Unstimulated Saliva Flow Research Articles

Salivary and serum cortisol levels, salivary alpha-amylase and unstimulated whole saliva flow rate in pregnant and non-pregnant

To compare salivary and serum cortisol levels, salivary alpha-amylase (sAA), and unstimulated whole saliva (UWS) flow rate in pregnant and non-pregnant women. A longitudinal study was conducted at a health promotion center of a university hospital. Nine pregnant and 12 non-pregnant women participated in the study. Serum and UWS were collected and analyzed every trimester and twice a month during the menstrual cycle. The salivary and serum cortisol levels were determined by chemiluminescence assay and the sAA was processed in an automated biochemistry analyzer. Significant differences between the pregnant and non-pregnant groups were found in median [interquartile range] levels of serum cortisol (23.8 µL/dL [19.4-29.4] versus 12.3 [9.6-16.8], p<0.001) and sAA (56.7 U/L [30.9-82.2] versus 31.8 [18.1-53.2], p<0.001). Differences in salivary and serum cortisol (µL/dL) and sAA levels in the follicular versus luteal phase were observed (p<0.001). Median UWS flow rates were similar in pregnant (0.26 [0.15-0.30] mL/min) and non-pregnant subjects (0.23 [0.20-0.32] mL/min). Significant correlations were found between salivary and serum cortisol (p=0.02) and between salivary cortisol and sAA (p=0.01). Serum cortisol and sAA levels are increased during pregnancy. During the luteal phase of the ovarian cycle, salivary cortisol levels increase, whereas serum cortisol and sAA levels decline.

Sodium gradient, xerostomia, thirst and inter-dialytic excessive weight gain: a possible relationship with hyposalivation in patients on maintenance hemodialysis

PurposeThe aim of the study was to assess whether hyposalivation is linked with increased thirst sensation and weight gain in hemodialysis (HD) patients and whether there is any connection between hyposalivation and sodium balance.MethodsOne hundred and eleven participants (64 males and 47 females) receiving maintenance hemodialysis, mean age 59.1 ± 13.6 years old, were involved in the study. All participants completed a survey evaluating thirst intensity (DTI) and xerostomia inventory (XI). In addition, pre-dialysis sodium concentration and inter-dialytic weight gain (IWG) were assessed. The division into no-hyposalivation and hyposalivation groups was based on an unstimulated whole saliva (UWS) flow rate.ResultsHyposalivation, UWS below 0.1 mL/min, was reported in 28.8 % of HD patients. In these participants, IWG was higher than in patients with UWS > 0.1 mL/min (3.65 ± 1.78 vs 3.0 ± 1.4; p = 0.042), as well as the pre-dialysis sodium gradient (3.22 ± 2.1 vs 1.6 ± 2.8; p = 0.031). The mean XI and DTI scores did not differ between study groups. In the hyposalivation group, pre-dialysis sodium serum gradient negatively correlated with saliva outflow (ρ = −0.61, p = 0.019) and positively with IWG (ρ = 0.49, p = 0.022). IWG correlated with XI (ρ = 0.622, p = 0.016) in hyposalivation group and with DTI in no-hyposalivation group (ρ = 0.386, p = 0.033).ConclusionsHyposalivation significantly correlates with IWG; however, its influence on thirst and self-reported mouth dryness seems to be weaker than expected. Additionally, hyposalivation was found to be associated with an elevated pre-dialysis sodium gradient.

Salivary flow rate and decayed, missing, and filled teeth (DMFT) in female patients with schizophrenia on chlorpromazine therapy

