Adult Human Skulls Research Articles

Comparison of 2 Canal Preparation Techniques in the Induction of Microcracks: A Pilot Study with Cadaver Mandibles

IntroductionThe purpose of this pilot study in a cadaver model was to compare 2 different shaping techniques regarding the induction of dentinal microcracks. MethodsThree lower incisors from each of 6 adult human cadaver skulls were randomly distributed into 3 groups: the control group (CG, no instrumentation), the GT group (GT Profile hand files; Dentsply Tulsa Dental, Tulsa, OK), and the WO group (WaveOne; Dentsply Tulsa Dental). In the GT group, manual shaping in a crown-down sequence with GT Profile hand files was performed. In the WO group, Primary WaveOne files were used to the working length. Teeth were separated from the mandibles by careful removal of soft tissue and bone under magnification. Roots were sectioned horizontally at 3, 6, and 9 mm from the apex using a low-speed saw. Color photographs at 2 magnifications (25× and 40×) were obtained. Three blinded examiners registered the presence of microcracks (yes/no), extension (incomplete/complete), direction (buccolingual/mesiodistal), and location. Data were analyzed with chi-square tests at P < .05. ResultsMicrocracks were found in 50% (CG and GT) and 66% (WO) of teeth at 3 mm, 16.6% (CG) and 33.3% (GT and WO) at 6 mm, and 16.6% in all 3 groups at 9 mm from the apex. There were no significant differences in the incidence of microcracks between all groups at 3 (P = .8), 6 (P = .8), or 9 mm (P = 1). All microcracks were incomplete, started at the pulpal wall, and had a buccolingual direction. ConclusionsWithin the limitations of this pilot study, a relationship between the shaping techniques (GT hand and WaveOne) and the incidence of microcracks could not be shown compared with uninstrumented controls.

Incidence and location of Zygomaticofacial foramen in adult human skulls

This study was to investigate the morphology, topographic anatomy and variations of Zygomaticofacial foramen (ZFF). Frequency variations and Location/distance of ZFF from surrounding standard landmarks were evaluated in 100 adult human dry skulls. The frequency of ZFF was varied from being single to as many as four foramina and absence of ZFF, which was classified into Type I – V for single, double, triple, four foramina and absence of ZFF respectively. The frequency (%) of these types was Type I: 46 & 51, Type II: 31 & 26, Type III: 4 & 6, Type IV: 1 & 1 and Type V: 18 & 16 respectively on right & left sides of the skulls. The mean distance of Zygomaticofacial foramen from Zygomaticomaxillary suture, nearest part of Orbital margin, Frontozygomatic suture, Zygomaticotemporal suture and Zygomatic angle was 13.8 & 12.2mm, 6.8 & 6.9mm, 24.8 & 26.7mm, 20.8 & 21.5mm and 12.4 & 13.5mm respectively on right & left sides of skulls. Knowledge on these variables will be helpful for surgeons for various surgical procedures like Orbitozygomatic craniotomy, for nerve block and Malar reduction surgeries.

Anatomic study of the occipital condyle and its surgical implications in transcondylar approach.

Background:Craniovertebral surgeries require the anatomical knowledge of craniovertebral junction. The human occipital condyle (OC) is unique bony structure connecting the cranium and the vertebral column. A lateral approach like transcondylar approach (TA) requires understanding of the relationships between the OC, jugular tubercle, and hypoglossal canal. Hence, the aim of the present study was to analyze the morphological variations in OCs of dry adult human skull.Materials and Methods:The study was carried out on 142 OC of 71 adult human dry skulls (55 males and 16 females). Morphometric parameters such as length, width, thickness, intercondylar distances, and the distances from the OC to the foramen magnum, hypoglossal canal and jugular foramen were measured. In addition, the different locations of the hypoglossal canal orifices in relation to the OC and different shapes of the OC were also noted.Results:The average length, width and height of the OC were found to be 2.2, 1.1 and 0.9 cm. The anterior and posterior intercondylar distances were 2.1 and 3.9 cm, respectively. Maximum and minimum bicondylar distances were 4.5 and 2.6 cm, respectively. The intra-cranial orifice of the hypoglossal canal was found to be present in middle 1/3rd in all skulls (100%), and extra-cranial orifice of the hypoglossal canal was found to be in anterior 1/3rd (98%) in relation to OC. The oval shaped OC (22.5%) was the most predominant type of OC observed in these skulls.Conclusion:Occipital condyle is likely to have variations with respect to shape, length, width and its orientation. Therefore, knowledge of the variations in OC along with careful radiological analysis may help in safe TAs during skull base surgery.

