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Fibers of the facial muscles occasionally extend, cross the midline, and connect to surrounding structures on the contralateral side, perhaps enabling the mouth to make more delicate movements and generate more facial expressions. This case report describes a variant in which the extended fibers of the mentalis crossed the midline and indicates the relationship of these fibers to the surrounding structures. Some of the deepest fibers of the mentalis descended inferomedially and crossed transversely just below the chin prominence to attach to the periosteum of the mandible on the contralateral side. The variation presented in this study shed light on the interactions of the mentalis with the surrounding muscles.

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.

While palsy of the L5 nerve root due to stretch injury is a known complication in complex lumbosacral spine surgery, the underlying pathophysiology remains unclear. The goal of this cadaveric study was to quantify movement of the L5 nerve root during flexion/extension of the hip and lower lumbar spine. Five fresh-frozen human cadavers were dissected on both sides to expose the lumbar vertebral bodies and the L5 nerve roots. Movement of the L5 nerve root was tested during flexion and extension of the hip and lower lumbar spine. Four steps were undertaken to characterize these movements: (1) removal of the bilateral psoas muscles, (2) removal of the lumbar vertebral bodies including the transforaminal ligaments from L3 to L5, (3) opening and removing the dura mater laterally to visualize the rootlets, and (4) removal of remaining soft tissue surrounding the L5 nerve root. Two metal bars were inserted into the sacral body at the level of S1 as fixed landmarks. The tips of these bars were connected to make a line for the ruler that was used to measure movement of the L5 nerve roots. Movement was regarded as measurable when there was an L5 nerve excursion of at least 1 mm. The mean age at death was 86.6 years (range 68–89 years). None of the four steps revealed any measurable movement after flexion/extension of the hip and lower lumbar spine on either side (

The facial muscles have significant roles for vocalization, feeding, and facial expression in both human and non-human primates. Of these, the anatomy of the incisivus labii superioris (ILS) and incisivus labii inferioris (ILI), which are considered as the accessory bundle of the orbicularis oris (OO) in humans, has rarely been documented in the literature. Our current understanding of the function of the ILS and ILI is that they probably retract the upper and lower lips. Also, there is no account of these muscles in non-human primates in the current literature. The aim of this study was to reveal the ILS and ILI in non-human primates. Five Macaca fascicularis, one Macaca fuscata, one Macaca fuscata yakui, and one Pan troglodytes were dissected. Seven formalin-fixed cadavers and one fresh cadaver were included. Both the ILS and ILI were observed in all specimens. The ILS originated from the incisive fossa of the maxilla and inserted into the OO. The mentalis (MT) and ILI arose from the incisive fossa of the mandible and inserted into the OO and the skin of the chin area. The MT and ILI in the P. troglodytes examined were thicker than in the other three non-human species, and the ILS and ILI in the three macaques were similar in shape to those of humans. The difference of these muscles may result in different functions of the lip such as during vocalization, feeding, and facial expression.

This paper aimed to better describe the anatomy of the superficial anterior atlanto-occipital ligament of the craniocervical junction and discuss this ligament's potential function and clinical implications. A broad literature review on the anatomical features and findings of the superficial anterior atlanto-occipital ligament was performed. The superficial anterior atlanto-occipital ligament is located anterior to the anterior atlanto-occipital membrane. However, the physiological role of the superficial anterior atlanto-occipital ligament is still unclear due to a lack of anatomical and biomechanical studies although one study has suggested that this ligament is a secondary stabilizer of the craniocervical junction. Further studies are needed to clarify the function and anatomy of the superficial anterior atlanto-occipital ligament.

The ansa cervicalis is an important nerve of the cervical plexus. Knowledge of its anatomy can prevent patient complications.

