mm and 34.99±3.0 mm, and the width of the orbit in the coronal plane is approximately 1.40 times the width of the FM. We proved that the estimation of FM dimensions based on orbital measurements is also statistically valid and safe. Using orbital measurements, it is possible to estimate FM dimensions which are difficult to reach directly in living humans.

Reliability of Post-Mortem Computed Tomography in Measuring Foramen Magnum Dimensions

Introduction: Reliability of foramen magnum dimensions using post-mortem computed tomography (PMCT) to obtain standardized measurements for biological profiling with interest in sexual dimorphism needs to be evaluated prior to a larger scale population-based study. Method: This was a retrospective cross-sectional study of 40 Malaysian adult decedent PMCT skulls. Standardized morphometric evaluation of two foramen magnum parameters, the foramen magnum anterior-posterior diameter (FMAPD) and transverse diameter (FMTD), were performed by three readers at two separate times. Statistical analysis included intraobserver and interobserver relative technical error of measurement (RTEM), coefficients of reliability (R), and t-test. Results: Error rates (RTEM) for FMAPD demonstrated intraobserver values of 3.65–3.84% (R = 0.73–0.75, substantial reliability) and interobserver values of 4.12–5.23% (R = 0.56–0.68, moderate to substantial reliability). Error rates (RTEM) for FMTD demonstrated intraobserver values between 4.52% and 5.00% (R = 0.57–0.70, moderate to substantial reliability) and interobserver values between 5.50% and 6.38% (R = 0.48–0.64, moderate to substantial reliability). Discussion: To improve precision of a population-based study, we recommend specialized operator training in the use of PMCT software, adequate sample size, clear landmark definitions, and consideration of population affinity as a confounder.

Measurement of Foramen Magnum Dimensions in Computed Tomography of Head

Introduction: Dimensions of the foramen magnum are clinically important because of the vital structures passing through it and for sex determination of the skull. The objective of this study was to measure various dimensions of the foramen magnum in Computed Tomography (CT) and correlate them with sex. Methods: Descriptive cross-sectional study was done on 120 CT head images in the Department of Radiology and Imaging, from July to October 2019. The shape of the foramen magnum (FM), anteroposterior diameter (APD), transverse diameter (TD), FM area and FM index were calculated. Statistical analysis was done with SPSS 25 and Excel 2016. Discriminant function analysis and binary logistic regression analysis were used for gender verification. RESULTS: The mean values of the APD, TD, area and FM index in males and females were 33.56 ± 4.30 mm, 29.76 ± 4.10 mm, 792.94 ± 191.60 mm2, 85.01 ± 8.67 and 30.01 ± 2.04 mm, 25.33 ± 4.6 mm, 599.63± 128.13 mm2, 83.17 ± 7.78 respectively. All dimensions were significantly greater in males (r = 0.906, P&lt;0.001). The most common shape of the foramen magnum was oval (40.8%). The accuracy of sex identification was 68.3% using dimensions of the foramen magnum. Conclusion: There was sexual dimorphism in the diameter and area of the foramen magnum which can be used for sex determination.

Morphometry of Foramen Magnum: An Anatomical Study

Introduction: The knowledge of foramen magnum dimensions is important for clinicians to highlight the malformations like Arnold Chiari malformation and Achondroplasia. Its morphometry is helpful for neurosurgeons and for forensic experts as well. Foramen magnum (FM) is a large oval opening in the occipital bone of skull that transmits part of brain stem, spinal cord and many related structures&#x0D; Aims &amp; Objectives: To determine the variations in transverse and antero posterior diameters of foramen magnum and foramen magnum index in dry skulls of adults in Pakistani population.&#x0D; Place and duration of study: The study was conducted at FMH College of Medicine &amp; Dentistry, Lahore in December 2021 on 99 dry human skulls.&#x0D; Material &amp; Methods: The foramen magnum of 99 dry skulls of human adults of unspecified gender and of unknown exact age, from the collection of Anatomy Department in FMH college of Medicine and Dentistry, Lahore, Pakistan, was examined to evaluate the dimensions of FM. Digital caliper was used to measure the antero-posterior diameter (APD) and transverse diameter (TD) of foramen magnum (FM) in dry skulls of human adults and then foramen magnum index FMI was calculated by dividing APD by TD.&#x0D; Results: The mean values of transverse and antero posterior diameters of foramen magnum in dry human skulls were found as23.18+7.68 and 29.22+7.52 respectively. The mean value of foramen magnum index was 1.30+0.22.&#x0D; Conclusion: Our study determined variations in diameters of FM and FMI in the skulls of Pakistani population. Antero posterior diameter of foramen magnum is more than its transverse diameter and majority of skulls show oval shaped FM. The results of this study may help the neurosurgeons, anthropologists, morphologists, clinical anatomists and forensic experts.

