Craniometric Points Research Articles

Anatomical Variations in the Pseudosylvian Fissure Morphology of Brachy-, Dolicho-, and Mesaticephalic Dogs.

The purpose of the study is the following: (1) to anatomically characterize the right and the left pseudosylvian fissure (Psf) morphology; (2) to determine Psf variations between both hemispheres and between the three considered groups; and (3) to understand how these variations may influence brain surgery for dogs. Also we sought to determine whether there are any potential differences between brachy- (B), dolicho- (D), and mesaticephalic (M) dogs. The present study considered 138 brain hemispheres (N = 138) from 69 adult dog cadavers and used bregma craniometric point (b- the junction of coronal and sagittal cranial vault sutures) to characterize the Psf location on the superolateral brain surface. For statistical analysis, P values <0.05 were considered significant. The Psf was easily identified in all specimens at both hemispheres. Statistically significant differences for Psf width were registered between the groups, presenting M as the narrowest Psf regions. Fissure body length can be sorted in ascending order as D < M < B in both hemispheres, with the left Psf bigger than the right for all considered skulls. The greatest difference was registered in the B group with the left Psf 25.0% bigger than the right. Bregma has proved to be useful to appoint Psf location as more superior or inferior in the encephalic lateral surface, exhibiting in all groups the left Psf a superior position. For the groups the most inferior location was registered in M and the most superior in D. Understanding the Psf morphology and anatomical variations may provide important information to ensure safer intracranial procedures.

Generation and Detection of Cranial Landmark

Purpose When a surgeon examines the morphology of skull of patient, locations of craniometric landmarks of 3D computed tomography(CT) volume are one of the most important information for surgical purpose. The locations of craniometric landmarks can be found manually by surgeon from the 3D rendered volume or 2D sagittal, axial, and coronal slices which are taken by CT. Since there are many landmarks on the skull, finding these manually is time-consuming, exhaustive, and occasionally inexact. These inefficiencies raise a demand for a automatic localization technique for craniometric landmark points. So in this paper, we propose a novel method through which we can automatically find these landmark points, which are useful for surgical purpose. Materials and Methods At first, we align the experimental data (CT volumes) using Frankfurt Horizontal Plane (FHP) and Mid Sagittal Plane(MSP) which are defined by 3 and 2 cranial landmark points each. The target landmark of our experiment is the anterior nasal spine. Prior to constructing a statistical cubic model which would be used for detecting the location of the landmark from a given CT volume, reference points for the anterior nasal spine were manually chosen by a surgeon from several CT volume sets. The statistical cubic model is constructed by calculating weighted intensity means of these CT sets around the reference points. By finding the location where similarity function (squared difference function) has the minimal value with this model, the location of the landmark can be found from any given CT volume. Results In this paper, we used 5 CT volumes to construct the statistical cubic model. The 20 CT volumes including the volumes, which were used to construct the model, were used for testing. The range of age of subjects is up to 2 years (24 months) old. The found points of each data are almost close to the reference point which were manually chosen by surgeon. Also it has been seen that the similarity function always has the global minimum at the detection point. Conclusion Through the experiment, we have seen the proposed method shows the outstanding performance in searching the landmark point. This algorithm would make surgeons efficiently work with morphological informations of skull. We also expect the potential of our algorithm for searching the anatomic landmarks not only cranial landmarks.

English

Pterion a cranio-metric point has been described according to its location, type and relationship with the surrounding bony landmarks. 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. AIM & OBJECTIVE: The study was set to explore the morphometry of Pterion in the human dry skulls of Uttarakhand region. The data may be useful for the anthropologists, forensic pathologists, neurosurgeons and maxillo-facial surgeons. MATERIAL AND METHOD: 40 dry human skulls of unknown sex collected from the department of anatomy of SGRR medical college. Instrument used for linear measurements - Sliding Caliper. ANALYTICAL TEST: Students 't' test. RESULT: Sphenoparietal type accounted 86.25%, frontotemporal 11.25% and stellate 2.5% collectively on the both sides of skull. The pterion is located 3.25 ±1.05cm behind frontozygomatic suture and 3.76 ±6.62cm above the temporozygomatic suture. CONCLUSION: Pterion is less likely to be diagnosed as a fracture site due to nonoccurrence of epipteric type of pterion in human skull of Uttarakhand. Pterion can be easily located with its relation to bony landmarks, and is most preferable approach in neurosurgery.

