Optic Canal Size is an Indicator for the Accessory Optic Canal: Applications for Anterior Clinoidectomy.

BACKGROUND: The ophthalmic artery normally travels with the optic nerve through the optic canal. However, sometimes, the ophthalmic artery travels through a foramen within the optic strut named an accessory optic canal, double optic canal, or ophthalmic canal. This variant puts individuals at an increased risk for blindness or death during anterior clinoidectomy due to unforeseen hemorrhage of the ophthalmic artery or internal carotid artery when the optic strut is separated from the body of the sphenoid bone. Several features make the accessory optic canal difficult to recognize on imaging: its variant nature, small size, and ability to masquerade as a caroticoclinoid foramen or a pneumatized sphenoidal structure. Hence, improved methods of presurgical identification are warranted. The aim of this study was to assess the size and shape of the optic canal, with and without a concomitant accessory optic canal, to determine whether measurement of the optic canal may provide useful information regarding the presence of an accessory optic canal. METHODS: In 191 dry crania, optic canals with and without concomitant accessory optic canals were assessed for the following parameters: canal area, canal perimeter, circularity, solidity, the axes and aspect ratio of a best-fit ellipse, and roundness. RESULTS: Normal optic canals were found to have a larger area (P = 0.036), perimeter (P = 0.043), and minor axis of a best-fit ellipse (P = 0.031) than the optic canals that occurred alongside accessory optic canals. CONCLUSIONS: Asymmetry in optic canal size can help indicate the presence of a unilateral accessory optic canal before surgery.

Sphenoid sinus in the Holstein cow: A sectional and 3D reconstructive anatomical study.

Cattle disorders affecting the sphenoid sinus are underreported, likely due to difficulties in imaging and lacking topographic knowledge. This study aimed to provide a detailed description of the normal anatomical and morphometric features of the cattle sphenoid sinus. Twelve healthy adult Holstein cow heads were used, and the sinus was examined using CT, anatomical sectioning and 3D modelling. The sinus was bilaterally detected in all animals but exhibited structural asymmetry and significant interindividual differences in morphological characteristics. Three parts of the sinus were defined, namely the rostral, median and alar parts, which conform to the morphological structure of the sphenoid bone. The rostral part was bilateral in shape and located on the orbit wall of the presphenoid bone in all animals. The median part, which pneumatized the body of the sphenoid bone, was observed bilaterally in seven animals, while the alar part, which pneumatized the wing of the sphenoid bone, was formed bilaterally in four animals. The sinus volume and surface area were 11 ± 8 cm3 and 49 ± 30 cm2 , respectively. These findings may aid in the diagnosis of cattle sphenoid sinus disorders and contribute to the knowledge of regional anatomy for radiologists and clinicians.

Paraclinoid aneurysms clipping through an extradural sphenoid ridge keyhole approach.

BACKGROUND: Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical clipping. METHOD: A description of the surgical technique was made by the senior author, a vascular neurosurgeon experienced with the use of this approach in the management of paraclinoid aneurysms exemplified through a clinical case. CONCLUSION: Microsurgical clipping through an extradural sphenoid ridge keyhole approach for small and midsize paraclinoid aneurysms is an excellent treatment modality with good clinical and surgical results.

How I do it: micro-neurosurgical resection of spheno-orbital meningioma with customized orbit reconstruction technique.

BACKGROUND: Spheno-orbital meningioma (SOM) is a rare intracranial pathology with intraosseous hypertrophy and intraorbital extension. METHOD: We described a middle-aged female with SOM who was managed in a micro-neurosurgical manner. The titanium implant was customized and applied to rebuild the orbital wall to prevent postoperative enophthalmus. CONCLUSION: Despite technical demands, favorable cosmetic, and clinical outcomes without complications can be achieved by meticulous surgical technique following radical resection. CLINICAL TRIAL REGISTRATION: NA.

Sphenoid bone localization in the setting of highly aggressive and refractory Multiple Myeloma: A case report.

