Parotid Gland

Fig. 8.65 — Parotid Gland. (A) Lateral view showing facial nerve branches and parotid duct. (B) Cross-sectional relations. — Gray's Anatomy for Students

1. Overview

2. Location & Borders

3. Lobes

• The superficial lobe lies lateral to the facial nerve, overlying the lateral surface of the masseter.
• The deep lobe lies medial to the facial nerve, situated between the mastoid process and the mandibular ramus; it can extend into the pretyloid compartment of the parapharyngeal space.

4. Parotid (Stensen's) Duct

• Leaves the anterior edge of the gland midway between the zygomatic arch and the corner of the mouth.
• Traverses across the external surface of the masseter muscle in a transverse direction.
• At the anterior border of the masseter, turns medially into the buccal fat pad.
• Pierces the buccinator muscle and opens into the oral cavity opposite the crown of the second upper molar tooth.

An accessory parotid gland may be present superiorly related to the duct.

5. Structures Passing Through the Gland

1. Facial nerve [CN VII] — most superficial
2. Retromandibular vein — intermediate
3. External carotid artery — deepest

6. Facial Nerve Relations

• Upper divisions: temporofacial branches
• Lower divisions: cervicofacial branches

Surgical landmark identification of the facial nerve:

• Tympanomastoid suture line
• Posterior belly of digastric muscle (marks depth of nerve)
• Tragal pointer (nerve lies ~1 cm deep and inferior to the tip of the tragal cartilage)
• Retrograde identification from a peripheral branch

7. Blood Supply

Arterial

• The external carotid artery courses medially within the gland, dividing into:
  • Maxillary artery (passes horizontally, deep to the mandible)
  • Superficial temporal artery (exits the upper border, gives off the transverse facial artery)
• Posterior auricular artery — given off before the terminal division

Venous

• The superficial temporal vein and maxillary vein join within the gland to form the retromandibular vein.
• The retromandibular vein divides below the gland into:
  • Posterior branch → joins external jugular vein
  • Anterior branch → joins facial vein → drains to internal jugular vein (lies just deep to the marginal mandibular branch of CN VII)

8. Nerve Supply (Innervation)

Secretomotor (Parasympathetic) Pathway

1. Glossopharyngeal nerve [CN IX] — provides preganglionic parasympathetic fibers via the tympanic branch (Jacobson's nerve) → tympanic plexus → lesser petrosal nerve
2. Preganglionic fibers synapse in the otic ganglion (just inferior to foramen ovale)
3. Postganglionic fibers travel with the auriculotemporal nerve (branch of V3) → parotid gland

Sympathetic

• Superior cervical ganglion supplies postganglionic sympathetic fibers (vasoconstrictor to the gland)

Sensory

• Auriculotemporal nerve (branch of mandibular nerve [V3], exits skull via foramen ovale) provides sensory innervation to the gland and the external ear; it also carries the secretomotor fibers described above.

Skin overlying the gland

• The great auricular nerve (C2, C3) — divides into anterior and posterior branches — provides cutaneous innervation. The posterior branch can sometimes be preserved during parotidectomy to reduce auricular numbness.

9. Lymphatic Drainage

10. Histology

11. Clinical Correlations

Frey's Syndrome (Auriculotemporal Syndrome)

Parotid Stones (Sialolithiasis)

Parotid Tumors

• ~90% of all salivary gland neoplasms occur in the parotid.
• ~75% are benign; ~25% are malignant or of variable aggressiveness.
• Most common benign tumor: Pleomorphic adenoma (mixed tumor)
• Common benign tumor: Adenolymphoma (Warthin's tumor)
• Malignant tumors (in descending frequency): mucoepidermoid carcinoma, adenoid cystic carcinoma, adenocarcinoma, epidermoid carcinoma, undifferentiated carcinoma, carcinoma ex pleomorphic adenoma.
• Deep lobe tumors can extend into the pretyloid compartment of the parapharyngeal space, presenting as a parapharyngeal mass.
• Facial nerve sacrifice risk must be considered in all parotid surgery; damage to upper branches prevents voluntary eyelid closure (risk of corneal injury); lower branch damage causes facial asymmetry.

Acute Suppurative Parotitis

Mumps Parotitis

Parotidectomy

• The facial nerve divides the gland into superficial and deep lobes and is the critical surgical landmark.
• Superficial parotidectomy (preserving CN VII) is the procedure of choice for most benign tumors.
• Total parotidectomy may involve the external carotid artery medially.

