OPTION 1

• The parotid gland normally extends anteriorly over the masseter muscle, and inferiorly over the posterior belly of the digastric muscle. 
• The parotid duct passes anteriorly across the external surface of the masseter muscle and then turns medially to penetrate the buccinator muscle of the cheek and open into the oral cavity adjacent to the crown of the second upper molar tooth. 
• The parotid gland encloses the external carotid artery, the retromandibular vein, and the origin of the extracranial part of the facial nerve [VII]. 
Structures within the Parotid Gland  
From medial to lateral side, these are as follows: 
1. Arteries: The external carotid artery enters the gland through its posteromedial surface. The maxillary artery leaves the gland through its anteromedial surface. The superficial temporal artery gives transverse facial artery and emerges at the anterior part of the superior surface. 
2. Veins: The retromandibular vein is formed within the gland by the union of the superficial temporal and maxillary veins. In the lower part of the gland, the vein divides into anterior and posterior divisions which emerge close to the apex (lower pole) of the gland. 3. Facial nerve is the nerve of the second branchial arch. The facial nerve leaves the skull by passing through the stylomastoid foramen.