Multiple Myeloma (MM) is the most common primary osseous malignancy in adults, and it mainly affects men aged between 50 and 70 years. Although rare, central nervous system (CNS) involvement in MM is possible, and it has very poor prognosis. Therefore, fast and accurate diagnosis of CNS manifestation of MM is paramount. Here we describe a case of sphenoid bone localization in a patient with highly aggressive and refractory MM.

Crista Galli Morphometry and Morphology: An Anatomical, Radiological, and Machine Learning Application Study / Crista Galli Morfometría y Morfología: Un Estudio de Aplicación Anatómica, Radiológica y de Aprendizaje Automático

SUMMARY: The study purposed to examine the morphometry and morphology of crista galli in cone beam computed tomography (CBCT) and apply a new analysis, supervised Machine Learning techniques to find the answers to research questions "Can sex be determined with crista galli morphometric measurements?" or "How effective are the crista galli morphometric measurements in determining sex?". Crista galli dimensions including anteroposterior, superoinferior, and laterolateral were measured and carried out on 200 healthy adult subjects (98 females; 102 males) aged between 18-79 years. Also, crista galli was classified with two methods called morphological types and Keros classification. In this study, the Chi-square test, Student's t-test, and Oneway ANOVA were performed. Additionally, Machine Learning techniques were applied. The means of the CGH, CGW, and CGL were found as 14.96 mm; 3.96 mm, and 12.76 mm in males, respectively. The same values were as 13.54 mm; 3.51 mm and 11.59±1.61 mm in females, respectively. The CG morphometric measurements of males were higher than those of females. There was a significant difference between sexes in terms of morphological classification type. Also, when the sex assignment of JRip was analyzed, out of 102 male instances 62 of them were correctly predicted, and for 98 female instances, 70 of them were correctly predicted according to their CG measurements. The JRip found the following classification rule for the given dataset: "if CGH<=14.4 then sex is female, otherwise sex is male". The accuracy of this rule is not high, but it gives an idea about the relationship between CG measurements and sex. Although the issue that CG morphometric measurements can be used in sex determination is still controversial, it was concluded in the analysis that CG morphometric measurements can be used in sex determination. Also, Machine Learning Techniques give an idea about the relationship between CG measurements and sex.

En el estudio se propuso examinar la morfometría y la morfología de la crista galli del hueso etmoides usando tomografía computarizada de haz cónico (CBCT) y aplicar un nuevo análisis, técnicas de aprendizaje automático supervisado para encontrar las respuestas a las preguntas de investigación "¿Se puede determinar el sexo con mediciones morfométricas de la crista galli?" o "¿Qué tan efectivas son las medidas morfométricas de la crista galli para determinar el sexo?". Las dimensiones de la crista galli, incluidas los diámetros anteroposterior, superoinferior y laterolateral, se midieron y realizaron en 200 sujetos adultos sanos (98 mujeres; 102 hombres) con edades comprendidas entre los 18 y los 79 años. La crista galli se clasificó con dos métodos llamados tipos morfológicos y clasificación de Keros. En este estudio, se realizaron la prueba de Chicuadrado, la prueba t de Student y ANOVA de una vía. Adicionalmente, se aplicaron técnicas de Machine Learning. Las medias de CGH, CGW y CGL se encontraron en 14,96 mm; 3,96 mm y 12,76 mm en hombres, respectivamente. Los mismos valores fueron 13,54 mm; 3,51 mm y 11,59 ± 1,61 mm en mujeres, respectivamente. Las medidas morfométricas del CG de los hombress fueron más altas que las de las mujeres. Hubo una diferencia significativa entre sexos en cuanto al tipo de clasificación morfológica. Además, cuando se analizó la asignación de sexo de JRip, de 102 instancias masculinas, 62 de ellas se predijeron correctamente, y de 98 instancias femeninas, 70 de ellas se predijeron correctamente de acuerdo con las mediciones de CG. El JRip encontró la siguiente regla de clasificación para el conjunto de datos dado: "si CGH<=14.4, por tanto el sexo es femenino, de lo contrario, el sexo es masculino". La precisión de esta regla no es alta, pero da una idea de la relación entre las medidas del CG y el sexo. Aunque la pregunta si las medidas morfométricas CG se pueden usar en la determinación del sexo sigue aún siendo controvertida. Se concluyó en el análisis que las medidas morfométricas CG se pueden usar en la determinación del sexo. Además, las técnicas de aprendizaje automático dan una idea de la relación entre las medidas de CG y el sexo.

