Anatomical Variation

Mandibular and maxillary nerve supplies are described in most anatomy textbooks. Nevertheless, several anatomical variations can be found and some of them are clinically relevant. Several studies have described the anatomical variations of the branching pattern of the trigeminal nerve in great detail. The aim of this review is to collect data from the literature and gives a detailed description of the innervation of the mandible and maxilla. We carried out a search of studies published in PubMed up to 2011, including clinical, anatomical and radiological studies. This paper gives an overview of the main anatomical variations of the maxillary and mandibular nerve supplies, describing the anatomical variations that should be considered by the clinicians to understand pathological situations better and to avoid complications associated with anaesthesia and surgical procedures.

Recurrent laryngeal nerve (RLN) palsy is the most common and serious complication after thyroid surgery. Visual identification of the RLN during thyroid surgery has been shown to be associated with lower rates of palsy, and although it has been recommended as the gold standard for RLN treatment, it does not guarantee success against postoperative vocal cord paralysis. Anatomical variations of the RLN, such as extra‐laryngeal branches, distorted RLN, intertwining between branches of the RLN and inferior thyroid artery, and non‐recurrent laryngeal nerve, can be a potential cause of nerve injury due to visual misidentification. Therefore, intraoperative verification of functional and anatomical RLN integrity is a prerequisite for a safe thyroid operation. In this article, we review the literature and demonstrate how to identify and handle the anatomical variations of the RLN with the application of intraoperative neuromonitoring in the form of high resolution photography, which can be ...

Mandibular and maxillary nerve supplies are described in most anatomy textbooks. Nevertheless, several anatomical variations can be found and some of them are clinically relevant. Several studies have described the anatomical variations of the branching pattern of the trigeminal nerve in great detail. The aim of this review is to collect data from the literature and gives a detailed description of the innervation of the mandible and maxilla. We carried out a search of studies published in PubMed up to 2011, including clinical, anatomical and radiological studies. This paper gives an overview of the main anatomical variations of the maxillary and mandibular nerve supplies, describing the anatomical variations that should be considered by the clinicians to understand pathological situations better and to avoid complications associated with anaesthesia and surgical procedures.

Bacula are relatively small in terrestrially mating species of pinnipeds (otariids and elephant seals, Mirounga), perhaps reflecting adaptive size reduction to minimize bacular fracture. Fur seals and sea lions (Otariidae) are a good group with which to investigate this question, because most species copulate solely on land and body size varies interspecifically. We studied bacular size and relative growth in the largest extant otariid, the Steller sea lion (Eumetopias jubatus). Bacula roughly tripled in length and increased 30-fold in mass between 1 and 8 years of age. Allometric relationships changed over development; bacular length and mass changed from being initially positively allometric to body length to negatively allometric and isometric, respectively; bacular mass and thickness were positively allometric to body length throughout life, and apical growth was isometric then was positively allometric to bacular length. In adults (Ͼ7 years of age), bacula averaged 18.1 cm length (6.2% of body length), 36.7 g mass, and 2.02 g/cm density (mass : length). The baculum of Eumetopias is about the same length relative to body length as in other adult male otariids but is about twice the density, presumably to increase strength. Information on small or aquatically mating species of otariid are needed to extend our findings and interpretations.

