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Anatomy of the superior labial frenulum (SLF), at first glance, seems to be well established. However, existing studies on the SLF lack description of the incisivus labii superioris (ILS), which cannot be ignored when discussing the SLF. We believe that thorough understanding of the SLF necessitates the anatomical knowledge of the ILS. This study aimed to elucidate the anatomical relationship between the orbicularis oris (OO), ILS, and SLF. A total of 20 formalin fixed human cadaveric specimens were used for gross anatomical and/or histological observation. For histological observation, all specimens were stained with Masson-trichrome. The SLF was a mucosal fold between the gingival mucosa and alveolar mucosa with connective tissue deep to it. The connective tissue attached to the alveolar bone in the junction between the right and left ILS. Skeletal muscle fibers other than orbicularis oris was found in one specimen, which were considered the ILS. During a frenulectomy, removal of the connective tissue bundle is required to prevent recurrence of the high SLF insertion.

The term Metaverse ("meta" defined as beyond, transcendence or virtuality, and "verse" meaning universe or world) denotes a "virtual reality space" for anatomy teaching. To ascertain how many anatomists are familiar or are using this adjunct in teaching, we conducted a short survey at the 2022 annual meeting of the American Association of Clinical Anatomists (AACA). Interestingly, only six respondents (9.4%) had used a Metaverse for teaching anatomy. Moreover, the vast majority of attendees were anatomy educators or basic science faculty, but not practicing physicians/surgeons or other actively practicing health care professionals; a group where this technology has been used much more commonly. The present manuscript was authored by anatomy educators, practicing physicians and other actively practicing health care professionals with backgrounds in diverse medical fields, that is, anatomists, medical doctors, physician assistants, dentists, occupational therapists, physical therapists, chiropractors, veterinarians, and medical students. Many of these authors have used or have been exposed to a Metaverse in the clinical realm. Therefore, the aim of the paper is to better understand those who are knowledgeable of a Metaverse and its use in anatomy education, and to provide ways forward for using such technology in this discipline.

The mastoid emissary vein (MEV) describes a transosseous connection between the sigmoid dural venous sinus and the suboccipital venous plexus. In cases of outflow stenosis or malformation, the MEV may become dilated and a source of pulsatile tinnitus (PT) amenable to treatment. We describe a case of PT secondary to MEV treated successfully via endovascular coil embolization and conduct a systematic review of the literature.We performed a systematic review without meta-analysis of studies involving management of dilated MEV on January 14, 2022, and describe a case of PT secondary to an enlarged MEV treated via coil embolization.A total of 13 studies were selected for full review. Reports identified MEV presenting as PT in 60% (12 of 20) of cases, intraoperative hemorrhage in mastoid surgery in 15% (3 of 20), a compressive scalp mass in 10% (2 of 20), and thrombophlebitis, facial swelling, or an incidental finding in 5% (1 of 20) each. Forty-five percent (9 of 20) underwent treatment, with all experiencing symptom resolution or improvement. Surgery included transvenous coil embolization in 33.3% (3 of 9), flap reconstruction in 22.2% (2 of 9), and surgical packing, ligation, and thrombectomy in 11.1% (1 of 9) each. Dilated MEV was reported concurrently with impeded drainage pathways in 35% (7 of 20) of reports.Dilated MEV has been reported as an etiology of pulsatile tinnitus and appears amenable to treatment via open and endovascular means. Endovascular coil embolization appears to offer effective symptom resolution, however, available literature exists only in case reports and small series. Further investigation is highly warranted.

Posterior costotransversectomy in the thoracic spine is commonly used for degenerative diseases, tumors, trauma, and other operative indications. It involves resection of the rib head after the ligamentous complexes have been disconnected from the transverse process and lateral vertebral body. The current literature provides only vague descriptions of the steps involved in rib disconnection with respect to posterior costotransversectomy.Through cadaveric studies and in vivo application, a stepwise method for rib disconnection is described.This manuscript is the first to outline an anatomical method for rib disconnection during costotransversectomy.

Approaches to the jugular foramen can be challenging. Adding to this difficulty is the potential for a bony septation to occur in the foramen thus subdividing its contents. Although such bony septations in the jugular foramen are known, the anatomic details of these structures have not been studied well. Therefore, the present anatomic study was performed.One hundred adult human skulls (200 sides) underwent evaluation for the presence or absence of a bony septation within the jugular foramen. The source, morphology, and size were all documented. A classification scheme was developed to better describe the varied types of morphology of the jugular foramen bony septa. Select bony septations were submitted to histologic analysis using hematoxylin and eosin and Masson's trichrome.Bony bridges were found on 8.5% of sides. These were bilateral in 3% of skulls. Eight (47%) were incomplete (type I). Nine sides (53%) were found to have completely articulated bony bridges (type II) and these had articulation between the bony processes as either touching (type IIa), joint-like (type IIb), or completely fused (type IIc) morphologies. Multiple septa were observed on 2.5% of sides and these were classified as type III septa. Histologically, both incomplete and complete septa were found to be composed of normal bone tissue.Our study found significant variations regarding the bony septa of the jugular foramen. Knowledge of this anatomy can be useful for preoperative planning and intraoperative navigation with approaches to the skull base that target pathology of the jugular foramen.