The aim of the present study was to determine the contribution of the orbicularis oculi (OOc) to the zygomaticus major (Zmj) in connecting the orbital region to the corner of the mouth. The OOc and Zmj of 22 embalmed adult Korean cadavers were dissected in 44 hemifaces. The OOc fibers were traced to determine their contribution to the Zmj. Parts of the superficial bundle in the orbital region of the OOc extended directly or indirectly to the Zmj in 22.7% of the specimens. The anatomical contribution of the OOc to the Zmj was divided into three categories depending on whether the connection between them was direct or indirect: (1) superficial orbital OOc fibers extended directly to the Zmj in 6.8% of the specimens, (2) superficial orbital OOc fibers extended to the zygomaticus minor and their small portion joined to the upper fibers of the Zmj in 15.9% of the specimens, and (3) no connection was identified between the OOc and Zmj in 77.3% of the specimens. The results of this study provide further anatomical insight into the relationship between the OOc and zygomaticus muscle complex. This information could be helpful for elucidating the anatomy of smiling and treatment and surgery designs for balanced or ideal smiles.

Lymphoepithelial carcinoma (LEC) is a rare tumor characterized by the undifferentiated or poorly differentiated malignant epithelial cells with marked reactive lymphoplasmacytic infiltrate. In the major salivary glands, LEC commonly occurs in the parotid gland and rarely seen in the submandibular gland. We present a case of submandibular gland LEC found in a 64 years-old Japanese male with Epstein-Barr virus infection. The patient underwent radical neck dissection and postoperative chemoradiotherapy. No evidence of recurrence has been detected during the 5-year follow-up.

Study Design: In vitro biomechanical study. Objective: The transverse ligament is the strongest ligament of the craniocervical junction and plays a critical role in atlanto-axial stability. The goal of this cadaveric study, and the subsequent study (part II), was to reevaluate the force required for the transverse ligament and alar ligament to fail in a more physiological biomechanical model in elderly specimens. Methods: Twelve C1-2 specimens were harvested from fresh-frozen Caucasian cadavers with a mean age at death of 81 years (range 68-89 years). Only the transverse ligament was preserved, and the bony C1-2 complex was left intact. The dens was pulled away from the anterior arch of C1 using a strength test machine that applies controlled increasing force. After testing, the axis was split in half to check for hidden pathologies and osteoporosis. The differences in the failure force between sex and age groups (group 1: 80 years) were compared. Results: The mean force required for the transverse ligament to fail was 236.2 ± 66 N (range 132-326 N). All but 2 specimens had significant osteoporotic loss of trabecular bone. No significant differences between sex and age groups were found. Conclusions: The transverse ligament’s failure in elderly specimens occurred at an average force of 236 N, which was lower than that reported in the previous literature. The ligament’s failure force in younger patients differs and may be similar to the findings published to date.

The mental artery is a terminal branch of the inferior alveolar artery arising from the maxillary artery. It often communicates with the submental and inferior labial arteries branching off the facial artery. To our knowledge, few reports have described its anatomy and clinical significance in detail. The aim of this paper was to clarify the anatomy of the mental artery. Ten sides from five embalmed Caucasian cadaveric heads were used. The facial artery was identified at the point passing through a notch for the facial vessels and was traced medially. The mental artery and its anastomoses with other arteries were observed in detail. It was detected on all sides. Fourteen anastomoses were found, eight with the inferior labial artery and six with the submental artery. On one side, the mental artery directly supplied the lower lip with no anastomosis. The inferior labial artery tended to anastomose with the mental artery superior to the mental foramen and was likely to anastomose with the submental artery anterior to the mental foramen. We clarified the detailed anatomy of the mental artery. Our results could provide dentists with information that will help them to make oral surgery safer and more successful.

The ansa cervicalis is a neural loop in the neck formed by connecting the superior root from the cervical spinal nerves (C1-2) and the inferior root descending from C2-C3. It has various anatomical variations and can be an important acknowledgment in specific operations of the neck region. This is a review the anatomy, variations, pathology and clinical applications of the ansa cervicalis.

