Assessing the frequency and variability of accessory zygomatic sutures in dry skulls: clinical insights and potential implications.

PURPOSE: This study aimed to determine the presence and incidence of accessory sutures and bipartite zygomatic bone types, and their effects on population affinity and clinical significance. METHODS: We examined 120 dry skulls and 50 zygomatic bones to evaluate the presence, frequency, and location of accessory zygomatic sutures as well as subtypes of bipartite zygomatic bones. Morphometric analysis included measuring the total width and length of the zygomatic bone with accessory sutures (ASs), the total length of the AS, and the shortest distance between the AS and various anatomical landmarks. RESULTS: Bipartite zygomatic bone was observed in 14 of 120 dry skulls (11.6%) and 1 of 50 zygomatic bones (2%), indicating an overall incidence of 16 occurrences (8.82%). The ASs were predominantly located posterolaterally in 11 cases (six males, five females), anteromedially in two cases (one male, one female), superiorly in one case (male), and superolaterally in one case (male). Significant differences were noted in the distribution of the ASs (p < 0.001). Notably, a vertical inferior bipartite zygomatic type, which has not been reported in the literature, was identified. Correlations were observed between the various anatomical landmarks. Among females, the length of AS was significantly different (p = 0.038). Significant differences were also noted in the shortest distance between the AS and the zygomaticofacial foramen (ZFF) based on the body side (p = 0.034). CONCLUSIONS: Our study suggests that the bipartite zygomatic bone is not a common occurrence, indicating its significance as a morphological variation present in certain individuals. The type VII bipartite zygomatic bone exhibited the highest incidence rate, suggesting potential ethnic-specific differences in the prevalence of certain subtypes. The consistent pattern of suture distribution, along with the asymmetry and variability in suture patterns, emphasizes its potential clinical relevance.

Finds of Skulls of Juvenile Kurdalagonus maicopicus (Cetacea, Cetotheriidae) in the Upper Miocene of the Republic of Adygea.

Fragments of two skulls of young cetotheriid baleen whales were described from the Fortep'yanka 2 locality (Russia, Republic of Adygea, Maikop district, Fortep'yanka River valley, Upper Miocene, Upper Sarmatian, Blinovskaya Formation). The finds were attributed to Kurdalagonus maicopicus (Spasskii, 1951) based on the morphology of the posterior (mastoid) process of the petrosal bone, the structure of the posterior edge of the temporal fossa, and the S-like shape of the supraoccipital ridges. The skull proportions and the degree of suture closure made it possible to determine the individual age of the whales within a year. New finds significantly complement the data on the structure of the sutures of the lateral wall of the skull and age-related variability of cranial morphology in representatives of the genus Kurdalagonus.

Fractality of Cranial Sutures.

It has long been known that skull suture has a typical fractal structure. Although the fractal dimension has been utilized to assess morphology, the mechanism of the fractal structure formation remains to be elucidated. Recent advances in the mathematical modeling of biological pattern formation provided useful frameworks for understanding this mechanism. This chapter describes how various proposed mechanisms tried to explain the formation of fractal structures in cranial sutures.

Cranial sutures.

Cranial sutures are not of great concern to the modern neurosurgeon, except when abnormalities interfere with the skull's shape and its ability to expand during childhood. It is a commonplace that a craniotomy may cross a variety of sutures without providing any extra difficulty to the operator. The sagittal suture does remain useful as a definition of the midline of the cranium and as an indicator of the underlying sinus. Galen for reasons that are far from clear, "observed" relationships between the sutures, the meninges and the pericranium which led him to advise avoidance of any surgical proximity to the sutures. The result of this proscription was a severe limit of the access surgeons considered was appropriate and thus limited their ability to care for their patients.

Comparative digital reconstruction of Pica pica and Struthio camelus and their cranial suture ontogenies.

To date, several studies describe post-hatching ontogenetic variation in birds; however, none of these studies document and compare ontogenetic variation of the entire skull in multiple avian species. Therefore, we studied ontogenetic skull variation of two bird species with very different ecologies, Pica pica, and Struthio camelus, using µCT based 3D reconstructions. For each specimen, we performed bone-by-bone segmentation in order to visualize and describe the morphological variation of each bone during ontogeny and estimated the average sutural closure of the skulls to identify different ontogenetic stages. Although bone fusion of P. pica occurs more rapidly than that of S. camelus the general sequence of bone fusion follows a similar trend from posterior to anterior, but a more detailed analysis reveals some interspecific variation in the fusion patterns. Although growth persists over a longer period in S. camelus than in P. pica and adults of the former species are significantly larger, the skull of the most mature S. camelus is still less fused than that of P. pica. Different growth and fusion patterns of the two species indicate that the interspecific ontogenetic variation could be related to heterochronic developments. Nevertheless, this hypothesis needs to be tested in a broader phylogenetic framework in order to detect the evolutionary direction of the potential heterochronic transformations.

Pterion variation in the skulls of rhesus macaques from Cayo Santiago: Inheritance, development, and pathology.

