💧 Salivary Gland Hypofunction Mechanism Simulator

Normal Salivary Gland Function

Three paired glands secrete saliva continuously and adequately.

• 0.3–0.4: Total resting flow (mL/min, healthy baseline)
• ~20%: Parotid contribution (serous, enzyme-rich)
• ~65%: Submandibular contribution (mixed seromucous)
• ~8%: Sublingual contribution (mucin-rich, viscous)

Three paired major glands

Parotid, submandibular, and sublingual glands work together.

Healthy adults produce about one liter of saliva daily.

Ducts deliver saliva into the mouth

Stensen's and Wharton's ducts channel secretions orally.

Balanced composition sustains oral health

Enzymes, mucins, and buffers protect teeth and tissue.

Parotid Gland Hypofunction

Reduced parotid output lowers the watery, enzyme-rich fraction.

• ↓ 65%: Parotid flow (serous acinar loss)
• ↓: Amylase output (starch digestion impaired)
• ↓: Bicarbonate buffering (less acid neutralization)
• more acidic: Oral pH swing (reduced buffering capacity)

Serous acini produce watery fluid

Parotid acini secrete thin, enzyme-rich, bicarbonate-heavy saliva.

Parotid saliva supplies most of the bicarbonate buffer.

Amylase and buffering decline together

Less parotid flow means less starch digestion and buffering.

Cheek and molar dryness appears first

Stensen's duct output near the molars drops noticeably.

Submandibular & Sublingual Hypofunction

Reduced mixed seromucous secretion thins the protective mucin coat.

• ↓ 70%: Submandibular flow (largest resting contributor lost)
• ↓: Mucin concentration (less viscoelastic coating)
• ↓: Lubrication adequacy (friction rises on mucosa)
• reduced: Floor-of-mouth wetness (Wharton's duct output falls)

Submandibular glands dominate resting flow

They normally supply most saliva at rest.

Submandibular glands provide about two-thirds of resting saliva.

Mucins provide lubrication and coating

Sublingual mucus protects mucosa from friction and drying.

Speech and swallowing feel effortful

Thinner lubrication makes chewing and talking harder.

Combined Salivary Gland Hypofunction

All three gland pairs underperform, and total flow drops sharply.

• ↓ 80%: Total flow (well below normal baseline)
• high: Xerostomia risk (subjective dry mouth likely)
• slow: Oral clearance rate (food and debris linger)
• acidic drift: Salivary pH (buffering overwhelmed)

Flow falls below the functional threshold

Below roughly 0.1 mL/min, the mouth feels dry.

Below 0.1 mL/min resting flow, xerostomia symptoms typically appear.

Multiple functions fail simultaneously

Lubrication, buffering, and clearance all decline together.

Common causes compound gland damage

Sjögren's syndrome, radiation, and medications drive combined loss.

Functional Consequences of Hypofunction

Impaired saliva raises decay, infection, and discomfort risk.

• elevated: Caries risk (less remineralization and clearance)
• elevated: Oral infection risk (reduced antimicrobial defense)
• reduced: Mucosal comfort (friction, soreness, fissuring)
• depleted: Antimicrobial proteins (lysozyme, lactoferrin, sIgA fall)

Lubrication loss causes mucosal damage

Dry tissue cracks, chafes, and becomes sore.

Chronic hypofunction significantly raises dental caries and candidiasis risk.

Buffering loss accelerates tooth decay

Acid lingers longer without bicarbonate neutralization.

Antimicrobial proteins normally guard the mouth

Lysozyme, lactoferrin, and sIgA control microbial growth.