Absence of retromandibular vein associated with atypical formation of external jugular vein in the parotid region / 대한해부학회지

Veins of the head and neck exhibiting anatomical variations or malformations are clinically significant. Anatomical variation in the external jugular vein is very common. However, anatomical variation in the retromandibular vein is rare. In this paper, we report a rare case of complete absence of the retromandibular vein. In the absence of the retromandibular vein, the maxillary vein divided into anterior and posterior divisions. The posterior division joined the superficial temporal vein to form an atypical external jugular vein, and the anterior division joined the facial vein to form an anonymous vein. In clinical practice, radiologists and surgeons use the retromandibular vein as a guide to expose the branches of the facial nerve during superficial parotidectomy. Therefore, absence of the retromandibular vein is a hurdle during this procedure and may affect the venous drainage pattern from the head and neck.

Absence of retromandibular vein associated with atypical formation of external jugular vein in the parotid region / 대한해부학회지

Veins of the head and neck exhibiting anatomical variations or malformations are clinically significant. Anatomical variation in the external jugular vein is very common. However, anatomical variation in the retromandibular vein is rare. In this paper, we report a rare case of complete absence of the retromandibular vein. In the absence of the retromandibular vein, the maxillary vein divided into anterior and posterior divisions. The posterior division joined the superficial temporal vein to form an atypical external jugular vein, and the anterior division joined the facial vein to form an anonymous vein. In clinical practice, radiologists and surgeons use the retromandibular vein as a guide to expose the branches of the facial nerve during superficial parotidectomy. Therefore, absence of the retromandibular vein is a hurdle during this procedure and may affect the venous drainage pattern from the head and neck.

Analysis of the morphometry and variations in the extensor digitorum brevis muscle: an anatomic guide for muscle flap and tendon transfer surgical dissection / 대한해부학회지

The extensor digitorum brevis muscle (EDB) is a practical option for use as an island flap or free flap when reconstructing soft tissue defects in the ankle as well as in the entire lower limb. It is frequently used to correct crossover toe deformity and other painful toe disorders. We evaluated the morphometry of the EDB in 44 formalin-fixed limbs. Length and width of the muscles were measured. Surface area was calculated as the product of length and width of the muscle. The length of each tendon was also measured from its origin to the point of distal attachment. Presence of any additional tendons was noted. Mean length, width, and surface area of the muscle were 7.39+/-0.71 cm, 4.1+/-0.37 cm, and 30.5+/-4.78 cm2 on the right side and 7.2+/-0.84 cm, 3.9+/-0.37 cm, and 28.4+/-5.35 cm2 on the left side, respectively. Morphometry of the tendons revealed that the tendon of the great toe had the highest mean length (9.5 cm) and the tendon of the fourth toe had the lowest mean length (6.3 cm). Four of the limbs studied (9.09%) had only three tendons. Three of the limbs studied (6.81%) had five tendons, and in one exceptional case (2.27%), six tendons were detected. These observations have significant value and are applicable to plastic and orthopedic surgery.

Communication of the anterior branch of the great auricular nerve with the cervical branch of facial nerve and its variant nerve endings deep in the parotid gland / Comunicación del ramo anterior del nervio auricular mayor con el ramo cervical del nervio facial y sus terminaciones nerviosas profundas variantes en la glándula parótida

The communications between the branches of cervical plexus and cervical branch of facial nerve are common and are well known. However, this communication usually occurs between the transverse cervical nerve and cervical branch of facial nerve. During routine dissection classes for the Medical undergraduate students, we came across an anatomical variant of anterior division of great auricular nerve. This variation was found in a 60-year-old male cadaver of South Indian origin and it was unilateral. The great auricular nerve arose from the loop of ventral rami of C2 and C3 spinal nerves and divided into anterior and posterior branches. The anterior branch ran obliquely upwards and forwards on the surface of the sternocleidomastoid muscle along with the external jugular vein towards the apex of parotid gland and divided into many branches. One of these branches gave a communicating branch to cervical branch of facial nerve outside the parotid gland. Nerve endings of the remaining branches were found to penetrate the interlobular septa and a few of them were seen deep in the gland along the ducts and near the vessels. The functional significance of anatomic variations of nerve endings in relation to ducts, thin vessels deep in the parotid gland, observed in the present case are yet to be evaluated...

Las comunicaciones entre los ramos del plexo cervical y ramo cervical del nervio facial son comunes y bien conocidos. Sin embargo, esta comunicación por lo general ocurre entre el nervio cervical transverso y el ramo cervical del nervio facial. Durante las clases de disección de rutina para los estudiantes de pregrado de medicina, nos encontramos con una variante anatómica de la división anterior del nervio auricular mayor, unilateral, en un cadáver de sexo masculino de 60 años, del Sur de la India. El nervio auricular mayor se originó desde el bucle de los ramos ventrales de los nervios espinales C2 y C3, y dividió en ramos anterior y posterior. El ramo anterior se dirigió oblicuamente hacia arriba y adelante sobre la superficie del músculo esternocleidomastoideo junto con la vena yugular externa hacia el ápice de la glándula parótida y se dividió en numerosos ramos terminales. Uno de estos ramos dió un ramo comunicante al ramo cervical del nervio facial fuera de la glándula parótida. Las terminaciones nerviosas de los ramos restantes penetraron en los septos interlobulares. Algunos de éstos se observaron profundos en la glándula a lo largo de los conductos y cerca de los vasos. La importancia funcional de las variaciones anatómicas de las terminaciones nerviosas en relación a los conductos y vasos finos profundos en la glándula parótida aquí observados aún no se han evaluado...