ABSTRACT
SUMMARY: The pear-shaped bony orbit connects with intracranial cavity via foramina's and fissures. The Meningo-orbital Foramen (MOF) is usually present in greater wing of sphenoid close to lateral edge of Superior orbital fissure. It provides a route for an anastomosis between the orbital branch of the middle meningeal artery (MMA) and recurrent meningeal branch of Ophthalmic Artery (OA) and hence, risk of damage during surgeries can occur. To verify occurrence and location, with morphology of MOF in dry orbits and the impending clinical hazards in surgeries pertaining to the orbit, document and analysis it to determine a standardized guideline. The presence for MOF was studied in 446 dry orbits with its location from the supra orbital margin (SOM), front zygomatic suture (FZS), the lateral tubercle of Whitnall (WT)and the lateral end of superior orbital fissure (SOF) along with its patency, laterality and number of foramina's present. Nylon probes, long divider/pins, compass and Vernier callipers was used to check the patency and various parameters. The study noted the percentage prevalence of MOF as 69 % with communication with middle cranial fossa (MCF) being 76 % of 69 % and the average distance from SOM, FZS, WT and lateral end of SOF being 35.58 mm, 24.9 mm, 26.6 mm and 0.92 mm. On comparison with various population studies, certain similarities and differences with regards to different parameters were noted. Prevalence of MOF was mostly unilateral and showed multiple foramina, that can act as channels for arteries, a variant of MMA or OA, that supply orbital structures or tumour growths. Thus, awareness of this variation is of prime importance to ophthalmologists and neurosurgeons as well as interventional radiologists, in preventing haemorrhagic condition which could further raise the difficulties in operative procedures and surgical outcomes.
RESUMEN: La órbita ósea en forma de pera se conecta con la cavidad intracraneal a través de forámenes y fisuras. El foramen meningoorbitario (MOF) suele estar presente en el ala mayor del esfenoides cerca del margen lateral de la fisura orbitaria superior. Proporciona una ruta para una anastomosis entre la rama orbitaria de la arteria meníngea media (MMA) y la rama meníngea recurrente de la arteria oftálmica (OA) y, por lo tanto, puede ocurrir riesgo de daño durante las cirugías. Para verificar la ocurrencia y ubicación, con la morfología de MOF en órbitas secas y los peligros clínicos inminentes en cirugías de la órbita, documentarlo y analizarlo para determinar una pauta estandarizada. Se estudió la presencia de MOF en 446 órbitas secas desde el margen supraorbitario (MOS), sutura cigomática frontal (FZS), el tubér- culo lateral de Whitnall (WT) y el extremo lateral de la fisura orbitaria superior (SOF) junto con su permeabilidad, lateralidad y número de forámenes presentes. Se utilizaron sondas de nailon, divisores / pasadores largos, brújula y calibradores Vernier para comprobar la permeabilidad. En el estudio se pudo observar que la prevalencia porcentual de MOF era del 69 %, siendo la comunica- ción con la fosa craneal media (MCF) del 76 % del 69 % y la distancia promedio desde SOM, FZS, WT y el extremo lateral de SOF era de 35,58 mm, 24,9 mm, 26,6 mm y 0,92 mm. En comparación con varios estudios de población, se observaron ciertas similitudes y diferencias con respecto a diferentes parámetros. La prevalencia de MOF fue mayoritariamente unilateral y mostró múltiples forámenes, que pueden actuar como canales para las arterias, una variante de MMA u OA, que irrigan estructuras orbitarias o crecimientos tumorales. Por lo tanto, la conciencia de esta variación es de primordial importancia para los oftalmólogos y neurocirujanos, así como para los radiólogos intervencionistas, en la prevención de una enfermedad hemorrágica que podría aumentar aún más las dificultades en los procedimientos y los resultados quirúrgicos.
Subject(s)
Humans , Orbit/anatomy & histology , Orbit/diagnostic imaging , Surgical Flaps , Meningeal Arteries/anatomy & histology , Meningeal Arteries/diagnostic imaging , Ophthalmic Artery/anatomy & histology , Ophthalmic Artery/diagnostic imaging , IndiaABSTRACT
Introduction: The supraorbital notch (SON) is present at the junction of sharp lateral two-thirds and roundedmedial third of supraorbital margin. The neurovascular bundle exit via this notch/foramen. The morphometricvariations of the supraorbital ridge, notch, or foramen are not uncommon. The knowledge of these parameters isimportant to preserve the neurovascular bundle during surgery in this area.Materials and Methods: This study included seventy skulls obtained from department of Anatomy, Doon governmentmedical college Dehradun and Sri Guru Ram Rai Institute of medical and health sciences Dehradun followingstandard guidelines. All the parameters were observed and measured with the help of vernier caliper andreported in the tabulated form.Results: Out of seventy skulls, bilateral supraorbital notch and supraorbital foramen were found in 37.14% and14.28% respectively. Unilateral notch and contralateral foramen was found in eight skulls i.e. 11.42%. notch orforamen was absent in 5.71% skulls. The distance from SON/F to the midline (nasion) and frontozygomaticsuture were 25.86±3.11 and 29.89±2.19 mm. respectively . The mean distance between supraorbital notch orforamen to infraorbital foramen was 42.33 ±3.11 mm.Conclusion: Topographical anatomy of supraorbital ridge, notch and foramen and its variation is important toprevent the complications after surgical procedure in this area.
