Compression of the radial nerve is most commonly described at the supinator muscle (i.e., arcade of Frohse). However, radial nerve compression can occur in the arm. Therefore, the purpose of this article is to review both etiologies of radial nerve entrapment and the sites at which this can occur in the arm. The clinical presentation of radial nerve entrapment in the arm and how it differs from that of entrapment at other sites is reviewed and the conditions potentially predisposing to nerve entrapment are described. Particular attention is paid to the nerve’s course and potential variants of the anatomical structures in the arm. In each case, the recommended course of management for the neuropathy is described. Injury of the radial nerve can arise from a varied set of pathologies including trauma, tumors, anomalous muscles, and intramuscular injections. Physicians should have a good working knowledge of the anatomy and potential mechanisms for radial nerve injury.

The inferior alveolar nerve block (IANB) procedure delivers anesthetics to the pterygomandibular space through which the lingual nerve (LN) and inferior alveolar nerve (IAN) travel. Injury to the LN has been reported more often than injury to the IAN. However, the number of anatomical studies of LN injury is limited. We aimed to establish evidence by investigating LN and IAN anatomy at the level of the mandibular foramen (MF). Forty-four sides from 22 Caucasian cadaveric heads (16 fresh-frozen and six formalin-fixed cadavers) were used in this study. The LN and IAN were laterally dissected, and the diameter and the distance between the two nerves were measured at the level of the MF. The mean diameters of the LN and IAN were 2.57 mm and 2.53 mm in fresh-frozen specimens and 2.97 mm and 2.93 mm in formalin-fixed specimens, respectively. The mean diameters of the LN and IAN in all the specimens were 2.65 mm and 2.64 mm. The distance between the posterior edge of the LN and anterior edge of the IAN at the level of the MF ranged from 1.62 to 8.36 mm with a mean of 5.33 ± 1.88 mm. These findings could elucidate the risk of LN injury during the IANB procedure.

Winged scapula is caused by paralysis of the serratus anterior or trapezius muscles due to damage to the long thoracic or accessory nerves, resulting in loss of strength and range of motion of the shoulder. Because this nerve damage can happen in a variety of ways, initial diagnosis may be overlooked. This paper discusses the anatomical structures involved in several variations of winged scapula, the pathogenesis of winged scapula, and several historical and contemporary surgical procedures used to treat this condition. Additionally, this review builds upon the conclusions of several studies in order to suggest areas for continued research regarding the treatment of winged scapula.

The bifid mandibular canal (BMC) is an anatomical variant of the mandible that is often observed on cone-beam computed tomographic images. We identified a BMC during routine cadaveric dissection. The upper mandibular canal contained the inferior alveolar nerve and artery, and the lower mandibular canal contained a large inferior alveolar vein. This latter vein left the mandible through a lateral lingual foramen and joined the anterior jugular vein. Additionally, this vein gave rise to small tributaries to the mental foramen and anterior surface of the mandible from the second mandibular canal. To our knowledge, this is the first report illustrating the contents of a BMC and drainage of a vein into the large anterior jugular vein.