Background/purposeThe purpose of the study was to investigate relationship between saliva flow rates, estrogen levels, and caries prevalence in female psychiatric patients under antipsychotic therapy. Materials and methodsSixty-one institutionalized psychiatric females (31 patients treated with chlorpromazine only and 30 patients treated with chlorpromazine and biperiden) were compared with 36 unmedicated healthy females. The unstimulated whole saliva (UWS) flow rate and serum estrogen were measured. Caries prevalence was recorded in terms of decayed, missing, and filled teeth (DMFT). ResultsThe UWS flow rate in the control group was 0.35 ± 0.18 mL/min and the DMFT 18.8 ± 5.7. In comparison, UWS flow rates were 0.25 ± 0.15 mL/min (P = 0.003) and 0.07 ± 0.05 mL/min (P = 0.000) in patients on chlorpromazine and patients on chlorpromazine as well as biperiden, respectively, and DMFT values were 22.7 ± 4.6 (P = 0.003) and 26.5 ± 5.3 (P = 0.000), respectively. Patients on chlorpromazine with amenorrhea had reduced UWS flow rate and estrogen levels with respect to controls (P = 0.036; P = 0.000, respectively). Correlation analysis revealed significant correlations between UWS flow rate and DT, DMFT, number of used drugs and estrogen level. ConclusionIt seems that chlorpromazine-induced hyposalivation included (apart from its antimuscarinic effect) a neuroendocrine effect which affected the estrogen levels.

Stimulating whole saliva affects the response of antimicrobial proteins to exercise

This study investigated the salivary secretion rates of antimicrobial proteins in response to prolonged, exhaustive exercise in both stimulated (STIM) and unstimulated (UNSTIM) saliva flow sample methods. Twenty-four trained men cycled for 2.5 h at 60% V̇O₂max and then to exhaustion at 75% V̇O₂max. Timed collections of whole saliva were made before exercise, mid-exercise, at the end of the moderate exercise bout and post-exhaustive exercise. After each UNSTIM collection, a STIM sample was collected following chewing flavored gum for 1 min. Saliva was analysed for lysozyme, α-amylase and salivary immunoglobulin A (s-IgA), and secretion rates were calculated. Saliva flow was 156% higher in STIM compared with UNSTIM (P < 0.001) and decreased with exercise in STIM only (P < 0.001). Exercise increased lysozyme and α-amylase levels and secretion rates were 144% higher and 152% higher in STIM compared with UNSTIM for lysozyme and α-amylase, respectively (all P < 0.001). S-IgA concentration (P < 0.05) and secretion rate (P < 0.001) increased with exercise but were both lower in STIM compared with UNSTIM (P < 0.001). In conclusion, a STIM saliva flow collection during exercise by chewing flavored gum increased the quantity of saliva and the secretion of lysozyme and α-amylase, but had a limited impact on the secretion of s-IgA.

Effect of Swallowing Exercises in Independent Elderly

The aim of this study was to investigate the effects of swallowing exercises on oral function in independent elderly patients visiting the Department of Prosthodontics at Tokyo Dental College Chiba Hospital. Twenty-nine patients aged over 65 years (15 men and 14 women; mean age, 75.0 years) in whom treatment was completed at this college were enrolled in the study. The patients were instructed on how to perform swallowing exercises monthly (including at baseline) for the first 2 months from the start of the study and asked to perform those exercises at least once daily. At the beginning and end of the study (a 3-month study period), the Repetitive Saliva Swallowing Test was conducted and occlusal force, oral diadochokinesis, unstimulated whole saliva flow rate, stimulated whole saliva flow rate, salivary pH at rest, and salivary buffering capacity measured to determine the effects of the exercises on oral function. Analyses demonstrated significant increases in diadochokinesis rate (/ta/ and /ka/) and unstimulated whole saliva flow rate (p<0.05), suggesting that the swallowing exercises promote the maintenance and improvement of oral function in the independent elderly.

Efficacy and safety of rituximab treatment in early primary Sjögren's syndrome: a prospective, multi-center, follow-up study