Clinical Characteristics and Prognostic Analysis of Osteolytic and Hyperostosis Sphenoid Orbital Meningiomas: A Single-Center Experience.

Reactive hyperostosis of spheno-orbital meningiomas (SOMs) often occurred in the sphenoid wing, while osteolytic SOMs (O-SOMs) were rarely discussed. This study preliminarily evaluated the clinical characteristics of O-SOMs and analyzed prognostic factors affecting the recurrence of SOMs. We retrospectively analyzed the medical records of consecutive patients who underwent surgery for a SOM between 2015 and 2020. According to the bone changes of sphenoid wing, SOMs were divided into O-SOMs and hyperostosis SOMs (H-SOMs). A total of 31 procedures were performed in 28 patients. All cases were treated by pterional-orbital approach. It was confirmed that 8 cases were O-SOMs and the other 20 cases were H-SOMs. Total tumor resection was performed in 21 cases. There were 19 cases with Ki 67 ≥3%. The patients were followed up for 3 to 87 months. Proptosis improved in all patients. All O-SOMs had no visual deterioration, while 4 H-SOMs cases had visual deterioration. There was no significant difference in clinical outcomes between the two types of SOM. The recurrence of SOM was related to the degree of resection, but not to the type of bone lesions, invasion of cavernous sinus and Ki 67.

The Pterygosphenoidal Triangle: Surgical Anatomy and Case Series in Endoscopic Endonasal Skull Base Surgery.

BACKGROUND: Safe exposure of the lacerum segment of the carotid artery remains a challenge in endoscopic endonasal surgery. OBJECTIVE: To introduce the pterygosphenoidal triangle as a novel and reliable landmark for facilitating access to the foramen lacerum. METHODS: Fifteen colored silicone-injected anatomic specimens were dissected using an endoscopic endonasal approach to the foramen lacerum region in a stepwise manner. Twelve dried skulls were studied and 30 high-resolution computed tomography scans were analyzed to measure the borders and angles of the pterygosphenoidal triangle. Surgical cases incorporating the foramen lacerum exposure between July 2018 and December 2021 were reviewed to provide surgical outcomes of the proposed surgical technique. RESULTS: The pterygosphenoidal triangle is delineated by the pterygosphenoidal fissure medially and the vidian nerve laterally. The palatovaginal artery is located at the base of the triangle anteriorly, while the apex is formed by the pterygoid tubercle posteriorly, which leads to the anterior wall of the foramen lacerum and lacerum internal carotid artery. In the reviewed surgical cases, 39 patients underwent 46 foramen lacerum approaches for resection of pituitary adenoma (12 patients), meningioma (6 patients), chondrosarcoma (5 patients), chordoma (5 patients), or other lesions (11 patients). There were no carotid injuries or ischemic events. Near-total resection was achieved in 33 (85%) of 39 patients (gross-total in 20 [51%]). CONCLUSION: This study details the pterygosphenoidal triangle as a novel and practical anatomic surgical landmark for safe and effective exposure of the foramen lacerum in endoscopic endonasal surgery.

Morphological and Metrical Relationships Between Sphenoid Sinus and Sella Turcica: Possible Applications in Transnasal Transsphenoidal Surgery.