The pterion is the sutural juncture of the frontal, parietal, sphenoidal, temporal, and zygomatic bones on the lateral aspect of the cranium. As a craniometric landmark, the pterion has a taxonomic valence, in addition to a common neurosurgical entry point in medicine. Variation in the articulation patterns at the pterion have been documented between primate species yet have a high degree of uniformity within species, suggesting a genetic control for this complex region of the skull. In this study, pterion pattern variation was investigated in 1627 Rhesus macaque crania of the Cayo Santiago colony. The colony's associated skeletal collections accompany known age, sex, and maternal lineages. Pterion pattern prevalence rates were tested against matrilines, as well as cranial shape, and cranial sutural fusion ages (including individuals with prematurely fused sutures). Five patterns were identified, the most prominent being the prevailing Old World Monkey frontotemporal (FT) articulation (83.4%). The relative frequency of those not exhibiting the FT pattern was found to vary considerably between matrilineal families (p = 0.037), ranging from 5.3% to 34.2%. Mothers with the non-FT pterion pattern were three times as likely to bear non-FT offspring. Cranial shape additionally varied with pterion type. Males exhibiting zygomaticotemporal (ZT) and sphenoparietal (SP) articulations possessed a relatively longer and narrower cranium than those with the default FT type (p = < 0.001). Cranial sutural fusion ages were not found to differ between pterion types, though all individuals with craniosynostosis (6; 0.38%) exhibited the FT type. The study provided strong evidence for a genetic source for pterion pattern as well as outlining a relatively novel relationship with cranial shape and sutural fusion ages. A unifying explanation may lie in those genes involved in both sutural and craniofacial development, or in the variation of brain growth processes channeling sutural articulation at the pterion. Both may be heritable and responsible for producing observed matrilineal differences in the pterion.

Are the Ethmoidal Foramina Through the Frontal Bone, Ethmoid Bone, or Frontoethmoidal Suture?

INTRODUCTION: To investigate the locations of the anterior, middle, and posterior ethmoidal foramina and their relationships to the frontoethmoidal suture. METHODS: One hundred twenty sides from sixty adult human skulls were used. Specimens with significant damage to the medial orbit wall were excluded. The number of ethmoidal foramina (anterior, middle, and posterior) on the medial orbital wall and the relationship of each foramen to the frontoethmoidal suture were recorded and classified as follows: Type I: superior to the frontoethmoidal suture; Type II: on the frontoethmoidal suture; Type III: inferior to the frontoethmoidal suture. RESULTS: Of the ninety-four sides, fourteen (14.9%) had one foramen, sixty-two (66.0%) had two , and eighteen (19.1%) had three. In total, 192 ethmoidal foramina were observed. Among the fourteen sides with one foramen, eight foramina were anterior and six were posterior. Among the 192 ethmoidal foramina, 162 were eligible for fur ther classification (74 anterior, 14 middle, and 74 posterior). Types I, II, and III ethmoidal foramina were found in 38.3% (62/162), 61.7% (100/162), and 0% (0/162), respectively. CONCLUSIONS: Our current study found a higher incidence of type I than previously reported. It is important to be aware of the significant incidence of foramen variations when the medial orbit wall is manipulated during surgery. Unless caution is observed, an inadvertent surgical injury can occur and lead to life-threatening complications. Therefore, a good understanding of orbital anatomy and its potential variations is critical for improving patient out comes.

Ultrasonic mapping of midpalatal suture - An ex-vivo study.

OBJECTIVE: Rapid maxillary expansion is a common orthodontic procedure to correct maxillary constriction. Assessing the midpalatal suture (MPS) expansion plays a crucial role in treatment planning to determine its effectiveness. The objectives of this preliminary investigation are to demonstrate a proof of concept that the palatal bone underlying the rugae can be clearly imaged by ultrasound (US) and the reconstructed axial view of the US image accurately maps the MPS patency. METHODS: An ex-vivo US scanning was conducted on the upper jawbones of two piglet's carcasses before and after the creation of bone defects, which simulated the suture opening. The planar images were processed to enhance bone intensity distribution before being orderly stacked to fuse into a volume. Graph-cut segmentation was applied to delineate the palatal bone to generate a bone volume. The accuracy of the reconstructed bone volume and the suture opening was validated by the micro-computed tomography (µCT) data used as the ground truth and compared with cone beam computed tomography (CBCT) data as the clinical standard. Also included in the comparison is the rugae thickness. Correlation and Bland-Altman plots were used to test the agreement between the two methods: US versus µCT/CBCT. RESULTS: The reconstruction of the US palatal bone volumes was accurate based on surface topography comparison with a mean error of 0.19 mm for pre-defect and 0.15 mm and 0.09 mm for post-defect models of the two samples, respectively when compared with µCT volumes. A strong correlation (R2 ≥ 0.99) in measuring MPS expansion was found between US and µCT/CBCT with MADs of less than 0.05 mm, 0.11 mm and 0.23 mm for US, µCT and CBCT, respectively. CONCLUSIONS: It was possible to axially image the MPS opening and rugae thickness accurately using high-frequency ultrasound. CLINICAL SIGNIFICANCE: This study introduces an ionizing radiation-free, low-cost, and portable technique to accurately image a difficult part of oral cavity anatomy. The advantages of conceivable visualization could promise a successful clinical examination of MPS to support the predictable treatment outcome of maxillary transverse deficiency.