VALIDATION METRICS OF THE MASTOID TRIANGLE

AbstractThe purpose of this study was to validate the technique developed by Paiva and Segre for sex identification using the mastoid process. Total mastoid area is calculated by adding the right and left triangular areas defined by three distinct craniometric points: the Asterion, Porion and the Mastoidale. Eight skulls (40 males and 40 females) were analysed and total area calculated using Heron's formula. The mean total area of the male skulls is higher compared to females (1461.06 mm2 vs 1222.79 mm2). Independent t-tests reveal that there are significant differences between males and females, with p-values less than 0.0001.

Determination of Stature from Head Length of People of Gujarati Origin

When a victim is unknown, anthropologist plays a key role in preparing biological profile. Developing such profile entitles studying remains noting genetic characteristic of shape and size, which allow estimation of age, sex, population and ancestry. Estimation of stature is considered as an important parameter in medico-legal and forensic examination. An attempt is made to find out correlation and to derive a regression formula between head length and body height in Gujarat region. The material consists of 239 students from Gujarat University. Students were selected as subject because of the easy. The age was in the range of 21 to 25 years. The length of head was measured between two craniometric points, glabella and inion. Spreading caliper was used to measure head length. Height of the subject was measured with standard height measuring instrument in anatomical position. Measurements were taken at fixed time to avoid diurnal variation. The result obtained was analysed and attempt was made to derive a formula between head length and total height of an individual. The result shows that there is a definite correlation between head length and height of an individual. In spite of the racial and ethnical variation, this formula may be a definite correlation between head length and height of an individual.

The Dorsal Sagittal Venous Sinus Anatomical Variations in Brachycephalic, Dolichocephalic, and Mesocephalic Dogs and Their Significance for Brain Surgery

Dorsal sagittal venous sinus (DSVS) is an encephalic structure located in the midline of brain dorsal surface, starting behind the frontal venous sinus and following the brain falx in its extension. Knowing DSVS morphology and cranial-cerebral relationships it is very important for surgeon when he is planning the placement of craniotomies, in order to prevent the damage of this structure. The main purpose of this study were to establish craniometric points that can be used as key points of neurosurgical importance providing an anatomic framework to brain access regarding the localization of DSVS, and to characterize the morphology of DSVS in the three groups considered in study according their type of skull (brachycephalic-B, dolychocephalic-D and mesocephalic-M). The study was performed on 138 formalin-fixed cerebral hemispheres of 69 adult dog cadavers (23 of each group) which had been removed from the skulls after the introduction of plastic catheters through properly positioned burr holes placed on the five craniometric points considered: asterion(ast), bregma(br), glabella(g), stephanion(st) and pterion(pt). From the three groups, DSVS length and width were different, his geometry in B assumed a triangular appearance and in D, M a "butterfly" shape. From all craniometric points considered, only bregma (br) can be useful as a landmark to delimitate DSVS morphology in all three groups. Asterion in M, stephanion in B, glabella and pterion in all three groups, can not be used to compose a framework that help to understand skull surface projection of DSVS morphology, since their measurements were not uniform.

Determination of Sex from Juvenile Crania by Means of Discriminant Function Analysis*,†

This study provides evidence of craniofacial growth variation between the sexes in juveniles of European descent. Data were collected from lateral cephalometric radiographs belonging to the Michigan Craniofacial Growth Study. The collection consists of longitudinal lateral radiographs that represent individuals 5-16 years of age. Each radiograph was manually traced on hyprint vellum from which eight craniometric points were identified. From these points, 20 craniofacial measurements were recorded and then analyzed by means of a canonical discriminant function analysis. Sex classification equations were then created by applying a backward stepwise procedure to the discriminant functions. The analysis demonstrates the presence of sexually dimorphic differences in craniofacial growth. The neurocranium is the most sexually dimorphic region of the juvenile craniofacial skeleton, until the onset of puberty. Size is the main source of variation with males having taller and longer heads than females. Overall, sex classification in the sample ranges from 78 to 89% accuracy.