INTRODUCTION: Transsphenoidal surgeries imply the risk of intraoperative lesions to the neurovascular structures surrounding the sphenoid sinus (SS). Aim of the present study is to assess the metrical and morphologic relationships existing between SS and sella turcica (ST). MATERIALS AND METHODS: Two hundred computed tomography-scans of patients were selected. For each patient volumes of SS were calculated from their 3-dimensional models segmented through ITK-SNAP program. Variants of SS in pneumatisation and sellar diameters [antero-posterior (AP) diameter, depth, and length] were evaluated on each computed tomography-scan. Correlations among different measurements were assessed through Spearman test ( P <0.01), whereas associations between sellar parameters and presence of pneumatisation variants were assessed through Mann-Whitney test ( P <0.01). RESULTS: In males, pneumatization of the greater wings was related to smaller AP diameter ( P <0.01) and depth of ST ( P <0.01), whereas in females lower values of depth were found in patients with pneumatization of the pterygoid processes ( P <0.01). In both sexes, a positive correlation was found between AP diameter and, respectively, length and depth of ST ( P <0.01), together with a negative correlation between volume of SS and depth of ST ( P <0.01). Lastly, in females a positive correlation was found between age and, respectively, length and depth of ST ( P <0.01). CONCLUSIONS: The present study highlighted new metrical and morphologic relationships between volume and pneumatisation of SS and diameters of ST. Knowledge of these correlations allows to understand more clearly, in the preoperative setting, the surgical working space. Further studies are needed, especially for what concerns the relationship between sellar measurements and age in females.

Comparison of three-dimensional maxillary growth across spheno-occipital synchondrosis maturation stages.

BACKGROUND: This study aimed to three-dimensionally compare the maxillary growth among the spheno-occipital synchondrosis (SOS) maturation stages in both genders. METHODS: This is a cross-sectional study of a retrospective type in which cone-beam computed tomography (CBCT) images of 500 patients aged 6 to 25 years (226 males and 274 females) were analyzed. The SOS was evaluated using the four-stage scoring system; completely open, partially fused, semi-fused, or completely fused. The SOS scoring and three-dimensional cephalometric measurements were analyzed by Invivo 6.0.3 software. Descriptive and analytical statistics were performed and a P-value < 0.05 was considered statistically significant. RESULTS: There was a statistically significant difference in maxillary measurements among SOS maturation stages in both genders (P < 0.05). The mean differences in the maxillary growth among the SOS maturation stages between SOS stages 2 and 3 were higher than those between stages 1and 2 and stages 3 and 4 for maxillary length and height in both genders. However, the mean difference in the maxillary width was higher between SOS stages 1 and 2 than those stages 2 and 3 and stages 3 and 4. On other hand, there may be lesser maxillary growth between SOS stages 3 and 4 for maxillary width, length (in males), and height. The growth curves showed high active growth of the maxilla as the SOS was still fusing (especially stage 2 and 3) than those of the fused (stage 4). Moreover, the acceleration of growth occurred earlier in females than males regarding chronological age but not for SOS maturation stages. CONCLUSIONS: The SOS maturation stages are valid and reliable maxillary skeletal maturation indicators for three-dimensional maxillary growth in both genders.

Anatomical configurations of the optic canal in the sphenoid sinus in a Hispanic population: computed tomography based study.

OBJECTIVE: The prevalence of the optic canal anatomical variants across the sphenoid sinus varies widely among different ethnic groups. This study aimed to analyse the anatomical variants of the optic canal and their relationship to sphenoid sinus pneumatisation in a Hispanic population. METHOD: A review of 320 sphenoid sinuses by high-resolution computed tomography was performed. DeLano's classification of the optic canal, presence of dehiscence, septa insertion, sphenoid sinus pneumatisation and presence of Onodi cells were established. RESULTS: Dehiscence of the optic canal was observed in 4.7 per cent (n = 15) of the analysed sinuses. Type 4 and 3 optic canals were significantly more frequent among postsellar sphenoid sinuses than other patterns of sphenoid sinus pneumatisation (p = 0.002 and p = 0.018). A type 4 optic canal has a higher tendency to present inserted septum than other optic canal types (p = 0.014). CONCLUSION: This study described the optic canal variants in a Hispanic population, which complements existing literature addressing other ethnicities.

Timing of Spheno-Occipital Synchondrosis Closure in Cleft Lip and Palate Patients in Iranian Population.

