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The jugular foramen harbors anatomically complex bony, venous and neural structures. It is closely associated with small canals including the mastoid, tympanic, and cochlear canaliculi, and the stylomastoid foramen. The minute intraosseous branches of Arnold's and Jacobson's nerves (1 mm in length) remain difficult to study with current imaging techniques, so cadaveric dissection is the most reliable approach. Our aim was to examine the variations of Jacobson's and Arnold's canaliculi and nerves and to provide detailed cadaveric graphics. To reveal the anatomical structures of small canals around the jugular foramen, 25 sides of dry skulls and 14 sides of cadaveric heads were examined. Intraosseous branches varied more in Arnold's nerve than Jacobson's nerve. In our cadaveric dissection, all specimens formed a single canal for Jacobson's nerve connecting the jugular foramen to the tympanic cavity. The intraosseous course of Arnold's nerve varied in its communication with the facial nerve. A descending branch crossing the facial nerve was identified in five of 14 sides, an ascending branch in 13. In two specimens, an ascending branch clearly reached the base of the stapedius muscle. Classical anatomical studies of cadavers remain a supplementary tool for analyzing these tiny structures. The present study confirms Gray's findings of 1913. Variations of these nerves could be even more complex than previously reported. Our study provides additional information regarding the anatomy of Jacobson's and Arnold's nerves. This article is protected by copyright. All rights reserved.

The lateral ulnar collateral ligament (LUCL) is considered one of the main stabilizers of the elbow. However, its anatomical description is not well established. Imaging techniques do not always have agreed upon parameters for the study of this ligament. Therefore, herein, we studied the macro and microanatomy of the LUCL to establish its morphological and morphometric characteristics more precisely.Fifty-five fresh-frozen human elbows underwent dissection of the lateral collateral ligament. Morphological characteristics were studied in detail. US and MR were done before dissection. Two specimens were selected for PGP 9.5S immunohistochemistry. Ten additional elbows were analyzed by E12 sheet plastination.LUCL was identified in all specimens and clearly defined by E12 semi-thin sections. It fused with the common extensor tendon and the radial ligament. The total length of the LUCL was 48.50mm at 90°, 46.76mm at maximum flexion and 44.10mm at complete extension. Three morphological insertion variants were identified. Both US and MR identified the LUCL in all cases. It was hypoechoic in the middle and distal third in 85%. The LUCL was hypointense on MR in 95%. Free nerve endings were present on histology.The LUCL is closely related to the anular ligament. It is stretched during flexion and supination. US and MR can reliably identify its fibers. Anatomical data are relevant to the surgeon who repairs the ligaments of the elbow. Also, to the radiologist and pain physician who interpret imaging and treat patients with pain syndromes of the elbow.

Most of the studies of the mandible's anatomical variations have presented the authors' speculations, and only a limited number has provided evidence that demonstrated the actual complications injury to the variant structures caused. To our knowledge, no study has evaluated the risks associated with these variant anatomical structures' injury. We reviewed articles that described clinical cases of the injury to, and anatomical studies of, three anatomical variants of the mandible-the accessory mental, lingual, and retromolar foramina-with which dentists are relatively familiar and that are mentioned often in the context of implant and third molar surgeries, to describe risk assessment methods with which to evaluate potential complications preoperatively. Only a limited number of the clinical reports of injury to the mandible's accessory foramina were available. The potential severe complication of injury of the accessory mental foramen (AMF) is sensory disturbance of the lower lip. Risk of neurosensory disturbance of lower lip can be assessed by AMF/MF ratio and positional relations to the MF. Potential severe complication of injury of the lingual foramen is bleeding and hemorrhage in the oral cavity's floor. Risk of bleeding can be assessed by diameter and positional relation between the mental spine/mylohyoid line. A risk assessment of the retromolar foramen could not be made because of inadequate data. We hope the risk assessments suggested will encourage dentists to predict intraoperative/postoperative complications caused by damaging the mandible's accessory foramina. Clin. Anat. 32:672-677, 2019. © 2019 Wiley Periodicals, Inc.

