Anatomic variability in the relation between the retromandibular vein and the facial nerve: a case report, literature review and classification.

Knowledge of anatomic variations concerning head and neck veins is important to surgeons performing interventions in these regions, as well as to radiologists. The retromandibular vein is used as a guide to expose the facial nerve branches inside the parotid gland, during parotid surgery and open reduction of mandibular condyle fractures. It is also used as a landmark for localisation of the nerve and compartmentalisation of parotid gland lesions preoperatively, during computed tomography, magnetic resonance imaging and sonography. In this paper, the anomalous retromandibular vein's course on the left side of a male cadaver is described. The vein was formed around the nerve, while the maxillary vein travelled medial to the facial nerve branches and superficial to the superficial temporal vein. Interestingly, the facial nerve temporofacial division crossed again the superficial temporal vein upwards, forming a "nerve fork". The incidence of the reported variability of the relationship between the retromandibular vein and the facial nerve are discussed with a detailed literature review. Accordingly, the typical deep position of the retromandibular vein in relation to the facial nerve is estimated to 88.17% to all sides. Furthermore, an updated classification system is proposed, including 4 types and subtypes.

The accessory deep peroneal nerve: a review of the literature.

The accessory deep peroneal nerve (ADPN) is a common variant branch of the superficial peroneal nerve. It unrarely participates in the innervation of the extensor digitorum brevis muscle and interferes with the differential diagnosis of peroneal nerve lesions. Several electrophysiological and anatomical studies have been conducted in order to document the topography, characteristics and prevalence of ADPN, presenting significantly different results. ADPN existence is of great clinical and surgical importance, thus the aim of this study is to select and present all the relevant data available in the literature.