• (a) Presenting parts — 5
• (b) Capsule — 2
• (c) Structures passing through gland — 5
• (d) Nerve supply — 5
• (e) Applied — 3

Q1. Parotid Gland — 20 Marks

Fig. — Parotid Gland. (A) Lateral view showing facial nerve branches, parotid duct, and vessels. (B) Cross-sectional relations. — Gray's Anatomy for Students

(a) Presenting Parts — [5 Marks]

Location & Shape

• the ramus of the mandible anteriorly
• the base of the skull superiorly
• the mastoid process posteriorly

• Superiorly up to the zygomatic arch
• Inferiorly down to the lower border of the mandible
• Anteriorly halfway across the masseter muscle (and over the sternocleidomastoid posteriorly)

Lobes

• Superficial lobe — 80% of the parenchyma; lies lateral to the facial nerve, overlying the masseter
• Deep (retromandibular) lobe — lies medial to the facial nerve, between the mastoid process and mandibular ramus; can extend into the pretyloid compartment of the parapharyngeal space

Parotid (Stensen's) Duct

• Leaves the anterior border of the gland midway between the zygomatic arch and the corner of the mouth
• Runs horizontally over the masseter muscle
• At the anterior border of masseter, turns medially through the buccal fat pad
• Pierces the buccinator muscle
• Opens into the oral cavity at the level of the crown of the 2nd upper molar tooth

Accessory parotid gland: Present in 21–61% of individuals; lies on the masseter anterior to Stensen's duct, with a secondary duct joining the main duct.

Lymphatics

(b) Capsule — [2 Marks]

Formation

• Vessels, nerves (facial nerve), and lymph nodes are all trapped within the capsule/substance of the gland
• The capsule merges with the investing (deep cervical) fascia — from the zygoma and temporomandibular joint above, over the masseter anteriorly, to the styloid base, posterior belly of digastric, and sternocleidomastoid posteroinferiorly

Structure

• The capsule is formed from the split investing layer of the deep cervical fascia (parotidomasseteric fascia)
• Superficial part is thin and closely related to the tragal and conchal cartilage
• Deep part is thick and attaches to the mastoid process
• The thick inferior portion separates the parotid from the submandibular gland
• The superficial musculoaponeurotic system (SMAS) is closely approximated to this capsule

Clinical Importance of Capsule

(c) Structures Passing Through the Gland — [5 Marks]

1. Facial Nerve [CN VII] — Most Superficial

• Exits the skull through the stylomastoid foramen (posterolateral to styloid process, anteromedial to mastoid process)
• Enters the posteromedial surface of the parotid and forms the pes anserinus (goose's foot)
• Divides into upper (temporofacial) and lower (cervicofacial) divisions within the gland
• Five terminal branch groups emerge from the gland's borders:

The facial nerve divides the parotid into superficial (80%) and deep (20%) lobes — Patey's faciovenous plane.

2. Retromandibular Vein — Intermediate

• Formed within the gland by the union of the superficial temporal vein and maxillary vein
• Passes inferiorly through the gland
• Divides just below the inferior border into:
  • Posterior branch → joins the posterior auricular vein → external jugular vein
  • Anterior branch → joins the facial vein → internal jugular vein (lies just deep to the marginal mandibular branch of CN VII — surgical landmark)

3. External Carotid Artery — Deepest

• Enters via the inferior border of the gland
• Gives off the posterior auricular artery within the gland
• Divides into its two terminal branches near the lower border of the ear:
  • Maxillary artery — passes horizontally, deep to the mandible
  • Superficial temporal artery — exits the superior border after giving off the transverse facial artery

Other Structures (Embedded or Related)

• Intraparotid lymph nodes — embedded within the substance (particularly in superficial lobe)
• Great auricular nerve (C2, C3) — runs on the surface of the gland
• Auriculotemporal nerve — enters and carries secretomotor fibers to the gland

(d) Nerve Supply — [5 Marks]

1. Secretomotor (Parasympathetic) — The Main Pathway

Inferior salivatory nucleus (medulla)
        ↓
Glossopharyngeal nerve [CN IX]
        ↓
Jacobson's nerve (tympanic branch of CN IX)
→ enters via inferior tympanic canaliculus
        ↓
Tympanic plexus (in middle ear)
        ↓
Lesser petrosal nerve (preganglionic parasympathetic)
→ exits skull via foramen ovale (or a small canal near it)
        ↓
Otic ganglion (just below foramen ovale, medial to mandibular nerve V3)
→ SYNAPSE here
        ↓
Postganglionic secretomotor fibers
→ join the AURICULOTEMPORAL NERVE (branch of V3)
        ↓
Parotid gland