Golden Ratio for the Foramen Magnum On CT Images: A Morphological and Morphometrical Study

The foramen magnum (FM) is a transition zone between the spine and skull. There is a study in the literature showing the golden ratio (4.62) and harmony between both FM and the anteroposterior and transverse diameters of the skull. The aim of this study is to examine the existence of this ratio on CT images and to investigate whether this ratio changes according to the FM shape types. In this study, 402 adult CT images belonging to the Turkish population were examined. Maximum cranial length (MCL), maximum cranial width (MCW) and the FM length (FML) and FM width (FMW) were measured. The different shapes of the FM were macroscopically classified. The number and incidence of each type in the studied skull was registered. In the 402 CT images used in the study, 12 FM shapes were detected. Three of the shape types observed in our study have not been reported in the literature until now, and were found in our study for the first time. In addition, our data supported that by using the ratio of 4.62, there was a great harmony between the skull and FM. The results obtained from the research show that there is a ratio of 4.62 between the basic cranial measurements and FM dimensions in all shapes except triangular shape. It is thought that repeating the calculated coefficients over more different FM shapes will contribute to the effectiveness of the proposed golden ratio.

ORIGINAL ARTICLE ON THE MORPHOLOGICAL STUDY OF FORAMEN MAGNUM

Introduction: Centrally in the deepest part of posterior cranial fossa is the largest foramen, Foramen magnum surrounded by basilar part of occipital bone on either side. Because of relation between the FM and the vital structures passing through it, study on its morphometric features is of great signicance. Aim and objectives: The objectives were to study the various morphological features of the foramen magnum in dry skulls using an analogue Vernier calliper. Materials and methods: 50 dry skulls (8 base skulls, 42 full skulls) of human cadaver of unknown age and sex were obtained to study the morphometric features like shapes, anteroposterior and transverse diameters and FM index in the department of Anatomy, Kanyakumari Government medical college, Asaripallam. Results: The classication of determined shapes were round in 29.7%, hexagonal in 18.2%, egg shaped in 16.9%, oval in 12.7%, tetragonal in 11.4%, pentagonal in 3.7% and irregular in 7.4%. In 12% of the skulls the occipital condyles were found to protrude into the foramen. The mean value of anteroposterior and transverse diameter was found to be 35 ±1.2mm, and 28 ± 1.4 mm respectively and average foramen magnum index was 1.25 ± 0.8. Conclusion: Foramen magnum dimensions are used for sex determination. The structural integrity of foramen magnum is usually preserved in re accidents and explosions due to its resistant nature and secluded anatomical position. The data obtained from protrusion of occipital condyles would help in neurosurgical approach of foramen magnum meningiomas.

Sex and Age Determination by Measurement of Foramen Magnum Dimensions on Computer Tomography Scanning Study in the Iranian Population.

Individual distinguishing evidence may be an imperative field of measurable investigation which demonstrates higher correct expectation rates. This process of recognizable Evidence is facilitated by the assurance of sex and age. In circumstances where there are fragmented and mangled skeletal remains, sex assurance is moderately troublesome, and it becomes important to set up the precision of cadaver bones. Therefore, this study aims to evaluate sexual dimorphism and age determination by measuring foramen magnum (FM) dimensions in the Iranian population using digital computed tomography scan. The study sample consisted of a modern adult Iranian population of 120 males and 109 females (age range: 15-50 years). Length, width, and area of FM, also FM index were measured on base skull computed tomography scan. All of the parameters of FM (length, width, area, and FM index), were larger in men than women. The accuracy of sex determination was up to 50.2. The highest accuracy for sex determination was FM width (67.9). This study also helps craniofacial surgeon for exact reference value of FM, which are authorize neurosurgeons' accessibility to the brain stem approach and FM region with minimum retraction. It can be concluded from the result, that morphometric analyze of FM is useful for sex determination but cannot be suitable for age determination.

