Saliva consists of essential proteins, electrolytes, minerals, small organic molecules and water.
Two Types of Saliva:
Serous – water thin amylase (starch digestion) lipase (fat digestion) easy to replace stimulated by eating, smell, taste produced by the major salivary glands
Mucous – thick, visous lubricating properties for the tissues difficult to replace causes the most problems when low, especially at rest 0.05 ml/min at rest (sleep, not eating), mostly mucous glands produced by the minor salivary glands
With xerostomia, the salivary glands (parotid, sublingual and submandibular) produce about 90% of the saliva in the mouth. In a healthy individual, these three pairs of glands make about 3/4 teaspoon of saliva each minute. When chewing, the glands produce about 1 tablespoon per minute.
Major salivary glands (parotid, sublingual and submandibular) produce about 90% of the saliva in the mouth. In a healthy individual, these pairs of glands make about 3/4 teaspoon of saliva each minute. When chewing, the glands produce about 1 tablespoon per minute.
What is the Function of Saliva?
Lubrication: Keeps the mouth and throat moist to aid in chewing and swallowing food, Cleanses the mouth of food particles
Protection: Limits bacterial, viral and fungal growth, the causes of mouth infections and tooth decay, Bathes teeth with protective minerals to help prevent cavities, Helps to protect teeth from hot or cold temperatures, Coats soft tissues for phonation and food passage, Maintains ecological balance, Enhances soft tissue repair, Barrier for desication and environmental insults, Maintain neutral pH to maintain tooth integrity (Ca, F ions), pellicle
Digestion: Breaks down food so in order to enhance taste (bitter, sweet, salty, sour), Through the actions of amylase, lipase, Serous saliva moistens food and solubilizes food for taste perception
Communication: Keeps mouth moist, which makes speaking easier
Taste: Facilitates taste, chemicals must be in solution, Alters taste, salivary chemicals influence taste
What Causes Saliva Loss?
Radiation Treatments: People who are going through or have completed radiation therapy for head and neck cancer may notice a big change in the amount and quality of saliva in their mouths. That is because radiation often damages healthy tissues that may include the salivary glands. When this happens, the salivary flow decreases. This loss of saliva leads to a condition known as xerostomia or dry mouth.
Medication: More than 400 commonly prescribed drugs, such as pain relievers, antidepressants, high blood pressure medicines, and sinus and allergy medications can cause dry mouth to occur. These types of drugs interrupt the message the brain sends to the glands to produce more saliva needed. Alcohol, whether it is in mouthwash or beer, can also cause dry mouth and can lead to instant halitosis
Disease: Decreases in salivary flow can be linked to a variety of diseases, such as Sjogern’s Syndrome which is an autoimmune disease that affects the many glands in the body. Other diseases like diabetes, cardiac failure, edema, dehydration, scleroderma, and graft vs. host disease can also cause saliva loss. Obstructions in salivary gland ducts, i.e. large stone trapped in duct of major salivary gland. Mucocele or sialolitiasis are small blockages and do not contribute to dry mouth.
Deleterious Oral Sequelae
As Saliva Levels Decrease, Symptoms of Dry Mouth May Increase: Decrease in Salivary Flow, Dry Mouth, Mucositis (inflamed mouth), Mouth Infection, Weight Loss, Tooth Decay
As the saliva level drops, harmful bacteria begin to increase and helpful bacteria levels decrease. This decrease may lead to severe complications like mouth pain, difficulty chewing, swallowing and speaking, taste disturbances, weight loss, mouth infections and tooth decay. Other noticeable problems one may experience include a dry, cracked tongue, bleeding gums, cracks at the corners of the mouth, badly fitting dentures and frequent dryness in the eyes, nose, skin and throat.
Slight tongue changes may occur at levels of 90% loss of mucous saliva. Some symptoms may be: reddening, deep fissuring, total papillary atrophy, severe lobulation, red/smooth atrophied tongue, loss of fungiform papillae.There also may be an overgrowth of yeast (hyphae) or Candida infection because of the loss of immunoglobulins. This Candida infection can cause median rhomboid glossitis producing red/white patches where the white wipes off leaving the red lesions. Median rhomboid glossitis may be difficult to distinguish between geographic tongue also check for dry/burning mouth to distinguish between the two. Contact lesions can also form on the palate from the tongue.
Dentures, in a dry mouth, are very susceptible to yeast infections. This can cause sore, red, denture stomatitis, intraorally, that need to have aggressive treatment to provide some relief. Some treatments include: moisturizing gel, oral balance (placed between the denture and the oral tissues). Extraorally, angular chelitis can also occur.
Teeth do not dissolve in saliva when pH is neutral (ca, F ions). However, if there is a decrease in salivary flow, there is a decrease in pH and a decrease in the protective pellicle formation allowing demineralization of tooth structure (seen commonly first around the cervical margin of the tooth). Teeth are more susceptible to excessive and/ or unusual wear patterns. Chipping/fracturing is also common if the teeth are undermined with decay. Recurrent decay can also occur, as well as sensitivity from decay or excessive wear.
Other Mouth Infections and Lesions:
Herpetic ulcers, apthous ulcers.
Sjogerns’s Syndrome Sjogern’s presents challenges both in diagnosis and therapy. It is chronic systemic inflammatory disorder of unknown etiology. Age and sex is not a factor. Common to have sjogern’s with another connective tissue disease such as Rheumatoid Arthritis, Lupus Erythematosus, Scleroderma, Cirrhosis. Symptoms: dry/red eyes (Keratoconjunctivitis Sicca) and other mucous membranes, digestive problems, dry skin, xerostomia (periodontal concerns, decay etc.), tongue changes, angular chelitis, swelling of the parotid gland.
Dental implications include: dry mouth, difficulty swallowing/eating, candida infections, parotid gland enlargements, gingivitis and periodontitis is accelerated, caries at the cervical margin, root surface and incisal edge.
Burning Mouth Syndrome
About 1.3 million American adults, mostly postmenopausal women, are affected with burning mouth syndrome (BMS). There is no consensus on the cause or treatment. However, its onset can be related to a previous dental procedure or illness, upper respiratory infection. Multiple complaints: burning, dryness, taste changes. The spontaneous pain begins by late morning and usually reaches peak intensity by evening, which makes falling asleep difficult yet does not awaken the patient during the night. BMS patients can experience taste disturbances, usually a persistent bitter taste. Eating seems to relieve the pain. Tests to determine the difference between BMS and Xerostomia: check salivary flow rates, visual inspection for lesions, dryness assessment, taste (no decrease in taste buds) function assessment. Treatment: Clorazepam 0.25 mg/day (aform of benzodiazepine)
Treatment Of Xerostomia
Mild: artifical saliva (Mouth Kote), moisturizing agents (Biotene and Oral Balance-gel, toothpaste, rinses, denture grip), fluoride/remineralizing agents (Prevident, rinses, varnishes etc.), simple salivary stimulants (gum with Xylitol, sugarless lozenges), Sonicare and a good self care regimen, drinking plenty of water, avoid foods that are dry, spicy or acidic that may have an irritating effect on dry oral tissue, eat a healthy balanced diet, regular oral health care visits to detect and treat.
Mild-Moderate: same as above, antibacterials (CHX), antifungals (Nystatin), pharmacological salivary stimulants (Salagen or pilocarpine), parasympathetic, cholinergic, salivary glands, git, sweet glands, exocrine glands, 5 mg/d, 10mg, patients feel better after 6-12 weeks, for maximum effect, must use for a minimun of 6 weeks
Moderate-Severe: same as above, but more aggressive – pilocarpine up to 30mg/d