The frontal nerve is the largest branch of the ophthalmic nerve. This nerve gives rise to two terminal branches, the supraorbital (SON) and supratrochlear nerves (STN). To the best of our knowledge, there are no reports describing the detailed proximal course of these nerves while inside the orbit. Therefore, the goal of this study was to clarify the anatomy of the SON and STN inside and at their exit from the orbit. Twenty sides from ten fresh-frozen cadavers were used in this study. Intra and extra orbital dissections were performed to observe the course of the SON and STN. Additionally, measurements of the nerves were made at these locations. The course of the SON and STN inside the orbit was classified into three groups depending on the STN branching pattern from the SON. The group without any branch from the SON and STN inside the orbit was the most common. The exit points of these nerves were via the supraorbital notch, foramen, or neither a notch nor foramen. A distinct fibrous band was consistently found tethering the nerve except in specimens with nerves traversing a bony foramen. The mean diameters of the SON and STN were 1.3 ± 0.2 and 0.7 ± 0.1 mm, respectively. The results of this study further our knowledge of the course and morphology of the SON and STN and might be useful for better understanding and potentially treating some forms of migraine headache due to SON or STN compression/entrapment. Clin. Anat. 33:332-337, 2020. © 2019 Wiley Periodicals, Inc.

Herein we present a case of a horseshoe kidney with crossed fused renal ectopia. Both of these pathologies are congenital anomalies; however, to date, there are few cases that present with both. In this case, discovered during routine dissection, the fused kidney was mostly left-sided and very low in the pelvis. No renal artery arose from the right wall of the abdominal aorta, and the right renal vein drained into the lower part of the inferior vena cava (IVC) where the right and left common iliac veins joined. It is essential for clinicians and surgeons to understand these types of congenital anomalies, as they could impact patient care.

The condylar canal and its associated emissary vein serve as vital landmarks during surgical interventions involving skull base surgery. The condylar canal serves to function as a bridge of communication from the intracranial to extracranial space. Variations of the condylar canal are extremely prevalent and can present as either bilateral, unilateral, or completely absent. Anatomical variations of the condylar canal pose as a potential risk to surgeons and radiologist during diagnosis as it could be misinterpreted for a glomus jugular tumor and require surgical intervention when one is not needed. Few literature reviews have articulated the condylar canal and its associated emissary vein through extensive imaging. This present paper aims to further the knowledge of anatomical variations and surgical anatomy involving the condylar canal through high-quality computed tomography (CT) images with cadaveric and dry bone specimens that have been injected with latex to highlight emissary veins arising from the condylar canal.

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.

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.

Diverticular pouch in the oral cavity is a rare disease, and its etiology is unclear. The authors present a rare case of diverticular pouch in the buccal mucosa. A 79-year-old man visited our hospital with a chief complaint of food impaction in the right buccal mucosa. Intraoral examination revealed a pouch just inferior to the parotid papilla. Histopathological examination after excisional biopsy showed that the epithelial cells lining the pouch were continuous with the mucous membrane and a diagnosis was made of diverticular pouch of the buccal mucosa. Twenty-five months after the patient's initial visit no recurrence has been noted. Further clinico-pathological studies are required to understand diverticular disease in the buccal mucosa. This case might help dentists to become more aware of these lesions and collect data for further investigations.

Introduction: The superficial anterior atlanto-occipital ligament (SAAOL) is a narrowband located anterior to the anterior atlanto-occipital membrane. Nearly forgotten, it has not been well described in older anatomical textbooks and is missing in the current anatomical literature. As all of the binding structures of the craniocervical junction (CCJ) are important in maintaining stability, this study aims to clarify the anatomy and potential function of the SAAOL. Materials and Methods: The CCJ from ten fresh-frozen cadavers was studied. These specimens were derived from three males and seven females, and the age at death ranged from 57 to 91 years (mean, 79.8 years). The length, width, and thickness of the SAAOL were measured. In five specimens, the force to failure was recorded. Results: The SAAOL was found between the anterior tubercle of the atlas and the occiput and located as central thick fibers in front of the anterior atlanto-occipital membrane in 9 (90%) specimens. In one specimen, the vertical band to the occipital bone did not attach to the anterior tubercle of the atlas, but extended to the anterior aspect of the axis. The mean length, width, and thickness of the SAAOL were 19.8, 6.2, and 0.6 mm, respectively. The force to failure for the ligament was 38.8 N. Conclusion: The SAAOL was a constant structure of the anterior atlanto-occipital joint. This ligament seems to be a secondary stabilizer of the CCJ by limiting the extension of CCJ. Knowledge of this ligament may help in further understanding of craniocervical stability.