Growth and size-scaling of the baculum and testes in the moderately polygynous hooded seal (Cystophora cristata) were studied using 107 specimens of known age (1 month to 28 years) from the northwestern Atlantic. Bacular growth was rapid between 2 and 5 years of age: length increased 150% and "density" (i.e., mass/length) increased 8-fold and mass 20-fold. Growth continued throughout life. In large, old (>14 years) males, the baculum averaged 20.7 cm in length, 2.1 g/cm in density, and 44.4 g in mass. Bacular length increased relative to body length until seals were about 5 years of age, after which it averaged 8.2%. Testicular growth continued until the seals were about 12 years of age. Testes from breeding males >12 years old averaged 11.2 cm in length, 4.6 cm in width, and 138 g in mass; length averaged 4.9% of body length. In males 2-5 years of age, bacular and testicular sizes were positively allometric relative to body length; in older males, bacular mass and density were positively allometric, and bacular length and testicular size isometric, relative to body length. Bacular size was mostly positively allometric relative to testicular size (bacular length exhibited some isometry). Compared with that of the related and ecologically similar harp seal (Pagophilus groenlandicus), which is presumed to have a promiscuous mating system, the baculum of the hooded seal was structurally simpler and grew more quickly but reached a relatively smaller size in adults (8.2 vs. 9.9% of body length). Relative testicular length was also smaller (4.9 vs. 5.7% of body length) and bacular density lower (2.1 vs. 2.8 g/cm) than in the harp seal. These observations suggest that intra-or inter-sexual competition via copulation is weaker in the hooded seal. Résumé : La croissance et la taille relative du baculum et des testicules ont été étudiées chez le Phoque à capuchon (Cystophora cristata), un animal modérément polygyne, par examen de 107 spécimens d'âge connu (1 mois à 28 ans) de l'Atlantique du nord-ouest. La croissance du baculum est rapide de 2 à 5 ans et accuse une augmentation de longueur de 150%, une augmentation de la « densité » par un facteur de 8 (i.e., masse/longueur) et une augmentation de la masse par un facteur de 20. La croissance se poursuit durant toute la vie. Chez les vieux mâles (>14 ans), le baculum est en moyenne de 20,7 cm de longueur, de 2,1 g/cm de densité et de 44,4 g de masse. La longueur du baculum augmente relativement à la longueur du corps jusqu'à l'âge de 5 ans environ, après quoi elle fait 8,2% de la longueur du corps. La croissance des testicules se poursuit jusqu'à l'âge de 12 ans environ. Les testicules des mâles reproducteurs de plus de 12 ans ont en moyenne 11,2 cm de longueur, 4,6 cm de largeur et 138 g de masse; leur longueur est égale en moyenne à 4,9% de la longueur du corps. Chez les mâles de 2-5 ans, la taille du baculum et celle des testicules ont une relation allométrique positive avec la longueur du corps; chez les mâles âgés, la masse et la densité du baculum sont également en relation allométrique positive avec la longueur du corps, alors que la longueur du baculum et la taille des testicules sont en relation isométrique avec la longueur du corps. La taille du baculum est généralement en relation allométrique positive avec la taille des testicules (la longueur du baculum est parfois isométrique). Comparativement à la situation qui prévaut chez le Phoque commun (Pagophilus groenlandicus), un phoque apparenté et écologiquement semblable dont le système d'accouplement est présumément basé sur la promiscuité, le baculum du Phoque à capuchon est de structure plus simple et de croissance plus rapide, mais sa taille à l'âge adulte est relativement plus faible (8,2 vs. 9,9% de la longueur du corps); la longueur relative des testicules est également plus petite (4,9 vs. 5,7% de la longueur du corps) et la densité du baculum, plus faible (2,1 vs. 2,8 g/cm) chez le Phoque à capuchon. Ces observations indiquent que la compétition entre individus du même sexe et entre individus de sexes opposés via l'accouplement est plus faible chez le Phoque à capuchon. [Traduit par la Rédaction] Miller et al. 479

resumen Antecedentes: La tomografía computada (TC) de senos parnasales (SPN) juega un rol importante en la evaluación preoperatoria de los pacientes previo a la cirugía endoscópica de SPN. La asimetría del techo etmoidal es crítica durante el evento quirúrgico, ya que puede predisponer a consecuencias peligrosas como son hemorragia, fístula de líquido cefalorraquídeo y complicaciones intracraneales. El objetivo del trabajo es determinar la incidencia de la asimetría en la altura del techo etmoidal o fóvea etmoidalis. Material y método: Estudio retrospectivo, descriptivo, comparativo de cortes coronales de TC, en individuos cuyas edades variaron entre 1 y 95 años de edad, en el que se utilizaron 102 TC de SPN, de individuos valorados por cefalea, sinusitis o traumatismo craneoencefálico (TCE). La altura del techo etmoidal fue valorada para determinar simetría entre los lados derecho e izquierdo. Resultados: Se determinó asimetría cuando la relación entre los lados derecho e izquierdo mostraban diferencia > 5%. En 86 estudios (84.3%) se determinó asimetría entre la altura del techo etmoidal derecho e izquierdo. De estos 86, 35 (40.6%) presentaron el techo derecho de localización más baja, mientras que 51 (59.5%) el izquierdo fue más bajo. El techo etmoidal fue simétrico en 16 estudios (15.7%.). Es importante mencionar que, las diferencias en la altura del techo etmoidal fueron estadísticamente significativas en 37.25% de los casos.