Chest computed tomography (CT) has been the preferred imaging modality during the pandemic owing to its sensitivity in detecting COVID-19 infections. Recently, a large number of COVID-19 imaging datasets have been deposited in public databases, leading to rapid advances in COVID-19 research. However, the application of these datasets beyond COVID-19-related research has been little explored. The authors believe that they could be used in anatomical research to elucidate the link between anatomy and disease and to study disease-related alterations to normal anatomy. Therefore, the present study was designed to investigate the prevalence of six well-known anatomical variants in the thorax using open-access CT images obtained from over 1000 Iranian COVID-19 patients aged between 6 and 89 years (60.9% male and 39.1% female). In brief, we found that the azygos lobe, tracheal bronchus, and cardiac bronchus were present in 0.8%, 0.2%, and 0% of the patients, respectively. Variations of the sternum, including sternal foramen, episternal ossicles, and sternalis muscle, were observed in 9.6%, 2.9%, and 1.5%, respectively. We believe anatomists could benefit from using open-access datasets as raw materials for research because these datasets are freely accessible and are abundant, though further research is needed to evaluate the uses of other datasets from different body regions and imaging modalities. Radiologists should also be aware of these common anatomical variants when examining lung CTs, especially since the use of this imaging modality has increased during the pandemic.

The aim of the present case is to describe an interesting variation of the additional head of the rectus femoris.A male body donor, 81 years old at death, was subjected to routine anatomical dissection for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland.We have found an example of an accessory head of the quadriceps femoris, a double-headed rectus femoris in which the proximal attachment is connected to the rectus femoris muscle originating from the anterior inferior iliac spine. The muscle belly of this additional structure is separate but fused distally with the vastus lateralis muscle. It then passes into the patellar ligament inserted into the tibial tuberosity.Knowledge of the possible occurrence of an additional head is nevertheless important for clinicians, especially for orthopedists performing reconstructive surgeries. It could also be significant for physiotherapists arranging rehabilitation plans after such surgeries because it could potentially help to achieve faster recovery.

The aim of this study is to demonstrate the relationship between the proximal attachment of the coracobrachialis muscle and the short head of the biceps brachii and the distal attachment of the pectoralis minor. Their correlation with the bifurcated coracoid process (CP) will be also assessed. On the basis of these observations, a new classification of structures attached to the coracoid process is proposed. Classical anatomical dissection was performed on one hundred forty-five upper limbs. Three types of relationship between the coracobrachialis muscle and the short head of the biceps brachii were observed in the cadavers. In type I (occurring in 54%), the coracobrachialis and the short head of the biceps brachii created a common junction attached to a single CP. Type II was divided into two subtypes (a and b). Subtype IIa (frequency 10%) was represented by independent proximal attachments of the short head of the biceps brachii and the coracobrachialis muscles to the CP. In subtype IIb (frequency 5%), the coracobrachialis muscle was two-headed (the first head located under the second) and not connected to the short head of the biceps brachii; all heads were attached to a single CP. Type III (frequency 31%) was characterized by a two-headed coracobrachialis muscle, the first head originating from a bifurcated CP laterally to the short head of the biceps brachii and the second medially to this structure. Different variations connected with the mentioned structures could be problematic for surgeons during operations, so detailed knowledge of them could contribute to more efficient procedures.

We have described a novel nerve plexus of the upper neck. By exploring how the individual components of this specific anterolateral nerve plexus communicate with each other, patient care could be improved regarding the preoperative diagnosis, intraoperative navigation, and minimally invasive treatment.Using a surgical microscope, 11 adult cadaveric heads (22 cadaveric hemi-sides) were dissected. The region of the junction between the atlanto-occipital and craniocervical junctions was explored, specifically, the innervation of this region via adjacent nerve connections. Branches from these regional nerve sources were analyzed for interconnections, and, when found, these branches were documented and measured.A delicate nerve plexus was found overlying the anterolateral C1-C2 junction in all specimens. The plexus was contributed by the sympathetic trunk, vagus nerve, hypoglossal nerve, and C1 and C2 ventral rami. We termed this plexus the anterolateral cervical atlanto-occipital (ALCAO) plexus. On all but 2 cadaveric hemi-sides (91%), the C2 ventral ramus provided the most input into the plexus, with 1-2 branches. On 2 cadaveric hemi-sides, the C1 ventral ramus was the primary contributor and, on average, this nerve contributed 1-2 branches to the plexus. For 8 cadaveric hemi-sides (36.4%), the C1 fibers that are known to travel with the hypoglossal nerve and be distributed to the geniohyoid and thyrohyoid muscles arose from C1 nerve fibers that first traversed the ALCAO plexus. The sympathetic trunk contributed 1-4 lateral branches, with most of these arising superiorly from the superior cervical ganglion. The vagus nerve contributed 1-2 lateral branches and the hypoglossal nerve contributed 1-2 anteromedial branches. This plexus was located more or less lateral to the sympathetic trunk and superior cervical ganglion and medial to the transverse process of C1 and C2. The plexus innervated the rectus capitis lateralis, rectus capitis anterior, and lateral atlanto-occipital joint and, on 4 cadaveric hemi-sides, the atlantoaxial joint. Additionally, small branches were seen traveling to the anterior atlantoaxial and anterior atlanto-occipital membranes on 55% and 77.2% of the cadaveric hemi-sides, respectively. On 6 hemi-sides, very small branches from the ALCAO plexus ended in the periosteum over the anterolateral aspect of the anterior arch and transverse process of the C1 vertebra.It is important to recognize that the course of these interneural connections varies and could result in unforeseen complications during surgical procedures. A comprehensive knowledge of these neural connections will be useful when considering surgery and evaluating pathology of the neck and skull base.

The eponymous term torcular Herophili has been used for the confluence of sinuses. Although no original writings of Herophilus are extant, his accomplishments and descriptions live on in the writings of such authors as Galen. However, in regard to the torcular Herophili, there are some inconsistencies in the secondary sources and their translations regarding what was actually originally described by Herophilus. Herein, we review the history of the term torcular Herophili, which is so often used in clinical medicine.