Adenosquamous carcinoma (ASC) is a rare malignant tumor of the oral and maxillofacial region that displays histologic features of both adenocarcinoma and squamous cell carcinoma. ASC in the midline dorsum of the tongue is exceedingly rare. We report the case of a 48-year-old man who presented with a painless mass in the midline dorsum of the tongue. Although the case was diagnosed as adenocarcinoma by biopsy, a final diagnosis of ASC was established after surgery. Ten months after the patient's initial visit, no recurrence or metastasis has been noted. ASC in the middle dorsum of the tongue is exceedingly rare, and no examples have been reported hitherto.

The retromolar canal (RMC) and foramen (RMF) are anatomic variants in the retromolar area of the mandible. The purpose of this study was to clarify the relationship between the RMC and RMF and related complications, and to reveal how the RMC could impact the mandibular anatomy using cone-beam computed tomography (CBCT) and panoramic images (PAN). CBCT and PAN images of 50 patients were retrospectively analyzed to investigate the morphology of the RMC and RMF, and their impact on impacted third molar surgery and orthognathic surgery. In PAN images, neither the RMC nor RMF was detected. In CBCT images, the RMCs were detected in 26% (13/50) of the patients. A double RMC was detected on one side of one patient. The diameter of the RMC ranged from 0.8 to 2.9 mm (mean; 1.5 ± 0.6 mm), and the RMF ranged from 0.6 to 2.3 mm (mean; 1.1 ± 0.5 mm). No patients experienced unexpected bleeding. Unilateral postoperative hypoesthesia of the buccal gingiva in the molar region was reported in 6.7% of patients with the RMC. Hypoesthesia of the buccal gingiva in the lower molar region may be the main complication when the RMC is damaged.

The great auricular nerve (GAN) has been used for trigeminal and facial nerve repair and the inferior alveolar nerve (IAN) are often sacrificed during segmental mandibulectomy. To our knowledge, only 1 case report has discussed IAN repair using GAN after segmental mandibulectomy. The goal of this study is to clarify the feasibility of using GAN for IAN repair. Eleven sides from 6 fresh frozen Caucasian cadavers were used for this study. The mean age at the time of death was 82.3 years. A submandibular skin incision was made 2 finger breadths below and parallel to the inferior border of the mandible. The GAN was identified and then the mental foramen was found via extraoral dissection. The buccal cortical bone was removed 5 mm posterior to the mental foramen to the wisdom tooth area. Next, the anteroposterior length of the window was measured. The diameter of the IAN at the first molar tooth area was measured. Finally, the GAN was cut with maximum available length to compare to the length of the window in the mandible. The anteroposterior length of the window and diameter of the IAN ranged from 23.1 to 31.2 mm and 1.2 to 2.1 mm, respectively. The length of the available GAN was longer than the ipsilateral bony window of the mandible on all sides. This study might encourage surgeons to consider a new way to treat patients who undergo segmental resection of the mandible with surgical neck dissection with injury to their IAN.

The Stafne bone cavity (SBC), also called the static bone cavity, salivary inclusion cyst, latent cyst, and lingual bone defect is an asymptomatic bony defect that is commonly located inferior to the mandibular canal and slightly above the inferior border of the mandible. It is rare to see the actual bony defect in the cadaver because of its relatively low incidence of 0.1% to 6.06%. We report a unilateral SBC found in a 76-year-old at death male Caucasian cadaver and involving the right mandible. The SBC was oval in shape with a smooth surface and measured 10.8×6.0 mm. The SBC was continuous with the right mylohyoid groove. Since actual photographs of the SBC are lacking in the literature, this report might provide additional insight for better understanding the SBC.