2. Sympathetic

• Postganglionic fibers from the superior cervical ganglion travel along the external carotid artery plexus → parotid gland
• Effect: vasoconstriction; produces small amounts of thick, mucoid saliva

3. Sensory

• Auriculotemporal nerve (branch of V3, mandibular division of trigeminal [CN V])
  • Exits skull through foramen ovale
  • Provides sensory innervation to the parotid gland and the skin overlying it, the external acoustic meatus, and the auricle

4. Skin Overlying the Gland

• Great auricular nerve (C2, C3) — anterior and posterior branches; provides cutaneous sensation over the parotid region and lower part of the auricle

(e) Applied Anatomy — [3 Marks]

1. Frey's Syndrome (Auriculotemporal/Gustatory Sweating Syndrome)

• Cause: Injury to the auriculotemporal nerve (during parotidectomy, incision for parotid abscess, or trauma)
• Mechanism: Aberrant regeneration — the cut parasympathetic secretomotor fibers regrow and reinnervate the cutaneous sweat glands (which are normally supplied by sympathetic fibers but also respond to ACh)
• Features: At mealtimes, the skin over the parotid region becomes red, hot, and sweaty (gustatory sweating and flushing); cutaneous hyperaesthesia may also be present
• Treatment: Botulinum toxin injection into the affected skin (blocks ACh release)

2. Parotid Tumors

• ~90% of salivary gland neoplasms occur in the parotid gland
• ~75% benign, ~25% malignant or intermediate
• Most common benign: Pleomorphic adenoma (mixed tumor) — slow-growing, painless, at the angle of the jaw; sudden rapid growth + pain = malignant transformation
• Adenolymphoma (Warthin's tumor) — arises in the lower pole of the parotid at the level of the lower border of mandible, slightly lower than pleomorphic adenoma; bilateral in 10%
• Malignant tumors (decreasing order): Mucoepidermoid carcinoma > Adenoid cystic carcinoma > Adenocarcinoma > Epidermoid carcinoma > Undifferentiated carcinoma
• Facial nerve involvement: Any parotid tumor must be assessed for its relation to CN VII branches. Damage to upper branches → inability to close eye (risk of corneal ulceration); damage to lower branches → facial asymmetry

3. Parotidectomy & Facial Nerve Landmarks

1. Tragal pointer — facial nerve lies ~1 cm deep and inferior to the tip of the tragal cartilage
2. Tympanomastoid suture line — nerve exits just anterior to this
3. Posterior belly of digastric — marks the depth of the nerve
4. Retrograde identification — tracing peripheral branches back to the trunk

4. Acute Parotitis & Abscess

• Infection ascends from the oral cavity (poor oral hygiene, dehydration)
• Features: brawny, oedematous swelling with signs of inflammation
• Fluctuation is a late sign due to the thick, unyielding fascial capsule
• Parotid calculi (stones): less common than submandibular stones (parotid secretion is watery); cause pain on salivation — lemon juice test reproduces symptoms

QUESTION PAPER — COMPLETE ANSWERS

Q1. Parotid Gland under Following Headings — (20 Marks)

(a) Presenting Parts — [5 Marks]

Location

• Ramus of mandible — anteriorly
• Mastoid process + base of skull — posteriorly/superiorly
• Sternocleidomastoid muscle — posteroinferiorly

• Superiorly → up to the zygomatic arch
• Inferiorly → down to lower border of mandible (tail of the parotid)
• Anteriorly → halfway across the masseter muscle

Lobes

Parotid (Stensen's) Duct

• Leaves the anterior border of gland midway between zygomatic arch and corner of mouth
• Runs horizontally across the masseter
• At anterior border of masseter turns medially through buccal fat pad
• Pierces buccinator muscle
• Opens in oral cavity opposite crown of 2nd upper molar tooth

Accessory parotid gland: Present in 21–61% of individuals; found on the masseter anterior to Stensen's duct, with its own accessory duct joining Stensen's duct.

