PAROTID REGION STEVEN J. ZEHREN, PH.D. GENERAL REMARKS GENERAL REMARKS AND RELATIONSHIPS Sublingual fold Parotid gland Cervical branch of VII Sublingual gland Mylohyoid m. (cut) Digastric m. (anterior belly) Submandibular gland Digastric m. (posterior belly) Facial vein SALIVARY GLANDS (HISTOLOGY) PAROTID GLAND: Totally serous SUBMANDIBULAR GLAND: Mostly serous; partly mucous SUBLINGUAL GLAND: Almost completely mucous Palatine glands Molar minor salivary glands RELATIONSHIPS OF THE PAROTID GLAND (PAROTID BED) PAROTID BED (RELATIONSHIPS OF PAROTID GLAND) Ext. auditory meatus Mastoid process Styloid process Sternocleidomastoid m. Post. belly of digastric m. Carotid sheath (& contents) Ramus of mandible Stylohyoid m. PAROTID BED (HORIZONTAL SECTION) Masseter m. Ramus of mandible Medial pterygoid m. Facial n. (VII) Retromandibular v. Ext. carotid a. Parotid gland Stylohyoid m. Sternocleidomastoid m. Post. belly of digastric m. Carotid sheath & contents LATERAL PHARYNGEAL SPACE Oropharynx Superior constrictor of pharynx Lateral pharyngeal space Medial pterygoid Parotid gland STRUCTURES WITHIN THE PAROTID GLAND Facial n. Retromandibular v. External carotid a. FACIAL NERVE (VII) WITHIN PAROTID GLAND Temporal branches Zygomatic branches Main trunk of VII TO ZANZIBAR BY MOTOR CAR Buccal branches Marginal mandibular branch Cervical branch Medial pterygoid m. Ramus of mandible Main trunk of facial n. Masseter m. Mastoid process Parotid gland Temporofacial division Temporal br. Zygomatic brs. Main trunk of facial n. Buccal brs. Cervicofacial division Marginal mandibular br. Cervical br. Superficial temporal v. Maxillary v. Facial v. Posterior auricular v. External jugular v. Retromandibular v. Common facial v. (to IJV) Superficial temporal a. Maxillary a. External carotid a. PAROTID FASCIA PAROTID FASCIA Parotid fascia Investing layer of deep cervical fascia Stylomandibular lig. Stylomandibular lig. Submandibular fossa PAROTID DUCT (STENSON’S DUCT) RELATIONSHIPS OF PAROTID DUCT Zygomatic arch Transverse facial a. Accessory parotid gland Parotid duct Buccinator m. Masseter m. Parotid gland TERMINATION OF PAROTID DUCT Parotid papilla (opposite maxillary 2nd molar) NERVE SUPPLY TO THE PAROTID GLAND AUTONOMIC INNERVATION OF PAROTID GLAND Otic ganglion V3 Auriculotemporal n. Lesser petrosal n. IX (Glossopharyngeal n.) Inf. salivatory nucleus Parotid gland Medulla Tympanic plexus Tympanic n. Presynaptic parasympathetic Postsynaptic parasympathetic AUTONOMIC INNERVATION OF PAROTID GLAND (DISSECTION, MEDIAL VIEW) Tympanic cavity V3 (Mandibular n.) Otic ganglion Auriculotemporal n. Lesser petrosal n. SENSORY INNERVATION TO THE PAROTID GLAND Auriculotemporal n. (V3) FREY’S SYNDROME (GUSTATORY SWEATING) FREY’S SYNDROME Auriculotemporal n. (V3) Great auricular n. (C2,3) Gustatory Sweating (Frey's Syndrome) This woman had undergone a parotidectomy for a benign mixed tumor of the parotid gland a year before this photo was taken. The picture was taken just as she was taking some food by mouth. Note that upon gustatory stimulation there is localized sweating over the area where the skin flap was raised for the parotidectomy. With removal of the parotid the secretory fibers carried by the auriculotemporal nerve were cut. These unsatisfied nerve ends regrew to join the sympathetic nerve ends on the elevated skin flap. When parotid secretion is called for the sweat glands From Mosby, “Clinical Anatomy Interactive Lesson” respond. TREATMENT & PREVENTION OF FREY’S SYNDROME MEDICAL 1. Topical anticholinergic creams/lotions. 2. Intracutaneous injection of Botulinum toxin A. SURGICAL 1. Transmeatal tympanic neurectomy. 2. Procedures which involve the interposition of a tissue barrier (eg., fascia lata or fat grafts). 3. Sternocleidomastoid muscle flap. TYMPANIC NEURECTOMY Promontory of middle ear cavity with tympanic nerve (branch of IX) and plexus under mucosa Mastoid process STERNOCLEIDOMASTOID MUSCLE FLAP ROTATED ONTO THE DEEP LOBE OF THE PAROTID GLAND BLOOD SUPPLY & LYMPHATIC DRAINAGE OF THE PAROTID GLAND Superficial temporal a. Maxillary a. External carotid a. Superficial temporal v. Maxillary v. Facial v. Posterior auricular v. External jugular v. Retromandibular v. Common facial v. (to IJV) Parotid nodes Deep cervical nodes END OF LECTURE