Anatomical Study of the Pterion in a South African Population of KwaZulu-Natal / Estudio Anatómico del Pterion en una Población Audafricana de KwaZulu-Natal

SUMMARY: Morphologically the Pterion marks the location of the four cranial bones, viz. frontal bone, sphenoid angle of the parietal bone, squamous part of the temporal bone and the greater wing of the sphenoid bone. Population-specific differences exists in the position and union of the Pterion. The Pterion is also an important neurosurgical landmark for surgical procedures, viz. Pterional/lateral approach, as it provides wide access to the base of the skull. This study aimed to determine the position and incidence of the various sutural patterns of the Pterion in a South African population of KwaZulu-Natal. This retrospective study was conducted bilaterally on 36 dry human skulls (11 females and 25 males) obtained from the Department of Clinical Anatomy at University of KwaZulu-Natal. Ethical clearance obtained from the Biomedical Research Ethics Committee. The morphometric parameters of the Pterion were measured using a digital Vernier caliper, while the morphological characteristics were examined using Murphy's classification scheme to determine (if any) laterality or sex differences exists. The mean distance of the Centre of the pterion from midpoint of zygoma was 44.4+/-4.1 mm in males and 45.1+/-4.6 mm in females. While the distance from frontozygomatic suture was 32.7+/-4.7 mm and 32.6+/-4.8 mm in males and females, respectively. Sphenoparietal type of pterion was most prevalent at 55.6 %, followed by the frontotemporal, stellate and epipteric type with an incidence of 27.8 %; 11.1 % and 5.6 %, respectively. No statistically significant difference for sex or laterality were documented in this study. The present study concluded that the sphenoparietal type of sutural pattern was most prevalent with an incidence of 55.6 %. While the epipteric type was the least prevalent. The comprehensive data about the position of the Pterion is important to neurosurgeons, forensics scientists and anthropologists.

Morfológicamente, el pterion marca la ubicación de los cuatro huesos craneales: hueso frontal, ángulo esfenoidal del hueso parietal, parte escamosa del hueso temporal y el ala mayor del hueso esfenoides. Existen diferencias específicas de la población en la posición y unión del pterion. El pterion es también un hito neuroquirúrgico importante para los procedimientos quirúrgicos en el bordaje pterional/lateral, ya que proporciona un amplio acceso a la base del cráneo. Esta investigación tuvo como objetivo determinar la posición y la incidencia de los diversos patrones suturales del pterion en una población sudafricana de KwaZulu-Natal. Este estudio retrospectivo se realizó bilateralmente en 36 cráneos humanos secos (11 mujeres y 25 hombres) obtenidos del Departamento de Anatomía Clínica de la Universidad de KwaZulu-Natal. ALa autorización ética fue otorgada porel Comité Ético de Investigación Biomédica. Los parámetros morfométricos del pterion se midieron usando un calibrador Vernier digital, mientras que las características morfológicas se examinaron usando el esquema de clasificación de Murphy para determinar, si existe alguna lateralidad o diferencias sexuales. La distancia media del centro del pterion desde el punto medio del cigoma fue de 44,4+/- 4,1 mm en hombres y de 45,1+/-4,6 mm en mujeres. Mientras que la distancia desde la sutura frontocigomática fue de 32,7+/-4,7 mm y 32,6+/-4,8 mm en hombres y mujeres, respectivamente. El tipo de pterion esfenoparietal fue el más prevalente con un 55,6 %, seguido del tipo frontotemporal, estrellado y epiptérico con una incidencia del 27,8 %; 11,1 % y 5,6 %, respectivamente. En el estudio no se documentaron diferencias estadísticamente significativas para el sexo o la lateralidad. Concluimos que el tipo de patrón de sutura esfenoparietal fue el más prevalente con una incidencia del 55,6 %. Mientras que el tipo epiptérico fue el menos prevalente. Los datos completos sobre la posición del pterion son importantes para los neurocirujanos, los científicos forenses y los antropólogos.

Osteological Study of the Parietal Foramen in the Adult Human Skull Bones and its Clinical and Surgical Correlations / Estudio Osteológico del Foramen Parietal en los Huesos del Cráneo Humano Adulto y sus Correlaciones Clínicas y Quirúrgicas

SUMMARY: Parietal emissary foramina (PEF) are small holes, which are localized between the middle and posterior thirds of the parietal bone posterior surface close to the sagittal suture. PEF are important structures that protect the parietal emissary vein, which passes through it. During neurosurgery procedures, parietal foramina (PF) knowledge is crucial. This work aimed to evaluate presence and location of the PF in the skull of an adult human. Moreover, measure the distance amidst PF and the sagittal suture's midline to ascertain its clinical repercussions. 74 adult human skulls, without gross pathology, were observed for the PF's existence. The PF's and sagittal suture's midline distance were measured. According to the PF patterns of presence, five groups were distributed. Finally, specimens were photographed and subjected to statistical analysis. The PF was absent in 7 skulls (9.5 %). There were 9 skulls (12.2 %) exhibited central parietal foramen where the parietal foramen lies on the sagittal suture. 17 skulls (23 %) showed right unilateral parietal foramen, whereas 15 skulls (20.3 %) demonstrated left unilateral parietal foramen. The final 26 skulls (35.1 %) exhibited bilateral parietal foramen. This descriptive study supplies valuable information of PF variations, which is crucial for neurosurgeons in modifying surgical techniques and procedures to alleviate injury to PF-emerging structures such as emissary veins.

Los forámenes emisarios parietales (FEP) son pequeños orificios que se localizan entre los tercios medio y posterior de la superficie posterior del hueso parietal, cerca de la sutura sagital. Los FEP son estructuras importantes que protegen la vena emisaria parietal, que lo atraviesa. Durante los procedimientos de neurocirugía, el conocimiento de los forámenes parietales (FP) es crucial. Este trabajo tuvo como objetivo evaluar la presencia y ubicación del FP en el cráneo de hombres adultos, además, medir la distancia entre el FP y la línea mediana de la sutura sagital para conocer su repercusión clínica. Se examinaron 74 cráneos humanos adultos, sin patología grave, para determinar la existencia del FP. Se midió la distancia de la línea mediana de la sutura sagital y del FP. De acuerdo con los patrones de presencia del FP, se distribuyeron en cinco grupos. Finalmente, los especímenes fueron fotografiados y sometidos a análisis estadístico. El PF estaba ausente en 7 cráneos (9,5 %). Hubo 9 cráneos (12,2 %) que presentaban un PF central localizándose en la sutura sagital. 17 cráneos (23 %) presentaban un FP unilateral derecho, mientras que 15 cráneos (20,3 %) se observó un FP unilateral izquierdo. Los 26 cráneos restantes (35,1 %) exhibieron FP bilaterales. Este estudio descriptivo proporciona información valiosa sobre las variaciones del FP, que es fundamental para los neurocirujanos en el momento de modificar las técnicas y los procedimientos quirúrgicos para aliviar las lesiones de las estructuras emergentes del FP, como las venas emisarias.