Mastoid emissary foramina: an anatomical morphological study with discussion on their evolutionary and clinical implications.

The identification of mastoidal emissary veins is of importance in the neurosurgical practice to diagnose abnormal and normal structures. In the present study, the objectives were to estimate the prevalence rate of mastoidal emissary foramina in the temporal bones of the adult skull and to study their number and morphology. The present study included 48 adult human skulls which were obtained from the gross anatomy laboratory of our institution. The mastoid parts of 96 temporal bones were macroscopically observed for the prevalence, number and morphology of the emissary foramina. It is observed that, the mastoidal emissary foramen was present in 88 temporal bones (91.7%) of our specimens. The foramen was observed single in 60 temporal bones (62.5%), double in 22 bones (22.9%), and triple in 6 temporal bones (6.2%). The mastoidal emissary foramen was absent in 8 (8.3%) temporal bones. The foramen was bilaterally absent in 3 (3.1%) skulls. It was unilaterally absent in 2 (2.1%) skulls and both were on the left side. The mastoidal emissary vein is prevalent in a large number (91.7%) of cases. It was observed that the accessory mastoidal emissary foramina were present in 29.1% of cases. Recognition of the mastoid emissary veins and accessory mastoid emissary veins during the otologic surgery is critical to avoid the significant bleeding. In the neurosurgical practice, the knowledge is important due to variability in the number of mastoidal emissary veins and their connection to the venous sinuses.

The Paracondylar Skull Base: Anatomical Variants and Their Clinical Implications.

The knowledge of the vasculature around the paracondylar region is important in neurosurgical procedures such as the paracondylar and lateral supracondylar approaches. The objectives of the present study were to determine the prevalence of paracondylar emissary foramina in the adult skull bases and to study the morphology of condylar canals and hypoglossal canals. The present study included 48 adult human skulls that were obtained from the gross anatomy laboratory of our institution. The paracondylar region was macroscopically observed for the variant foramina, canals and grooves. It was observed that the paracondylar emissary foramen was present in 16 skulls (33.3%). The foramen was found bilaterally in 7 skulls (14.6%) and unilaterally in 9 skulls (18.7%). The hypoglossal canal was single in 35 (72.9%) skulls, double in 11 skulls (22.9%), and triple in 2 skulls (4.2%). The paracondylar process (2.1%) and the paracondylar groove (2.1%) were seen in 1 skull each. The posterior condylar canal was found to be patent in 19 (39.6%) skulls. The present study observed that, the paracondylar emissary vein is not rare in occurrence as it is observed in 33.3% of cases. The identification of the paracondylar emissary veins and accessory vessels is important to avoid dangerous bleeding during the surgery. The morphological knowledge of the foramina around the paracondylar region is enlightening to the chiropractors, neurosurgeons and radiologists.

Morphometric study of Jugular Foramen at base of the skull in South Gujarat region

The jugular foramen is the main route of venous outflow from the skull and is characterised by laterality based on the predominance of one of the sides. Intracranial meningiomas, paragangliomas (glomus jugulare, from the jugular ganglion of the vagus nerve), schwannomas, metastatic lesions and infiltrative inflammatory processes from surrounding structures such as the middle ear may affect the structures passing through this foramen. We studied one hundred dry, adult human skull of unknown sex and measured sagittal and transverse diameter of Jugular foramen. Jugular foramen were also observed for the presence of dome, septation and right or left dominance. Mean transverse diameter of jugular foramen was 11.61mm and mean sagittal diameter was 7.12mm.The size of the jugular foramen varied on the two sides. R>L were 75%, R<L were 31%, R=L were 2%.The jugular bulb dome was present bilaterally in 23%, on the right side only in 30%, on the left side only in 11%, and absent in 36%.Complete septation was present in 16% on the right side and 14% on the left side. Partial separation was present in 29% on the right side and in 25% on the left side. Knowledge of morphology, compartments and morphometry is important for neurosurgeons dealing with space occupying lesions in jugular foramen.