STUDY OF MORPHOMETRIC ANALYSIS OF FORAMEN MAGNUM IN DRY HUMAN SKULL AT SMS MEDICAL COLLEGE, JAIPUR, RAJASTHAN

Background: The present study was conducted for analysis of the morphometry shape and determination of sex by foramen Magnum.&#x0D; Methods: After applying inclusion and exclusion criteria 30 dried human skull of unknown age and sex were slected for present study from the Department of anatomy, S.M.S. Medical College, Jaipur, Rajasthan. In case of skull bones, all 30 cranial bases were visually assessed for FM shape classification. Each FM shape was classified into one of the 8 types: oval, egg, round, tetragonal, pentagonal, hexagonal, combination of 2 different semicircles and irregular.&#x0D; Results: The mean anteroposterior diameter of foramen magnum male and female skull bones were found to be 37.17±1.76 mm and 33.92±3.50 mm respectively.The mean transverse diameter of foramen mgnum in male and female skull bones were found to be 29.49±2.68 mm and 29.38±2.47 mm respectively.The mean area of foramen magnum male and female skull bones were found to be 818.05±119.66 mm² and 847.57±105.85 mm² respectively.The mean index of foramen magnum in male and female skull bones were found to be 84.00±5.41 and 80.27±5.79 respectively.Overall skull bones showed a medium type of foramen magnum index .&#x0D; Conclusion: We concluded that the several anatomic parameters such as shape and dimensions of foramen magnum should be taken into consideration during surgery involving the craniovertebral junction. Also these can be used during forensic and anthropological investigation of unknown individuals for determining gender, ethnicity, etc&#x0D; Keywords: Skull, foramen magnum, skull.

Foramen Magnum as Determinant of Sexual Dimorphism in Sri Ganganagar Population

Background: In explosions, mass disasters, and warfare, human remains are got in fragmented states. Only strong bones that resist fracture can be used for personal identification in forensics. The foramen magnum (FM) dimension at the base of the skull is one such region that can be used for sex discrimination using radiographs. Aim and Objectives: To test evaluate sexual dimorphism in FM morphometric measurements and shape using digital submentovertex (SMV) radiograph among the Sri Ganganagar population. Materials and Methods: 100 digital SMV radiographs (50 males and 50 females) were randomly selected from the daily radiographic record of the patients with an age range of 25 to 65 years who visited the OPD and require SMV radiographs for diagnosis. The selected SMV radiographs were assessed for FM dimensions (longitudinal and transverse diameters, circumference, area, and FM index). Also, one particular shape was assigned to FM based on the radiographic image according to Chethan et al. classification. All the measurements were performed by two maxillofacial radiologists independently, and the data thus obtained were subjected to discriminant analysis for the evaluation of sexual dimorphism. Results: Values of four parameters out of five (transverse diameter, circumference, area, and foramen index) were found statistically significantly higher in males. The most common morphology of FM was an egg shape (50%), whereas round (3%) was the least common morphology. Circumference FM was the best indicator of gender determination followed by area, transverse diameter. and foramen index. The SMV radiographs for FM showed an overall accuracy of 69.73% in sex determination. Conclusion: The study showed that SMV radiographic FM morphometric measurements can be used for sex determination among the Sri Ganganagar population.

Sex estimation from foramen magnum parameters in adult Turkish population: A computed tomography study.

Identification of skeletal relics is crucial for medicolegal purposes. Sex estimation is one of the critical parts providing the identification of skeletal relics. In forensic practice, sex estimation requires multidisciplinary studies of such as forensic medicine, anatomy, dentistry and radiology. Recently, radiological studies on this subject have been increasing with the developing technology. The objective of this study is to examine the usage of radiological dimensions of foramen magnum for sex estimation in human skulls by developing discriminant functions in Turkish population. We analyzed 600 (300 males and 300 females) Computerized Tomography (CT) images of Turkish individuals aged between 21 and 50. Four measurements were obtained from CT images. All measurements in males were significantly greater than in females, and they provided the higher sex classification accuracy. The area of the foramen magnum calculated by Radinsky's formula was the best measurement for sex estimation with a 75% accuracy rate. In conclusion, the CT images of foramen magnum show sexual dimorphism in our population. To use population specific data would be the most appropriate approach for sex estimation.