Variations at the junction of embryonic internal carotid and vertebrobasilar systems are rare and associated with a high incidence of stroke. During cadaver dissection, we demonstrated for the first time a case of hypoplastic right vertebral artery associated with partial duplication of the distal part of the right P1 segment of a partial fetal posterior cerebral artery (FPCA) and bilateral duplication of superior cerebellar arteries (SCAs), of which, the upper right SCA originated from PCA. We hypothesize that the poor development of the right half of the vertebrobasilar system caused the persistence of FPCA with anomalous origin of the right upper SCA as well as partial duplication of P1 segment of PCA as a remnant of the weak anastomosis between the embryonic right PCA and the basilar system. Such complex variations provide a huge challenge in their diagnosis and in choosing the suitable treatment modality for the stroke.

Introduction: Sciatic nerve is the largest peripheral nerve in human body which has overtime shown numerous anatomical variations either morphometric, pelvic exit patterns that have significant clinical consequences. Objective: The aim of this systematic review was to critically evaluate the morphometric characteristics and analyse variations of sciatic nerve in relation to exit patterns among African populations. Materials and Methods: Here a highly comprehensive literature search was conducted in multiple databases namely; PubMed, Scopus, Science Direct, Google Scholar and majorly focusing on studies published across between January 2009 sciatic nerve-SN and May 2025. Thereafter, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed that yielded 18 eligible studies out of 268 that were initially identified. Findings: From these studies, it can be noted that variations of sciatic nerve in reference to level and type of SN bifurcation were significant. There was a further considerable relationship between SN, piriformis muscle and sexual dimorphism in nerve morphology. It was also noted that bifurcation of SN above or within piriformis was the most common having highly exhibited a pattern associated with piriformis syndrome and complication associated with hip and pelvic surgeries. Moreover, majority of these studies consistently demonstrated morphometric differences in sex and laterality which warrants surgical planning, nerve block procedures and clinical diagnosis. There was also a substantial heterogeneity across different African populations with its frequency ranging from 8% to over 30%. Conclusion: Therefore, systematic review points out urgent need for region-specific anatomical studies, standardization in classification systems, incorporation of SN anatomical variability into surgical education and practice. It is thereby, recommended that understanding these differences is crucial for diminishing intraoperative jeopardies. This would improve patient upshots in sciatic nerve-related interventions across African healthcare settings.

Introduction: Sciatic nerve is the largest peripheral nerve in human body which has overtime shown numerous anatomical variations either morphometric, pelvic exit patterns that have significant clinical consequences. Objective: The aim of this systematic review was to critically evaluate the morphometric characteristics and analyse variations of sciatic nerve in relation to exit patterns among African populations. Materials and Methods: Here a highly comprehensive literature search was conducted in multiple databases namely; PubMed, Scopus, Science Direct, Google Scholar and majorly focusing on studies published across between January 2009 sciatic nerve-SN and May 2025. Thereafter, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed that yielded 18 eligible studies out of 268 that were initially identified. Findings: From these studies, it can be noted that variations of sciatic nerve in reference to level and type of SN bifurcation were significant. There was a further considerable relationship between SN, piriformis muscle and sexual dimorphism in nerve morphology. It was also noted that bifurcation of SN above or within piriformis was the most common having highly exhibited a pattern associated with piriformis syndrome and complication associated with hip and pelvic surgeries. Moreover, majority of these studies consistently demonstrated morphometric differences in sex and laterality which warrants surgical planning, nerve block procedures and clinical diagnosis. There was also a substantial heterogeneity across different African populations with its frequency ranging from 8% to over 30%. Conclusion: Therefore, systematic review points out urgent need for region-specific anatomical studies, standardization in classification systems, incorporation of SN anatomical variability into surgical education and practice. It is thereby, recommended that understanding these differences is crucial for diminishing intraoperative jeopardies. This would improve patient upshots in sciatic nerve-related interventions across African healthcare settings.

