14 HEAD AND NECK 



raise the fascia from the gland, dissecting carefully forwards, 

 upwards, and downwards. As the extremities and the anterior 

 border of the gland are approached, look carefully for nerves 

 and vessels which emerge from beneath them, and also for 

 the duct of the gland, which appears from under cover of the 

 anterior border about a finger's breadth below the zygoma. 

 The duct has thick walls, is of considerable size, and is easily 

 recognised. It runs forwards across the masseter and turns 

 round the anterior border of the muscle, bending at right angles 

 to its original course. It pierces, in turn, the fascia covering 

 the buccinator muscle, the buccinator muscle itself and the 

 mucous membrane of the mouth ; and it opens into the vestibule 

 of the mouth, on a small papilla, opposite the second molar tooth 

 of the maxilla. Above the duct and below the zygomatic arch 

 find (i) the accessory parotid, a small detached part of the parotid 

 which lies a short distance in front of the anterior border of the 

 main mass of the gland ; (2) the transverse facial vessels ; and 

 (3) the zygomatic branches of the facial nerve. Below the duct 

 find the buccal and the mandibular branches of the facial nerve. 

 At the upper end of the parotid seek for the superficial temporal 

 vessels. Posterior to them lies the auriculo-temporal branch 

 of the third division of the trigeminal nerve, and anterior to 

 them, the temporal branches of the facial nerve. From the 

 lower extremity of the gland emerge (i) the cervical branch of 

 the facial nerve, (2) the posterior facial vein (O.T. anterior 

 division of the temporo-maxillary vein), and (3) a tributary of 

 the external jugular vein (Fig. 15). 



Follow the temporal branch of the facial nerve upwards and 

 forwards to the frontal belly of the epicranius and the upper 

 part of the orbicularis oculi. As the temporal branch is cleaned 

 the anterior part of the strong temporal fascia will be exposed. 

 It is attached to the upper border of the zygomatic arch, the 

 posterior border of the zygomatic bone, and the temporal line 

 on the frontal bone. Springing from it, above the posterior part 

 of the zygoma, is the anterior muscle of the auricle, and at a 

 higher level the superior muscle of the auricle. Attempt to define 

 both the muscles and the branches which pass to them from the 

 temporal division of the facial nerve. A short distance behind 

 a prominent tubercle, which can be felt on the posterior border 

 of the zygomatic bone, the zjgomatico -temporal branch of the 

 rnflvill a ry division -oi- the, trigeminal nerve pierces the temporal 

 fasciaLand communicates with the temporal branch of the facial 

 nerve. An attempt should be made to secure the zygomatico- 

 temporal nerve and to define the connection. 



Further dissection is required before the zygomatic buccal 

 and mandibular branches of the facial nerve can be traced to 

 their terminations. As the dissection proceeds the deeper 

 muscles of the face, branches of the trigeminal nerve and the 

 internal maxillary artery will be exposed, whilst at the same time 

 the externally maxillary artery and its branches and the anterior 

 facial vein and its tributaries must be cleaned. 



Follow the upper zygomatic branches of the facial nerve 

 forwards to their termination in the lateral part of the orbicu- 

 laris oculi, then reflect that muscle towards the median plane 

 and under cover of it, emerging from the zygomatic bone, 

 find the zygorgQlico-facial branch of the maxillary division of 