Analysis of the Asterion Morphology in Relation to Its Clinical Significance / Análisis de la Morfología del Asterion en Relación con su Importancia Clínica

SUMMARY: The asterion presents a significant anthropological marking and meeting point between three sutures. It is a surface landmark for the transverse-sigmoid venous sinus complex and is also a surgical landmark for access to the posterior cranial fossa, giving it clinical importance. The aim of this research was to analyze the shape of the asterion and to set the measurement methods that will determine distance between the asterion and surrounding features. The study sample, as a part of the Osteological collection of the Department of Anatomy, Faculty of Medicine Novi Sad, consisted of 43 skulls. Morphometric analysis was related to the measurement of the defined parameters and descriptive analysis presented the classification of asterion in relation to the presence of sutural bones, as well as the determination of the position of the asterion according to the transverse-sigmoid venous complex. There was a statistically significant difference between male and female skulls for all the measured parameters. The results show that 34.88 % were type 1 (one or more sutural bones are present) and 65.12 % were type 2 asteria (no sutural bones are present). More frequent occurrence of asteria type 2 was seen on both, male and female skulls. The most frequent position of the asteria on both sides of the skull was in the transverse- sigmoid venous complex (76.92 % on the right side vs. 72.22 % on the left cranial side). Clinical significance of knowing the area of asterion is reflected in order to make the surgical, as well as diagnostic procedures, as successful as possible.

El asterion presenta una importante marca antropológica y punto de encuentro entre tres suturas. Es un punto de referencia de superficie para el complejo del seno venoso sigmoideo transverso y también es un punto de referencia quirúrgico para el acceso a la fosa craneal posterior, lo que le confiere importancia clínica. El objetivo de esta investigación fue analizar la forma del asterión y establecer los métodos de medición que determinarán la distancia entre el asterión y las características circundantes. La muestra del estudio, que forma parte de la colección osteológica del Departamento de Anatomía de la Facultad de Medicina de Novi Sad, estuvo compuesta por 43 cráneos. El análisis morfométrico se relacionó con la medición de los parámetros definidos y el análisis descriptivo presentó la clasificación del asterion en relación a la presencia de huesos suturales, así como la determinación de la posición del asterion según el complejo venoso transverso-sigmoideo. Hubo una diferencia estadísticamente significativa entre los cráneos masculinos y femeninos para todos los parámetros medidos. Los resultados muestran que el 34,88 % eran tipo 1 (hay uno o más huesos suturales presentes) y el 65,12 % eran asteria tipo 2 (no hay huesos suturales presentes). Se observó una aparición más frecuente de asteria tipo 2 en cráneos tanto masculinos como femeninos. La posición más frecuente de la asteria en ambos lados del cráneo fue en el complejo venoso sigmoideo transverso (76,92 % en el lado derecho vs. 72,22 % en el lado craneal izquierdo). La importancia clínica de conocer el área de asterion se refleja en que los procedimientos quirúrgicos y de diagnóstico tengan el mejor resultado posible.

The morphometric study of parietal emissary foramen related with clinical implications in Thais / Estudio morfométrico del foramen emisario parietal relacionado con las implicaciones clínicas en tailandeses

SUMMARY: Parietal emissary foramina (PEF) are an important structure which the parietal emissary vein passes through. Aims of this study were to study morphometry of the PEF and its clinical implications. The present study examined in 800 parietal bones (400 Thai skulls; 200 males and 200 females). A total of 587 emissary foramina were found in 344 skulls. The PEF were found on the right side (298), left side (256). One hundred fifty-five unilateral, 189 bilateral, and 33 center of PEF were found in our study. The average of foramina to sagittal suture were 5.67 ? 2.73 mm on the right and 5.91 ? 2.37 mm on the left in male, while in female it was 5.28 ? 2.61 mm on the right and 5.48 ? 2.54 mm on the left. The shape was mostly circular with mean diameter of 1.27 ? 0.56 mm on the right, 1.23 ? 0.52 on the left and 1.11 ? 0.49 mm at the center in male. In female, the mean diameter of 1.19 ? 0.42 mm on the right, 1.12 ? 0.41 mm on the left and 1.60 ? 0.92 mm at the center. The ratio of distance from the external occipital protuberance (EOP)to PEF and to glabella in males on the right side is 0.342 cm. (3/8) and 0.349 cm. (3/8) on the left side. While the ratio of females is 0.367 cm. (3/8) and 0.388 cm. (3/8), respectively. Our finding obtained in this study scientists can be essentially benefited for anatomists, radiologists, neurosurgeons, and forensic to aware this anatomical structure.