Air insufflation has been used for various surgical procedures such as during laparoscopy. We hypothesized that the use of pressurized air might enable cadaveric dissection to differentiate smaller veins better than traditional dissection techniques. In three fresh-frozen cadavers, the inferior vena cava (IVC) and right or left femoral veins were exposed just distal to the inguinal ligament and a needle placed into one of them. Pressurized air was then placed into the cannulated femoral vein using an air compressor. In all specimens, the IVC and most of its tributaries, both left and right sides, were clearly insufflated. When the IVC was traced superiorly by resecting the diaphragm through the caval foramen, the right atrium and ventricle were also found to be dilated. Additionally, venous variants that would have not been obvious without dilatation of the IVC were identified. Air dissection of the venous system in fresh-frozen cadavers aids in anatomical dissection. Such a model might also serve as a surgical training model and teaching tool as it better mimics life-like anatomy and physiology. We term this technique "cadaveric air dissection." Clin. Anat. 32:566-572, 2019. © 2019 Wiley Periodicals, Inc.

The genitofemoral nerve is a branch of the lumbar plexus originating from the ventral rami of the first and second lumbar spinal nerves. During routine dissections of this nerve, we have occasionally observed that the genital branch of the genitofemoral nerve gave rise to the femoral branch, and the femoral branch of the genitofemoral nerve gave rise to the genital branch. Therefore, this study aimed to investigate the aforementioned distributions of the genitofemoral nerve in a large number of cadaveric specimens. Twenty-four sides from fourteen fresh-frozen cadavers derived from nine males and five females were used in this study. For proximal branches of the genitofemoral nerve, that is, as they first arise from the genitofemoral nerve, the terms "medial branch" and "lateral branch" were used. For the final distribution, the terms "genital branch" and "femoral branch" were used. On eight sides (33.3%) with nine branches, one or two branch(s) from either the medial or lateral branch became coursed as the femoral or genital branches (five became femoral and four became genital branches). Our study revealed that the distribution of the genitofemoral nerve is more complicated than previously described. The "medial branch" and "lateral branch" that we have used in the present study for describing the proximal branches of the genitofemoral nerve are more practical terms to describe the genitofemoral nerve. Clin. Anat. 32:458-463, 2019. © 2019 Wiley Periodicals, Inc.

The piriformis muscle is clinically implicated in pain disorders, posterior approaches for total hip arthroplasty, and iatrogenic injury to the muscle and the surrounding nerves. The piriformis muscle has been said to receive innervation from L5 to S3 ventral rami with most sources using S1 and S2 ventral rami as the most common innervation this muscle. However, descriptions of the nerve in the literature are vague. Therefore, the aim of this study was to clarify the anatomy of the nerve supply to the piriformis muscle. Twenty sides from ten fresh-frozen cadavers were studied. Specifically, via anterior dissection of the sacral plexus, branches to the piriformis were identified. Once identified, the nerves to the piriformis muscle were traced proximally to clarify their origin. Nerves supplying the piriformis muscle existed on all sides. On 80% of sides, the piriformis was innervated by two to three nerves. The origin of these nerves was from the superior gluteal nerve on 14 sides (70%), inferior gluteal nerve on one side (5%), L5 ventral ramus on one side (5%), S1 ventral ramus on 17 sides (85%), and S2 ventral ramus on 14 sides (70%), respectively. The most common nerve branches to the piriformis are from the superior gluteal nerve, and the ventral rami of S1 and S2. Based on our study, a single "nerve to piriformis" does not exist in the majority of specimens thus this term should be abandoned. Clin. Anat. 32:282-286, 2019. © 2018 Wiley Periodicals, Inc.