Lymphatics

(b) Capsule — [2 Marks]

Formation (Key Point: Delayed Encapsulation)

Structure

• The capsule is formed from the split investing layer of deep cervical fascia (parotidomasseteric fascia)
• Superficial layer — thin, closely related to tragal and conchal cartilage
• Deep layer — thick, attaches to the mastoid process
• The capsule merges with the investing fascia from:
  • Zygoma + TMJ → above
  • Masseter → anteriorly
  • Styloid base + posterior belly of digastric + SCM → posteroinferiorly
• The thick inferior portion separates the parotid from the submandibular gland
• SMAS (superficial musculoaponeurotic system) is closely applied to this capsule

Clinical Importance

• Because of late encapsulation, vessels, nerves, and lymph nodes are trapped inside the gland
• The thick unyielding capsule means fluctuation is a late sign in parotid abscess
• Fascia fuses widely (temporalis above → digastric below; buccinator anteriorly → mastoid posteriorly) — making parotidectomy a difficult dissection

(c) Structures Passing Through the Gland — [5 Marks]

1. Facial Nerve [CN VII] — Most Superficial

Fig. — Parotid Gland. (A) Lateral view. (B) Cross-section. — Gray's Anatomy for Students

• Exits skull through the stylomastoid foramen (posterolateral to styloid process, anteromedial to mastoid process)
• Enters the posteromedial aspect of the parotid, forming the pes anserinus (goose's foot)
• Divides into upper (temporofacial) and lower (cervicofacial) trunks
• Five terminal branch groups emerge from the gland's borders:

The facial nerve divides the gland into superficial (80%) and deep (20%) lobes — clinically known as Patey's faciovenous plane

2. Retromandibular Vein — Intermediate Depth

• Formed within the gland by union of superficial temporal vein + maxillary vein
• Passes inferiorly through the gland
• Divides below the inferior border into:
  • Posterior branch → joins posterior auricular vein → external jugular vein
  • Anterior branch → joins facial vein → internal jugular vein (lies just deep to marginal mandibular branch of CN VII — surgical landmark)

3. External Carotid Artery — Deepest

• Enters via the inferior border of the gland
• Gives off posterior auricular artery within the gland
• Divides into two terminal branches near the lower border of the ear:
  • Maxillary artery → passes horizontally, deep to the mandible
  • Superficial temporal artery → exits the upper border, giving off the transverse facial artery

Other Structures Embedded/Related

• Intraparotid lymph nodes — embedded (mostly in superficial lobe)
• Great auricular nerve (C2, C3) — on surface of gland
• Auriculotemporal nerve — enters the gland, carrying secretomotor fibers

(d) Nerve Supply — [5 Marks]

1. Secretomotor (Parasympathetic) — The Main and Most Important Pathway

Inferior salivatory nucleus (medulla oblongata)
          ↓
Glossopharyngeal nerve [CN IX]
          ↓
Jacobson's nerve (tympanic branch of CN IX)
→ enters via inferior tympanic canaliculus
          ↓
Tympanic plexus (in middle ear, on promontory)
          ↓
Lesser petrosal nerve (preganglionic parasympathetic fibers)
→ exits skull via foramen ovale (or small canaliculus nearby)
          ↓
OTIC GANGLION (just below foramen ovale, medial to V3)
→ SYNAPSE here
          ↓
Postganglionic secretomotor fibers
→ join the AURICULOTEMPORAL NERVE (branch of V3)
          ↓
PAROTID GLAND

• Acinar secretion and ductal transport
• Vasodilation of the gland
• Contraction of myoepithelial cells → Profuse watery saliva

2. Sympathetic Innervation

• Postganglionic fibers from the superior cervical ganglion
• Travel along the external carotid artery plexus → parotid gland
• Effect: Vasoconstriction; produces small amounts of thick mucoid saliva

3. Sensory Innervation

• Auriculotemporal nerve (branch of V3 — mandibular nerve)
• Exits skull via foramen ovale
• Provides sensory innervation to:
  • The parotid gland itself
  • Skin overlying the gland
  • External acoustic meatus and auricle

4. Cutaneous (Skin over Gland)

• Great auricular nerve (C2, C3) — anterior and posterior branches

(e) Applied Anatomy — [3 Marks]

1. Frey's Syndrome (Auriculotemporal / Gustatory Sweating Syndrome)

• Cause: Injury to the auriculotemporal nerve during parotidectomy or incision for parotid abscess
• Mechanism: Aberrant regeneration — cut parasympathetic secretomotor fibers regrow and mistakenly reinnervate sweat glands of overlying skin (which are also cholinergic)
• Features: During meals — skin over parotid region becomes red, hot, and sweaty (gustatory sweating and flushing); cutaneous hyperaesthesia may be present
• Treatment: Botulinum toxin injection into affected skin