The venous plexus (internal carotid venous plexus) surrounding the petrous part of the internal carotid artery (ICAp) is said to be one drainage pathway of the cavernous sinus. These veins have many potential clinical implications including iatrogenic hemorrhage during surgical approaches to the skull base and carotid-cavernous fistulas. Because there are few morphological data about this venous plexus at the skull base, this descriptive/quantitative study was performed to elucidate its anatomy.Six latex-injected cadaveric heads (twelve sides) were dissected via a superior craniotomy approach in which the ICAp was exposed by drilling away the overlying bone. A venous plexus surrounding parts of the ICAp in all sides was documented along with the positions of its major tributaries and their connections.The veins were most concentrated near the junction of the ICAp and the cavernous part of the internal carotid artery, and usually along the medial and lateral sides of the ICAp. Tributaries included branches joining the basilar venous plexus posteriorly and branches joining the veins surrounding the foramen ovale anteriorly.Detailed knowledge of the anatomy of this venous plexus surrounding the ICAp is useful for interpreting imaging of the skull base and valuable for surgeons operating in this part of the cranium.

The hallmark of evidence-based medicine is the meta-analysis (MA). For much of its rich history, the field of anatomy has been dominated by descriptive, cadaveric studies. In the last two decades, quantitative measurements and statistical analyses have frequently accompanied such studies. These studies have directly led to the publication of anatomical MAs, which have ushered in the exciting field of evidence-based anatomy. Although critical appraisal tools exist for clinical MAs, none of them are specifically tailored for anatomical MAs. Therefore, the purpose of this article is to provide a framework by which clinical anatomists and others can critically appraise anatomical MAs using the Critical Appraisal Tool for Anatomical Meta-analysis (CATAM). Using a running example from a recently published MA, we show how to use the CATAM rubric in a step-by-step fashion. Each scored section of the CATAM rubric is summated into a total score (maximum 50 points). This score is then referenced to a conversion chart, which assigns a qualitative value to the MA in a range from "very good" to "poor." Future studies can investigate the interrater reliability of the instrument, and possibly subject the CATAM rubric to a Delphi panel. As anatomical MAs become more commonplace at surgical grand rounds and journal clubs in academic medical centers throughout the world, we hope that the CATAM rubric can help facilitate meaningful discussions about the quality and clinical relevance of anatomical MAs.

The pectoralis major and pectoralis minor muscles are located in the anterior chest wall. This region is characterized by high morphological variability. During dissection an additional muscle was found, originating from the lateral border of the pectoralis major muscle. After fusion it passed into the tendinous part coursing under the insertion of the pectoralis major muscle, then formed a common junction with the short head of the biceps brachii muscle, the distal attachment of which is on the coracoid process. Such an accessory structure could lead to neurovascular compression and cause thoracic outlet syndrome, of which pain is usually the first symptom. This muscle has not been described in the literature so far and for that reason we can name the present case as an unique structure.

Hakuba's triangle is a superior cavernous sinus triangle that allows for wide and relatively safe exposure of vascular and neoplastic lesions. This study provides cadaveric measurements of the borders of Hakuba's triangle and describes its neurovascular contents in order to enrich the available literature. The anatomical borders of the Hakuba's triangle (lateral, medial, and posterior borders) were defined based on Hakuba's description and identified. Then the triangle was dissected to reveal its morphology and relationship with adjacent neurovascular structures in Embalmed Caucasian cadaveric specimens. The oculomotor nerve occupied roughly one-third of the area of the triangle and the nerve was more or less parallel to its medial border. The mean lengths of the lateral border, posterior border, and medial border were 17 mm ± 0.5 mm, 12.2 mm ± 0.4 mm, and 10.6 mm ± 0.4 mm, respectively. The mean area of Hakuba's triangle was 63.9 mm

Brain herniation is one of the most feared complications of many neurological pathologies. However, current understanding of the mechanisms behind brain herniation syndromes is poor. By investigating the correlations between raised intracranial pressure (ICP) and herniation of the cerebellar tonsils, we hope to develop a model that can be used to study intracranial fluid dynamics and its effects on brain tissue. This will facilitate evaluation of patients with elevated ICP and development of novel treatments including surgical approaches for decompressing the posterior cranial fossa and upper cervical spine. A standard suboccipital surgical approach was used to expose the foramen magnum and observe movements of the cerebellar tonsils in fresh cadavers. A urinary Foley catheter balloon in the parietal extradural space was used to simulate a mass effect while ICP was monitored. The baseline anatomy differed widely among the cadaver specimens. However, and overall, we found that as ICP rises, the cerebellar tonsils descend through the foramen magnum at a rate of 0.3 mm per 1 mmHg increase in ICP. A mean descent of 6.2 mm was observed for a mean ICP increase of 17 mmHg. In this cadaveric study, we present a method and model for exploring brain herniation syndromes in the context of ICP changes. This could allow for further models to study the effects of other neuropathologies on the cerebellar tonsils, including posterior cranial fossa mass lesions and cerebellar hemorrhage.