Ulnar neuropathy at the cubital tunnel is common. However, a rare form of ulnar neuropathy here is due to compression from an accessory muscle, the anconeus epitrochlearis. Reports in the literature regarding the details of this muscle's innervation are vague, so the aim of the present study was to characterize this anatomy more clearly. This was a combined review of magnetic resonance imaging (MRI) from patients with an anconeus epitrochlearis and ulnar neuropathy and cadaveric dissections to characterize the innervation of this variant muscle. A review of 11 patients and three reports of ulnar neuropathy and an anconeus epitrochlearis in the literature revealed no MRI changes consistent with acute denervation of this muscle. However, in two cases, there were signs of chronic denervation of the muscle. Dissection of five cadavers revealed that the nerve supply to the anconeus epitrochlearis originated proximal to the medial epicondyle, traveled parallel to the ulnar nerve, terminated on the deep aspect of this muscle, and had a mean length of 60 mm. This clinicoanatomical study provides evidence that the innervation of the anconeus epitrochlearis is proximal to the muscle and on its deep aspect. Clin. Anat. 32:218-223, 2019. © 2018 Wiley Periodicals, Inc.

Dyspareunia can be described as continuous unremitting or intermittent pain associated with intercourse. It can be classified based on the location of the pain - entry or deep dyspareunia, or based on when the pain was first experienced - primary or secondary dyspareunia. There are different causes of dyspareunia and some of the most important causes include the following: vulvodynia, postpartum dyspareunia, endometriosis, inadequate vaginal lubrication or arousal, and other anogenital causes such as hemorrhoids and anal fissures. In this review, our objective is to apply the anatomical knowledge of dyspareunia to patient care, increase awareness among clinicians about the diverse etiology of dyspareunia and ensure that the whole patient, not just the pain of dyspareunia is being treated as the causes of dyspareunia can be due to various pathologies. Clin. Anat., 31:1013-1017, 2018. © 2018 Wiley Periodicals, Inc.

The inferior gluteal nerve has been traditionally described as a solely motor branch innervating the gluteus maximus. However, during routine dissection of the gluteal region, a cutaneous branch of the inferior gluteal nerve was identified. As the gluteal region is vulnerable to the development of pressure ulcers and iatrogenic injury with for example, surgical approaches and injection therapies, a comprehensive understanding of its cutaneous innervation is important. Therefore, the aim of this study was to elucidate the anatomy of this cutaneous branch of the inferior gluteal nerve in a series of cadavers. Twelve sides from six fresh-frozen cadaveric specimens were dissected. When a cutaneous branch was identified piercing the gluteus maximus, its origin from the inferior gluteal nerve was verified and the diameter and length of it measured. Additionally, for localization, the distance from the midline to the exit point of the cutaneous branch from the gluteus maximus was measured. One to two cutaneous branches were identified as arising from the inferior gluteal nerve on nine sides (75%). The branch(es) were usually located in the lower outer quadrant of the gluteus maximus. These branches had a mean distance of 12.5 cm from the midline. Their mean diameter and length was 0.7 mm and 28.6 cm, respectively. On all sides with a cutaneous branch of the inferior gluteal nerve, the skin over the posterior aspect of the greater trochanter was innervated by superior and inferior cluneal nerves and supplemented by cutaneous branch(es) of the inferior gluteal nerve. Side or sex was not a predictor of the presence of a cutaneous branch of the inferior gluteal nerve. To our knowledge, a cutaneous branch derived from the inferior gluteal nerve has not been previously described. Based on our cadaveric findings, the majority of individuals will have the area of skin over the greater trochanter innervated by this nerve. Therefore, surgeons and pain specialists should be aware of its presence and might develop surgical procedures that help avoid it or develop technical advances that target it for various pain syndromes in this area. We propose naming these cutaneous branches the lateral cluneal nerves, which would necessitate renaming the middle cluneal nerves to medial cluneal nerves. Clin. Anat. 31:937-941, 2018. © 2018 Wiley Periodicals, Inc.