Introduction: Sciatic nerve is the largest peripheral nerve in human body which has overtime shown numerous anatomical variations either morphometric, pelvic exit patterns that have significant clinical consequences. Objective: The aim of this systematic review was to critically evaluate the morphometric characteristics and analyse variations of sciatic nerve in relation to exit patterns among African populations. Materials and Methods: Here a highly comprehensive literature search was conducted in multiple databases namely; PubMed, Scopus, Science Direct, Google Scholar and majorly focusing on studies published across between January 2009 sciatic nerve-SN and May 2025. Thereafter, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed that yielded 18 eligible studies out of 268 that were initially identified. Findings: From these studies, it can be noted that variations of sciatic nerve in reference to level and type of SN bifurcation were significant. There was a further considerable relationship between SN, piriformis muscle and sexual dimorphism in nerve morphology. It was also noted that bifurcation of SN above or within piriformis was the most common having highly exhibited a pattern associated with piriformis syndrome and complication associated with hip and pelvic surgeries. Moreover, majority of these studies consistently demonstrated morphometric differences in sex and laterality which warrants surgical planning, nerve block procedures and clinical diagnosis. There was also a substantial heterogeneity across different African populations with its frequency ranging from 8% to over 30%. Conclusion: Therefore, systematic review points out urgent need for region-specific anatomical studies, standardization in classification systems, incorporation of SN anatomical variability into surgical education and practice. It is thereby, recommended that understanding these differences is crucial for diminishing intraoperative jeopardies. This would improve patient upshots in sciatic nerve-related interventions across African healthcare settings.

Objective: Objective: Objective: Objective: To determine the effect of lower pole renal anatomy in terms of infundibuloureteropelvic angle (IUPA), infundibulocalyceal length (ICL), infundibular width (IW) on the formation of solitary stone of the lower pole of kidney in our set up.

Objectives: The study aimed to assess the prevalence and morphology of bifid mandibular canal (BMC) using cone beam computed tomography (CBCT) among a group of Yemeni adults.
Materials and Methods: The presence and type of BMC were evaluated among 400 CBCT images. Prevalence rate of BMC was also determined according to gender. Further, the diameter and length of BMCs were measured using Ez3D plus software. Chi‑square analysis and the analysis of variance (one‑way ANOVA) were used.
Results: The study concluded that BMCs were found in 60 (15%) of total cases. There was no significant correlation between gender and BMC prevalence. Forward BMC was the most common type (48.3%), followed by retromolar BMC (35.0%) then dental BMC (16.7%); while not even one case of buccolingual BMC was observed. There was a significant difference in the mean diameter of BMC (P value = 0.016). There was a significant difference in the mean length of BMC (P = 0.001).
Conclusion: The prevalence of BMCs in Yemeni adults is relatively high, and forward BMC was the most common type. Detecting BMCs by using CBCT imaging is highly recommended prior to any mandibular surgery.

Background: Clinoid space is revealed when the anterior clinoid process (ACP) is removed, and it makes anterior vertical segment of the internal carotid artery (ICA) visible. Also, the presence of Carotico-clinoid foramen (CCF) makes the ICA from the cavernous sinus emerges through it and endangers the artery during anterior clinoidectomy which necessitates understanding the variable dimensions of ACP. Aim and Objectives: This study intended to investigate the morphology and morphometry of the ACP and to document the prevalence of the CCF in a select group of the South African population. Materials and Methods: The study was carried out on a total of 32 open crania (n=64 ACP) obtained from the University of KwaZulu-Natal, Nelson Mandela School of Medicine, Discipline of Clinical Anatomy using digital vernier caliper to measure the dimensions of the ACP. Results: The mean length, basal width, and thickness of the ACP on the right were10.18±1.34mm, 10.27±0.73mm, and 5.81±0.80mm and the left side was 10.89±0.94mm, 11.63±0.90mm, and 4.78±0.64mm respectively. The left ACP was significantly longer, wider, and thinner than the right ACP. Type I (short and broad) ACP was the most prevalent type, occurring in 53.13% of the studied population. Out of the 32 skulls studied, the CCF was observed in 6 (18.75%) cases. Five out of the six skulls (83.33%) had a bilateral complete CCF, and 1 (16.67%) had a unilaterally incomplete CCF. Conclusion: The ACP in our setting differs from other populations in terms of type, dimensions, and prevalence of the CCF and these should be considered when interpreting skull base radiographs and planning anterior clinoidectomy.