IntroductionPrimary Sjögren’s syndrome (pSS) is an autoimmune disorder affecting exocrine glands; however, a subgroup of pSS patients experience systemic extra-glandular involvement leading to a worsening of disease prognosis. Current therapeutic options are mainly empiric and often translated by other autoimmune diseases. In the last few years growing evidence suggests that B-cell depletion by rituximab (RTX) is effective also in pSS. Patients with early active disease appear to be those who could benefit the most from RTX. The aim of this study was to investigate the efficacy and safety of RTX in comparison to disease modifying anti-rheumatic drugs (DMARDs) in early active pSS patients.MethodsForty-one patients with early pSS and active disease (EULAR Sjogren’s syndrome disease activity index, ESSDAI ≥ 6) were enrolled in the study. Patients were treated with either RTX or DMARDs in two different Rheumatology centers and followed up for 120 weeks. Clinical assessment was performed by ESSDAI every 12 weeks up to week 120 and by self-reported global disease activity pain, sicca symptoms and fatigue on visual analogic scales, unstimulated saliva flow and Schirmer’s I test at week 12, 24, 48, 72, 96, and 120. Laboratory assessment was performed every 12 weeks to week 120. Two labial minor salivary gland (MSG) biopsies were obtained from all patients at the time of inclusion in the study and at week 120.ResultsOur study demonstrated that RTX treatment results in a faster and more pronounced decrease of ESSDAI and other clinical parameters compared to DMARDs treatment. No adverse events were reported in the two groups. We also observed that RTX is able to reduce glandular infiltrate, interfere with B/T compartmentalization and consequently with the formation of ectopic lymphoid structures and germinal center-like structures in pSS-MSGs.ConclusionsTo our knowledge, this is the first study performed in a large cohort of early active pSS patients for a period of 120 weeks. We showed that RTX is a safe and effective agent to be employed in pSS patients with systemic, extra-glandular involvement. Furthermore, our data on pSS-MSGs provide additional biological basis to employ RTX in this disease.

Depressive Symptoms and Untreated Dental Caries in Older Independently Living South Brazilians

Background: The importance of psychological reactions in modifying oral health behaviors and salivary immunity has been shown previously, but few studies assessed whether psychological reactions are associated with caries in populations. Thus, the aim of this study was to examine the association of depressive symptoms with untreated caries using a hierarchal approach. Methods: In this cross-sectional study, a random sample of 390 South Brazilians aged 60 years or more was evaluated using a structured questionnaire assessing sociodemographic, behavior, health and depressive symptoms (Geriatric Depression Scale) data. Oral examinations were carried out in order to assess: (1) dental status, using the DMFT index; (2) dental plaque, using the Visible Plaque Index, and (3) unstimulated saliva flow, using the spit method. A hierarchical model based on the framework of caries was carried out to assess whether depressive symptoms were associated with prevalent untreated dental caries (or D >0). Results: Depressive symptoms, number of teeth and plaque accumulation were significant predictors of caries with respect to the D >0 outcome. Conclusion: Our findings suggest that depressive symptoms may act as determinants of caries, adding to the body of knowledge supporting the importance of psychological reactions in oral health/disease processes.

Evaluation of saliva flow rates, Candida colonization and susceptibility of Candida strains after head and neck radiation

Hyposalivation is a long-term effect in patients receiving head and neck radiation. Radiotherapy can predispose oral colonization by Candida species of the mucosa. This study aims to evaluate the correlation between hyposalivation, measured by unstimulated saliva flow rates (SFR) and fungal colonization of the oral cavity, and also the resistance of isolated Candida strains to antimicrobial therapy. Fifty-three consecutive patients with radiotherapy were examined for late radiation damage on dental hard tissue and the salivary glands (SFR over a period of 5 min). The SFR were divided into three different values of hyposalivation: grade I (SFR 0.1-0.25 ml/min), grade II (SFR ≤0.1 ml/min), and grade III (SFR = 0.0 ml/min). Candidal colonization was defined using Sabouraud agar and identified using API 20C AUX (biomerieux) in the patients' rinsing water. Susceptibility was tested with Etest (amphotericin B, ketoconacole, voriconacole, and fluconacole). Hyposalivation grade I was detected in 23% (9.1 × 10(1) colony forming units (cfu); range, 200-5,900 cfu), hyposalivation grade II in 26% (4.3 × 10(1) cfu; range, 110-3,300 cfu), and hyposalivation grade III in 51% (2.0 × 10(3) cfu; range, 300-19,475 cfu) of patients. A significant correlation between the SFR and candidal colonization and clinical presentation (European Organization for Research and Treatment of Cancer (EORTC) score) was detected (Mann-Whitney test, p = 0.031). Twenty Candida albicans and 27 non-albicans species were identified. The resistance of C. albicans was higher than that of non-albicans strains against antimicrobial agents. By comparison, amphotericin B showed the greatest and fluconazole the least effect. A higher value of hyposalivation correlates with a higher risk of candidal colonization in patients who have received radiotherapy and also with a higher EORTC score. The spectrum of Candida is wide and susceptibility against antifungal therapy differs. In long-term examinations of patients with xerostomia after radiotherapy, the EORTC score can be used to measure hyposalivation. Reduced susceptibility of C. albicans might introduce complications to therapy. Findings of more non-albicans strains show a change in colonization which should be examined in further studies.

