Patients with reduced saliva production, in addition to the relatively annoying feeling of dryness, show concomitant atrophy of the oral mucosa with consequent sensitivity, both in the intake of solids and fluids and presenting difficulty even in speech due to friction of the tongue and cheeks against the teeth. In addition, there is difficulty in swallowing the food bolus and quite often fungal infections (see related section). The teeth undergo extensive decay and more intense periodontal disease due to the loss of the protective capacity of the saliva.
Decreased saliva production may caused by to a variety of factors such as medications that result in this dry mouth sensation as a side effect and previous radiotherapy to the head and neck area that may have caused atrophy and/or degeneration of the salivary glands. Other factors include systemic diseases such as uncontrolled diabetes mellitus and, in the context of autoimmune diseases, Sjögren’s syndrome. Occasionally, patients may report episodes of dry mouth that may be due to causes such as mouth breathing, especially during sleep and heavy smoking. Of course, we should not forget that a relative feeling of dry mouth is observed in conditions of dehydration (due to reduced fluid intake) while the patient must be clinically evaluated to assess whether they objectively suffer from dry mouth and that it is merely not a subjective symptom often induced by stress (see burning mouth syndrome).
Diagnostic methodology requires a detailed history, clinical evaluation of saliva production and possibly, if deemed necessary for a patient, appropriate laboratory tests, salivary gland biopsy and collaboration with Doctors of other specialties. This will accurately determine the cause of the problem.
Regarding the treatment, topical saliva substitutes as well as systemically administered drugs that assist with the proper function of the salivary glands can be administered. In addition, in cases of systemic diseases, depending on the underlying cause, appropriate treatment should be given that will reduce the advancement of this disease and the accompanying effects on the salivary glands. From a dental point of view, it is also necessary to have thorough and regular checks of the teeth for periodontal treatment and restoration of any signs of decay, as well as to control development of fungal infection with appropriate treatment.