Objectives: Analyze the anatomic variations of the testicular veins in human cadavers and fetuses. Materials and Methods: One hundred male adult cadavers and 24 fetuses were studied. Four anatomic aspects were considered: 1) Number of testicular veins, 2) The local of vein termination, 3) Type and number of collaterals present and 4) Testicular vein termination angle. Results: Cadavers -Right side -One testicular vein occurred in 85% and 2 veins in 5% of the cases. There were communicating veins with the colon in 21% of the cases. Left side -One testicular vein occurred in 82%, two veins in 15%, three veins in 2% and four veins in 1% of the cases. There were communicating veins with the colon in 31% of the cases. Fetuses -Right side -One testicular vein occurred in all cases. This vein drained to the vena cava in 83.3% of the cases, to the junction of the vena cava with the renal vein in 12.5% and to the renal vein in 4.2%. There were communicating veins with the colon in 25% of the cases. Left side -One testicular vein occurred in 66.6% of the cases, and 2 veins in occurred 33.3%. Communicating veins with the colon were found in 41.6% of the cases. The testicular vein presents numeric variations and also variations in its local of termination. In approximately 30% of the cases, there are collaterals that communicate the testicular vein with retroperitoneal veins. These anatomic findings can help understanding the origin of varicocele and its recurrence after surgical interventions.

Anatomic variants of the muscles of the hand have important clinical implications. We report a case of bilateral extensor digitorum brevis manus (EDBM), a rare muscle found on the dorsum of the wrist and hand in an adult female formalin-fixed cadaver. In both hands the muscle inserted proximally in the dorsal surface of the distal radius and finished inserting in the common extensor tendon of the middle finger. The anatomic and clinical implications of this variant are discussed here.

The renal artery when it reaches close to the hilum of kidney where it cleaves into anterior and posterior divisions were receives around 75% and 25% of blood respectively. Further these branches divide into many segmental branches. These segmental arteries does not have collateral system, so when there is any occlusion of these arteries which results in the ischemia of the particular segment of kidney. Anatomists believe that knowledge of presence of lower polar artery is essential for polar nephrectomy. Prior knowledge of variations in the renal vessels is required for urological surgery for preoperative investigations as there are reports of surgical complications which include enormus haemorrhage. In this study we analyzed the different variations in the intra renal branch of inferior segmental artery.

Carotid dolichoarteriopaties (tortuosity, kinking and coiling) represents a common angiographic and Du- plex scanning finding, but choosing the right method for treatment is still a subject of numerous debates. The aim of this study was to analyze the clinical features of the patients with carotid dolichoarteriopathies who referred for surgery to Clinic of Cardiovascular Surgery from the Emergency Institute for Cardiovascular Diseases and Transplantation, Targu Mures and the type of surgery performed. When these anomalies are the cause of cerebrovascular insufficiency surgical treatment is indicated and the surgeon must be familiarized with all the techniques and choose the right one tailored to each patient.