Unstimulated saliva 17β-estradiol and xerostomia in menopause

One of the most common oral manifestations of menopause is xerostomia. As gingival tissue is sensitive to changes in the female sex steroids; the aim of this study was to evaluate the relationship between saliva 17β-estradiol and severity of xerostomia. A case–control study was carried out in 64 selected menopausal women aged 42–75 years with or without xerostomia (32 as case and 32 as control) conducted at the Clinic of Oral Medicine, Tehran university of medical sciences. Xerostomia inventory (XI) score was used as an index of xerostomia severity. The saliva 17β-estradiol was measured by an enzyme immunoassay kit. The mean unstimulated saliva flow rate and concentration of 17β-estradiol were significantly lower in case than control. There were significant negative correlation between XI score and unstimulated whole saliva flow rate and also concentration of 17β-estradiol in menopausal women. It seems that there is a negative correlation between xerostomia severity and saliva 17β-estradiol in menopausal women.

SU‐E‐T‐42: Changes in Submandibular Gland Volume during Radiotherapy

Purpose: To examine submandibular gland volume changes by CT throughout the course of Intensity Modulated Radiation Therapy treatment for head and neck cancers. Method and Materials:CT images from 15 patients were analyzed to evaluate the change in volume of the left and right submandibular glands over the course of treatment (30–35 fractions). Each patient had received daily CT imaging using a CT‐on‐rails unit. Eleven of these patients had pre‐ and post‐treatment measurements of the stimulated and unstimulated saliva flow. Submandibular gland contours were drawn on the first fraction CT. The contours were then deformably mapped to the weekly CTs using an in‐house deformable registration tool. The volume of each gland was extracted, and changes in volume assessed. The changes in gland volume were compared with saliva flow measurements using using the R2 value from a linear fit. Results: All 15 patients showed decreases in gland volume over the course of treatment. The mean gland volume at the start of treatment was 10.6cc (range: 6.9–16.4cc). The mean volume reduction was 32.8% (range: 10.8 – 46.6%), 3.6cc (1.3 – 5.6cc). There was no clear statistical correlation between gland volume decrease and either stimulated or unstimulated salivary function. Conclusions: This study shows a significant reduction in submandibular gland volume over the course of radiation therapy. A more thorough study should be conducted to try and link gland volume decrease with saliva production.

Does hyperbaric oxygen treatment have the potential to increase salivary flow rate and reduce xerostomia in previously irradiated head and neck cancer patients? A pilot study

Irradiated head and neck cancer survivors treated in the Hyperbaric Oxygen (HBO) Unit, Copenhagen University Hospital, spontaneously reported improvement of radiation-induced dry mouth feeling. The aim of this pilot study was to evaluate salivary flow rate and xerostomia before and after HBO in irradiated head and neck cancer patients. Eighty patients eligible for HBO treatment on the indication of prevention/treatment of osteoradionecrosis or soft tissue radiation injury were consecutively sampled, of whom 45 had hyposalivation (i.e. unstimulated whole saliva (UWS) flow rate <0.1ml/min), and 69 complained of xerostomia. UWS and stimulated whole saliva (SWS) were collected prior to and after 30 sessions of hyperbaric oxygen treatment over 6weeks. Xerostomia was assessed using the visual analogue scale (VAS). Each HBO session involved compression to 243kPa (2.4 ATA) for 90min while breathing 100% oxygen from a facemask or hood. There was a significant decrease in xerostomia (p<0.001) and slight increase in UWS (p<0.001) and SWS (p<0.001) flow rate, from before HBO as compared to after. Twenty-five of 45 patients with hyposalivation achieved an increased UWS flow rate after HBO. In 12 of these, the flow rates increased to levels not associated with hyposalivation. Patient-assessed improvement of xerostomia and slightly increased UWS and SWS secretion after HBO treatment suggest that HBO may have a beneficial effect on radiation-induced salivary gland damage.