RESUMEN: El foramen emisario parietal (FEP) es una importante estructura a través de la cual atraviesa la vena emisaria parietal. Los objetivos de este estudio fueron estudiar la morfometría del FEP y sus implicaciones clínicas. Se examinaron 800 huesos parietales (400 cráneos tailandeses pertenecientes a 200 hombres y 200 mujeres). Se encontró un total de 587 FEP en 344 cráneos, de los cuales 298 estaban presentes en el lado derecho y 256 en el lado izquierdo, siendo 155 FEP unilaterales, 189 bilaterales y 33 localizados en el centro. El promedio de la distancia de los FEP a la sutura sagital en los hombres fue de 5,67 ? 2,73 mm a la derecha y 5,91 ? 2,37 mm a la izquierda, mientras que en las mujeres fue de 5,28 ? 2,61 mm a la derecha y 5,48 ? 2,54 mm a la izquierda. La forma era mayoritariamente circular con un diámetro medio de 1,27 ? 0,56 mm en el lado derecho, 1,23 ? 0,52 en el lado izquierdo y 1,11 ? 0,49 mm en el centro en los cráneos de los hombres. En las mujeres, el diámetro medio del FEP en el lado derecho fue de 1,19 ? 0,42 mm, en el lado izquierdo 1,12 ? 0,41 mm 1,60 ? 0,92 mm en el centro. La relación de la distancia desde la protuberan- cia occipital externa al FEP y a la glabela en el lado derecho en los hombres fue de 0,342 cm (3/8) y en el lado izquierdo 0,349 cm (3/8). Mientras en las mujeres fue de 0,367 cm (3/8) y 0,388 cm (3/8), respectivamente. Nuestros hallazgos obtenidos en este estudio puede ser útil para que los anatomistas, radiólogos, neurocirujanos y científicos forenses conozcan esta estructura anatómica.

Anatomic position of the asterion and implication for neurosurgical procedure / Posición anatómica del asterion y sus implicancias en el procedimiento neuroquirúrgico

SUMMARY: The asterion is the joining of the lambdoid, parietomastoid, and occipitomastoid sutures. It is classified into two types, type I shows small bones or woven bones, while in type II, woven bones are non-existent. In this study, forty cadavers were conducted and observed the asterion on both sides of skulls showing the approximate ratio of type II and type I was 3:2. The asterion was located by measuring the distances from the asterion to skull landmarks, including inion, the root of zygoma, and mastoid tip. The mean distance between asterion and inion was 62.9 ? 6.0 mm. The mean distance between asterion and the root of zygomatic arch was 58.3 ? 6.1 mm, whereas the mean distance between asterion and mastoid tip was 51.1 ? 5.3 mm. The most common location related to the asterion was the dural venous sinuses on 65 % of tested sides, followed by infratentorial dura and supratentorial dura (25 % and 10 %, respectively). However, the authors found no differences between sexes, sides, and types in any underlying structures.

RESUMEN: El asterion es la unión de las suturas lambdoidea, parietomastoidea y occipitomastoidea. Clasificado en dos tipos, el tipo I muestra huesos pequeños o hueso laminar, mientras que en el tipo II, el hueso laminar es inexistente. En este trabajo se estudiaron 40 cadáveres y se observó el asterion en ambos lados de los cráneos correspondientes, mostrando una proporción aproximada de tipo II y tipo I de 3:2. El asterion se localizó midiendo las distancias asociadas a puntos de referencia del cráneo: el inion, la raíz del arco cigomático y el ápice del proceso mastoides. La distancia media entre el asterion y el inion fue de 62,9 ? 6,0 mm. La distancia media entre el asterion y la raíz del arco cigomático fue de 58,3 ? 6,1 mm, mientras que la distancia media entre el asterion y el ápice del proceso mastoides fue de 51,1 ? 5,3 mm. La localización más común relacionada con el asterion fueron los senos venosos durales en el 65 % de los lados evaluados, seguido de la duramadre infratentorial y la dura supratentorial (25 % y 10 %, respectivamente). Sin embargo, los autores no encontraron diferencias entre sexo, lados y tipo en ninguna estructura subyacente.

Propuesta de clasificación de huesos suturales / Classification proposal of sutural bones

RESUMEN: Los huesos suturales tienen importancia anatómica y médico-legal. Se observan en las suturas de la cabeza ósea y tradicionalmente son descritos como planos, supernumerarios, irregulares, inconstantes, independientes y de variable morfología y frecuencia. Actualmente, no existe una clasificación única de estos huesos que incorpore todas las categorías descritas en la literatura. El objetivo de este trabajo fue proponer una clasificación actualizada de estos elementos, en función de una revisión bibliográfica exhaustiva y el análisis de cráneos de individuos chilenos. La muestra utilizada correspondió a 113 huesos suturales presentes en 12 cráneos secos, de individuos adultos chilenos. En la clasificación se consideró su ubicación en la cabeza (cráneo o cara), su origen embrionario, su relación con una fontanela, su forma, su posición en la cara y su relación con las tablas óseas. Los datos obtenidos se registraron en formulario especialmente diseñado y se tomaron fotografías digitales. Como resultado general, pudimos desarrollar una propuesta de clasificación de huesos suturales completa y satisfactoria y con ella se analizó los huesos de la muestra, pudiendo evidenciar la presencia de todas las categorías del instrumento. También pudimos constatar que en la totalidad de los cráneos utilizados se observaron huesos suturales, que los cráneos masculinos presentan un mayor número de estos huesos, pero que en los cráneos femeninos fue posible reconocer todas los tipos de huesos suturales, entre otros resultados. También se evidenció un tipo de hueso sutural no descrito anteriormente, el hueso sutural craneal puntiforme. Como conclusión de este trabajo, es importante destacar que los huesos suturales presentan características comunes a otras estructuras utilizadas en identificación forense, es decir, son perennes, únicos, de fácil observación, de fácil comparación y gran variabilidad, por estas razones la presente propuesta de clasificación permite ser planteada como una metodología auxiliar en la identificación humana.

