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The middle cluneal nerves (MCNs) are stated to arise from the sacral dorsal rami of S1 to S3 and supply the gluteal skin, but their detailed anatomy is unclear and often variably depicted and described. Therefore, the goal of this study was to revisit the anatomy of the MCNs and provide a clearer picture of their morphology. Five fresh-frozen Caucasian cadavers (10 sides) (2 men and 3 women) were dissected for this study. The sacral dorsal rami from each posterior sacral foramen were identified and traced laterally to identify the MCNs. The contribution, pathway, and distribution of the MCNs were investigated. Each sacral dorsal ramus joined to form the posterior sacrococcygeal plexus. A total of 25 MCNs were identified. The MCNs were formed by the sacral dorsal rami of S1-2 in 48% (12/25), S1-3 in 4% (1/25), S1-4 in 20% (5/25), S2-3 in 8% (2/25), and S2-4 in 20% (5/25). The MCNs pierced the gluteus maximus by 2 different pathways and supplied the gluteal skin or the gluteus maximus muscle. We clarified the anatomy and variations of the MCNs and revisited its current nomenclature. Such knowledge might improve diagnoses and invasive procedure outcomes in patients with pathology in the region of the MCNs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: Many dental procedures are at risk of injuring the lingual nerve. We performed this study to better elucidate the microanatomy that exists between the ipsilateral lingual and hypoglossal nerves so that iatrogenic injury can be avoided. Methods: Adult human cadaveric tongues (ten sides) underwent Sihler's staining to identify the microanatomy between the lingual and hypoglossal nerves. Results: The lingual nerve entered the middle part of the anterior two-thirds of the tongue from its lateral side and divided into two to four thick branches. These branches were then disseminated to the anterior, middle, and posterior parts of the anterior two-thirds of the tongue via 7-14 thin nerve bundles as terminal branches. The hypoglossal nerve entered the tongue at the posterior border of its anterior two-thirds and traveled forward to the apex of the tongue on all sides. All specimens were found to have communicating branches between the lingual and hypoglossal nerves at its anterior, middle, and posterior thirds. Conclusions: Our results indicate that the ipsilateral lingual and hypoglossal nerves constantly have three connections on each side between them. This knowledge might aid the dentist in minimizing iatrogenic nerve injury. [ABSTRACT FROM AUTHOR]

Purpose: In this study, we aimed to reveal the detailed anatomy of mental nerve branches to the inferior labial glands. Methods: Embalmed cadaveric heads were used in this study and the mental nerve branches to the inferior labial glands were dissected. Branches to the glands were then excised for histological observation. Results: On all sides, the inferior labial glands were innervated by small branches arising from mental nerve branches that innervated the lower lip. No nerve branches to the inferior labial gland crossed the midline. Histological observation found that the tissue to the inferior labial gland were composed primarily of nerve fibers with a small number of surrounding vessels. Histological findings in examined specimens were consistent. Conclusion: The inferior labial glands were innervated by small branches of the mental nerve to the lower lip. [ABSTRACT FROM AUTHOR]

The anatomy and definition of the petroclinoid ligament (PCL) and its relationship with the abducens nerve are variably described. The goal of this study was to clarify the anatomy of the PCL and better elucidate its relationship with the abducens nerve. Thirty-six sides from 18 fresh-frozen adult cadaveric heads were used in this study. Specimens were all Caucasian and derived from 10 males and 8 females. The mean age at death was 79 years. Dissection of the PCL and abducens nerve was performed using a surgical microscope. The anterior and posterior attachments of the PCL, and position of the abducens nerve were noted. Subsequently, the width, thickness, and length of the ligament, and diameter of the abducens nerve were measured. Thirty-one sides (86.1%) were found to have a PCL, on two sides (5.6%), the PCL was ossified, and on three sides (8.3%), the PCL was absent. The width, thickness, and length of the PCL ranged from 0.54 to 3.39, 0.07 to 0.49, and 3.27 to 17.85 mm, respectively. No PCL had an anterior attachment onto the posterior clinoid process but rather, the clivus. Therefore, based on our findings, the PCL would be better described as the petroclival ligament. [ABSTRACT FROM AUTHOR]

Objective Distal branches of the C1 nerve that travel with the hypoglossal nerve have been well investigated but relationships of C1 and the hypoglossal nerve near the skull base have not been described in detail. Therefore, the aim of this study was to investigate these small branches of the hypoglossal and first cervical nerves by anatomic dissection. Methods Twelve sides from 6 cadaveric specimens were used in this study. To elucidate the relationship among the hypoglossal, vagus, and first and cervical nerve, the mandible was removed and these nerves were dissected under the surgical microscope. Results A small branch was found to always arise from the dorsal aspect of the hypoglossal nerve at the level of the transverse process of the atlas and joined small branches from the first and second cervical nerves. The hypoglossal and C1 nerves formed a nerve plexus, which gave rise to branches to the rectus capitis anterior and rectus capitis lateralis muscles and the atlanto-occipital joint. Conclusions Improved knowledge of such articular branches might aid in the diagnosis and treatment of patients with pain derived from the atlanto-occipital joint. We believe this to be the first description of a branch of the hypoglossal nerve being involved in the innervation of this joint. [ABSTRACT FROM AUTHOR]