Association of candy weight loss rate with whole saliva flow rates

The association of candy weight loss rate (CWLR) with whole saliva flow rates (WSFRs) was analyzed. The unstimulated whole saliva flow rate (UWSFR), stimulated whole saliva flow rate by the gum test (SWSFR-GT) and stimulated whole saliva flow rate by the Saxon test (SWSFR-ST) were measured in 300 healthy young adults. CWLR was measured by passively holding sugar candy between the tongue dorsum and hard palate. The degree of discomfort was evaluated by the visual analog scale. CWLR was significantly correlated with UWSFR, SWSFR-GT, and SWSFR-ST with Pearson's correlation coefficients of 0.1847 (P = .0013), 0.2097 (P = .0003), and 0.2332 (P < .0001), respectively; however, these were much smaller than those of 0.6858 (P < .0001) between UWSFR and SWSFR-GT, 0.5071 (P < .0001) between UWSFR and SWSFR-ST, and 0.5424 (P < .0001) between SWSFR-GT and SWSFR-ST. The degree of discomfort was significantly lower in the measurement of CWLR than in any WSFRs (P < .0001). CWLR cannot be used as an independent alternative to WSFRs, although it can be measured with less discomfort.

Emphasising the importance of determining appropriate criteria for evaluation of xerostomia

To the Editor: We read the article by Visvanathan et al. (1) about “xerostomia” enthusiastically. It explained that the mean salivary flow rate is highly variable (usually 0.25 ml/min) and the values less than 0.12–0.16 ml/min are considered abnormal (2). According to the literature, stimulated whole saliva flow rates of < 0.7 ml/min and unstimulated whole saliva flow rates of < 0.1 ml/min are considered as salivary gland hypofunction (3-5). So, it would be better to clarify whether the stimulated or unstimulated flow rate is the subject matter and the criteria for measuring each one be detailed. None.

Treatment of severe drooling with botulinum toxin in amyotrophic lateral sclerosis and Parkinson's disease: Efficacy and possible mechanisms

Objective. Drooling in neurodegenerative diseases is associated with social impediment. Previous treatments of drooling have little effect or are effective but with severe side effects. Therefore, there is a need to test new methods such as the use of botulinum toxin type A (BTX-A). Material and methods. This open, prospective study deals with treatment of drooling in 12 patients with amyotrophic lateral sclerosis and three with Parkinson's disease. Injections of BTX-A (Botox) were given into the parotid (25–40 units) and submandibular (15–30 units) glands with ultrasonographic guidance. After BTX-A treatment, the patients were followed for 2 months with evaluations every second week by means of self-assessed rating scales for drooling intensity, discomfort and treatment effect, and determination of unstimulated whole saliva (UWS) flow rate, and inorganic and organic UWS composition. The treatment was repeated up to four times, but seven patients dropped out shortly after the first treatment due to marked worsening of their disease-related condition. Results. Drooling and flow were reduced (P < 0.05) 2 weeks after treatment, without side-effects. The maximal reductions during the observation period were 40% for drooling and 30% for flow. There was a systematic variation in flow during the observation period, with an initial decrease and then an increase followed by a second decrease. Amylase activity and total protein concentration generally increased with decreasing flow (P ≤ 0.03). Conclusion. Inhibition of acetylcholine release from postganglionic parasympathetic nerve endings by injection of BTX-A into salivary glands seemed useful for secondary sialorrhoea, although cyclic variations in flow may occur, possibly due to transitory sprouting and regeneration.