SUMMARY: The sutural bones have anatomical and medico-legal importance. They are observed in the sutures of the bony head and are traditionally described as flat, supernumerary, irregular, inconstant, independent and of variable morphology and frequency. Currently, there is no single classification of these bones that incorporates all the categories described in the literature. The objective of this work was to propose an updated classification of these elements, based on an exhaustive bibliographic review and the analysis of the skulls of Chilean individuals. The sample used corresponds to 113 sutural bones present in 12 dry skulls of Chilean adults. The classification considers its location on the head (skull or face), its embryonic origin, its relationship to a fontanelle, its shape, its position on the face, and its relationship to bone tables. The data obtained was recorded in a specially designed format and digital photographs were taken. As a general result, we were able to develop a complete and satisfactory classification of sutural bones proposal and with it, the bones of the sample were analyzed, showing the presence of all categories of the instrument. We were also able to verify that sutural bones were observed in all the skulls used, that male skulls present a greater number of these bones, but that in the female skulls it was possible to recognize all types of sutural bones, among other results. A type of sutural bone not previously described, the shaped point cranial sutural bone, was also evidenced. As a conclusion to this work, it is important to highlight that sutural bones present characteristics common to other structures used in forensic identification, that is, they are perennial, unique, easily observed, easily compared and great variability, for these reasons the present classification proposal allows it to be proposed as an auxiliary methodology in human identification.

Anatomical variations and morphometric study of pterion in a Thai population associated with clinical implications / Variaciones anatómicas y estudio morfométrico del pterion en una población tailandesa asociada con implicaciones clínicas

SUMMARY: The objective of this study was to consider the type of variation and to estimate the landmarks for localizing the pterion. One hundred twenty Thai dry skulls were selected randomly from the Forensic Osteology Research Center, Faculty of Medicine, Chiang Mai University. The distances of the parameters were measured via Vernier caliper. The sphenoparietal type is the most dominant in the Thai population with 88.75 %. In the male, the distance of the midglabella to the pterion was 9.94?0.64 mm The distance of the frontozygomatic suture to the pterion was 35.41?4.38 mm The distance of the zygomatic arch to the pterion was 39.39?4.69 mm and the distance of the mastoid process tip to the pterion was 86.88?4.44 mm In the female, the distance of the midglabella to the pterion was 9.27?0.63 mm The distance of the frontozygomatic suture to the pterion was 33.08?4.12 mm The distance of the zygomatic arch to the pterion was 33.08?4.12 mm and the distance of the mastoid process tip to the pterion was 83.62?5.16 mm. The pterion approach is the most popular method for neurosurgical procedures, and it provides anatomical variations in the pattern. The sphenoparietal type of pterion is the most common form and the stellate type of pterion is the least common form in Thai skulls. Sex influences the location of the pterion. These findings will be of importance to predict the pterion type in Thai skull and estimate the localization of pterion by using a bony landmark. Knowledge of the precise location of the pterion is an important landmark in the neurosurgical approach.

RESUMEN: El objetivo de este estudio fue considerar el tipo de variación del pterion y estimar los puntos de referencia para localizarlo. Se seleccionaron al azar 120 cráneos secos de individuos tailandeses del Centro de Investigación de Osteología Forense de la Facultad de Medicina de la Universidad de Chiang Mai. Las distancias de los parámetros se midieron mediante un caliper Vernier. El tipo esfenoparietal es el más dominante en la población tailandesa con 88,75 %. En el hombre, la distancia de la glabella al pterion fue de 9,94 ? 0,64 mm. La distancia de la sutura frontocigomática fue de 35,41 ? 4,38 mm La distancia del arco cigomático fue de 39,39 ? 4,69 mm y la distancia del ápice del proceso mastoideo al pterion fue de 86,88 ? 4,44 mm. En la mujer, la distancia de la glabella al pterion fue de 9,27 ? 0,63 mm. La distancia de la sutura frontocigomática al pterion fue de 33,08 ? 4,12 mm. La distancia del arco cigomático al pterion fue de 33,08 ? 4,12 mm y la distancia del ápice proceso mastoideo al pterion fue de 83,62 ? 5,16 mm. El abordaje del pterion es el método más utilizado para procedimientos neuroquirúrgicos y proporciona variaciones anatómicas en el patrón. El tipo esfenoparietal del pterion es la forma más común y el tipo estrellado del pterion es la forma menos común en los cráneos tailandeses. El sexo influye en la ubicación del pterion. Estos hallazgos serán importantes para predecir el tipo de pterion del cráneo en tailandeses y a la vez estimar su localización mediante el uso de un punto de referencia óseo. El conocimiento de la ubicación precisa del pterion es un hito impor- tante en el abordaje neuroquirúrgico.

Morphologic and morphometric evaluation of the wormian bones / Evaluación morfológica y morfométrica de los huesos wormianos

Wormian (sutural) bones are accessory small bones located on the skull. These bones consist of extra ossification centers around cranial sutures. This study was carried out in 28 dry human skulls with unknown age and sex in the Department of Anatomy, Cukurova University. The aim of the study was to investigate incidence and to determine morphologic and morphometric characteristics of wormian (sutural) bones. Total incidence of wormian bone presence was 42.86 % (n=12) and most of them were located on lambdoid suture (57.14 %). Wormian bones were seen at lambdoid suture at a rate of 62.5 %, occipito-mastoid suture 9.37 %, asterion 18.76 %, lambda 9.37 %, and were not seen on pterion, bregma, parietotemporal, sagittal and coronal sutures. Wormian bones were seen on left side at a rate of 65.62 % and 34.38 % on right side of skull. According to our study, wormian bone shapes were seen as quadrangular (56.26 %), triangular (15.62 %) and irregular (28.12 %). The mean values of wormian bones were as follows; vertical diameter: 12.29±4.48 mm and horizontal diameter: 10.93±4.39 mm. For cephalic index, the result of our study shows that most of our skulls with or without wormian bones belong to dolichocephalic group. Knowledge of variations and characteristics of skull is important for forensic medicine, anatomy, radiology and neurosurgery fields and for literature data or clinical practices.