Although superior gluteal nerve (SGN) injury can have significant morbidity, to date, surgical strategies for its repair are scant in the literature. Specifically, neurotization options have not been explored. To address this deficiency in the literature, the current cadaveric feasibility study was performed. Via a transgluteal approach on 16 cadaveric sides, the proximal sciatic nerve and the entrance of the SGN into the gluteus medius and minimus were identified. Additionally, branches from the sciatic nerve to the hamstring muscles were traced proximally to confirm their position in relation to the sciatic nerve as a whole. These branches were cut at the level of the ischial tuberosity and teased away from the sciatic nerve proximally to the greater sciatic foramen and transferred superolateral to the SGN. The diameter of each nerve branch was measured as well as its available length for reaching the SGN. All branches of the sciatic nerve to the hamstring muscles arose from the anteromedial part of the nerve. The mean diameters of the branches to the semimembranosus, semitendinosus, and biceps femoris muscles were 2.1, 1.9, and 1.5 mm, respectively. The mean diameter of the SGN was 3.1 mm and the mean distance from this entrance point to the ischial spine was 7.2 cm. The mean length of the donor nerve was 8.5 cm. Based on our study, use of a tibial-innervated hamstring branch as a donor for nerve transfer to the SGN is feasible.

PURPOSE Since cone-beam computed tomography was developed, a number of radiological studies on the bifid mandibular canals (BMCs) and trifid mandibular canals (TMCs) have been reported. However, many of the suggested subtypes of the BMC described in the literature seem to be normal branches of the inferior alveolar nerve. This might be due to a lack of revisiting classic anatomical studies in the field of radiology. Therefore, such studies are revisited here. METHODS A database search using PubMed and Google Scholar was conducted on BMC and TMC. Eighty-nine articles underwent full-text assessment. The reported three classifications of BMC and the six modified classifications were reviewed and compared to the intramandibular inferior alveolar nerve branches. RESULTS Some subtypes of BMC and TMC simply represent normal inferior alveolar nerve branches, i.e., retromolar branch, molar branch (alveolar branch/dental branch), large mental branch, or communicating branch. Others such as Naitoh's type III BMC and forward canal might be a true BMC. CONCLUSION We found that the bifid mandibular canal is an additional intramandibular canal running parallel to the mandibular canal with/without confluence with the main canal through comparison of classifications of BMC/TMC between the radiology and anatomy fields.

Background Stereoelectroencephalography (sEEG) is an increasingly popular surgical technique used clinically to study neural circuits involved in medication-refractory epilepsy, and it is concomitantly used in the scientific investigation of neural circuitry underlying behavior. Methods Using PRISMA guidelines, the U.S. National Library of Medicine at the National Institutes of Health PubMed database was queried for investigational or therapeutic applications of sEEG in human subjects. Abstracts were analyzed independently by 2 authors for inclusion or exclusion. Results The study search identified 752 articles, and after exclusion criteria were applied, 8 studies were selected for in-depth review. Among those 8 studies, 122 patients were included, with indications ranging from schizophrenia to Parkinson disease. All the included studies were single-institution case series representing level IV scientific evidence. Conclusions sEEG is an important method in epilepsy surgery that could be applied to other neurologic and psychiatric diseases. Information from these studies could provide additional pathophysiologic information and lead to further development and refinement of neuromodulation therapies for such conditions.

Background The veins and dural venous sinuses of the skull base are important to understand in terms of imaging findings, diagnoses, and surgery. However, to date and to the best of our knowledge, the transosseous veins of the petrous part of the temporal bone have not been studied. Methods Ten latex-injected adult cadaveric specimens (20 sides) were dissected to identify the intraosseous and transosseous veins. The petrous part of the temporal bone was drilled away, and the petrous part of the internal carotid artery and the veins of the middle and posterior cranial fossa adjacent to the petrous part of the temporal bone were exposed. Results Transosseous veins traveling through the petrous part of the temporal bone were identified on all 20 sides. In general, these were most concentrated near the anterior and posterior parts of the petrous part of the temporal bone. Most traveled more or less vertically from the petrous ridge and related superior petrosal sinus internally through the petrous part of the temporal bone toward the inferior petrosal sinus or horizontally, uniting the veins of the floor of the middle cranial fossa with the veins of the posterior cranial fossa. These transosseous veins connected the veins in the middle cranial fossa with the veins of the posterior cranial fossa. Most (70%) of these transosseous veins were also found to have small connections to the internal carotid venous plexus. Conclusions To the best of our knowledge, previous studies have not reported on transosseous veins of the temporal bone or described their anatomy of connecting the veins of the middle and posterior cranial fossae.

The supracondylar process is a nonpathological projection from the distal humerus that in some patients, can result in compression of regional neurovascular structures, for example, median nerve. Since the first description of the supracondylar process in 1818, it has also been a focus of anthropological study because of its possible relevance to human origins and relationships to other species. Although its overall incidence is low, it is more common in races of European descent. It is particularly interesting for anatomists and anthropologists, but knowledge of its anatomical relationships and effect on pathological processes helps in the diagnosis and treatment of supracondylar process syndrome. One of the most detailed descriptions of this variant process stems from the work of Buntaro Adachi. Herein, a translation of his findings is provided and a review of the supracondylar process and its potential pathological presentations presented.

Introduction In this review, cases of herpes zoster (HZ) infection following receipt of COVID-19 vaccines will be analyzed. We also present two cases of oral HZ following the COVID-19 vaccine and discuss this clinical anatomy. Materials and methods A database search using PubMed was conducted in August 2021 and twenty articles were found to be eligible for review. Patient data and vaccine information were analyzed. In addition, two cases of oral HZ infection following the receipt of COVID-19 vaccines are presented. Results A total of 399 cases were identified. The affected dermatomes mimicked the regular distribution of HZ. For the dermatomes of the face, the various reports used different ways to describe the areas involved; CNV, CNV1, CNV2, CNV3, lower jaw, forehead, and under the eyebrow (CNV, 2 cases; CNV1, 4 cases; CNV2, 3 cases; CNV3, 3 cases). Some patients who had a history of varicella zoster virus (VZV) vaccination had HZ following the COVID-19 vaccination. Two patients with oral HZ following vaccination were found to have involvement of the greater palatine nerve. Conclusions Vaccine-related HZ cases have been reported worldwide. Although many studies with a larger number of cases are ongoing, detailed information can be obtained from case reviews as reported herein. This article is protected by copyright. All rights reserved.