Background: The vertebral arteries originate from the root of the neck as the first branches of the subclavian arteries. Variations of vertebral arteries are congenital anomalies occurring during embryonic development. Anatomic variations of the left vertebral artery are clinically symptomless and recognized incidentally during angiographic assessments or imaging techniques so the diagnosis of these anomalies is a serious challenge. Anomalous origin of vertebral arteries may lead to neurologic disorders. It is, thus, important to identify variations of the large vessels of the aortic arch when planning neck and cervical spine interventions and diagnostic radiology. For this reason, we would like to present this rare case of left vertebral artery showing a different origin. Case report: In this work, we describe a 60-year-old female patient with headache, lethargy and blurred vision. We employed magnetic resonance angiography for both the brain and neck. There was no lesion in the brain. Incidentally, we found that the root of the left vertebral artery was anatomically aberrant. The left vertebral artery arose from the nearest section of the left external carotid artery, next to the bifurcation of the left common carotid artery, which is a rare variation. Conclusion: Understanding the state of anomalous variations of the origin of the vertebral artery might have crucial implications in angiographic and surgical procedures. It is beneficial to perform more screening with noninvasive studies like neck magnetic resonance angiography in clinical cases with potential symptoms coexisting with other diseases in order to predict possible future problems in intracranial and extracranial interventions.

Endometrioid endometrial carcinoma has an overall good prognosis. However, variable five-year survival rates (92%-42%) have been reported in FIGO stage I, suggesting the involvement of other factors related to tumor biological behavior. These may be related to the role played by epithelial-mesenchymal transition (EMT) and cancer stem cells in endometrial carcinogenesis. In this context, our review highlights the prognostic significance of several types of myoinvasion in low grade, low stage endometrioid endometrial carcinoma, as a reflection of these molecular changes at the invasive front. According to recently introduced myoinvasive patterns, the diffusely infiltrating and microcystic, elongated, and fragmented (MELF) patterns show loss of hormone receptors, along with EMT and high expression of cancer stem cell markers, being associated with a poor prognosis. Additionally, MELF pattern exhibits a high incidence of lymphovascular invasion and lymph node metastases. Conversely, the...

The celiac trunk is normally divided into the left gastric artery (LGA), splenic artery (SA), and common hepatic artery (CHA). The combination between these arteries and the superior mesenteric artery (SMA) generates various combinations. We report here such a rare anatomic variant, namely the hepatomesenteric trunk (HMT), combined with a gastrosplenic trunk (GST). The variant was identified using computed tomography angiograms of a 62-years-old woman. The GST emerged from the aorta within the aortic hiatus of the diaphragm, a previously unknown possibility. Further, an accessory left hepatic artery originated from the LGA. The phrenic arteries had independent aortic origins. The HMT divided into the CHA and the SMA posterior to the origin of the hepatic portal vein (PV), above the pancreas. The CHA initially had a right course, towards the superior border of the PV, then it descended with a transpancreatic course posterior to the PV, reached its inferior/right border, and divided a...

Introduction: Phoenix abscess in maxillary second premolars with three-root morphology presents unique diagnostic and therapeutic challenges. This rare anatomical variation occurs in less than 1% of cases and requires meticulous treatment planning. Case Presentation: A 38-year-old male patient presented with facial swelling and continuous throbbing pain in the right maxillary second premolar. Clinical examination revealed a deep occlusal cavity with tenderness and intraoral swelling. Radiographic evaluation showed periapical radiolucency and widening of the periodontal space. Endodontic access revealed three canals: mesiobuccal, distobuccal, and palatal. Chemomechanical preparation was performed using rotary Hero Gold files with 5.2% NaOCl irrigation and 17% EDTA. Obturation was completed using CeraSeal sealer with gutta-percha cones. Outcomes: Complete resolution of symptoms was achieved with successful healing at 6-month follow-up. Periapical healing was confirmed radiographically, and the tooth was functionally restored with a metal-ceramic crown. Conclusion: Successful endodontic treatment of three-rooted maxillary second premolars requires thorough canal exploration, adequate disinfection protocols, and appropriate obturation techniques. Bioceramic sealers offer excellent biocompatibility and sealing properties for complex anatomical variations.