2. Parotid Tumors

• ~90% of salivary gland neoplasms occur in the parotid gland
• ~75% benign, ~25% malignant/intermediate
• Most common benign: Pleomorphic adenoma — slow-growing, painless, at angle of jaw; sudden rapid growth + pain = malignant transformation
• Adenolymphoma (Warthin's tumor) — arises at lower pole of parotid near lower border of mandible; bilateral in 10%; occurs in older male smokers
• Malignant tumors (decreasing order): Mucoepidermoid carcinoma > Adenoid cystic carcinoma > Adenocarcinoma > Epidermoid carcinoma > Undifferentiated carcinoma
• Facial nerve involvement → upper branch damage → inability to close eye (corneal ulceration); lower branch damage → facial asymmetry

3. Parotidectomy — Facial Nerve Landmarks

1. Tragal pointer — nerve lies ~1 cm deep and inferior to tip of tragal cartilage
2. Tympanomastoid suture line — nerve exits just anterior to this
3. Posterior belly of digastric — marks depth of nerve
4. Retrograde dissection — tracing peripheral branches back to main trunk

Q2. Venous Drainage of the Face — Short Note (5 Marks)

Introduction

Facial Vein — Main Drainage

Fig. 8.71 — Intracranial Venous Connections of the Face. — Gray's Anatomy for Students

Formation

• Formed near the medial corner of the orbit by union of the supratrochlear vein and supra-orbital vein → forming the angular vein, which becomes the facial vein as it descends inferiorly

Course

• Descends across the face just posterior to the facial artery
• Runs obliquely (lateral to medial) downward across the cheek
• At the inferior border of the mandible, it parts from the facial artery
• Passes superficial to the submandibular gland
• Drains into the internal jugular vein

Tributaries

• Superior and inferior palpebral veins (eyelids)
• External nasal vein (dorsum of nose)
• Superior and inferior labial veins (lips)
• Deep facial vein (from pterygoid plexus)
• Buccal vein (cheek)
• Mental vein (chin)
• Infraorbital vein

Transverse Facial Vein

• Accompanies the transverse facial artery across the face
• Drains into the superficial temporal vein within the substance of the parotid gland

Deep (Intracranial) Venous Connections — Clinically Important

Critical Feature: No Valves The facial vein and all venous channels in the head have NO valves — blood can move in any direction.

Danger Area / Danger Triangle of the Face

• The area bounded by the upper lip and nose (angles of the mouth to the root of the nose)
• Infections in this area (boils, furuncles) can spread intracranially via:
  • Facial vein → Angular vein → Ophthalmic veins → Cavernous sinus
• Can lead to cavernous sinus thrombosis — a life-threatening complication with features of: proptosis, chemosis, ophthalmoplegia, headache, fever
• Clinical rule: Never squeeze a boil in the "danger area" of the face

Applied

• Cavernous sinus thrombosis: Spread of infection from the face (especially nasolabial region) via the valveless facial/ophthalmic veins
• Facial vein used in surgery: The facial vein serves as a landmark for identifying the marginal mandibular branch of the facial nerve (nerve lies superficial to the vessels at the mandibular border)

Q3. Carotid Triangle — Short Note (5 Marks)

Definition

Boundaries

Fig. 8.173 — Carotid Triangle. — Gray's Anatomy for Students

Contents

Arteries

1. Common carotid artery — ascends through the triangle
2. External carotid artery — branches immediately after bifurcation; gives off multiple branches in the triangle:
   • Superior thyroid artery
   • Ascending pharyngeal artery
   • Lingual artery
   • Facial artery
   • Occipital artery
3. Internal carotid artery — ascends with no branches in the neck
4. Carotid sinus — dilation at the bifurcation (at the level of superior border of thyroid cartilage, C3/C4 level); contains baroreceptors (pressure receptors) innervated by the glossopharyngeal nerve [IX]
5. Carotid body — at the bifurcation; contains chemoreceptors (detects O₂, CO₂, pH) innervated by branches of CN IX and CN X (vagus)

Veins

1. Internal jugular vein — descends within the carotid sheath, lateral to the carotid arteries
2. Tributaries to the common facial vein

