1 6 HEAD AND NECK 



(see p. 122). After the various structures mentioned have been 

 cleaned proceed to the study of the anterior facial vein, the 

 external maxillary artery, and the terminal branches of the 

 facial nerve. 



Vena Facialis Anterior (O.T. Facial). The anterior 

 facial vein is a less tortuous vessel than the external maxillary 

 artery, to which it corresponds ; and it lies posterior to the 

 artery, and on a slightly more superficial plane (Fig. 15). It 

 commences as the angular vein, which is formed at the medial 

 commissure of the eyelids, by the union of the frontal, and 

 supra-orbital veins, which descend from the forehead. It 

 passes downwards and backwards, in a comparatively straight 

 line, to the anterior inferior angle of the masseter, which it 

 crosses immediately behind the external maxillary artery ; then 

 it pierces the deep fascia of the neck, and enters the sub- 

 maxillary triangle. In the upper part of the face it lies on 

 the quadratus labii superioris ; then it is situated between the 

 zygomaticus and the risorius superficially and the buccinator 

 deeply ; and as it crosses the anterior angle of the masseter 

 it is covered with the skin, superficial fascia, and the platysma. 



Tributaries. In addition to the frontal and supra-orbital 

 veins, it receives external nasal, palpebral, superior labial, 

 inferior labial, masseteric and superficial parotid tributaries. 

 As it crosses the buccinator muscle it is joined by the deep 

 facial vein, which connects it with the pterygoid plexus of 

 veins in the infra-temporal region. 



Arteria Maxillaris Externa (O.T. Facial). The ex- 

 ternal maxillary artery is a tortuous vessel which enters the 

 face at the lower and anterior angle of the masseter, after 

 turning round the lower border of the mandible and piercing 

 the deep fascia of the neck. From that point it runs 

 forwards and upwards to the angle of the mouth, where it 

 assumes a more vertical direction, and becomes the angular 

 artery, which ascends, in the substance of the angular head 

 of the quadratus labii superioris, to the medial commissure of 

 the eyelids. Immediately after its entrance into the face it 

 is comparatively superficial, being covered by skin, superficial 

 fascia, and platysma, and it is easily compressed against the 

 bone. More anteriorly it lies between the zygomaticus 

 superficially and the buccinator deeply, then between the 

 quadratus labii superioris and the caninus, which springs 

 from the maxilla below the infra-orbital foramen. Its 