Acting in medial rotation of the arm, the subscapularis (SM) is the most powerful and largest muscle of the rotator cuff. It is morphologically variable, especially in the number of tendons, place of insertion, and number of bellies, and it is sometimes fused with another muscle. An accessory subscapularis muscle (ASM) is among the morphological variations of the SM, but it is a really rare variant. The present case describes a very rare ASM that is divided into proximal tendinous attachment, intermediate fleshy muscular belly and distal tendinous attachment. Its origin is located on the lateral border of the scapula, but some fibers are connected with the muscular part of the SM. Its distal attachment is fused with the capsule of shoulder joint, above the tendinous insertion of the SM. Such an arrangement allows for greater stabilization of the joint. Moreover, there is a possibility that it could be used during treatment of ruptured SM tendons.

We aimed to localize the pharyngeal branches of the pharyngeal plexus to preclude postoperative complications such as dysphagia resulting from injury to those branches. Cranial nerves IX and X and the sympathetic trunk were dissected on 10 sides in the necks of embalmed adult cadavers of European descent to identify the pharyngeal branches so that anatomical landmarks could be identified and injury thereby avoided. In all sides, the pharyngeal branches originated from the glossopharyngeal and vagus nerves and the superior cervical ganglion and entered the posterior pharyngeal wall at the C2-C4 levels within 10 mm medial to the greater horn of the hyoid bone. All pharyngeal branches were anterior to the alar fascia. Based on our anatomical study, vagus nerve branches to the pharyngeal muscles enter at the C3/C4 vertebral levels. Such knowledge might help decrease or allow surgeons to predict which patients are more likely to develop dysphagia after cervical spine surgery.

Background: The fibular collateral ligament is a permanent and extracapsular ligament of the knee joint. It is located on the lateral aspect of the knee and extends from the lateral epicondyle of the femur to the lateral surface of the head of the fibula. As one of the main knee joint ligaments it is a stabilizer of the posterolateral corner of the knee and resists varus stress. The case report displays the bifurcated variant of the fibular collateral ligament. The aim of this study is to determine which of those bands should be considered dominant. Materials and methods: Classical anatomical dissection was performed on the left knee joint. The fibular collateral ligament was thoroughly cleansed around its origin, distal attachments, and course. Appropriate morphometric measurements were collected. Results: A bifurcated variant of the fibular collateral ligament with inverted proportions of its two bands (main and accessory one) constitutes our findings. It originated on the lateral epicondyle of the femur. Then it divided into two bands (A1 and A2). Band A1 inserted to the head of the fibula. A bony attachment of band A2 was located on the lateral aspect of the lateral condyle of the tibia. Conclusions: Although the fibular collateral ligament is a permanent structure it presents morphological variations. It is important to constantly extend morphological knowledge for all scientists concerned in anatomy.

An elongated coronoid process (ECP) can lead to impingement of the coronoid process on the body or arch of the zygomatic bone when opening the mouth. The etiology of ECP is unclear, but several theories have been postulated. We present a case of an ECP found in a 63-year-old in a Caucasian cadaveric specimen. The length of the coronoid process was 26.6 mm on the left side and 26.3 mm on the right side. To our knowledge, this is the longest coronoid process reported in the extant literature. The details of this case and the clinical significance are discussed.

The sacroiliac joint is a diarthrodial synovial joint in the pelvis. Anatomically, it is described as a symphysis, its synovial joint characteristics being limited to the distal cartilaginous portion on the iliac side. It is a continuous ligamentous stocking comprising interconnecting ligamentous structures and surrounding fascia. Its ligaments, the primary source of its stability, include the anterior, interosseous and dorsal sacroiliac, the iliolumbar, sacrotuberous, and sacrospinous. Structural reinforcement is also provided by neighboring fascia and muscles. Lower back pain is a common presentation of sacroiliac joint disease, the best-established treatments being corticosteroid injections, bipolar radiofrequency ablation, and sacroiliac joint fusion.

The COVID-19 pandemic has brought difficult times to anatomy educators and medical/dental students. Under normal circumstances, gross anatomy classes give students opportunities to touch and observe human bones and cadaveric tissues, thus enhancing their understanding; such morphology is difficult to learn from textbooks alone. As many studies have shown, three-dimensional (3D) technologies used in online lectures can serve as alternatives to real specimens for providing knowledge of anatomy. However, such technologies are often expensive. The goal of this study was to create 3D anatomy models for online lectures using a free cellphone app. Free application software (Qlone) was used to create 3D anatomical models. The extracranium and intracranium of adult skull, fetal skull, mandible, temporal bone, second cervical vertebra, and ilium were all scanned and exported to the computer in 3D format. A total of 53 anatomical structures were evaluated by nine observers. Although the 53 structures used in this study did not include all the structures that students need to learn, visibility was good/acceptable for most of the 53. The free and simple 3D scanning app used in this study could enable anatomy educators to provide better content to students during online lectures.