Window anatomy for neurosurgical approaches

Knowledge of the cranium projections of the gyral structures is essential to reduce the surgical complications and to perform minimally invasive interventions in daily neurosurgical practice. Thus, in this study the authors aimed to provide detailed information on cranial projections of the eloquent cortical areas. Ten formalin-fixed adult human skulls were obtained. Using sutures and craniometrical points, the crania were divided into 8 windows: superior frontal, inferior frontal, superior parietal, inferior parietal, sphenoidal, temporal, superior occipital, and inferior occipital. The projections of the precentral gyrus, postcentral gyrus, inferior frontal gyrus, superior temporal gyrus, transverse temporal gyri, Heschl gyrus, genu and splenium of the corpus callosum, supramarginal gyrus, angular gyrus, calcarine sulcus, and sylvian fissure to cranial vault were evaluated. Three-fourths of the precentral gyrus and postcentral gyrus were in the superior parietal window. The inferior frontal gyrus extended to the inferior parietal window in 80%. The 3 important parts of this gyrus were located below the superior temporal line in all hemispheres. The orbital and triangular parts were in the inferior frontal window, and the opercular part was in the inferior parietal window. The superior temporal gyrus was usually located in the inferior parietal and temporal windows, whereas the supramarginal gyrus and angular gyrus were usually located in the superior and inferior parietal windows. The farthest anterior point of the Heschl gyrus was usually located in the inferior parietal window. The mean positions of arachnoid granulations were measured as 3.9 +/- 0.39 cm anterior and 7.3 +/- 0.51 cm posterior to the bregma. Given that recognition of the gyral patterns underlying the craniotomies is not always easy, awareness of the coordinates and projections of certain gyri according to the craniometric points may considerably contribute to surgical interventions.

A Forensic Investigation of Human Cranial Remains Recovered From New York City via CT Imaging and Morphometric Analysis

Cranial remains were discovered during construction activity in NYC. A forensic workup was undertaken to determine sex, race, age and manner of death. Cranial elements identified included a partial calvaria with spanchnocranium, a left zygoma, and a broken mandible. An almost complete neurocranium with missing portions of the cranial base and left segments of parietal and temporal bones was documented. Quantitative measures were taken using available craniometric points. Various methods used to assess skeletal elements permitted skull reconstruction followed by CT imaging performed at Mount Sinai Hospital. Size and overall rugose expression of cranial features (pronounced mastoid process, strong browridge) suggest a male identification. Calvaria shows excellent ectocranial and endocranial preservation with no distinctly noticeable taphonomic deformities, although three‐dimensional CT reconstructions revealed evident warping on the right side of the cranial vault suggesting the skull lied flat on that side. Race was determined to be Caucasian though a cranial index of 71 fell within the dolicocephalic range indicative of an African phenotype. Caucasoid affinities exhibited by skull included marked projection of nasal bones, narrow nasal breadth, and lack of facial prognathism. Craniodental analysis suggests an adult age at the time of death. Manner of death, however, remains undetermined.Grant Funding SourceNone

History of the Peoples of the Great Hungarian Plain in the First Millennium: A Craniometric Point of View