CONTEXT Pancreaticoduodenectomy entails ligation of vascular arcades arising from the celiac and superior mesenteric arteries. These are known to have anatomical variations. OBJECTIVE This study was aimed at analyzing the spectrum of arterial anomalies and their clinical impact on the procedure itself. PATIENTS The study includes 200 consecutive patients who underwent a pancreaticoduodenectomy between September 2003 and May 2009 after excluding those having distant metastases or local unresectability. MAIN OUTCOME MEASURES The records of the patients were studied to assess the incidence of arterial anomalies and the operative complexities involved in a pancreaticoduodenectomy. RESULTS Fifty-three patients (26.5%) had arterial anomalies. The complexity of the surgery was determined by the course of these arteries. The mean duration of surgery was 420 + or - 32.0 minutes in patients with arterial anomalies versus 370 + or - 38.5 minutes in those with a normal arterial anatomy (P=0.005...

The Circle of Willis (CoW) is a critical arterial network at the base of the brain that maintains cerebral blood flow during vascular compromise. Although classically described as a complete ring, anatomical and imaging studies show variations in approximatel y 40-68% of individuals, which can significantly affect neurosurgical and cerebrovascular procedures. A 2025 classification system identifies four main CoW configurations: Type I (complete, ~60%), Type II (posterior communicati ng artery hypoplasia or aplasia, ~20%), Type III (anterior communicating or anterior cerebral artery hypoplasia or aplasia, ~10%), and Type IV (fetaltype posterior cerebral artery, ~10%). Meta-analyses confirm that posterior circulation variants are most common, with notable population differences, including higher prevalence in South Asian cohorts. Clinically, these variations limit collateral circulation and increase the risk of ischemic complications during surgery. Advances reported in 2025-such as robotic surgical planning, intraoperative 4D flow MRI, artificial intelligence-based risk prediction, and adaptive deep brain stimulation-support safer, anatomy-guided interventions. Routine preoperative vascular imaging and individualized surgical planning are essential to optimize neurovascular outcomes.

The Flexor digitorum brevis (FDB) muscle of the plantar aspect of the foot typically forms four tendons that insert into the lateral four toes. Although variations in tendon number and insertion patterns are common (13-83% worldwide), they are critically understudied with respect to biomechanical implications, especially in populations with high prevalence for variation (77.3% in South Asians). The present case report describes the unilateral absence of the fourth FDB tendon of a 60-year-old male cadaver of South Asian origin using comprehensive morphometric analysis using digital callipers: muscle belly length measured 82.20 mm and widths varied (proximal: 9.10 mm, midpoint: 11.4 mm, distal: 5.92 mm); the remaining three tendons measured 79.09 mm, 65.24 mm, and 56.77 mm. This quantitative documentation adds to limited morphometric data available for South Asian populations and provides population-specific reference values crucial to surgical planning as well as demonstrating a need for biomechanical analysis and standardized clinical assessment protocols in high-variation populations.

The human mandible has been a fascinating subject of study and extensive research in the realm of human anatomy because of its intricate structure and remarkable variation. One important mandibular anatomical component with clinical significance is the mental foramen. An uncommon anatomical variant is accessory mental foramen. Nevertheless, after mandibular surgery, special attention should be given to the potential existence of one or more auxiliary mental foramen in order to prevent neurovascular problems. In this instance, we describe a variant that was perceived as an incidental radiologic finding: bilateral accessory mental foramen.

Background: The sacrum forms an essential component of the pelvic girdle and exhibits marked anatomical variability. Of particular clinical interest is the sacral hiatus, which serves as the access point for caudal epidural anaesthesia. Knowledge of its morphology and dimensions is also useful in forensic identification and medico-legal practice. Materials and Methods: The present cross-sectional study was performed on 200 dry adult human sacra obtained from the Departments of Anatomy at Zydus Medical College, Dahod, and B. J. Medical College, Ahmedabad. The sacral hiatus was evaluated for its shape, vertebral level of the apex and base, length, anteroposterior diameter at the apex, and intercornual distance at the base. Standard osteometric instruments were used for all measurements. Results: The sacral hiatus demonstrated considerable variation in shape and dimensions. The most frequently observed configuration was the inverted U shape, followed by inverted V and irregular types. The apex was most commonly located at the level of the fourth sacral vertebra, while the base was usually at the level of the fifth sacral vertebra. Most specimens showed a hiatus length between 11 and 30 mm, with an anteroposterior diameter at the apex commonly ranging from 4 to 6 mm. Conclusion: Appreciable anatomical variability exists in the sacral hiatus. Awareness of these variations is important for improving the success rate and safety of caudal epidural anaesthesia, particularly in the adult Indian population.

