Chapter 35: Salivary Gland Diseases

Anatomy

Parotid Gland

1. Lateral aspect of face.

2. Anterior border is the masseter muscle.

3. Superior border is the zygomatic arch.

4. Posterior border is the tragal cartilage and sternocleidomastoid muscle.

5. Inferior tail of parotid is between the ramus of the mandible and sternocleidomastoid muscle, overlying the digastric muscle.

6. Deep border is the prestyloid compartment of the parapharyngeal space.

7. Superficial and deep lobes of the parotid are divided by the facial nerve.

8. Eighty percent of the parotid parenchyma is the superficial lobe.

9. Parotid is overlying the posterior aspect of mandible.

10. Covered by parotidomasseteric fascia.

    1. Attaches to the root of zygoma.

    2. Thin fascia separates from tragal and conchal cartilage by blunt dissection.

    3. Thick fascia attaches to the mastoid process.

    4. Thick fascia at the anterior and inferior tip of the parotid separating the parotid from the submandibular gland.

11. Arterial anatomy.

    1. External carotid artery courses medial to the parotid gland dividing into the maxillary artery and the superficial temporal artery. Often encountered during total parotidectomy.

    2. The superficial temporal artery gives off the transverse facial artery.

12. Venous anatomy.

    1. The maxillary and superficial temporal veins form the retromandibular vein.

    2. Retromandibular vein joins the external jugular vein via the posterior facial vein.

    3. Retromandibular vein can give off an anterior facial vein that joins the internal jugular vein that is just deep to the marginal mandibularis branch of the facial nerve.

13. Stensen duct.

    1. Traverses over the masseter muscle.

    2. Duct punctum exits the oral mucosa adjacent to the second upper molar.

14. Great auricular nerve.

    1. Arises from C2 and C3 cervical nerve branches.

    2. Divides into anterior and posterior branches.

    3. The posterior branch can sometimes be saved, reducing auricular numbness.

15. Facial nerve.

    1. Extratemporal segment exits the skull base through the stylomastoid foramen posterolateral to the styloid process and anteromedial to the mastoid process.

    2. The facial nerve branches as it enters the parotid forming the pes anserinus.

    3. The upper divisions include the temporal-facial branches.

    4. The lower divisions include the cervico-facial divisions.

    5. Numerous branching patterns are possible.

    6. Facial nerve trunk and divisions more superficial in children younger than 2 years.

16. Anatomic landmarks to identify the facial nerve.

    1. Tympano-mastoid suture line.

    2. Posterior belly of the digastric muscle (marks depth of the nerve).

    3. Tragal pointer.

    4. Retrograde identification by tracing one of the facial nerve branches.

17. Autonomic nerve supply.

    1. Glossopharyngeal nerve (cranial nerve [CN] IX) supplies parasympathetic innervation.

    2. Superior cervical ganglion supplies sympathetic innervation.

18. Parapharyngeal space.

    1. Inverted pyramid with the base at the petrous bone of the skull base; medial boundary is the lateral pharyngeal wall; the lateral boundary is the medial pterygoid muscle; the posterior boundary is the carotid sheath and vertebral bodies; the anterior boundary is the pterygomandibular raphe.

    2. Deep parotid tumors can extend into the prestyloid compartment.

    3. Poststyloid compartment contains the carotid sheath and its neurovascular structures.

Submandibular Gland

1. Superior margin is the mandible and the inferior margin is the anterior and posterior bellies of the digastric muscle forming the submandibular triangle.

2. Arterial anatomy.

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