Morphometric study of Foramen Magnum at the base of human skull in South Gujarat

The foramen Magnum is a large opening in the occipital bone of the cranium. The dimensions of the foramen magnum are clinically important because vital structures passing through it may endure compression such as in cases of foramen magnum herniation, foramen Magnum meningiomas and foramen magnum achondroplasia. We studied one hundred dry, adult human skull of unknown sex and measured antero- posterior and transverse diameter with the help of vernier caliper. Additionally surface area of foramen magnum was also calculated. The mean antero-posterior diameter of the foramen magnum was 40.2mm(range 26-40mm) and the transverse diameter was 28.29mm(range 21.5-33.5mm). The mean surface area of foramen magnum was 755.37mm.The knowledge of dimensions of foramen magnum will be helpful radiological diagnostic procedures and neurosurgical procedures to approach in the region of Foramen Magnum. Considering above mentioned importance, this study is worthwhile. The foramen Magnum(FM) (Latin: 'great hole') is a large opening in the occipital bone of the cranium. Its transverse diameter is rather less than one third of the distance between the mastoid processes. The anterior border of the foramen magnum is formed by basilar process of the occipital bone, the lateral border by the left and right ex- occipitalis and posterior border is formed by the

Foramena Magnum Dimensions: An Aid in Identification of Gender

Determination of deceased sex is first step in skeletal analysis since estimation of age, race, and stature depends on sex of deceased. Total 100 adult human skulls (50 male and 50 female) of Hyderabad-Karnataka region are studied. Measurements like foramena magnum length and foramena magnum breadth were measured. The demarking point (D.P.) and identification point (I.P.) of both measurements was calculated and then percentage of bones identified by D.P. and I.P. was recorded. Though, the Demarking Point of a single parameter may not identify sex in all the bones but the accuracy is nearly 100% in the bones, which are identified. Percentage of skulls identified by IP and DP of foramena magnum length is more as compared to foramena magnum breadth. So foramena magnum length gives better prediction of sex as compared to foramena magnum breadth.

Identification of Gender from Dimensions of Palate

Determination of deceased sex is first step in skeletal analysis since estimation of age, race, and stature depends on sex of deceased. Total 100 adult human skulls (50 male and 50 female) available in the Department of Forensic Medicine and Toxicology and Department of Anatomy of M. R. Medical College and K. B. N. Medical College Gulbarga, Karnataka are studied. The demarking point (D.P.) and identification point (I.P.) of both measurements were calculated and then percentage of bones identified by D.P. and I.P. was recorded. Though, the Demarking Point of a single parameter may not identify sex in all the bones but the accuracy is nearly 100% in the bones, which are identified. Percentage of skulls identified by IP of palatal breadth in males is more as compared to palatal length where as identification from DP is equal. Percentage of skulls identified by IP and DP of palatal length in females is more as compared to palatal breadth. So palatal length gives better prediction of sex as compared to palatal breadth in case of females where as in case of males palatal breadth is better predictor of sex.

Anatomical variations of the human occipital condyles

Occipital condyles, located at the inferior sides of lateral parts of occipital bone, are important structures that connect the cranium and the vertebral column. Their size, shape, location and, also, their congruence with superior articular facets of the atlas vertebra are of great importance for the stability of craniovertebral junctions. The progress in medical diagnostic and surgical techniques in the area of foramen magnum, requires the knowledge regarding anatomical aspects of this region. The purpose of this study was to evaluate the measurements of the occipital condyles, as well as to analyse the variations in the shape of the condyles and their position in relation to the foramen magnum. This study included 25 adult human skulls (11 male and 14 female) from the Osteological collection of the Department of Anatomy at Medical Faculty in Novi Sad. Nine parameters, which define morfological properties of the occipital condyles, were measured using Vernier caliper. Also, the shape and location of the condyles, as well as the narrowness of the foramen magnum were described. Our findings show that length of the left occipital condyle, as well as distance between the posterior top of the left occipital condyle and basion are statistically greater in male crania, comparing to female crania. According to the shape of the occipital condyles, we classified them in seven groups. Predominant type is oval shaped. The condylar foramen is bilaterally present in 36 % and the occipital condyles bilaterally protrude the foramen magnum in 40 % of analyzed crania. Morphometric analysis of the occipital condyles showed variations in their size, shape, presence of condylar canal and relation to the foramen magnum.

