**3. Diagnosis of xerostomia**

The objective of the diagnosis is to provide treatment as early as possible, thus minimizing side effects in patients suffering from xerostomia. In order to establish a diagnosis of xerostomia, a clinical history is essential to identify the possible etiological factors [24]. It is necessary to investigate its causes. Thus, three orders of factors need to be known: the occurrence of systemic diseases, medication, and the history of radiation therapy. Questions are asked to the patient, trying to find out if he feels the dry mouth sensation, whether he needs to wet his mouth, if he can eat a wafer without drinking water, if the tongue chews the food and clings to the teeth, and the daily water intake daily among other issues [24, 25]. The qualitative clinical diagnosis of xerostomia is made through the observation of clinical signs such as palpation of the salivary glands, observation of the oral mucosa and its hydration, cracked lips, saliva under the tongue, appearance and texture of saliva, the identification of caries, candidiasis and burning sensation, and others [26].

kind of measuring has the advantage of being easily implemented, low-cost, and could be available to most of the population at risk [32]. The diagnosis of salivary gland dysfunction is based on data derived from the symptoms reported by the patient, clinical examination leading to verification of the clinical signs and determination of stimulated salivary flow [33]. A severe decrease in salivary flow may lead to a poor health-related quality of life, as well as a risk condition for the development of oral pathologies such as periodontal disease, caries,

Xerostomia: An Update of Causes and Treatments http://dx.doi.org/10.5772/intechopen.72307 19

The most severe conditions with effect on the salivary flow are SS and radiotherapy in the head and neck area, with the prevalence of xerostomia in almost 100% in these cases. These conditions are characterized by a progressive loss of secretory cells, and thus a progressive decline in saliva production [36, 37]. Less severe conditions may be dehydration, smoking, and inflammation or infection of the salivary glands [12]. In older people, the most common cause of xerostomia is the use of medications because the vast majority of the elderly are being treated with at least one drug that causes salivary hypofunction [32]. A summary of the main

The reduced salivary flow is commonly seen in the aging populations. This can be attributed to either age-related localized degeneration of salivary glands or systemic diseases [38, 39]. As the patient ages, the organs atrophy and often result in a decrease in salivary production. It was described that in older people the loss was about 30% of acinar cells, with substitution of secretory components by fibrous and adipose tissue [40]. Besides, there are changes in salivary levels of potassium, sodium, IgA, proline-rich protein, lactoferrin, and lysozyme in elderly [28, 40]. A reduction in salivary flow of older people was identified, even in those not using systemic drugs, suggesting a relation between salivary dysfunction and aging [41]. Smith determined that a stimulated salivary flow in healthy adults older than age 70 is lower

Systemic diseases Sjogren's syndrome, diabetes mellitus, Parkinson's disease, encephalitis, brain tumors,

transplantation, endocrine disorders, pancreatic insufficiency

Plummer Vinson disease, hypertension, HIV infection, systemic rheumatic diseases, sarcoidosis, Alzheimer's disease, cystic fibrosis, aplasia, chronic tuberculosis, primary biliary cirrhosis, hemolytic anemia, malignant lymphoma, systemic lupus erythematosus, scleroderma, dermatomyositis, pernicious anemia, hypothyroidism, amyloidosis

Radiotherapy and chemotherapy, infections, inflammation, tumors and sialolithiasis in salivary glands, salivary gland excision, vitamin A deficiency, menopause, stress, anxiety, dehydration, neurological disorders, senility, oral sensory dysfunction, iron deficiency, folic acid deficiency, uremia, polyuria, diarrhea, mouth breathing, bone marrow

and candidiasis [29, 34, 35].

**4. Causes of xerostomia**

than in adults under 50 [42].

**Table 2.** Systemic diseases and other causes of xerostomia.

**4.1. Aging**

Other causes of xerostomia (no drugs or systemic diseases)

causes of xerostomia can be seen in **Table 2**.

Several methods have been developed to evaluate the level of dryness of the mouth, the discomfort being the most used: sialography, sialochemistry, sialometry and scintigraphy, salivary gland biopsy, ultrasound, magnetic resonance, and computed tomography [19]. Sialography is a technique of imaging that involves the injection of a retrograde form of radiopaque material into the salivary duct system in order to define the anatomy of the glands. This test is very important to demonstrate the presence of nodules or sialectasis, but it has its disadvantages, such as: the difficulty of the technique, since it is invasive and the patient can react acutely or chronically with the contrast material. The biopsy of the major or minor salivary glands allows the detection of inflammatory infiltrations, acinar destruction and dilation of salivary channels with thick mucus, and sometimes fibrosis [27]. Ultrasound, magnetic resonance, and computed tomography are tests that may also contribute to the diagnosis of diseases of the salivary glands.

To establish the condition of the symptom or to evaluate a possible salivary glandular dysfunction, the most used mechanisms are the questionnaire of xerostomia developed by Fox et al. [11, 28] and the determination of salivary flow rate. Sialometry and scintigraphy (an imaging diagnostic method of nuclear medicine that allows the study of the physiology of the various organs) are complementary tests that must be performed in order to evaluate the involvement of the salivary glands in patients with xerostomia. Sialometry is a relatively common procedure in normal clinical practice and include determination of stimulated salivary flow rate (s-SFR), unstimulated salivary flow rate (u-SFR), palatal secretion (PAL), and parotid secretion (PAR). These measurements are the simplest methods of evaluating the salivary glandular function. It is essential to measure the salivary flow, that is, the amount of saliva produced per unit of time. Very low unstimulated and stimulated salivary flow rates or hyposalivation are defined as <0.1 and <0.7 mL/min, respectively [7]. At rest, secretion ranges from 0.25 to 0.35 mL/min and is mostly produced by the submandibular and sublingual glands [29]. Under stimulation, the parotids account for 50% of salivary volume [30]. Determining the stimulated and unstimulated salivary flow is a procedure to measure the amount of saliva it produces a person at a given time. Generally, the stimulated salivary flow is measured for 5 min and unstimulated salivary flow is measured for 15 min [31]. This kind of measuring has the advantage of being easily implemented, low-cost, and could be available to most of the population at risk [32]. The diagnosis of salivary gland dysfunction is based on data derived from the symptoms reported by the patient, clinical examination leading to verification of the clinical signs and determination of stimulated salivary flow [33]. A severe decrease in salivary flow may lead to a poor health-related quality of life, as well as a risk condition for the development of oral pathologies such as periodontal disease, caries, and candidiasis [29, 34, 35].