Los huesos wormianos o huesos suturales, son pequeños huesos accesorios ubicados en el cráneo. Estos huesos consisten en centros de osificación adicionales alrededor de las suturas craneales. Este estudio se realizó en 28 cráneos humanos secos con edad y sexo desconocidos en el Departamento de Anatomía de la Universidad de Cukurova. El objetivo del estudio fue investigar la incidencia y determinar las características morfológicas y morfométricas de los huesos wormianos. La incidencia total de presencia de hueso wormiano fue del 42,86 % (n = 12) y la mayoría de estos se localizó en sutura lambdoidea (57,14 %). Los huesos wormianos se observaron en la sutura lambdoidea a una tasa del 62,5 %, sutura occipito-mastoidea 9,37 %, asterion 18,76 %, lambda 9,37 %, y no se observaron en suturas pterion, bregma, parietotemporal, sagital y coronal. Los huesos wormianos se observaron en el lado izquierdo a una tasa del 65,62 % y del 34,38 % en el lado derecho del cráneo. Según nuestro estudio, las formas óseas se consideraron cuadrangulares (56,26 %), triangulares (15,62 %) e irregulares (28,12 %). Los valores medios de los huesos wormianos fueron los siguientes; diámetro vertical: 12,29 ± 4,48 mm y diámetro horizontal: 10,93 ± 4,39 mm. Referente al índice cefálico, el resultado de nuestro estudio muestra que la mayoría los cráneos con o sin huesos wormianos pertenecen al grupo dolicocefálico. El conocimiento de las variaciones y características del cráneo es importante para la medicina forense, la anatomía, la radiología y los campos de neurocirugía, como asimismo para los datos de la literatura o las prácticas clínicas.

Estudio morfométrico del punto asterional y su relación con los senos venosos durales / Morphometric study of the asterional point and its relationship with the dural venous sinuses

INTRODUCCIÓN: la importancia de conocer las diferentes reparaciones anatómicas que involucran la parte ósea de la fosa posterior con estructuras neurovasculares, disminuye la incidencia de complicaciones relacionadas con su acceso dentro del procedimiento neuroquirúrgico. MATERIALES Y MÉTODOS: estudio descriptivo basado en la evaluación de 90 hemicráneas secas, del Museo de Anatomía de la Universidad Mayor de San Andrés. RESULTADOS: la prevalencia de asterión tipo I fue de 28.9%, mientras que la de tipo II fue de 71.1%. La prevalencia del número de venas emisarias fue: una vena 54.4%, dos venas 42.2% y tres venas 3.3%. Los promedios para las características morfométricas son los siguientes: de Asterion a protuberancia occipital externa de 68.8 mm, de Asterion a cresta suprameatal de 50.1 mm, de Asterion a vena emisaria de 54.1 mm, de Asterion a Vértice del proceso mastoideo de 54.1 mm y de asterion a plano horizontal de Francfort 14.6 mm. La ubicación del asterión en el seno transverso fue la siguiente: al mismo nivel del seno, 47.8% de los casos, en el codo en 13.3%, superior al seno 31.1% e inferior a este en el 7.8%. CONCLUSIONES: hay una diferencia en algunos resultados morfométricos del asterión con respecto a otros autores, lo que podría determinar una configuración craneal diferente para nuestra población. Esto debe considerarse para evitar complicaciones durante el período transoperatorio en una cirugía de fosa posterior. Estos resultados reflejan la necesidad de realizar un estudio con una población más grande para obtener resultados reales, estableciendo así parámetros de corte que nos permitirán tener nuestra propia bibliografía sobre cómo proceder en nuestra actividad quirúrgica.

INTRODUCTION: the importance of knowing the different anatomical repairs that involve the bony part of the posterior fossa with neurovascular structures, decreases the incidence of complications related to its access within the neurosurgical procedure. MATERIALS AND METHODS: descriptive study based on the evaluation of 90 dry hemicranial, from the Anatomy Museum of the Universidad Mayor de San Andrés. RESULTS: the prevalence of asterion type I was 28.9%, while that of type II was 71.1%. The prevalence of the number of emissary veins was: One vein 54.4%, Two veins 42.2% and Three veins 3.3%. The averages for morphometric characteristics are as follows: from Asterion to external occipital protuberance 68.8 mm, from Asterion to suprameatal crest 50.1 mm, from Asterion to emissary vein 54.1 mm, from Asterion to Vertex from the mastoid process 54.1 mm and from asterion to horizontal plane of Frankfurt 14.6 mm. The location of asterion in the transverse sinus was the following: at the same level of the sinus 47.8% of the cases, in the elbow in 13.3%, superior to the sinus 31.1% and inferior to this in the 7.8%. CONCLUSIONS: there is a difference in some morphometric results of the asterion with respect to other authors, which could determine a different cranial configuration for our population. This should be considered to avoid complications during the transoperative period in a posterior fossa surgery. These results reflect the need to carry out a study with a larger population, in order to have real results, thus establishing cutting parameters that will allow us to have our own bibliography on how to proceed in our surgical activity.