The aim of this radiological micro-CT study and meta-analysis was to determine the morphological features of the root canal anatomy of the mandibular molars. The radiological study included micro-CT scans of 108 mandibular first, 120 mandibular second, and 146 mandibular third molars. For our meta-analysis, an extensive search was conducted through PubMed, Embase, and Web of Science to identify articles eligible for inclusion. Data extracted included investigative method (cadaveric, intraoperative, or imaging), Vertucci type of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and intercanal communications. In the mesial roots of mandibular molars, the most frequent Vertucci type of canal configuration was type IV, except for the mandibular third molar where type I was most common. Type I was most common in the distal root. There were usually two canals in the mesial root and one in the distal root. Two was the most common number of roots, and a third root was most prevalent in Asia. One apical foramen was most common in the distal root and two apical foramina in the mesial root. Intercanal communications were most frequent in the mesial root. Knowledge of the complex anatomy of the mandibular molars can make root canal therapy more likely to succeed. We recommend the use of cone-beam computed tomography before and after endodontic treatment to enable the root anatomy to be accurately described and properly diagnosed, and treatment outcome to be assessed. Clin. Anat. 31:797-811, 2018. © 2018 Wiley Periodicals, Inc.

The aim of this work was to conduct a radiological micro-CT study and meta-analysis to determine the morphological features of the root canal anatomy of the maxillary molars. The radiological study included micro-CT scans of 110 maxillary first molars and 98 maxillary second molars. To identify articles eligible for inclusion in our meta-analysis, PubMed, Embase, and Web of Science were search comprehensively. The following data were extracted: study type (cadaveric, intraoperative or imaging), Vertucci types of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and inter-canal communications. The mesiobuccal root was the most variable with respect to canal configuration, type I being the most common configuration followed by type II and type IV. Type I was the most common canal configuration in the distobuccal and palatal root. Regarding the number of canals in the maxillary first and second molars, one canal was most prevalent in all roots of the three molars, except for the mesiobuccal root of maxillary first molar, in which two canals were most prevalent. The most prevalent number of roots in all maxillary molars was three. Knowledge of endodontic anatomy determines the parameters of root canal treatment and significantly affects the probability of success. It is therefore especially important to know the morphology of the root canal system in order to perform endodontic treatment correctly. Clin. Anat. 31:838-853, 2018. © 2018 Wiley Periodicals, Inc.

The minor salivary glands in the retromolar trigone have rarely been studied. The aim of this study was to better define the anatomy of the minor salivary glands in the retromolar trigone and establish the relationships between these and adjacent structures. The gland in the retromolar trigone was exposed and its relationships to surrounding structures were observed on 20 cadaveric sides. The boundaries of the gland included the superior pharyngeal constrictor muscle, the tendon of the buccinator muscle, and loose connective tissue. The gland was not continuous with the pterygomandibular or parapharyngeal spaces, but loose connective tissue was present between glands in the retromolar trigone and the medial pterygoid muscle. To our knowledge, this is the first study to describe the detailed anatomy of the minor salivary gland in the retromolar trigone. We suggest that the minor salivary gland in the retromolar trigone should be named the "retromolar gland." Clin. Anat. 31:462-465, 2018. © 2018 Wiley Periodicals, Inc.

Our previous studies based on intraoral dissection of fresh cadavers demonstrated the fissure and loose connective tissues behind the mucosa between the incisivus labii inferioris (ILI) and buccinator (BM) muscles. However, this raised new questions about the relationship among these muscles, the fissure and the buccal space. To our knowledge, no pathway to the oral cavity from the buccal space has been previously demonstrated, although such a pathway would better explain some routes of infection. Therefore, the aim of this study was to clarify the relationship among the mimetic muscles attached to the mandible, the fissure, and the buccal space. Twenty sides from 10 fresh frozen adult cadaveric Caucasian heads were used. The relationships among the ILI, BM, mandible, and buccal space were investigated with dissection and fluoroscopy. In all specimens, the fissure between the lateral border of the ILI and the anterior border of the BM formed the entrance of a space (here termed the bucco-mandibular space), which corresponded to the buccal mucosa in the premolar region. The superior border of this space was formed by the platysma and associated fascia, which was continuous with the masseteric fascia. This fascia clearly separated this space from the buccal space, which was located lateral to the BM and superior to this space. Clin. Anat. 30:958-962, 2017. © 2017 Wiley Periodicals, Inc.