The femoral nerve is the largest branch of the lumbar plexus. It is normally composed of the ventral rami of spinal nerves L2 to L4. The psoas major has proximal attachments onto the T12 to L5 vertebrae and related intervertebral discs, fuses with the iliacus deep to the inguinal ligament and then attaches onto the lesser trochanter of the femur. Normally, the anatomical relationship is that the femoral nerve is located between the iliacus and psoas major. Herein, we report a case of the psoas quartus muscle related to several splits of the femoral nerve within the pelvis. Although the embryology for this is unclear, surgeons and physicians should be aware of such anatomical variants in order to better understand pain and entrapment syndromes and during surgical maneuvers in this region such as lateral transpsoas approaches to the lumbar spine.

The lingual nerve (LN) is a branch of the mandibular division of the trigeminal nerve, and its injury is one of the major complications during oral surgery. This study aims to investigate the anatomy of the LN in the lower third molar area. Twenty sides from ten fresh-frozen adult cadaveric Caucasian heads were examined to measure the diameter of the LN. The mean diameter of the LN was 2.20±0.37 mm (range, 1.61-2.95 mm). There were no statistically significant differences in the measurements between sexes, sides, or tooth status (dentulous or edentulous). Understanding the anatomical features of the LN is essential for performing any surgical procedure in the oral region.

Background Ligaments of the craniocervical junction play a critical role in stabilizing this region. Gerber's ligament has more or less been forgotten and, to our knowledge, never studied. Methods Dissection of the craniocervical junction was performed in 15 fresh frozen cadavers. In the prone position, the posterior elements of the upper cervical vertebrae and occiput were removed. After removing the contents of the spinal canal and posterior cranial fossa, the dura mater and tectorial membrane were reflected. The superior band of the cruciform ligament was reflected. When Gerber's ligament was identified, its attachments and morphometry were recorded. Lastly, Gerber's ligament was observed while range of motion of the craniocervical junction was performed. Results Gerber's ligament was identified in 7 specimens (46.7%). This structure arose anteriorly from the junction of the superior band and transverse part of the cruciform ligament. Gerber's ligament was always found to be just deep to the superior band of the cruciform ligament but traveled more anteriorly to attach onto the posterior aspect of the dens approaching, but not attaching onto, its apex. Mean length was 11 mm, and mean width was 7 mm. Thickness of the ligament was 0.5–1.1 mm. The ligament was found to become taut with minimal rotation of the atlantoaxial joint and extension of the craniocervical junction. Conclusions A good understanding of all ligaments of the craniocervical junction is important to surgeons and physicians treating patients with injury to the upper cervical spine.

Cone-beam computed tomography gives us much useful morphological information about the mandibular bone. Many studies of the mandible include findings from this technique. However, there have been no endoscopic studies of the mandible. Sixteen sides of eight dry mandibles resected from cadavers (age range 38-83 years) were examined by endoscopy. The head of the endoscope was 2.0 mm in diameter. We examined the mandibular foramen, lingula, mylohyoid groove, and mandibular canal. The mylohyoid grooves showed variations such as double grooves and canals. The mandibular lingula was located superior or medial to the the mandibular foramen. In a single case, the medial wall inside the mandibular canal showed a porous surface. The retromolar canal was observed in three sides. None of the images in the present study have been seen in other studies. Observation of the retromolar canal from the mandibular canal in particular can help dental students as well as oral and maxillofacial surgeons to understand its morphology. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1875-1880, 2017. © 2017 Wiley Periodicals, Inc.

Ameloblastic carcinoma is an extremely rare, aggressive, malignant tumour that is most common in the mandible. Because of its rarity there is no general approach to treatment. We present a rare case of an ameloblastic carcinoma with multiple metastases in a 63-year-old Japanese man that was treated in several different ways, including chemoradiotherapy and immunotherapy.

The depressor septi nasi is a facial muscle with many different descriptions of its anatomy. Therefore, the aim of this study was to clarify the relationship of the depressor septi nasi, incisivus labii superioris, and surrounding structures.Twenty sides from 10 fresh-frozen cadaveric heads were used in this study. The depressor septi nasi and incisivus labii superioris were dissected intraorally and extraorally, and the relationship with surrounding structures was observed.Eighteen of 20 sides had a depressor septi nasi. When present, the depressor septi nasi originated from the orbicularis oris above the central incisor and the medial portion of the inferior part of the incisivus labii superioris and inserted into the base of the medial crus of the major alar cartilage and nasal septum. These three muscles were three-dimensionally fused at the insertion point of the depressor septi nasi. There was no specimen where the depressor septi nasi originated directly from the maxilla. The depressor septi nasi runs obliquely from the nasal septum and the base of the medial crus of the major alar cartilage to the orbicularis oris and inferior part of the incisivus labii superioris.A better understanding of the depressor septi nasi, incisivus labii superioris, and surrounding structures might be important during various surgical techniques, especially rhinoplasty.