Introduction The general principles of anatomical terminology indicate that the "mandibular canal" should be named the "inferior alveolar canal" as it accommodates the inferior alveolar neurovascular bundles. Therefore, we performed a Delphi study to evaluate the current understanding and use of the terminology in different geographical regions and areas of expertise and to determine the appropriate terminology for this bony canal. Methods A Delphi panel was formed and questions sent and answered via email about: field of expertise (anatomy, oral surgery/oral and maxillofacial (OMF) surgery, oral radiology/OMF radiology, plastic surgery, ENT surgery, or dentistry with the exception of oral/OMF surgery and oral/OMF radiology), years of experience in the field of expertise, country currently working in, "what is the name of the bony canal that contains the inferior alveolar neurovascular bundle," and "what should the structure above be called, in general?" Results A total of 52 participants responded to the questionnaire. Half or more of the experts in anatomy, oral/OMF surgery, and ENT/Plastic surgery considered "mandibular canal" to be the most appropriate name for this bony canal. In contrast, more than half of all experts in oral/OMF radiology and dentistry, i.e., most fields of dentistry, considered "either mandibular canal or inferior alveolar canal" to be the appropriate name. Conclusions The results of the Delphi study and general principles suggest that an alternative term for the "mandibular canal" should be "inferior alveolar canal." This article is protected by copyright. All rights reserved.

Background The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically. Methods We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata. Results All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted. Conclusions Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.

Shoulder pathology is a very common medical presentation and can be due to anatomical variations. Therefore, knowledge of variants is important for the clinician treating patients with such complaints so that misdiagnosis is minimized and iatrogenic injury prevented. A review of the literature was performed of the variant anatomy of the pectoralis minor muscle. The aim of this review is to better inform clinicians who might treat patients with shoulder pathology so that if identified, variants of the pectoralis minor muscle are better appreciated.

Background Posterior cervical approaches for atlantoaxial and craniovertebral junction pathologies with or without instrumentation are often associated with excessive soft tissue dissection and bleeding consequent with disruption of the venous plexus. A few minimally invasive approaches to this region have been reported from clinical and cadaveric studies in an effort to minimize blood loss, reduce soft tissue dissection, and decrease postoperative pain; however, unilateral minimally invasive approaches have not been described. Here, we describe a minimally invasive atlantoaxial and craniovertebral approach. Methods Using fresh cadavers, we performed a novel, right-sided, muscle-sparing minimally invasive C1-C2 laminotomy with laminoplasty for access to the atlantoaxial level and craniovertebral junction and used the traditional approach on left sides. Results Using this approach, the atlantoaxial space and craniovertebral junction with wide and generous exposure via unilateral soft tissue dissection and muscle splitting was achieved. After exposure, the musculoosseous unit was easily repositioned, thus allowing for C1-C2 laminoplasty. Grossly, no damage to the vertebral artery or regional nerves was noted. Conclusions We present a novel, unilateral minimally invasive approach to reach the atlantoaxial and craniovertebral junction. This could allow for faster postoperative recovery, less pain and opioid requirement, and increased maintenance of atlantoaxial stability. Such a technique, after being confirmed in patients, could optimize this surgical technique.

Sacral fractures are often underdiagnosed but are relatively frequent in the setting of pelvic ring injury. Causes include traumatic insults and osteoporosis. Sacral fractures have become more frequent owing to the growth of the elderly population worldwide as osteoporosis is an age-related disease. Misdiagnosed and neglected sacral fractures can result in chronic back pain, spine deformity, and instability. Unfortunately, the wide range of classification systems hinders adequate communication among clinicians. Therefore, a complete understanding of the pathology, and communication within the interdisciplinary team, are necessary to ensure adequate treatment and satisfactory clinical outcomes. The aim of this manuscript is to present the current knowledge available regarding classification systems, clinical assessment, decision-making factors, and current treatment options.

Background/Objective Hydatid disease of the aorta is very rare. Hydatid disease can result in saccular aneurysm of the thoracic and abdominal aorta. Case report We report a rare case of saccular aneurysm of the distal descending thoracic aorta. The diameter of the aneurysm was 60 mm. It was managed by Thoracic Endovascular Aneurysm Repair. After 41 months, computed tomography angiography revealed a multi-loculated cystic lesion with 86 × 83×80 mm dimensions in the prevertebral area at the T10-T11 level with bony destruction and erosion of the anterior margin of the vertebral bodies. A computed tomography-guided fine-needle aspiration of the paravertebral cystic lesion was performed. Microscopic study of the fine-needle aspiration specimen demonstrated Echinococcosis granulosus diagnostic of hydatid disease. Conclusion It is concluded that the case was a mycotic aneurysm of the thoracic aorta secondary to vertebral hydatid disease.

The COVID-19 pandemic and mandatory social distancing has brought challenges to anatomy educators who generally need in-person classes. The purpose of this study is to share the experience of a distant online lecture on a surgical procedure and related anatomy in a three-dimensional (3D) virtual reality (VR) workspace and to compare it with reported teaching methods, that is, an in-person class and a Zoom online class. The lecture was delivered by three authors of this article in a VR workspace that enables people to meet through VR. The lectures were about combinations of dental surgical procedures and related clinical anatomy. Physically, the attendees could have been located anywhere in the world, so lecturers joined from the United States and the attendees were all from Japan. VR environment and its flexibility enabled attendees to join the lecture actively, helping them to gain understanding of the surgical procedure and anatomy more efficiently. The use of VR technology with a live communication tool demonstrated in this study has several advantages over previous education methods, although there are still technical issues or disadvantages that need to be addressed. Development of the technology and app/software is required so that more data can be processed at higher speed. Use of VR technology with a live communication tool could be an alternative teaching method. Its overall advantages are a closer look at the slides/monitor and concurrent observation of the multiple assets in various directions by multiple attendees. These advantages cannot be achieved by any other teaching method without VR assets with the workspace provided by Spatial. Even during the mandatory social distancing due to the COVID-19 pandemic, this could enable us to foster 3D understanding of surgery and related anatomy. Further study is now needed to evaluate the effectiveness of this newly proposed teaching method by comparing it with traditional in-person and online classes with a live communication tool.