This study aimed to evaluate the chronological age range associated with each stage of spheno-occipital synchondrosis (SOS) fusion in patients with cleft lip and palate compared to the noncleft group, using cone-beam computed tomography (CBCT) images.In this study, the degree of SOS fusion was assessed using a 4-stage scoring system on CBCT images of 190 individuals (92 patients with cleft lip and palate, 98 noncleft individuals). A χ2 test was performed to assess the correlation between age and fusion stage. The independent sample t tests were used to evaluate the differences in the mean values of the samples of each group and each sex, as well as the mean value of each stage (P < .05).The results showed that there was no significant difference in the timing of the SOS fusion stages between the patients with cleft palate and the noncleft group. Although the fusion process of SOS begins about one year earlier in females, the complete ossification occurs at the mean age of 18.5 for both sexes in the experimental group and the mean age of 19.0 in the noncleft group.The present study found no differences in the fusion stages of the spheno-occipital synchondrosis between patients with cleft lip and palate and healthy individuals.

Endoscopic endonasal transsphenoidal surgery in acromegaly with conchal sphenoid sinus.

BACKGROUND: A conchal non-pneumatized sphenoid sinus tends to be considered as unfavorable for transsphenoidal surgery because of procedural difficulties. Especially in acromegalic patients, the proportion of the conchal type of sphenoid sinus is potentially high compared with that of other patients who have a pituitary tumor. This report investigates the characteristics and surgery of the conchal type of sphenoid sinus in acromegaly along with the internal bone properties. CLINICAL PRESENTATION: A 70-year-old man with acromegaly underwent endoscopic endonasal transsphenoidal surgery. Intraoperatively, the anterior wall of the non-pneumatized sphenoid was cortical, however, the cancellous bone was very soft, included fatty tissue, and was easily removed by suction. The sellar lesion could be reached without any problems, and finally, total tumor resection was achieved. CONCLUSION: Based on this surgical case, the conchal sphenoid sinus of acromegaly is not always homogeneous solid bone but may contain soft fatty tissue. Therefore, although the sphenoidal characteristics may have an impact on the surgical procedures, precise assessment pre- and intraoperatively can make transsphenoidal surgery with conchal sphenoid sinus feasible.

Morphologic and Morphometric Measurements of the Foramen Ovale: Comparing Digitized Measurements Performed on Dried Human Crania With Computed Tomographic Imaging. An Observational Anatomic Study.

The foramen ovale (FO) of the sphenoid bone is clinically important for the interventional treatment of trigeminal neuralgia. Percutaneous procedures applied to treat the chronic pain condition typically involve the cannulation of this oval-like foramen located at the base of the skull. Anatomic variations of the FO have been reported to contribute to difficulties in the cannulation of this structure. Computed tomography (CT) can help the surgeon improve the accuracy and safety of the intervention. However, even with navigation technology, unsuccessful cannulation of the FO has been reported. The aim of this observational anatomic study was to define morphometric and morphologic data of the FO and to investigate for potential differences between measurements taken on dried human crania and digitized measurements of the FO measured on CT images. One hundred eighteen FOs were evaluated. Twenty FOs underwent CT scanning. The mean length of the foramen was 7.41±1.3 mm on the left side and 7.57±1.07 mm on the right. The mean width of the foramen was 4.63±0.86 mm on the left side and 4.33±0.99 on the right. The mean area on the left side was 27.11±7.58 and 25.73±6.64 mm 2 on the right. No significant left-right differences were found for any of these dimensions. The most important conclusion that we can draw is that the measurements can indeed be performed on CT images to obtain an accurate picture of the morphology. Considering the surgical importance of the FO and taking into consideration the limitations this study added to scientific knowledge, this study was constructive as far as neurosurgeons and anatomists are concerned.

Sphenoid dysplasia in patients with neurofibromatosis type 1: Clinical features and imaging findings including cerebrospinal fluid alterations.