Purpose Neurosensory disturbance of the infraorbital nerve is one of the many complications of the Le Fort osteotomy. An accessory infraorbital foramen (AIOF) can be one reason for such complications. Therefore, the purpose of the present study was to elucidate the distribution of the accessory infraorbital nerve (AION) arising from the AIOF. Materials and Methods We dissected 60 sides from 30 fresh-frozen cadaveric heads. Results An AIOF was found in 36.7% of the heads examined. When an AIOF was detected, the nerve was traced distally and proximally. The mean horizontal and vertical diameters of the AIOF were 1.64 ± 0.88 and 1.75 ± 0.87 mm, respectively. The largest AIOF was 3.42 × 3.79 mm. All AIOFs were located medial to the infraorbital foramen. Most of the AIONs (87.5%) had branches to the external nose. Conclusions The AION should always be remembered by surgeons to allow for improved outcomes and better understanding of the complications such as those occurring after Le Fort osteotomy.

Objective The sacral dorsal rami form the posterior sacrococcygeal plexus (PSCP), which has been scantly studied. This study's goal was to clarify the PSCP s detailed anatomy and discuss its clinical relevance. Methods Ten sides of 5 fresh-frozen cadavers were dissected for this research. After the muscles covering the sacrum were removed, the PSCP was identified and traced under the operating microscope until the entire plexus was exposed. The contributions to this plexus and its relations to surrounding anatomic structures were recorded. Results The PSCP was found on all sides and was composed of a medial trunk (MT), communicating branches, and a lateral trunk. Each sacral dorsal ramus's MT formed a series of loops created by adjacent sacral dorsal rami placed between the transverse tubercles and the posterior sacral foramina. The MT, communicating branches, and lateral trunk demonstrated potential entrapment sites. Conclusions To our knowledge, this is the first anatomic study that provides detailed images that indicate 3 potential sites where surrounding structures could entrap the PSCP. Knowledge of its detailed anatomy might help in better understanding low-back pain, targeting pain sources and guide spine surgeons for avoiding injury to these nerves.

The posterior auricular nerve (PAN) is the first branch of the facial nerve after it leaves the stylomastoid foramen. The literature describing the anatomy of the PAN is very sparse. Therefore, the purpose of this study was to clarify the detailed anatomical features of the PAN and consider its clinical and surgical applications. The authors examined 10 sides from 6 fresh frozen adult cadaveric Caucasian heads. The PAN was observed as the first branch of the facial nerve in all specimens. During the dissection of the PAN, the posterior auricular artery was constantly near the PAN. Moreover, the PAN was located under the investing layer of deep cervical facia covering the sternocleidomastoid and mastoid process in all specimens. The diameter of the PAN was 0.82 ± 0.21 mm (range from 0.55 to 1.21). The distance from the stylomastoid foramen to where the PAN branched from the facial nerve was 0.40 ± 1.25 mm (range from 0 to 4.35). The distance from the location of this branching point of the PAN to the entering point of the PAN to any muscles was 28.03 ± 5.51 mm (range from 19.71 to 38.75). Understanding the anatomical features of the PAN is essential for performing surgical procedures in this region.

