Hinman Connects Blog

How Dry I Am!

Thomas Viola, RPh, CCP

It is estimated that approximately 10% of the general population is affected by “oral dryness”. When a patient presents with this complaint, one of the first considerations for the dental professional is to determine whether the condition is “xerostomia” or “hyposalivation”.

Xerostomia is a rather subjective perception, a self-reported sensation of “having a dry mouth”. It is often referred to as a symptom, not a condition unto itself. Xerostomia may be age-related, disease-induced or drug-induced. Common complaints include a burning sensation in the mouth and on the tongue and a feeling of “sand in the mouth”.

Patients with xerostomia complain of oral dryness and the near constant need to supplement the moisture in their mouth. They are especially dry during sleep, often keeping liquids at bedside. Many patients experiencing sleep interruptions due to dryness and must often “unstick” their tongue from mouth surfaces upon awakening.

Hyposalivation refers to salivary gland dysfunction, a clinically measurable decrease in the quantity of, and the quality of, the saliva produced. For these patients, palpation of the salivary glands reveals enlargement and tenderness, but little or no secretion.

Saliva contains components which protect and promote the health of the oral tissues. The major component of saliva is fluid (water), which cleanses and helps remove food particles and pathogens and allows for proper chewing and swallowing. The fluid content of saliva also helps distribute dissolved food over the taste buds and mix dissolved enzymes with chewed food to aid in the further digestion and absorption of nutrients. Saliva contains mucins which coat and moisten the oral tissues and serve as a physical barrier to resist trauma, pathogens and toxins.

Saliva also contains active immunologic proteins which provide localized prevention of infection and maintain the balance of the oral microbial ecosystem by discouraging the activity of invasive and opportunistic pathogens. Saliva contains sodium bicarbonate to help maintain a healthy alkaline environment. This environment inhibits cariogenic bacterial activity and demineralization (along with dissolved calcium and phosphorus).

Since xerostomia results in a functional decrease in the quantity and quality of saliva produced, it is easy to see its potential oral complications. Loss of the key components of saliva and their beneficial effects results in dry, fragile oral tissues which are hypersensitive and at increased risk for trauma and infection, as well as tooth surfaces which are at increased risk for pathogenic activity and demineralization. Any existing periodontal disease is exacerbated by this process, and even the ability of the patient to wear dental appliances and prostheses is compromised.

Xerostomia also results in non-oral complications which result in a decrease in the patient’s quality of life. These issues include difficulty eating and swallowing (and an increased risk of choking and aspiration), difficulty speaking, halitosis, sores and cracks in the lips and the corners of the mouth and even heartburn and constipation.

It is estimated that well over 500 frequently prescribed medications and over-the-counter products are associated with xerostomia. It is the most often encountered oral adverse reaction of medications. While individual medications may contribute to the development of xerostomia on their own, these effects are often compounded when these medications are combined with other xerogenic medications, as is often the case for patients with multiple drug regimens.

Medications which cause xerostomia most commonly affect the autonomic nervous system, which regulates the flow rate and the chemical composition of saliva. The sympathetic system (“flight or fight”) controls the flow from the submandibular, and sublingual salivary glands, which are responsible for the production of low volume, high viscosity “mucinous” saliva. The parasympathetic system (“rest and digest”) control the flow from the parotid salivary gland, which is responsible for the production of high volume, low viscosity “serous” saliva.

So much attention is given to medication-induced xerostomia, it is easy to overlook the contribution that systemic diseases make to the development of xerostomia and the exacerbation of its complications. These diseases include cardiovascular disease (hypertension, stroke and congestive heart failure), respiratory disease (COPD and sleep apnea), gastrointestinal disease (acid reflux), diabetes and its complications (neuropathy) and renal disease. Other conditions such as cancer (chemotherapy and radiation of the head and neck), central nervous system disorders (anxiety, depression, psychoses, Parkinson’s Disease and Alzheimer’s Disease), autoimmune diseases (Sjögren’s Syndrome) and even dental surgery (post-surgical nerve trauma) are associated with the incidence of xerostomia.

Thus, medically complex patients are most at risk for xerostomia and its oral and non-oral complications. They may have multiple medical, physical, and cognitive conditions which may contribute to the development of xerostomia, while also limiting the patient’s ability to seek and receive dental care, maintain oral hygiene and comply with treatment plans. In addition, these patients may take multiple medications which may cause xerostomia, especially when combined in multiple drug regimens.

For more information on this topic, please come to my course at Hinman this March, "Hey, Spit Happens! An Overview of Disease-Induced and Medication-Induced Xerostomia, Pharmacologic Management, Dental Considerations and Patient Care Planning Strategies." I look forward to seeing you there!

Thomas Viola, RPh, CCP, the founder of “Pharmacology Declassified,” is a board-certified pharmacist who also serves the dental profession as a clinical educator, professional speaker and published author. Tom is on the faculty of ten dental professional degree programs and has received several awards for outstanding teacher of the year. Tom has presented hundreds of continuing education courses to dental professionals, nationally and internationally, in the areas of oral pharmacology and local anesthesia, and is well-known for his regular contributions to several dental professional journals. Contact Tom at Tom@tomviola.com, visit his website at www.TomViola.com or call (609) 504-9252.

Tom will speak at the 106th Hinman Dental Meeting, March 22-24, and his course information can be found here.