Medication-induced Xerostomia Secondary to Pain Management
Orofacial pain management generally does not occur in a diagnostic vacuum. The patients we see generally have other somatic pain syndromes secondary to trauma, chronic disease or psyche and are being managed concurrently by other health professionals. These pain syndromes are generally managed with multiple pharmaceutical products by very skilled medical professionals. Unfortunately, these powerful medications have negative secondary side-effects. One of the most damaging is the medication-induced hyposalivation that occurs during the course of treatment. The xerostomic complaints from the patients appear to have no resolution. The hyposalivation condition results in a reduced production and quality of saliva with these changes ultimately resulting in the loss of dentition or a dentition that is severely damaged.
We listen to patients’ complaints of xerostomia and note that many healthcare professionals suggest they drink more water. Not understanding the xerostomic syndrome results in mismanagement of the patient. Xerostomia is defined here as the subjective sensation and the objective diagnosis of persistent oral dryness and is generally described by patients in these terms. A subset of these patients may also report a burning mouth, mucosa, or tongue. Investigators have found that xerostomic complaints are experienced when a previously normal salivary flow rate is reduced by 40% to 50%.1
In the year 2000, the NIH published “The Surgeon General’s Report of Oral Health in America,” which concluded that: “The main function of saliva is not—as is commonly believed—to aid in digestion, but to protect the integrity of the oral tissues. The ability of saliva to limit the growth of pathogens—and in some instances even preventing them from establishing a niche in the biofilm community in the first place—is a major determinant of general, as well as oral, health. When salivary flow is compromised, the gateway to the body can open wide to local as well as to systemic pathogens.”2
“Saliva is indispensable for maintaining oral health. It lubricates the oral mucosa, promotes remineralization of the teeth, and protects the mouth against infections caused by pathogenic microorganisms. Although it is the main oral tissue protective fluid, its chief importance to the individual’s welfare is generally perceived only when the salivary flow rate decreases.”3
Caries Management by Risk Assessment
The February and March 2003 issues of the Journal of the California Dental Association (CDA) were dedicated to reviewing the scientific basis for the most current approach to caries management using risk assessment protocols for diagnosis, treatment and prevention, including non-surgical means for repairing—or remineralizing—tooth structure. The science, Caries Management by Risk Assessment (CAMBRA), was introduced and culminated with a consensus statement of national experts. Production of risk assessment criteria and forms for clinicians to use in practice was published for the profession. These latest CAMBRA guidelines were published in the CDA journal in 2007.4,5
Since CAMBRA is now well-documented in the literature, clinicians are increasingly using these guidelines in their practices to the benefit of their patients. CAMBRA has become “Standard of Care” regarding the issues of xerostomia, caries, and oral health. These xerostomic issues relate directly to quality and production of saliva and also to the issue of “medication-induced and maintained xerostomia.” Much of the medical and dental management of caries has historically been focused on the restoration of dental caries and symptoms of the transmissible bacterial infection. The change in biofilm, which occurs in the xerostomic environment, becomes the pathological agent regarding dental, periodontal, and mucosal pathologies. Both risk-assessment and professional interventions are based on the concept of altering the caries balance. We are using “The Caries Balance” model, where pathological factors of bacteria, absence of healthy saliva, and poor dietary habits (i.e., frequent ingestion of fermentable carbohydrates) battle protective factors such as saliva and sealants, antibacterials, fluoride. and an effective diet.6
Role of Saliva in Oral Health
To reinforce the CAMBRA guidelines it is noted that saliva plays such a significant role in a patient’s oral health that the American Dental Association published a forty-four page JADA “Special Supplement” report in May 2008.7 This report addresses composition, biofilm, dental caries, medication side-effects, flow-patterns, integrity of enamel and dentition, and additional issues. It also discusses saliva’s critical role in the preservation of oropharyngeal health. U.S. researchers have identified all 1,116 unique proteins found in human salivary glands and human saliva. It is also notable that patients who experience dry mouth (xerostomia) and diminished salivary output are at high-risk for gastritis, hoarseness, oral, and other pharyngeal disorders.
Xerostomic salivary changes can also play another role. In addition to the major salivary glands being affected, all of the accessory or minor salivary glands are affected. These are located in the oral mucosa, including the lip, cheeks, tongue, floor of the mouth, posterior hard palate, uvula, molar, retromolar, and peritonsillar regions. These glands must function normally in order to maintain a normal oral-health status. There are no salivary glands on the gums or on the anterior part of the hard palate. The well-known functions of normal saliva include:
It’s also important to mention the necessity for the flushing mechanism of the esophagus for protection against stomach acid. Therefore, the loss of saliva is thought to be associated with a loss of “protection.”