Objective The aim of this study was to define the structural relationship between the arcuate eminence (AE) and a known fixed external bony landmark, the root of the zygoma (ZR), and to determine its reliability as a consistent guide for guiding surgical approaches. To our knowledge, this is the only anatomical study to quantify the relationship between the AE and the ZR. Method Twenty-one dry temporal bones were measured using digital calipers. The distance from the posterior aspect of the ZR to the midpoint of the AE was measured. Additionally, the anteroposterior distance between the ZR and AE and vertical distance between the two structures were measured. Student's t-test was used to compare the left and right sides. Result An AE was found in every specimen. The mean ZR to AE distance was 30.9 mm. On most sides (91%), the ZR was located more inferiorly than the AE with a mean distance of 3 mm between the two structures. The mean distance between the AE and ZR was 17 mm. On all sides, the AE was located posterior to the ZR. No significant differences were found between sides. No anatomical variations or pathological conditions were noted in any of the specimens. Conclusion The ZR is an easily identifiable and consistent bony landmark often used by skull base surgeons. In this investigation, we measured the anatomical relationships between the ZR and AE. Such data might assist in planning surgical trajectories and minimizing complications when skull base pathologies are approached.

The venous drainage of the vertebral and paravertebral regions is important for a better understanding of hematogenous disease spread. Moreover, the spine surgeon must be well acquainted with this anatomy to minimize intraoperative and postoperative complications. A comprehensive review of the vertebral venous plexus (Batson plexus) was performed with a concentration on the clinical and surgical correlations of this venous network.

As the median nerve enters the carpal tunnel, it is a single nerve that soon bifurcates into lateral and medial branches into the hand. If the bifurcation is proximal to the carpel tunnel, a bifid median nerve (BMN) results. Carpal tunnel syndrome is often associated with a BMN with or without a persistent median artery. Individual keywords and MeSH phrases were searched in the Google Scholar, SCOPUS, and PubMed databases. Full texts were then collected and assessed for suitability. The prevalence of BMN at the wrist joint in normal and carpal tunnel syndrome wrists (precanal part) and the mean difference between groups were recorded. Only human data were used to test the findings. The pooled odds ratio (with minimal heterogeneity) was 1.50 [1.17-1.93, 95% CI]. The BMN cross-sectional area (CSA) was significantly greater than that of a solitary median nerve in normal wrists. The mean difference in CSA between the two was 1.50 mm

The interosseous crural nerve (IOCn) is said to arise distally from muscular branches of the tibial nerve innervating the deep muscles of the posterior compartment of the leg. Here, we present the results of a cadaveric study of the IOCn to clarify this nerve's morphology and to discuss its potential clinical relevance. On 26 sides from 13 cadaveric specimens, the IOCn was dissected. The IOCn was identified on 14 out of 26 sides (53.8%). The mean diameter and length of the IOCn were 0.46 mm (range 0.3-0.72 mm) and 20.9 mm (range 13.5-33.0 mm), respectively. The origin of the IOCn was from a branch to the popliteus muscle on all sides. The nerve was found to have vascular, muscular, and ligamentous branches. In 53.8%, the nerve reached the inferior tibiofibular joint, and in 46.2%, the nerve terminated in the interosseous membrane of the leg. At its distal part, the IOCn gave off multiple vascular branches to the fibular artery. On one side (7.1%), the nerve pierced the interosseous membrane and innervated muscles of the anterior compartment of the leg. We believe this to be the first anatomical study of the IOCn. The nerve was found to have vascular, muscular, and ligamentous branches. Surgeons operating in the deep posterior compartment of the leg and ankle and clinicians treating patients with unusual presentations or pathology of the leg and ankle should be aware of this structure.

Painful lesions on the plantar aspect of the first interphalangeal joint (IPJ) of the hallux can be attributed to structures called ossicles, nodules, or sesamoids. The aims of the present study were first to verify that ultrasonography (US) is a high-sensitivity tool for diagnosing an interphalangeal ossicle (IO), and second to prove that US-guided-shaving surgery (“milling”) is a safe and feasible technique for remodeling the IO. The study is divided into three parts. In the first part, the prevalence of IOs was estimated in 12 cadaver feet using US, anatomical dissection, and fluoroscopy. In the second, a detailed US and morphological description of the IO was obtained. In the third, six cadaver feet were subjected to surgical milling. IO prevalence was 41.6% in gross anatomy, 41.6% in US examination and just 16.6% in fluoroscopy. The ossicles had a mean length of 4 mm (± 2 mm) and a width of 7 mm (± 2 mm). The ossicles could be completely shaved in all specimens without injuring important anatomical structures. Our results indicate that US is a more precise tool for diagnosing an IO than X-ray. Moreover, our US-guided mini-invasive surgical technique appears feasible and safe.

Sufficient knowledge of anatomy is critical for oral and maxillofacial surgeons to provide the best treatment to their patients. The authors have recently established the "Clinical Anatomy Research Association in Oral and Maxillofacial Surgery." There is no doubt as to the benefits of collaboration between oral and maxillofacial surgeons/radiologists and anatomists. In this article, we share what was accomplished at the first annual online conference and discuss our mission for the future.

