Salivary glands and saliva explained

Reviewed by Dr. Samar Fadavi, DDS

Short answer: Your salivary glands make saliva, which protects teeth from decay, helps you chew, swallow and taste, and keeps the mouth comfortable. When saliva drops, often because of medications, cavities and gum problems rise quickly. Sipping water, using fluoride and seeing your dentist regularly help. Swelling, pain or a lump near a gland should be checked.

Where your salivary glands are

You have three pairs of major salivary glands and hundreds of tiny minor glands:

• Parotid glands sit in front of each ear and over the back of the jaw. They are the largest, and they release watery saliva near the upper back teeth, especially while you eat.
• Submandibular glands lie under the jawbone on each side. They make much of the saliva in your mouth at rest, and their ducts open under the tongue.
• Sublingual glands are the smallest major glands and sit under the tongue, in the floor of the mouth.
• Minor salivary glands are spread through the lips, cheeks, palate and throat, keeping the lining of the mouth moist.

Together they produce roughly half a litre to a litre and a half of saliva a day. Flow rises when you smell, taste and chew food, and falls during sleep. This guide explains what saliva does, why the mouth can become dry, common gland problems and how to protect your teeth. It is general information for patients in Scarborough, the Danforth and East Toronto.

What saliva does for you

• Protects teeth. Saliva washes away food and neutralizes acids made by plaque bacteria after you eat. It also carries calcium and phosphate that help repair early weak spots in enamel.
• Helps digestion. Enzymes in saliva start breaking down starches, and saliva moistens food so it can be chewed and swallowed.
• Supports taste. Flavours dissolve in saliva so taste buds can detect them.
• Fights germs. Saliva contains antibodies and natural antibacterial substances that help keep the mouth in balance.
• Keeps the mouth comfortable. It lubricates the lips, tongue and cheeks for speaking and helps dentures stay in place.
• Helps healing. Saliva contains growth factors that help small cuts and sores in the mouth heal.

Dry mouth: when saliva runs low

Dry mouth, also called xerostomia, is very common, especially in older adults. It is not a normal part of aging on its own. Most often it is caused by something that can be identified and managed.

Common causes

• Medications. Hundreds of medicines reduce saliva, including many for blood pressure, depression, anxiety, allergies, sleep, pain, bladder control and Parkinson’s disease. The effect adds up when you take several.
• Health conditions. Diabetes, Sjögren’s syndrome, thyroid conditions, some autoimmune conditions and dehydration can all lower saliva.
• Cancer treatment. Radiation to the head and neck can damage salivary glands. Some chemotherapy thickens saliva for a time.
• Mouth breathing and snoring. Breathing through the mouth at night dries the tissues, and sleep apnea machines can add to dryness.
• Habits. Smoking, vaping, cannabis, alcohol and large amounts of caffeine dry the mouth.

Signs of dry mouth

• A sticky, dry feeling or frequent thirst.
• Trouble chewing, swallowing or speaking, especially dry foods.
• Cracked lips, sores at the corners of the mouth or a burning tongue.
• Bad breath. Our guide to mouth odour explains the link.
• Dentures that rub or feel loose.
• New cavities, especially near the gum line or around old fillings.

Why dry mouth matters for your teeth

Without enough saliva, acids stay on teeth longer, food lingers and bacteria grow more freely. Cavities can develop quickly, sometimes several at once, often along the gum line and on exposed roots. Gum inflammation and fungal infections such as thrush also become more common. Many older adults who had healthy teeth for decades start getting new cavities after a medication change. Our guide on aging and dental health explains why this happens more after 60.

Steps to manage dry mouth

1. Sip water often. Keep a water bottle nearby and take small sips through the day and with meals.
2. Stimulate saliva. Chew sugarless gum or suck on sugarless lozenges, ideally with xylitol. Sour flavours trigger more flow but can be acidic, so use them in moderation.
3. Use extra fluoride. Brush twice a day with fluoride toothpaste. Your dentist may recommend a higher-fluoride toothpaste, a fluoride rinse or fluoride varnish at visits. Our guide on fluoride toothpaste explains how much to use.
4. Try saliva substitutes. Mouth sprays, gels and rinses made for dry mouth can ease discomfort, especially at night.
5. Add moisture at night. A bedroom humidifier and a glass of water by the bed help, and so does treating nasal congestion.
6. Review your medicines. Ask your doctor or pharmacist whether any medicine could be adjusted or timed differently. Never stop a medicine on your own.
7. Keep regular dental visits. People with dry mouth often benefit from more frequent check-ups and cleanings so problems are caught early.

What to avoid

• Avoid sipping sweet drinks, juice or sweetened coffee and tea through the day. With little saliva, sugar stays on teeth much longer.
• Avoid mouthwashes that contain alcohol. They can dry the mouth further.
• Limit caffeine, alcohol and salty or spicy foods if they make dryness worse.
• Avoid smoking, vaping and cannabis, which dry the mouth and raise the risk of gum disease.
• Avoid sucking on hard candies with sugar to relieve dryness. Choose sugarless options instead.
• Do not sleep in dentures if your mouth is dry. Dry tissue under a denture is more prone to sores and infection.

Other salivary gland problems

Salivary stones

Small hard deposits can form inside a gland or its duct, most often in the submandibular gland under the jaw. A stone can block saliva, causing swelling and pain that gets worse at mealtimes when saliva flow rises. Small stones sometimes pass on their own with hydration, warm compresses, gentle massage and sour candies. Larger stones may need removal by a physician or oral surgeon.