Mystery behind dimensions- “revealing gender by Foramen Magnum ”- a study

Abstract Introduction Human identification is of vital significance to the society and one of the positive indicators for identity is gender. This research paper presents a database of morphometric variables of Foramen Magnum and Occipital Condyle and their significance in gender determination along with different shapes of foramen magnum. Aim The aim of the study was to evaluate the dimensions and shapes of foramen magnum and occipital condyles as an aid in gender determination using computed tomographic (CT) images. Materials and methodology The present study included 60 axial CT scans of which 30 were males and 30 were females in the age range of 20-70 year fulfilling the inclusion and exclusion criteria. The various radiological parameters of foramen magnum and occipital condyles of 60 subjects including 30 males and 30 females were observed and significant sexual dimorphic differences were observed in various metric variables of Foramen Magnum and Occipital Condyle which were considerably larger in male population. Results Discriminant function analysis revealed an accuracy of 80% for Foramen Magnum, 78.3% for Occipital Condyle and 88.3% for concomitant dimensions of Foramen Magnum and Occipital Condyle. Conclusion This study is distinctive in that morphological variation of shapes of Foramen Magnum with respect to gender observed and certain different morphometric parameters which have been found to be statistically significant both for Foramen Magnum and Occipital Condyle have not been studied in the past. Hence, it can be concluded that morphometric evaluation of dimensions of Foramen Magnum and Occipital Condyle using recent and advanced radiological methods such as CT increases the accuracy of gender prediction.

Sex determination from fragmented human remains - hierarchy of the foramen magnum dimensions.

Although the foramen magnum is often described in the context of sex determination, to date, it has not been studied in relation to the Polish population. Considering interpopulation variation of human skull dimensions and shapes, study of a Polish population is needed. The aim of this paper is to evaluate a hierarchy of selected measurements of the foramen magnum in terms of their usefulness for sex determination and provide reference data for Polish non-modern populations in order to propose an alternative method of sex determination for fragmented human remains. Adult skulls from skeletal collection from Poland (N = 101, males 46.5% and females 53.5%) were measured to derive statistical functions. The anteroposterior diameter, transverse diameter, and the circumference of the foramen magnum were found to be significantly larger in males. Mollison's index and discriminant function analysis were performed to derive models for estimation of sex from the foramen magnum measurements and the ± 1 SD ranges of the dimensions were calculated. Each of foramen magnum dimensions was able to predict sex in above 90% of crania. Due to some limitations of this study and the need of population-specific standards, it is recommend employing the foramen magnum in sex determination only in cases of fragmented human remains and when no other method can be applied. Further investigation of possible factors influencing the variability of the foramen magnum size and shape should be conducted in larger and geographically more diverse samples, and this could contribute to forensic, clinical, anatomical, and anthropological studies of this anatomical structure.

Sexual dimorphism of foramen magnum: An Egyptian study

BackgroundHuman identification is of a paramount forensic concern. It includes sex determination which becomes extremely complex and tricky especially in fragmentary remains.Purpose of the studyWe aimed to evaluate the accuracy of ten dimensions of foramen magnum (FM) and occipital condyles in determination of sex among 367 subjects (204 females and 163 males), their ages ranged between 18-75 years. Multislice Computed Tomography images of skulls of the studied patients were obtained from the Radiology Department. Ten different anatomical variables of the FM were measured by two independent experienced radiologists blinded to the study.ResultsFM dimensions are unique and show significant sexual dimorphism in the studied Egyptian population especially with application of discriminant function analysis. These landmarks include foramen magnum length and width (FML, FMW), FM index, FM area, length of the right and left occipital condyles (LROC, LLOC), width of the right occipital condyle (WROC), maximum bicondylar distance (MBD) and minimum intercondylar distance (MnICD). LROC and FMW are highly significant discriminating variables predicting sex.ConclusionsIt is concluded that all the studied FM parameters showed significant differences between males and females except the left occipital condylar width with higher male values when compared to females. Additionally, the right occipital condylar length and FM width are highly significant discriminating variables which are strongly beneficial in prediction of sex. FM dimensions would provide a reliable additional tool for identification of sex among adult population and could be specific for Egyptians in case of fragmentary remains or damaged skulls.