ABSTRACT
Background: Pterion is an area present on anterior part of floor of temporal fossa, formed by four bones frontal,parietal, squamous temporal and greater wing of sphenoid joined each other and form ‘H’ shaped suture. Thereare important neurovascular structure lies beneath the pterion. It is weakest area of skull, as the bones here arevery thin so it is more prone to fracture by traumatic blow over it or by indirect blow from top or back of head.Pterion is an important extracranial landmark for lateral or pterional approaches in various neurosurgicalprocedures.Objectives: The aim of this study was to observe various types of pterion and to determine exact location ofpterion from various bony landmarks like Frontozygomatic suture and zygomatic arch.Materials and methods: The present study was carried out on 326 adult human dry skulls collected from variousmedical colleges of Gujarat. The lateral side of skull was visually assessed for the various types of pterion as perMurphy’s classification. The measurements were carried out from center of pterion to superior edges of midpointzygomatic arch (PMPZ) and from center of pterion to posterolateral aspect of frontozygomatic suture (PFZS).Measurements were taken using a digital vernier caliper.Results: We found all four types of pterion in our study. The most common type of pterion is Sphenoparietal 523(80.21%), followed by Epipteric 71 (10.89%), Frontotemporal 34 (5.22%) and Stellate 24 (3.68%). The meandistance of PMPZ was 36.85 ± 3.61 mm and PFZS was 29.69 ± 3.91. The Mean & SD of PMPZ & PFZS on right sidewas little more as compared to left side.Conclusion: The knowledge of various types of the pterion and exact location of center of pterion from variousbony landmarks are important not only to anatomist but also important for neurosurgeon for pterional approachesin various neurovascular surgery, for radiologist to accurate interpretation of radiograph, CT & MRI of skull andfor anthropologist to racial comparison.
ABSTRACT
The pterion is a point of sutural confluence seen in the norma lateralis of the skull where frontal, parietal, temporal and sphenoid bones meet. The position of the pterion exhibits population-based variations. Location of this point is important in surgical approaches to the anterior and middle cranial fossae. Specific measurements were taken on both sides of 90 (51 male, 39 female) Kenyan human skulls. The distances from the center of pterion to the frontozygomatic suture were 38.88+3.49 mm on the right side and 38.24+3.47 mm on the left side. The pterion was 30.35+3.40 mm and 30.34+4.34 mm above the mid point of the zygomatic arch on the right and left sides, respectively. Males had statistically significant higher pteria compared to females being 39.31+3.28 mm and 37.35+2.97 mm above the midpoint of the zygoma, respectively. Frontozygomatic suture and mid point of the zygoma can reliably be used in locating the pterion. This information may be useful in planning prior to surgery especially where neuronavigation devices equipments are scarce.
La pterion es un punto de confluencia sutural visto en la norma lateral del cráneo, donde se unen los huesos frontal, parietal, temporal y esfenoides. La posición del pterion exhibe variaciones en la población. La ubicación de este punto es importante en abordajes quirúrgicos a las fosas craneales anterior y la media. Mediciones específicas se han realizado en ambos lados de 90 cráneos humanos Kenyanos (51 varones, 39 mujeres). Las distancias desde el centro de pterion a la sutura frontocigomática fue de 38,88+3,49 mm en el lado derecho y 38,24+3,47 mm en el lado izquierdo. El pterion fue ubicado 30,35+3,40 mm y 30,34+4,34 mm por encima del punto medio del arco cigomático en los lados derecho e izquierdo, respectivamente. Los hombres presentaron un pterion estadísticamente significativo superior en comparación con las mujeres, siendo de 39,31+3,28 mm y 37,35+2,97 mm por encima del punto medio del cigoma, respectivamente. La sutura frontocigomática y el punto medio del cigoma pueden ser utilizados como referencia fiables para localizar a el pterion. Esta información puede ser útil en la planificación previa a la cirugía, sobre todo cuando los equipos dispositivos de neuronavegación son escasos.