Nerves

Applied Anatomy

1. Carotid pulse palpation: The common carotid artery can be palpated in the carotid triangle by pressing posteriorly at the level of the thyroid cartilage — used in cardiac arrest assessment and monitoring
2. Carotid sinus hypersensitivity: Pressure on the carotid sinus (e.g., tight collar, during examination) stimulates baroreceptors → reflex bradycardia + hypotension (vasovagal syncope / carotid sinus syndrome)
3. Carotid endarterectomy: Surgical procedure performed via the carotid triangle for symptomatic carotid stenosis to prevent stroke
4. Carotid body tumors (paragangliomas/chemodectomas): Arise from chemoreceptors at the bifurcation; present as a pulsatile, slowly enlarging mass in the anterior triangle — splays the internal and external carotid arteries (lyre sign on angiography); mobile side-to-side but not vertically
5. Ligation of common carotid artery: Endangers blood supply to ipsilateral brain and eye

Q4. Lacrimal Apparatus — Short Note (5 Marks)

Definition

Components

1. Lacrimal gland + its ducts
2. Lacrimal canaliculi (superior and inferior)
3. Lacrimal sac
4. Nasolacrimal duct

Lacrimal Gland

Fig. 8.86 — Lacrimal Apparatus (Anterior View). — Gray's Anatomy for Students

Position

• Located in the superolateral region of the orbit (anteriorly), in a bony depression called the lacrimal fossa in the frontal bone

Division

Ducts

• Numerous ducts from both parts empty into the lateral part of the superior fornix of the conjunctiva

Flow of Tears (Lacrimal Pathway)

Lacrimal gland (secretion)
        ↓
Lateral part of superior conjunctival fornix
        ↓
Across eyeball surface (lateral → medial, aided by blinking)
        ↓
Lacrimal lake (accumulates medially at medial canthus)
        ↓
Lacrimal puncta (superior + inferior) — openings on the medial margins of each eyelid
        ↓
Lacrimal canaliculi (superior + inferior) — pass medially
        ↓
Lacrimal sac (between anterior and posterior lacrimal crests; lies posterior to medial palpebral ligament; anterior to lacrimal part of orbicularis oculi)
        ↓
Nasolacrimal duct (descends through bony nasolacrimal canal)
        ↓
Inferior meatus of the nasal cavity (opens under the inferior nasal concha)

Blinking mechanism: The lacrimal part of orbicularis oculi (Horner's muscle) contracts during blinking — dilates the lacrimal sac and draws tears in through the canaliculi (lacrimal pump mechanism)

Nerve Supply of the Lacrimal Gland

1. Secretomotor (Parasympathetic)

Facial nerve [CN VII]
        ↓
Greater petrosal nerve (preganglionic parasympathetic)
        ↓
Nerve of pterygoid canal (joins with deep petrosal nerve)
        ↓
Pterygopalatine ganglion (SYNAPSE)
        ↓
Postganglionic fibers → join maxillary nerve [V2] → zygomatic nerve 
→ zygomaticotemporal nerve → small communicating branch
        ↓
Lacrimal nerve (branch of V1) → Lacrimal gland

2. Sympathetic

• Postganglionic fibers from superior cervical ganglion
• Travel along internal carotid artery plexus → deep petrosal nerve
• Join the nerve of pterygoid canal → follow same route as parasympathetic fibers → lacrimal gland

3. Sensory

• Lacrimal nerve — branch of ophthalmic nerve [V1] — provides sensory innervation to the lacrimal gland

Blood Supply

• Arterial: Lacrimal artery (branch of ophthalmic artery, itself a branch of the internal carotid artery)
• Venous: Drains via the ophthalmic veins

Applied Anatomy

1. Dacryocystitis

• Infection/inflammation of the lacrimal sac
• Usually due to obstruction of the nasolacrimal duct
• Presents as painful swelling at the medial canthus, below the medial palpebral ligament, with epiphora (watering eyes) and mucopurulent discharge
• Treatment: Warm compresses, antibiotics; surgical — dacryocystorhinostomy (DCR) to create a new drainage passage

2. Dacryocystorhinostomy (DCR)

• Surgical bypass of the blocked nasolacrimal duct, creating a new connection between the lacrimal sac and nasal cavity

3. Epiphora (Watering Eye)

• Overflow of tears onto the cheek
• Causes: Ectropion (everted punctum), blocked nasolacrimal duct, excessive tear production

4. Crocodile Tear Syndrome

• Aberrant regeneration following facial nerve (CN VII) palsy — parasympathetic fibers to salivary glands regrow and reinnervate the lacrimal gland
• Patient produces tears while eating (gustatory lacrimation)

5. Lacrimal Gland Tumors

• Most common are pleomorphic adenomas (benign mixed tumors)
• Present as painless swelling in the superolateral orbit, causing proptosis and downward displacement of the globe