The plantaris muscle is located in the posterior aspect of the superficial compartment of the lower leg, running from the lateral condyle of the femur to the calcaneal tuberosity. Classically, it is characterized by a small and fusiform muscle belly, which then changes into a long slender tendon. From the evolutionary point of view, the muscle is considered vestigial. However, it has recently been suspected of being a highly specialized sensory muscle because of its high density of muscle spindles. It has a noticeable tendency to vary in respect of both origin and insertion. Researchers have published many reports on the potential clinical significance of the muscle belly and tendon, including mid-portion Achilles tendinopathy, ‘tennis leg syndrome’, and popliteal artery entrapment syndrome. The right knee joint area was subjected to classical anatomical dissection, during which an atypical plantaris muscle was found and examined in detail. Accurate morphometric measurements were made. The muscle belly was assessed as bifurcated. Morphologically, superior and inferior parts were presented. There was a tendinous connection (named band A) with the iliotibial tract and an additional insertion (named band B) to the semimembranosus tendon. Both bands A and B presented very broad fan-shaped attachments. The human plantaris muscle is of considerable interest and has frequent morphological variations in its proximal part. Its specific characteristics can cause clinical problems and lead to confusion in diagnosis. More studies are needed to define its actual features and functions.

Abu al-Qasim Al-Zahrawi (936-1013 common era [CE]), also known in the West as Albucasis, was a great Arab physician and surgeon of the late 10th and early 11th centuries CE. He is best known for his surgical knowledge and expertise. His greatest contribution to medicine is the Kitab al-Tasrif, which includes thirty treatises on medical sciences. His early and great contributions to the field of surgery were seminal. For his endeavors in this field, a number of surgeons and scholars have dubbed him the "Father of Operative Surgery".

Temporary external fixation has been widely utilized in the stabilization of plateau fractures while waiting for an optimization of the soft tissue conditions before subsequent permanent internal fixation. Simultaneously, MRI is beneficial in the assessment of concomitant damage to ligaments and menisci so that these injuries could be promptly identified, and surgical planning executed at the time of definitive fixation of the bony injury. Increasing numbers of side-bars and pins have been previously suggested to increase frame rigidity, but at the same time, several studies have indicated the presence of MRI artifacts which may obscure key anatomical structures, even when MRI-compatible fixation devices are used. This study aims to identify, among six potential configurations, the construct that maximizes stability while most minimizing the number of MRI artifacts generated among different configurations commonly used.There is one or more configurations among the others that maximize stability while preserving a clinically acceptable level of MRI quality.Six constructs were recreated on cadaveric specimens and identified by the disposition of the bars: H, Anterior, Flash, Hashtag, Rhomboid, and Diamond. Stage one evaluated the amount of artifact produced during MRI on instrumented cadaveric legs, as well as the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) at five specific regions of interest. Stage two assessed the amount of compressional and torsional stiffness of the configurations on bone surrogate models.Image artifacts were not detected within the knee joint for all considered constructs. In terms of SNR The H, Anterior, Hashtag, and Diamond configurations were not significantly different from their control (p0.366) while the others were significantly different (p0.03). The values of CNR found for the H and Hashtag configurations were not significantly different from their controls (p0.07) while the remaining configurations were significantly different (p0.03). In compression, the H and Diamond configurations had similar stiffness (p=0.468) of 35.78N/mm and 31.44N/mm, respectively, and were stiffer than the other configurations. In torsion, the constructs have shown different stiffness (p0.001) with a minimum value of 0.66 Nm/deg for the Rhomboid configuration, which was significantly less stiff than the Anterior configuration (1.20 Nm/deg [p0.001]). There was no difference between the Diamond and H configurations (p=0.177) or between them and the Hashtag configuration (p=0.215).An external fixator construct directly bridging the femur and tibia without interconnections is the most stable and produces MRI scans without image artifacts that would interfere with diagnostic quality.V, basic science study, diagnostic imaging and mechanical testing.

Lower third molar removal is the most commonly performed dental surgical procedure. Nevertheless, it is difficult to ensure that all the informed consent forms given to patients are based on the best evidence as many newer publications could change the conclusions of previous research. Therefore, the goal of this review article is to cover existing meta-analyses, randomized control trials, and related articles in order to collect data for improved and more current informed consent.

This second installment of The Effects of Obesity on the Human Body considers the nervous, respiratory, and lymphatic systems. Those with obesity face countless psychological hurdles in addition to the respiratory burden and widespread inflammation that can suppress the immune system, resulting in the accumulation of excess fluid in body tissues.

Obesity is a worldwide issue that many global health authorities consider a growing epidemic. Having a positive correlation between increases in the industrialization of processed foods and sedentary occupations as well as a lack of access to healthcare in poorer socioeconomic areas, obesity is a multifactorial disease affecting several organ systems. The tendency for obesity to cause detrimental changes to the human body is a focal point for healthcare providers to establish more effective clinical treatment and management plans. Implementing comprehensive global educational programs to decrease the prevalence of this unforgiving disease is imperative for a healthier future. Herein, we have provided a comprehensive review of the health effects of obesity upon the human body for the interest of many practicing clinicians managing this health crisis.

Previous work has noted that math anxiety may have a profound effect on math performance; however extant research has relied on measures that explicitly assess math anxiety. This study examined the effects of implicit math anxiety on the performance of a math achievement task. We hypothesized that combined measure of implicit anxiety and explicit anxiety would better predict math achievement than measures of explicit math anxiety alone. In addition, we hypothesized that an individuals’ measured implicit anxiety and measured explicit anxiety would share only a modest correlation. To test these hypotheses, 175 participants completed measures of explicit anxiety, an implicit associations test designed to measure implicit anxiety, and a measure of math achievement. As expected, math achievement was better predicted when implicit anxiety was combined with explicit anxiety. Furthermore, scores on the implicit and explicit anxiety measures were not significantly correlated. These results suggest that implicit and explicit math anxiety are two distinct constructs, thus traditional methods for helping students deal with math anxiety may not be entirely successful if the implicit component is ignored.