The greater palatine foramina are a pair of bony foramina found at the posterior end of the hard palate close to the third molar teeth. These foramina transmit the greater palatine nerve (GPN) and vessels from the pterygopalatine fossa into the oral cavity. Along with the parasympathetic innervation of the palatal glands, the GPN is responsible for the transmission of general sensation from the hard palate and its mucoperiosteum, the adjacent maxilla and gingiva. [1] Due to the importance of structures passing through greater palatine foramen (GPF) as well as its close proximity to the third molar tooth, knowledge about GPF anatomy is important in surgeries of posterior maxilla, maxillary sinus, palatal reconstruction for cleft palate, and various dental procedures involving third molar tooth. [2,3] Apart from its implication in surgeries, for proper local and regional anesthesia of the region without risk of damage to adjacent structures or errant deposition of anesthetic agent in nasopharynx, a knowledge of GPF anatomy is essential. For intraoral maxillary nerve block, there are two widely used procedures, one is the high tuberosity approach and the other is the greater palatine canal (GPC) approach. Out of these two approaches, in GPC approach, the needle is inserted through the GPF, to reach up to pterygopalatine fossa, and anesthetic agent is injected. This is so far the safest approach with maximum success rate. [4] Background: Greater palatine foramen (GPF) transmits important neurovascular structures which may get injured during different operative procedures such as intraoral maxillary nerve block, cleft palate repair, and operative procedures involving maxillary sinus and maxillary molars. Hence, proper knowledge about the GPF is very essential. The aim of this study was to study the shape of GPF and its location in relation to molar tooth, measure the diameters of GPF, and measure the distances of GPF from different landmarks of palate. Methodology: A dry bone-based study was conducted on dry human skulls of Eastern Indian population using digital Vernier caliper. At first location of GPF in relation to maxillary molars was noted, followed by anteroposterior (AP) and transverse diameter of GPF and distance of GPF from incisive fossa, posterior border of hard palate (PBHP) and interpalatine suture was measured. Results: In 69.64% of cases, GPF was present medial to the maxillary molar tooth and most common shape is oval type which is found in 44.64% of cases. AP diameter was almost same in both the sides which is 5.13 mm in average and transverse diameter is 2.91 mm. The mean distance of GPF from incisive fossa, PBHP, and interpalatine suture (IPS) is as follows in sequence, 37.24 mm, 3.21 mm, and 13.68 mm. Conclusion: The findings from the present study can be used as a guide for locating GPF during different operative procedures such as palatal reconstruction in cleft palate, maxillary surgeries, and intraoral maxillary nerve block. GPF is located about 3 mm in front of PBHP, most commonly medial to the third maxillary molar, about 15 mm lateral to IPS in the present study among Eastern Indian population.

Recurrent laryngeal nerve (RLN) palsy is the most common and serious complication after thyroid surgery. Visual identification of the RLN during thyroid surgery has been shown to be associated with lower rates of palsy, and although it has been recommended as the gold standard for RLN treatment, it does not guarantee success against postoperative vocal cord paralysis. Anatomical variations of the RLN, such as extra‐laryngeal branches, distorted RLN, intertwining between branches of the RLN and inferior thyroid artery, and non‐recurrent laryngeal nerve, can be a potential cause of nerve injury due to visual misidentification. Therefore, intraoperative verification of functional and anatomical RLN integrity is a prerequisite for a safe thyroid operation. In this article, we review the literature and demonstrate how to identify and handle the anatomical variations of the RLN with the application of intraoperative neuromonitoring in the form of high resolution photography, which can be ...

Digastric muscle is characterized by presenting occasional variations. The suprahyoid region of an 83 year-old male cadaver was dissected and an anatomic variation of the digastric muscle was observed in its anterior belly. It consisted of an accessory bilateral anterior belly originating in the intermediate tendon and inserted into the mylohyoid raphe. The implications of this variation are discussed from a diagnostic and functional perspective.