The accessory phrenic nerve (APN) is a common anatomical variant with differing reports of prevalence in the literature. It can be injured during operative procedures to the neck and thorax or by regional anesthetic techniques in its vicinity. Our aim was to provide a comprehensive evidence-based assessment of the prevalence and origins of the APN. The databases PubMed, China National Knowledge Infrastructure, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science were searched comprehensively, followed by assessment of eligibility and extraction of data concerning the APN. The data were pooled into a meta-analysis. A total of 17 studies were included in the meta-analysis. Fourteen studies (n = 1,941 hemi-necks) reported data on APN prevalence resulting in an overall pooled prevalence estimate of 36.5%. Nine studies (n = 941 APNs) reported data on the origin of the APN. Most commonly the APN originated from the ansa cervicalis (16.5%) followed by the nerve to the subclavius (15.8%). Subgroup analysis on the basis of laterality and geographic region revealed no statistically significant findings. The APN is a highly variable anatomical structure present in over one third of the population, most often originating from the ansa cervicalis or the nerve to the subclavius. Clinicians need to be aware of the varying constellation of symptoms that can arise from APN injury. Ultimately, knowledge of APN variation could provide for better outcomes and reduction of iatrogenic injuries, particularly in high-risk patients prone to long-term complications from diaphragmatic dysfunction. Clin. Anat. 30:1077-1082, 2017. © 2017 Wiley Periodicals, Inc.

The sensory innervation of the inferior eyelid is mainly derived from the inferior palpebral branch (IPb) of the infraorbital nerve (ION). This study aimed to investigate another, to our knowledge, previously unknown branch, and elucidate its location and distribution. Twelve sides from seven fresh frozen cadaveric Caucasian heads were used in this study. The specimens were derived from two male and four female adult cadavers age. The diameter of the IPb of the ION (D1) and branch arising from the upper wall of the infraorbital canal (D2), and distance between the branching points of this branch and the anterior border of the orbit floor (L1) was measured. A branch to the lower eyelid was found arising from the infraorbital canal on the majority of sides. D1 ranged from 0.4 to 1.1 mm. The branch arising from the upper wall of the infraorbital canal was found 10 sides (83%). D2 ranged 0.6 to 1.0 mm. L1 ranged from 10.2 to 19.8 mm. All of the branches arising from the upper wall of the infraorbital canal (10 sides) primarily innervated to the inferior eyelid. We suggest this branch should be named the "posterior IPb" of the ION. Knowledge of this branch might decrease sensory loss following invasive procedures of the lower orbit. Clin. Anat. 30:835-838, 2017. © 2017Wiley Periodicals, Inc.

The extraocular muscles consist of the superior, inferior, lateral, and medial rectus muscles and the superior and inferior oblique muscles. This study aimed to create a new teaching model for demonstrating the function of the extraocular muscles. A coronal section of the head was prepared and sutures attached to the levator palpebral superioris muscle and six extraocular muscles. Tension was placed on each muscle from a posterior approach and movement of the eye documented from an anterior view. All movements were clearly seen less than that of the inferior rectus muscle. To our knowledge, this is the first cadaveric teaching model for demonstrating the movements of the extraocular muscles. Clin. Anat. 30:733-735, 2017. © 2017Wiley Periodicals, Inc.