We carried out an examination relying on six dimensions of 1,573 crania coming from the Great Hungarian Plain. The crania represent seven archeological periods: Sarmatian age (1-4th century), the period of transition (about 400-420), Hun and Gepidic epochs (about 420-455 and 455-567, respectively), early Avar age (about 568-670), late Avar period (about 670-895), the epoch of the Hungarian conquest and settlement (about 895-1000), and the Arpadian age (about 1000-1301). We were curious about the anatomical background behind cultural changes of the various populations that inhabited this area. After having noticed some discontinuities between the populations, as revealed by univariate analysis of single dimensions, we performed a principal-components analysis to see whether or not the diverse components showed eventual breaks in the sequence of the populations. Knowing that all the dominant populations had Asian roots, except for the Gepids of Germanic origin, we expected a considerable difference between the Gepidic population and all the other inhabitants. We also assumed that a conquest itself with a large-scale assimilation was unlikely to leave breaklike traits in anatomical patterns, except for aggressive conquests. We found that the second principal component (which correlated with cranial breadth and partly with height) showed a remarkable hiatus in both sexes between Gepids and early Avars. Having done a statistical proof (simultaneous tests for general linear hypotheses) of the observed phenomenon, we found that the gap referring to subsequent populations was significant only in males. A possible reason for this result is that the Avar conquest was much more radical than has been thought. In addition, considering that men were more likely to die in wars, women survived and were assimilated into the conquerors' populations with higher probability, so it is not surprising that the results of multicomparison tests are significant only in men.

History of the Peoples of the Great Hungarian Plain in the First Millennium: A Craniometric Point of View

We carried out an examination relying on six dimensions of 1,573 crania coming from the Great Hungarian Plain. The crania represent seven archeological periods: Sarmatian age (1–4th century), the period of transition (about 400–420), Hun and Gepidic epochs (about 420–455 and 455–567, respectively), early Avar age (about 568–670), late Avar period (about 670–895), the epoch of the Hungarian conquest and settlement (about 895–1000), and the Arpadian age (about 1000–1301). We were curious about the anatomical background behind cultural changes of the various populations that inhabited this area. After having noticed some discontinuities between the populations, as revealed by univariate analysis of single dimensions, we performed a principal-components analysis to see whether or not the diverse components showed eventual breaks in the sequence of the populations. Knowing that all the dominant populations had Asian roots, except for the Gepids of Germanic origin, we expected a considerable difference between the Gepidic population and all the other inhabitants. We also assumed that a conquest itself with a large-scale assimilation was unlikely to leave breaklike traits in anatomical patterns, except for aggressive conquests. We found that the second principal component (which correlated with cranial breadth and partly with height) showed a remarkable hiatus in both sexes between Gepids and early Avars. Having done a statistical proof (simultaneous tests for general linear hypotheses) of the observed phenomenon, we found that the gap referring to subsequent populations was significant only in males. A possible reason for this result is that the Avar conquest was much more radical than has been thought. In addition, considering that men were more likely to die in wars, women survived and were assimilated into the conquerors’ populations with higher probability, so it is not surprising that the results of multicomparison tests are significant only in men.

Surgical Anatomy of Microneurosurgical Sulcal Key Points

The brain sulci constitute the main microanatomic delimiting landmarks and surgical corridors of modern microneurosurgery. Because of the frequent difficulty in intraoperatively localizing and visually identifying the brain sulci with assurance, the main purpose of this study was to establish cortical/sulcal key points of primary microneurosurgical importance to provide a sulcal anatomic framework for the placement of craniotomies and to facilitate the main sulci intraoperative identification. The study was performed through the evaluation of 32 formalin-fixed cerebral hemispheres of 16 adult cadavers, which had been removed from the skulls after the introduction of plastic catheters through properly positioned burr holes necessary for the evaluation of cranial-cerebral relationships. Three-dimensional anatomic and surgical images are displayed to illustrate the use of sulcal key points. The points studied were the anterior sylvian point, the inferior rolandic point, the intersection of the inferior frontal sulcus with the precentral sulcus, the intersection of the superior frontal sulcus with the precentral sulcus, the superior rolandic point, the intersection of the intraparietal sulcus with the postcentral sulcus, the superior point of the parieto-occipital sulcus, the euryon (the craniometric point that corresponds to the center of the parietal tuberosity), the posterior point of the superior temporal sulcus, and the opisthocranion, which corresponds to the most prominent point of the occipital bossa. These points presented regular neural and cranial-cerebral relationships and can be considered consistent microsurgical cortical key points. These sulcal and gyral key points can be particularly useful for initial intraoperative sulci identification and dissection. Together, they compose a framework that can help in the understanding of hemispheric lesion localization, in the placement of supratentorial craniotomies, as landmarks for the transsulcal approaches to periventricular and intraventricular lesions, and in orienting the anatomic removal of gyral sectors that contain infiltrative tumors.