Infections

A gland can become infected, especially when saliva flow is low or a duct is blocked. Signs include a tender, swollen gland, a bad taste, pus inside the mouth, fever and redness over the area. Infections need prompt care and sometimes antibiotics.

Viral infections

Mumps is a viral infection that causes painful swelling of the parotid glands. Vaccination has made it much less common in Canada, but cases still occur. Other viruses can also cause gland swelling.

Mucoceles

A mucocele is a small, soft, bluish bump, often on the inside of the lower lip, that forms when a tiny minor gland is injured, for example by biting the lip. Many go away on their own, but ones that keep coming back may be removed.

Lumps and growths

Most salivary gland lumps are not cancer, but any new lump, especially one that is firm, growing, or linked with numbness or facial weakness, should be assessed. Your dentist checks the glands, neck and mouth during regular exams. Our guide to oral cancer explains what a screening includes.

How your dentist checks your salivary glands

At a routine exam, the dentist feels the area in front of the ears, under the jaw and in the floor of the mouth, looks at the openings of the gland ducts and notes how moist the mouth is. They may ask about thirst, swallowing and medication changes. If saliva seems low, they may recommend fluoride, more frequent cleanings or a conversation with your physician. Any concerning lump or persistent swelling is referred for further assessment.

Saliva and children

Children produce plenty of saliva, and drooling in babies is normal, especially during teething. Swelling of the cheeks or under the jaw in a child should be seen by a doctor, as it can be a sign of an infection such as mumps. Children who breathe through their mouth because of enlarged tonsils or allergies may have drier mouths and more cavities, so mention it at check-ups.

Eating comfortably with a dry mouth

Low saliva can make meals hard work. A few changes help food go down more easily and protect your teeth at the same time:

• Take a sip of water with each bite, and keep a glass at the table.
• Choose moist foods such as soups, stews, yogurt, eggs, fish and cooked vegetables.
• Add sauces, gravy, broth or a little olive oil to dry foods like rice, bread and meat.
• Cut food into small pieces and chew slowly.
• Limit very dry, crunchy or salty snacks such as crackers, chips and pretzels.
• Keep sweets and sweet drinks to mealtimes, and rinse with water afterward.
• Chew sugarless gum for a few minutes after eating to boost saliva and clear food.

If swallowing feels hard, food sticks in your throat, or you cough while eating, mention it to your doctor. Swallowing problems need their own assessment.

A dental plan for people with dry mouth

When saliva is low, prevention becomes more important. A typical plan may include:

• More frequent check-ups and cleanings, often every three to four months instead of every six.
• Fluoride varnish painted on the teeth at visits to strengthen enamel and exposed roots.
• Prescription-strength fluoride toothpaste for use at home.
• Close checks around fillings, crowns and the gum line, where new decay often starts.
• Denture checks to ease rubbing on dry tissue.

Many insurance plans and the Canadian Dental Care Plan include coverage for preventive care such as cleanings and fluoride, often with limits. Our team can check your coverage before treatment. See our CDCP page for details.

Questions to ask your pharmacist

Pharmacists are a great help with dry mouth caused by medicines. Bring your full list and ask: Which of my medicines can cause dry mouth? Can any be taken at a different time of day, such as in the morning instead of at bedtime? Is there a version with fewer drying effects? Which dry mouth products are safe with my other medicines? Write down the answers and share them with your dentist and doctor so everyone works from the same plan.

When to see a dentist or doctor

Book a dental visit, or see your doctor, if:

• Your mouth feels dry most days, or you need water to swallow food.
• You notice several new cavities or sensitive spots near the gum line.
• A gland swells or hurts, especially at mealtimes.
• You have a bad taste, pus or fever with swelling near the jaw or ear.
• You feel a new lump in the cheek, under the jaw or in the floor of the mouth.
• You are starting radiation to the head and neck. A dental check before treatment is important.

Our family dentistry page explains check-ups, fluoride and cleanings, and our seniors dental care page covers dry mouth and medications in later life.

Questions about salivary glands

Why is my mouth dry when I wake up?

Saliva flow drops during sleep, and mouth breathing or snoring dries the mouth further. Water by the bed, a humidifier and treating congestion help.

Can medications really cause cavities?

Yes, indirectly. Many medicines reduce saliva, and low saliva lets acids and bacteria harm teeth faster.

Does chewing gum help dry mouth?

Sugarless gum, especially with xylitol, stimulates saliva and can help protect teeth. Avoid gum with sugar.

Why does my jaw swell when I eat?

A blocked salivary duct, often from a stone, can cause swelling at mealtimes. Have it checked by your dentist or doctor.

Is dry mouth a normal part of aging?

Not on its own. Older adults are more likely to take medicines that reduce saliva, which is the most common cause.

What is the bump inside my lip?

A soft, bluish bump is often a mucocele from an injured minor gland. Have any lasting bump checked.

Can dry mouth affect my dentures?

Yes. Saliva helps dentures stay in place and protects the gums underneath. With a dry mouth, dentures may rub or feel loose. Saliva substitutes and a fit check help.

Does radiation treatment cause permanent dry mouth?

It can, depending on the area and dose. A dental check before treatment and extra fluoride afterward help protect the teeth.