Chronic dry eye (keratitis sicca) is a significant problem that in certain populations can result in corneal desiccation and the potential for blindness. Therefore, novel treatments for such disorders might decrease patient morbidity. The present study aimed to investigate a potential treatment for chronic dry eye via a cadaveric feasibility study. On 10 cadaveric sides, the parotid gland branch of the auriculotemporal nerve (ATN) was identified and anastomosed to an anterior superficial temporal branch (STb) of this same nerve. The STb was then transposed anteriorly and sutured to the lacrimal gland. The parotid branch of the ATN was easily identified on all sides. The STb of the ATN was easily identified and mobilized on all sides. This latter nerve had adequate length to be moved to the ipsilateral lacrimal gland on all sides. Rerouting parotid gland secretomotor fibers to the superficial branch of the ATN and then moving this branch to the lacrimal gland is a feasible surgical maneuver based on our cadaveric study. Clinical studies are now necessary to show utility of this procedure in patients with chronic dry eye. Clin. Anat. 30:839-843, 2017. © 2017Wiley Periodicals, Inc.

The internal nasal branch of the infraorbital nerve (ION) runs down the nose and around the ala to be distributed to the nasal septum and vestibule. The aim of this study was to measure the internal nasal branch around the ala of the nose and discuss its possible relevance in clinical/surgical practice. Twelve sides from seven specimens derived from fresh frozen and embalmed Caucasian cadaveric heads were dissected. The specimens included three males and four females. The ages of the cadavers at death ranged from 65 to 84 years. The diameter of the internal nasal branch, horizontal distance from the lateral contour of the ala (Point A) to the branch (distance H) and vertical distance from the bottom part of the ala (Point B) to the branch (distance V) were recorded. Distance H ranged from -1.6 to 1.5 mm on right sides and -1.0 to 1.5 mm on left sides. The diameter of the nerves at Point A ranged from 1.3 to 1.8 mm on right sides and 1.3 to 1.6 mm on left sides. Distance V ranged from -1.5 to 1.0 mm on right sides and -2.3 to 1.1 mm on left sides. The diameter of the nerves at Point B ranged from 0.7 to 1.3 mm on right sides and 0.8 to 1.2 mm on left sides. The results of this study are the first to detail the topography of the internal nasal branch of the ION. Clin. Anat. 30:817-820, 2017. © 2017Wiley Periodicals, Inc.

The importance of the position of the lingual nerve in the oral cavity cannot be understated for dentists and oral surgeons. Therefore, the location of the lingual nerve with various positions of the tongue is important. However, most dental and medical students are taught oral cadaveric anatomy where tissues are fixed. Therefore, the focus of this article is to demonstrate how the lingual nerve moves based on tongue movement in fresh tissues and how this is important for dentists and oral surgeons. Clin. Anat. 30:467-469, 2017. © 2017 Wiley Periodicals, Inc.

In 1922, Paul Hecker, a French physician and Head of Anatomy at the Medical College of Strasbourg, published a sentinel thesis on the ligaments of the craniocervical junction based on a study of comparative anatomy. Unfortunately, this dissertation has been lost to history and until now, was unavailable in the English language. Herein, we present a translation of Hecker's work with an update in its nomenclature, which with modern imaging capabilities of the craniocervical junction is germane and timely. Clin. Anat. 30:322-329, 2017. © 2017 Wiley Periodicals, Inc.

Physical examination of the abdomen is an essential skill. Knowledge of its clinical anatomy and application is vital for making diagnoses. Misinterpretation of anatomy during examination can have serious consequences. This review addresses understanding of the anatomy, methodology, and complications of abdominal physical examination. It includes particular reference to modern technology and investigations. Physical examination is performed for diagnostic purposes. However, the art of physical examination is declining as more and more clinicians rely on newer technology. This can have regrettable consequences: negligence, waste of time and resources, and deterioration of clinical skills. With a sound knowledge of clinical anatomy, and realization of the importance of physical examination of the abdomen, clinician, and patients alike can benefit. Clin. Anat. 30:352-356, 2017. © 2017 Wiley Periodicals, Inc.