Variations in the Structure of the Jugular Foramen of Human Skull

Context: The jugular foramen is one of the most fascinating foramen present at the base of the skull attracting the imagination of many Anatomists worldwide as many important structures pass through it, and amongst them the intriguing structure is the internal jugular vein. The shape and size of the jugular foramen is related to the size of the internal jugular vein and the presence or absence of a prominent superior bulb. As most of the textbooks of Anatomy describe that the right jugular foramen is usually larger than the left jugular foramen. Henceforth the present study was undertaken in 55 skulls from the dept. of Anatomy. Measurements were taken with the help of sliding vernier caliper. Study type: Cross-sectional descriptive type. Place and period of study: Department of Anatomy, Rajshahi Medical College, Rajshahi and Pabna Medical College, Pabna from April 2010 to June 2011. Materials and Methods: Total fifty five (55) human adult skulls were collected from the Anatomy department of Rajshahi Medical College, Rajshahi and Pabna Medical College, Pabna at different times of the study period. The study was conducted to observe variations in the structure of the jugular foramen of the human’s skull. Result: Out of 55 skulls (110 foramina) studied, the presence of dome indicating the presence of jugular bulb was found bilaterally in 100% of cases. 58.18% of cases showed that the size of right foramina were larger than the left foramina whereas 20% of cases showed that right foramina were equal to the left and in 21.82% of cases the left foramina were larger than the right side foramina. An important observation in the present study was the presence of either complete or partial septation in the jugular foramen. Conclusion: The findings of the study reveals that there are some differences among some parameters. The variations are might be due to the geographical variations of the skeletons. It needs further study with larger sample size from different geographical areas of Bangladesh. DOI: http://dx.doi.org/10.3329/bja.v10i2.17281 Bangladesh Journal of Anatomy, July 2012, Vol. 10 No. 2 pp 45-49

Study of duplication of optic canal in hundred dry human skull bones

Introduction: The pyradimal shaped bony orbit communicates with middle cranial fossa by means of optic canal which transmits optic nerve and ophthalmic artery. Unilateral, bilateral duplication of optic canal is a rare entity. Methods: One hundred adult human skull bones collected from north Karnataka region were studied for duplication of optic canal. Complete duplication, partial duplication, whether unilateral or bilateral duplication were studied. Results: Out of one hundred skull bones, in one case (1%), unilateral duplication of optic canal was noted which was complete and was on left side. Conclusion: The knowledge of duplication of optic canal increases the success rate of surgical procedures of optic canal and minimizes the risk of injury to optic nerve and ophthalmic artery.

Anatomical variations of supraorbital notch and foramen: a study on human adult Egyptian skulls

Background The clear knowledge of the location of the supraorbital foramen is essential when performing supraorbital endoscopic surgeries and regional nerve blocks. In this study, we made a detailed analysis of the supraorbital foramen (SOF), supraorbital notch (SON) and supraorbital ridge (SOR) of Egyptian skulls in a comparative study with those of other races and regions.