Cranial sutures and craniometric points detected on MRI

The main goal of the study was to determine on MRI the cranial sutures, the craniometric points and craniometric measurements, and to correlate these results with classical anthropometric measurements. For this purpose, we reviewed 150 cerebral MRI examinations considered as normal (Caucasian population aged 20-49 years). For each examination we individualized 11 craniometric landmarks (Glabella, Bregma, Lambda, Opisthocranion, Opisthion, Basion, Inion, Porion, Infra-orbital, Eurion) and three measurements. Measurements were also calculated independently on 498 dry crania (Microscribe 3-DX digitizer). To validate the MRI procedure, we measured four dry crania by MRI and with compass or digital caliper gauges. Cranial sutures always appeared without signal (black), whatever the MRI sequence used, and they are better visualized with a 5 mm slice thickness (compact bone overlapping). Slice dynamic analysis and multiplanar reformatting allowed the detection of all craniometric points, some of these being more difficult to detect than others (Porion, Infra-orbital). The measurements determined by these points were as follows: Vertex-Basion height=135.66+/-6.56 mm; Eurion-Eurion width=141.17+/-5.19 mm; Glabella-Opisthocranion length=181.94+/-6.40 mm. On the midline T1-weighted sagittal image, all median craniometric landmarks can be individualized and the Glabella-Opisthocranion length, Vertex-Basion height and parenchyma indices can be calculated. Craniometric points and measurements between these points can be estimated with a standard cerebral MRI examination, with results that are similar to anthropometric data.

3D-CT evaluation of facial asymmetry

Recently, 3-dimensional-computed tomography (3D-CT) imaging has been used in the diagnosis and surgical treatment planning of patients with craniofacial deformities. The present authors have developed a 3D-CT imaging procedure for a 3-dimensional coordinate point evaluation system to assess and diagnose patients with facial asymmetry. The CT data of 16 subjects was selected retrospectively as the control group from patients who had undergone CT examinations to diagnose conditions other than maxillofacial deformities. Anatomical landmarks modified from orthodontic craniometric (cephalometric) points were defined on the 3D-CT images and the asymmetry index of each point was calculated in millimeters. A diagrammatic chart with a baseline indicating the mean asymmetry indices plus the standard deviation in the control group was designed. The resulting diagrammatic chart was used to evaluate the degree of deformity in facial asymmetry patients. The topography of facial asymmetry was assessed. The 3D-CT imaging technique as described herein is a practical method of evaluating the morphology of facial asymmetry.

Landmarks to the cranial approaches

The knowledge of the craniotopography allows the delimitation of the cranial approaches. In this study the landmarks, defined in relation to the craniometric points and used in the different cranial approaches, were systematized. Twenty two landmarks are described: the first twelve are in relation to the skull base and the remainder are in relation to the skull vertex.

Sexing the human skull through the mastoid process.