The lingual foramina and canals can be categorized as median or lateral based on their relation to the midline of the mandible. Investigation of the mandibular lingual region is often done with gross anatomical dissections of cadavers, 2D panoramic radiographic imaging, CT, and cone beam CT (CBCT). While gross studies are the most reliable at qualifying canal contents and course, CBCT proved to be superior to other radiographic techniques for visualizing lingual foramina and canals. The submental and sublingual arteries, and their branches are found in the lingual vascular canals. There is tremendous variation between individuals in terms of the course of the lingual canals and their anastomosis with other vascular canals. Performing the dental implantation procedures in the anterior and posterior regions of the mandible can result in perforation of the lingual cortex, which could injure the arteries that lie within the lingual canal. If hemorrhage occurs, it could lead to life-threatening upper airway obstruction. Pre-surgical investigation to identify the diameter of the lingual foramina and canal as well as their distance from the alveolar process might be necessary to prevent hemorrhage for all patients. Clin. Anat. 30:194-204, 2017. © 2017 Wiley Periodicals, Inc.

The transversus nuchae muscle appears inconsistently in the occipital region. It has gained attention as one of the muscles composing the superficial musculoaponeurotic system (SMAS). The purpose of this study was to clarify its detailed anatomical features. We examined 124 sides of 62 cadavers. The transversus nuchae muscle was identified when present and examined after it had been completely exposed. We also examined its relationship to the occipital cutaneous nerves.The transversus nuchae muscle was detected in 40 sides (40/124, 32.2%) of 26 cadavers; it was present bilaterally in 14 and unilaterally in 12. It originated from the external occipital protuberance; 43% of the observed muscles inserted around the mastoid process, and 58% curved upward around the mastoid process and became the uppermost bundle of the platysma. In one case, an additional bundle originated from the lower posterior border of the sternocleidomastoid muscle and coursed obliquely upward along with platysma. Ninety percent of the muscles ran below the sling through which the greater occipital nerve passed; 65% of the lesser occipital nerves ran deep to the muscle, and 55% of the great auricular nerves ran superficial to it. Our observations clarify the unique anatomical features of the transversus nuchae muscle. We found that it occurs at a rate similar to that described in previous reports, but its arrangement is variable. Further investigations will be performed to clarify its innervation and other anatomical features. Clin. Anat. 30:32-38, 2017. © 2016 Wiley Periodicals, Inc.

Recent studies investigating accessory mental foramina using developments in diagnostic imaging have primarily defined the morphology of the foramina; however, few studies have described the structures passing through them. Additional clinical knowledge of the foramina is therefore required for preoperative diagnosis prior to surgery, including implant, periodontal and periapical surgery. In this study, we investigated the accessory mental foramina and the associated nerves and arteries in donated cadaveric mandibles using anatomical and radiological observation methods. We examined 63 mandibles with overlying soft tissue by cone-beam computed tomography and noted the existence of the accessory mental foramina. Mandibles with accessory mental foramina were subsequently analyzed. Additionally, the neurovascular bundles passing through these foramina were dissected using anatomical methods.The incidence of accessory mental foramina was 14.3%. The larger foramina tended to be located anteriorly or superiorly and proximal to the mental foramen, while the smaller foramina tended to be located posterosuperiorly and distal to the mental foramen. The mental foramen ipsilateral to the accessory mental foramen was smaller than the one contralateral to it. The comparatively distant and large accessory mental foramen included an artery.This study elucidated the relationship between accessory mental foramina and the associated nerves and arteries. We believe that the results will contribute to the clinical dentistry field.

Since three-dimensional computed tomography was developed, many researchers have described accessory mental foramina. The anatomical and radiological findings have been discussed, but details of accessory mental nerves (AMNs) have only been researched in a small number of anatomical and clinical cases. For this article, we reviewed the literature relating to accessory mental foramina (AMFs) and nerves to clarify aspects important for clinical situations. The review showed that the distribution pattern of the AMN can differ according to the position of the accessory mental foramen, and the reported incidence of AMFs differs among observation methods. A review of clinical cases also revealed that injury to large AMF can result in paresthesia. This investigation did not reveal all aspects of AMNs and AMFs, but will be useful for diagnosis and treatment by many dentists and oral and maxillofacial surgeons.