Lymphocytes Begin Infiltrating the Salivary Glands
Autoreactive T and B cells target the salivary gland as the first oral event.
- Acinar cells: Primary target (saliva-producing units)
- CD4+ T cells: Infiltrate type (periductal foci)
- Near normal: Saliva flow (compensated stage)
- Often silent: Symptom onset (years before diagnosis)
Focal lymphocytic sialadenitis
Lymphocyte clusters form around small salivary ducts.
Autoantibody involvement
Anti-Ro/SSA and anti-La/SSB antibodies mark gland attack.
Reserve capacity masks damage
Remaining acini compensate, so saliva output stays adequate.
Acinar Tissue Is Progressively Replaced by Infiltrate
Ongoing autoimmune attack destroys secretory acini faster than they regenerate.
- ~40-60%: Acinar loss (by this stage)
- Rising: Focus score (lymphocyte foci per 4mm²)
- Declining: Saliva flow (unstimulated rate falls)
- Symptoms emerge: Patient awareness (dry mouth noticed)
Fibrous replacement
Destroyed acini are replaced by fibrous, non-secretory tissue.
Duct epithelium changes
Ductal cells upregulate immune-signaling molecules, worsening the attack.
Xerostomia begins
Reduced flow starts drying speech, chewing, and swallowing.
Severe Hyposalivation Leaves the Mouth Chronically Dry
Glandular destruction now overwhelms compensation, and saliva output collapses.
- <0.1 mL/min: Unstimulated flow (diagnostic threshold)
- ~25-30%: Acinar tissue left (of original volume)
- Drops: Oral pH (buffering capacity lost)
- Impaired: Speech/swallowing (lubrication insufficient)
Loss of salivary buffering
Bicarbonate buffering fails, letting oral pH fall sharply.
Antimicrobial proteins depleted
Lysozyme and lactoferrin drop, weakening the mouth's defenses.
Daily function suffers
Eating dry food, talking, and sleeping all become harder.
Oral Mucosa Turns Atrophic, Fissured, and Fragile
Without lubrication, the mucosal surface thins, cracks, and injures easily.
- Compromised: Mucosal integrity (atrophic epithelium)
- Fissured, lobulated: Tongue changes (papillae loss)
- Common: Angular cheilitis (cracked mouth corners)
- Poor: Denture tolerance (friction ulcers form)
Epithelial thinning
Chronic dryness thins the mucosal lining over time.
Fissuring and trauma
Cracked mucosa tears easily from food or dentures.
Loss of protective mucin
Reduced mucin coating removes the mouth's lubricating shield.
Candidiasis and Rampant Caries Take Hold
Lost salivary protection lets fungal overgrowth and dental decay accelerate rapidly.
- ~70-80%: Oral candidiasis (of severe Sjögren's cases)
- Cervical, rampant: Caries pattern (atypical decay sites)
- Sharply elevated: Tooth loss risk (vs healthy controls)
- Frequent: Denture stomatitis (candida-driven inflammation)
Fungal overgrowth
Candida albicans thrives once antimicrobial saliva disappears.
Rampant dental caries
Lost remineralization drives decay at the gumline and roots.
Compounding cycle
Infection and decay further damage an already fragile mucosa.