The purpose of this study was to evaluate the significance for sex determination of the measurement of the area formed by the xerographic projection of 3 craniometric points related to the mastoid process: the porion, asterion, and mastoidale points. Sixty skulls, 30 male and 30 female, were analyzed. A xerographic copy of each side of the skull was obtained. On each xerographic copy, the craniometric points were marked to demarcate a triangle. The area (mm ) of the demarcated triangle for each side of the skull (right (D) and left (E) sides) was determined, and the total value of these measures (T) was calculated. Concerning the right area of the male and female skulls, 60% of the values overlapped; for the left area, 51.67% overlapped, and for the total area, 36.67% overlapped. The analysis of the differences between the sexes in the areas studied was significant for the 3 areas. Regarding the total area, which is the preferred measurement because of the asymmetry between the sides of the skull, the value of the mean was 1505.32 mm for male skulls, which was greater than the maximum value obtained in the female skulls. The value of the mean for female skulls was 1221.24 mm , less than the minimum value obtained for the male skulls. This study demonstrates a significant result in the 3 studied areas, (D), (E), and (T). The total area values show less overlapping of values between the sexes, and therefore can be used for sexing human skulls. For the population studied, values of the total area that were greater than or equal to 1447.40 mm belonged to male crania (95% confidence). Values for this area that were less than or equal to 1260.36 mm belonged to female crania (95% confidence).

Morphologic study of the mandibular fossa and the eminence of the temporomandibular joint in relation to the facial structures

To clarify the relationship between the temporal component of the temporomandibular joint and facial bone structure, we measured anthropologic craniometric points and the structure of the mandibular fossa, including the eminence in 33 Japanese male dry skulls, with a three-dimensional apparatus. The length from the articular tubercle to the medial glenoid tubercle is correlated with skeletal variables such as the length of the fossae, the width of the masseter origin, and the mandibular length. Therefore it appears that the frontal dimension is related to the facial development, which is attributable to bite force. Goniometrically, the angle between the line deepest point of the fossa—the midpoint of the eminence and the Frankfort horizontal plane (middle angle)—was negatively correlated only with the ANB angle, suggesting that a steeper middle angle of the eminence is related to a retrusive maxilla or protrusive mandible.(Am J Orthod Dentofac Orthop 1997;112:634-8.)

Sex determination by discriminant function analysis of lateral cranial form

To sex the cranium, morphological features of cranial specimens were quantified with a personal computer that automatically measures distance and gradient for 39 craniometric points in the lateral contour line of the skull, which were digitized by a tablet digitizer connected to the computer. Specimens used for discriminant analysis were 50 male and 50 female adult Japanese skulls. The lateral contour showed sex differences in the nasal bone, supraorbital ridge, forehead and vertex. The nasal bone and supraorbital ridge were more developed in male contour line, and the forehead was more rounded in female contour line. But compared with the supraorbital ridge and forehead, the vertex had a wide variety of contour lines in both sexes. The vertex seemed to be less reliable as the indicator of sex. The sex differences were better reflected by gradient than distance. From variables of the gradient and distance showing significant sex differences, the discriminant function was derived and tested in 21 other specimens (13 male and 8 female skulls). The mean ratio of correct sexing of the human skull by the discriminant function was 86%.

Teratological and radiocephalometric analysis of craniofacial malformations induced with retinoic acid in rhesus monkeys (Macaca mulatta).

Fifteen pregnant Macaca mulatta were treated with doses of 20 or 40 mg of retinoic acid between 19--45 or 17--45 days of gestation, respectively, for 4--8 consecutive days. Based on gross examination, ten malformed infants, including one stillbirth and one abortus, four normal infants, and one resorption were produced. The most critical sensitive period was between days 24--35 of gestation, and the malformations primarily involved the craniofacial skeleton. Ten treated infants and eight age-matched controls were cephalometrically analyzed using craniometric points as closely correlated as possible with those in humans in order to define the craniofacial malformations induced prenatally by retinoic acid. Although all ten animals had detectable linear and angular deviations from the controls, four had cephalometric patterns which appeared to be of similar developmental origin.

The cephalometric analysis of Cercopithecus aethiops.

A Steiner-based cephalometric study of 46 adult Vervet monkeys was undertaken using craniometric points as closely correlated to those in the human as possible. On tracings of each cephalogram 13 measurements were recorded. The results were statistically analysed. Whilst the monkey face does vary individually this variation is apparently much less than is that of the human face. It is possible that the positions of the monkey incisor crowns bear a relatively constant relationship to the soft tissue profile. The establishment of some cephalometric norms for the Vervet monkey may be useful for future growth studies.