English

Sex determination is used in anthropology, forensic medicine and medico-legal cases. It is (1) remarked that next to the pelvis, the skull is the most easily sexed portion of the skeleton. It has been suggested (2-5) that the measurements of the foramen magnum are useful for determining the sex. There are two osteological techniques used to determine the sex of an individual; the first is visual assessment to evaluate the morphological sex traits and second is the metrical, in which the skeletal assessment relies on methods based on measurements. The metric approach is more objective and less dependent on observer experience. AIM & OBJECTIVE: The aim of the present study is morphometric evaluation of foramen magnum dimensions in north Indian population and to use these dimensions for sex estimation. MATERIAL & METHOD: This study is conducted on 68 human adult skulls of known sex collected from museum of anatomy department of TMMC & RC Moradabad and also from nearby medical colleges of same geographical, cultural and climatic conditions. Well preserved cranial bases were used for this study. Digital stainless steel caliper, osteometric board and blunt craniophore were the instruments used in this study. ANALYTICAL TEST: t test. RESULTS: The dimensions of the foramen magnum were significantly higher in men's skulls. CONCLUSION: It is concluded that all values of female are lower than male values, which shows that these parameters are very important for sex determination and constitution of biological

Statistical analysis of biomechanical properties of the adult skull and age-related structural changes by sex in a Japanese forensic sample

The purpose of this research was to investigate the biomechanical properties of the adult human skull and the structural changes that occur with age in both sexes. The heads of 94 Japanese cadavers (54 male cadavers, 40 female cadavers) autopsied in our department were used in this research. A total of 376 cranial samples, four from each skull, were collected. Sample fracture load was measured by a bending test. A statistically significant negative correlation between the sample fracture load and cadaver age was found. This indicates that the stiffness of cranial bones in Japanese individuals decreases with age, and the risk of skull fracture thus probably increases with age. Prior to the bending test, the sample mass, the sample thickness, the ratio of the sample thickness to cadaver stature (ST/CS), and the sample density were measured and calculated. Significant negative correlations between cadaver age and sample thickness, ST/CS, and the sample density were observed only among the female samples. Computerized tomographic (CT) images of 358 cranial samples were available. The computed tomography value (CT value) of cancellous bone which refers to a quantitative scale for describing radiodensity, cancellous bone thickness and cortical bone thickness were measured and calculated. Significant negative correlation between cadaver age and the CT value or cortical bone thickness was observed only among the female samples. These findings suggest that the skull is substantially affected by decreased bone metabolism resulting from osteoporosis. Therefore, osteoporosis prevention and treatment may increase cranial stiffness and reinforce the skull structure, leading to a decrease in the risk of skull fractures.

New Practical Landmarks to Determine Sigmoid Sinus Free Zones for Suboccipital Approaches

Literature defines the landmarks to identify the courses and locations of the transverse and sigmoid sinuses on the outer surface of the skull and inner surface of the scalp. These natural landmarks may only be helpful after skin incision and are inadequate to determine the length and size of the skin incision. Still, there is a need to identify palpable landmarks easily to determine the ideal location to open the initial burr hole before an operation. Twenty-eight dried adult human skulls and 2 cadavers were evaluated. The zygomatic root, the inion, and the mastoid process were identified on the external, and the grooves for sigmoid and transverse sinuses, on the internal surfaces. The distances between the 3 landmarks and the midpoints, and the shortest distances of the midpoints to the border of the groove for sigmoid sinus and groove for transverse sinus were measured. Statistically significant differences were evaluated for both sides. Based on the measurements, the defined "artificial landmarks" can be considered safe points that involve no vascular structures and may be used to perform the initial burr hole during posterolateral approaches. Identification of the midpoints and palpation of the defined landmarks easily before the operation render the study feasible and practical unlike with natural landmarks. To avoid venous injury, the midpoints of mastoid-inion line and zygomatic root-inion line can be used safely in skin incision during posterior fossa approaches and craniotomy.