Neurotrophic keratitis is a rare corneal disease that is challenging to treat. Corneal neurotization (CN) is among the developing treatments that uses the supraorbital (SON) or supratrochlear (STN) nerve as a donor. Therefore, the goal of this study was to provide the detailed anatomy of these nerves and clarify their feasibility as donors for ipsilateral CN. Both sides of 10 fresh-frozen cadavers were used in this study, and the SON and STN were dissected using a microscope intra- and extraorbitally. The topographic data between the exit points of these nerves and the medial and lateral angle of the orbit were measured, and nerve rotation of these nerves toward the ipsilateral cornea were attempted. The SON and STN were found on 19 of 20 sides. The vertical and horizontal distances between the exit point of the SON and that of the STN, were 7.3±2.1 mm (vertical) and 4.5±2.3 mm, respectively. The mean linear distances between the medial angle and the exit points of each were 22.2±3.0 mm and 14.5±1.9 mm, respectively, and the mean linear distances between the lateral angle and the exit points of the SON and STN were 34.0±2.7 mm and 36.9±2.5 mm, respectively. These nerves rotated ipsilaterally toward the center of the orbit easily. A better understanding of the anatomy of these nerves can contribute to the development and improvement of ipsilateral CN.

An accessory foramen around the mandibular foramen is called an accessory mandibular foramen (AMF). The clinical anatomy of the AMF has not been well described. The aim of this study was to reveal the clinical anatomy of the AMF for a better understanding of its implication during ramus surgeries. Twenty-two sides fresh-frozen cadaveric heads with a mean age of 76.2 ± 14.4 years at death underwent dissection. The neurovascular bundles passing through the AMF were observed. Additionally, a hemi-face of a latex injected embalmed cadaver was dissected medially to laterally and the neurovascular bundles of the AMF investigated. A unilateral foramen, bilateral foramina, and absence of foramina were found in 45.4%, 18.2%, and 36.4%, respectively. The origin of the neurovascular bundle entering the AMF was a branch of the maxillary artery in 20% and a tributary of the inferior alveolar vein in 80%. In the latex embalmed cadaver, the AMF was found to contain a branch from the maxillary artery and a tributary of the maxillary vein. Given the practical meaning of the specific AMF located in the operative field of the ramus osteotomy, we suggest these be named “foramina for ramus osteotomy.”

Objective Posterior circulation strokes account for over one quarter of all ischemic strokes. The frequency of vertebral artery origin stenosis (VAOS) in patients with vertebrobasilar insufficiency (VBI) has been estimated to be as high 26%–32%, and VAOS is the direct cause of posterior circulation strokes in 9% of patients. This association could have a significant genetic component. This study examines the feasibility of the internal thoracic artery (ITA) as a donor vessel for revascularization in patients with VAOS. Methods Ten sides from 5 fresh-frozen white cadaveric necks derived from 3 women and 2 men were used in this study. The mean age of the cadavers at death was 77.2 years (range, 68–88 years). The subclavian artery, vertebral artery, and ITA were dissected. The length and diameter (proximal and distal) of the V1 segment and the length and diameter of the ITA were recorded. Finally, the ITA was transposed to the V1 segment of the vertebral artery (VA1). Results The mean length of the VA1 and its diameter at the proximal and distal parts were 35.51 and 3.69 mm, respectively. The mean length and diameter of the ITA were 26.53 and 3.27 mm, respectively. Rerouting the ITA to the VA1 was feasible without tension on all sides. Conclusions This study indicates that the ITA is anatomically and hemodynamically an excellent option for bypass surgery in a VAOS scenario. We present convincing and reproducible data to aid neurosurgeons in choosing the procedure best suited to their patients.

The ansa cervicalis is located around the carotid sheath and forms a neural loop, which consists of superior and inferior roots. It innervates the infrahyoid muscles. Anatomical variations of the superior root of the ansa cervicalis are uncommon. Herein, we present an extremely rare case of the superior root of the ansa cervicalis arising both from the hypoglossal and vagus nerves.

In the original publication, the given name and family name of the last author was incorrectly published. The correct given name and family name should be "R. Shane" and "Tubbs".

The carotid sinus nerve branches off the glossopharyngeal nerve just after its appearance from the jugular foramen, descends along the internal carotid artery, and enters the carotid sinus. There have been many studies of the pathway and the course of the carotid sinus nerve and its communications with surrounding nerves. The intercommunication is exceedingly complicated. Acknowledgment of its anatomic diversity can be important in specific operations dealing with this area. Herein we review the anatomy, variations, pathology, and clinical applications of the carotid sinus nerve.