INTRODUCTION: Neurofibromatosis Type 1 (NF-1) is a genetic disorder that occurs in 1:2500-3000 live births and may involve multiple organs. An uncommon but well-known phenomena is sphenoid dysplasia, which appears in 3-11% of the patients, and may result in significant lowering of the orbit. Understanding the cause and development of this process might predict its course and its treatment. METHODS: The records of 29 patients with PNF in the head and neck region were searched for location of the PNF and type of surgery. Photographs were studied for facial disturbances, including vertical dystopia, hypertelorism, ptosis, exophthalmos and enophthalmos. MR and CT scans were studied for the presence of PNF, aspect of the sphenoid bone, alteration in the CSF circulation, and other tumour involvement. RESULTS: Fourteen of 29 patients with PNF in the head and neck presented with sphenoid dysplasia. All 14 patients had their PNF located in the periorbital region. Increased locoregional CSF collections were seen in almost all of these patients. Besides glioma of the optical nerve or hamartomas in the cerebrum and cerebellum, there were no other tumours found. Surgical treatment varies from simple excision to excessive debulking of the PNF, reconstruction of the orbit and even enucleation. CONCLUSION: Although sphenoid dysplasia is uncommon in NF-1 patients, early recognition is important to prevent facial disfigurement and vision loss. Clinicians should be aware that abnormalities in the periorbital region and especially vertical dystopia might be the first sign of sphenoid dysplasia. Performing a CT or black-bone MR scan would be the next step to confirm or exclude sphenoid dysplasia and abnormal CSF dynamics.

Endonasal Exposure of Lateral Recess of the Sphenoid Sinus: Significance of Pterygoid Process Pneumatization.

BACKGROUND: Caudal pneumatization of the pterygoid process may impact endonasal exposure of the lateral recess of sphenoid sinus (LRSS). OBJECTIVES: This study aims to explore the implications of a pneumatized pterygoid process for an endonasal transpterygoid approach to the LRSS and to define strategies regarding the preservation or sacrifice of the vidian nerve. METHODS: Dissection of the LRSS (11 sides) was performed on 6 cadaveric specimens, preselected for the radiographic presence of an LRSS. In addition, the dimensions of the LRSS were measured on the deidentified CT images of 120 patients (240 sides). The sphenoid sinus was subdivided into 3 categories: Type 1 (no identifiable LRSS), Type 2 (lateral pneumatization of the greater wing above the vidian canal), and Type 3 (pneumatization of both the greater wing and the pterygoid process). RESULTS: On the cadaveric specimens, a Type 2 pneumatization often allowed access to the LRSS above the level of the vidian canal; thus, sparing the vidian neurovascular bundle. In Type 3 pneumatization, a frontal corridor through the pterygoid base could be created to reach the LRSS with preservation of the vidian nerve. Extreme Type 3 pneumatization, however, required the transposition or sacrifice of the vidian nerve to facilitate a full direct access to the superolateral LRSS. Measurements on CT images revealed that the extent of caudal pneumatization of the pterygoid process had no statistically significant correlation with the superolateral extension of the lateral recess in patients with Type 3 LRSS (P > .05). CONCLUSION: Pneumatization of the LRSS toward a caudal or superolateral direction may develop independent from each other. Caudal pneumatization of the pterygoid process seems to variably impact the endonasal exposure of the LRSS.

Comparison of spheno-occipital synchondrosis maturation stages with three-dimensional assessment of mandibular growth.

BACKGROUND: This study aimed to compare spheno-occipital synchondrosis (SOS) maturation stages with a three-dimensional assessment of mandibular growth. METHODS: This is a cross-sectional study of a retrospective type, in which cone-beam computed tomography (CBCT) images of 500 patients aged 6 to 25 years (226 males and 274 females) were analyzed. The SOS was evaluated using the four-stage scoring system; completely open, partially fused, semi-fused, or completely fused. The SOS scoring and three-dimensional cephalometric measurements were analyzed by Invivo 6.0.3 software. Descriptive and analytical statistics were performed, and a P-value < 0.05 was considered statistically significant. RESULTS: There was a statistically significant difference in mandibular measurements among SOS maturation stages in both sexes (P < 0.05). The skeletal growth increments of mandibular variables across the SOS stages had higher mean differences between SOS stages 2 and 3 than those between stages 1 and 2 and stages 3 and 4 in both sexes. The mandibular growth curves increased with chronological age (earlier in females) and SOS maturation stages (mostly in stages 1, 2, and 3 than stage 4). CONCLUSIONS: The SOS maturation stages are valid and reliable mandibular skeletal indicators as evaluated with three-dimensional cephalometric mandibular measurements. The findings of growth increments and constructed growth curves of mandibular growth might be helpful in diagnosis and treatment planning.