Morphological peculiarities of the hard palate

Abstract Our results were obtained on a total of 48 adult human skulls, assessing the morphological characteristics of the hard palate, measuring the palatine processes and analyzing the sutures (intermaxillary, interpalatine and maxillo-palatine); were determined the size, shape and features of the palatine foramens and incisive fossa. For the incisive fossa we describe three shapes: oval, round and rhombic. In 2 cases the incisive fossa was absent, being replaced by three round holes arranged in a triangle. The palatine process has a very irregular inferior face, being smoother only in its posterior quarter. Each palatine process of maxilla has a trapezoidal shape with the lesser base oriented anteriorly. The median palatine suture starts at the middle of the posterior circumference of the incisive fossa and ends, more often, on the line between second and third molars. The suture may be regular, located on the midline, so the two palatine processes of the maxilla are symmetrical and of equal size. The horizontal palatine lamina is thin, smooth and glossy, with very few vascular openings on its surface, mostly on its sides. The transverse palatine suture is most commonly curved posteriorly, with irregular contour and with an oblique posterior-lateral traject; it ends at the large palatine foramen. The large palatine foramens are voluminous, sometimes larger than the incisor one. The most common shape is oval and less frequently are rounded. The lesser palatine foramens are variable in number from 1 to 5; commonly are two on each side.

Location of the Zygomatico-orbital Foramen on the Inferolateral Orbital Wall: Clinical Implications

Purpose: To describe the location of the zygomatico-orbital foramen on the inferolateral orbital wall.Methods: This anatomic study examined 28 orbits of 14 dry human adult skulls. The zygomatico-orbital foramen was identified by passing a thin wire from the zygomatico-facial foramen to its orbital aspect and a thin flexible ruler was used to measure 1) the distance perpendicular to the closest point on the inferior orbital rim, 2) the distance from the inferior orbital fissure, and 3) the distance from the area used for retrobulbar injections.Results: The mean distance from the zygomatico-orbital foramen to the closest point on the inferior orbital rim was 4.7 mm (range from 1 to 7 mm). The mean distance from the inferior orbital fissure was 14.9 mm (range from 10 to 18 mm). The mean distance from the area of retrobulbar injection was 6.0 mm (range from 3 to 10 mm).Conclusions: The location of the zygomatico-orbital foramen within the inferolateral orbit is quite variable. This is the first study to attempt to quantify its proximity to the site of retrobulbar injection. We conclude that it is an important anatomical structure to consider when giving retrobulbar anesthesia, especially given the variability in technique among ophthalmologists.

Noninvasive Diagnosis of Blood Flow for Transcranial Doppler Ultrasonography

This paper describes noninvasive diagnosis of blood flow for Transcranial Doppler (TCD) ultrasonography. This trans-skull ultrasonic system measures the blood flow velocity in the human brain using an ultrasonic array probe with the center frequency of 1.0 MHz. The system determines the blood flow and locates the blood vessel using Doppler effects, which are defined by the center of gravity in the frequency domain. We employ three different thickness silicon tubes, which imitate blood vessels. This system detected the flow direction by Doppler Effect under skull and visualized the skull and flow direction. Under the conditions with 0.16–0.27 mm thickness bone and our equipment specification, we confirmed to enable to diagnose the blood flow under the bone. This result is superior to measure the blood flow from any part of the adult human skull. Moreover, we extracted the region of skull and blood vessel automatically.

Abnormal bone outgrowths and osseous structures around the foramen ovale may leads to mandibular compression or entrapment neuropathy

Foramina ovale is an important opening on the infratemporal surface of the posterior part of the greater wing of the sphenoid bone, any bone outgrowths and osseous structures around it could influence the anatomical organisation of the nerves and vessels that run through this opening. Accordingly the present study was designed to find out the bony outgrowths and osseous structures around the foramen ovale in available dried adult human skulls. The study was carried out using 100 dried adult human skulls irrespective of sex were obtained from the Department of Anatomy-Santhiram Medical College Nandyal, Department of Anatomy-Melaka Manipal Medical College (MMMC)-Manipal and Department of Anatomy- Viswabharati Medical College Kurnool. Among 100 dry adult skulls studied, sixty one (61%) of the skulls had neither any abnormal bony outgrowths nor osseous structures around the foramen ovale. Abnormal bone outgrowths in 22 skulls (22%) and osseous structures in seventeen skulls (17%) around the foramen ovale were noted. Anatomical knowledge of such abnormal bone outgrowths and osseous structures around the foramen ovale is important for neurosurgical procedures involving the percutaneous trigeminal rhizotomy for trigeminal neuralgia, transfacial fine needle aspiration technique in perineural spread of tumour and electroencephalographic analysis for seizure.