Premaxilla: up to which age it remains separated from the maxilla by a suture, how often it occurs in children and adults, and possible clinical and therapeutic implications: Study of 1,138 human skulls

ABSTRACT Objective: To evaluate topographic and temporal aspects of premaxillary bone and premaxillary-maxillary suture, since they are fundamental anatomical elements little explored clinically. Methods: 1,138 human dry skulls were evaluated, of which 116 (10.19%) of the specimens were children, and 1,022 (89.81%) were adults. The skulls were photographed and the percentage of premaxillary-maxillary suture opening was determined. Subsequently the data were tabulated and submitted to statistical analysis, adopting a level of significance of 5%. Results: The progression of premaxillary suture closure from birth to 12 years of age was 3.72% per year. In 100% of the skulls up to 12 years, the premaxillary-maxillary suture open in the palatal region was observed, while 6.16% of adults presented different degrees of opening. Conclusions: The premaxilla exists in an independent way within the maxillary complex and the presence of the premaxilla-maxillary suture justifies the success of anteroposterior expansions to stimulate the growth of the middle third of the face, solving anatomical and functional problems.

RESUMO Objetivo: avaliar aspectos topográficos e temporais do osso pré-maxilar e da sutura pré-maxilar/maxilar, por serem elementos anatômicos fundamentais pouco explorados clinicamente. Métodos: foram avaliados 1.138 crânios secos humanos, sendo 116 (10,19%) dos espécimes crianças e 1.022 (89,81%) adultos. Os crânios foram fotografados e determinou-se a porcentagem de abertura da sutura pré-maxilar/maxilar. Posteriormente, os dados foram tabulados e submetidos a análise estatística, adotando-se nível de significância de 5%. Resultados: a progressão de fechamento da sutura pré-maxilar/maxilar do nascimento aos 12 anos de idade foi de 3,72% ao ano. Em 100% dos crânios até 12 anos, observou-se a sutura pré-maxilar/maxilar aberta na região palatina, enquanto 6,16% dos adultos apresentavam diferentes graus. Conclusões: a pré-maxila existe de forma independente dentro do complexo maxilar e a presença da sutura pré-maxilar / maxilar justifica o sucesso de expansões anteroposteriores para estimular o crescimento do terço médio da face, solucionando problemas anatômicos e funcionais.

Premaxilla: an independent bone that can base therapeutics for middle third growth!

ABSTRACT Premaxilla, in its early descriptions, had the participation of Goethe. In our face, in a certain period of growth and development processes, premaxilla is an independent and, then, a semi-independent bone to finally be totally integrated to the maxilla. Formation of the premaxilla acts as a stabilization element inside the facial skeleton comparable to the cornerstone of a Roman arch and is closely related to the development of human face and its abnormal growth with characteristic malformations. Until when the premaxillary-maxillary suture remains open and offers opportunities to orthopedically influence facial growth to exert influence over facial esthetics and function? Contact with preliminary results in 1183 skulls from anatomic museums at USP, Unicamp and Unifesp led us to question therapeutic perspectives and its clinical applicability.

RESUMO A descrição inicial da pré-maxila teve a participação de Goethe. Na face, em determinado período do crescimento e desenvolvimento, têm-se a pré-maxila como um osso independente e, depois, semi-independente para, finalmente, se integrar totalmente à maxila. A formação da pré-maxila atua como um elemento estabilizador dentro do esqueleto facial, comparável com a pedra angular de um arco romano, e está intimamente relacionada com o desenvolvimento da face humana e seu crescimento anormal, com malformações características. Até quando a sutura pré-maxilar-maxilar continua aberta e oferece oportunidades para se influenciar ortopedicamente o crescimento facial e modificar a estética e função da face? O contato com estudos preliminares em 1.183 crânios de museus anatômicos da USP, Unicamp e Unifesp nos induziu a questionar sobre as perspectivas terapêuticas e aplicabilidades clínicas.

Huesos suturales umbilicados / Umbilicated sutural bones

Los huesos suturales son huesos supernumerarios observables en suturas y fontanelas del cráneo, variables en su número, forma, tamaño y posición. Formados desde centros de osificación normales y/o adicionales. Calleja en 1870, describe un hueso sutural en forma de anillo con un centro óseo (umbilicados). Nuestro objetivo de investigación, fue buscar y describir estos huesos. Se utilizaron 71 cráneos de adultos chilenos de ambos sexos, en los cuales se buscó, caracterizó, fotografió y midió a los huesos suturales umbilicados. Se hallaron dos cráneos con presencia de estos huesos, representando el 2,82 % del total de la muestra y el 8 % de los cráneos con huesos suturales. Los resultados concuerdan con la bibliografía, en cuanto a presencia de huesos suturales, así como su relación directa con el sexo y el tamaño del cráneo. También pudimos comprobar la observación y descripción de Calleja, encontrando huesos suturales que cumplían con su descripción. El conocimiento de estos huesos es de utilidad en la identificación médico legal.

The sutural bones are visible supernumerary bones in skull sutures and fontanelle, and are variable in number, shape, size and position. Formed from normal and /or additional ossification, Calleja in 1870, describes a sutural ring-shaped bone with a bone center (umbilicated). Our research objective was to look for and describe these bones. We used 71 skulls of Chilean adults of both sexes, in which we sought, marked, photographed and measured the molluscum sutural bones. Two (2) skulls were found with presence of these bones representing 2.82 % of the total sample and 8 % sutural skulls with bones. The results are consistent with the literature regarding presence of sutural bones, and their direct relationship to sex and size of the skull. We also noted the observation and description by Calleja, finding sutural bones that met their description. Knowledge of these bones is useful in forensic identification.