The Copenhagen Oral Health Senior Cohort: design, population and dental health

In order to study the way old age influence oral health, the Copenhagen Oral Health Senior Cohort (COHS) has been established. To describe the design, measurement procedures, and baseline values for COHS including spatial distribution of restorations and dental caries as well as reasons for non-participation. Seven hundred and eighty-three individuals aged 65 years or older, from a total of 1918 invited elderly people, underwent an interview regarding oral health-related behaviour and a clinical oral examination including measurement of unstimulated whole saliva flow rate. Twelve percent of the COHS was edentulous. The number of dental restorations was higher for women compared to men; however, men had more caries than women. Coronal caries was most frequent on mesial and distal surfaces and on the maxillary incisors and canines; root caries was most frequent on labial surfaces and evenly distributed within the dentition. Only 41% of all invited elderly people accepted the invitation, with old age and poor health being the primary reasons for non-participation. The baseline values for COHS show that a substantial proportion of the participants had retained a natural dentition and that dental caries was prevalent with the anterior maxillary teeth being most affected.

Predictors of Xerostomia after Head and Neck IMRT: Beyond the Parotid Glands

Predictors of Xerostomia after Head and Neck IMRT: Beyond the Parotid Glands

Stimulated and unstimulated saliva progesterone in menopausal women with oral dryness feeling

The aim of this study was to investigate the stimulated and unstimulated salivary progesterone in menopausal women with oral dryness (OD) feeling. A case-control study was carried out on 70 selected menopausal women aged 42-78years with or without OD feeling (35 as cases with xerostomia and 35 as control without xerostomia), conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences (TUMS). Unstimulated and paraffin-stimulated saliva samples were obtained by expectoration. The salivary concentration of progesterone was determined with an enzyme immunoassay kit. Statistical analysis of the Student's t test was used. The mean stimulated and unstimulated whole saliva progesterone concentrations and unstimulated saliva flow, but not stimulated saliva flow rate, was significantly lower in the case than in the control. The results showed that subjects with dry mouth had decreased unstimulated saliva flow and salivary progesterone compared with those without dry mouth. Thus, salivary progesterone level appears associated with OD feeling in menopause.

Effectiveness of rituximab treatment in primary Sjögren's syndrome: A randomized, double‐blind, placebo‐controlled trial

To study the efficacy and safety of B cell depletion with rituximab, a chimeric murine/human anti-CD20 monoclonal antibody, in patients with primary Sjögren's syndrome (SS) in a double-blind, randomized, placebo-controlled trial. Patients with active primary SS, as determined by the revised American-European Consensus Group criteria, and a rate of stimulated whole saliva secretion of > or =0.15 ml/minute were treated with either rituximab (1,000 mg) or placebo infusions on days 1 and 15. Patients were assigned randomly to a treatment group in a ratio of 2:1 (rituximab:placebo). Followup was conducted at 5, 12, 24, 36, and 48 weeks. The primary end point was the stimulated whole saliva flow rate, while secondary end points included functional, laboratory, and subjective variables. Thirty patients with primary SS (29 female) were randomly allocated to a treatment group. The mean +/- SD age of the patients receiving rituximab was 43 +/- 11 years and the disease duration was 63 +/- 50 months, while patients in the placebo group were age 43 +/- 17 years and had a disease duration of 67 +/- 63 months. In the rituximab group, significant improvements, in terms of the mean change from baseline compared with that in the placebo group, were found for the primary end point of the stimulated whole saliva flow rate (P = 0.038 versus placebo) and also for various laboratory parameters (B cell and rheumatoid factor [RF] levels), subjective parameters (Multidimensional Fatigue Inventory [MFI] scores and visual analog scale [VAS] scores for sicca symptoms), and extraglandular manifestations. Moreover, in comparison with baseline values, rituximab treatment significantly improved the stimulated whole saliva flow rate (P = 0.004) and several other variables (e.g., B cell and RF levels, unstimulated whole saliva flow rate, lacrimal gland function on the lissamine green test, MFI scores, Short Form 36 health survey scores, and VAS scores for sicca symptoms). One patient in the rituximab group developed mild serum sickness-like disease. These results indicate that rituximab is an effective and safe treatment strategy for patients with primary SS.

Salivary changes and dental erosion in bulimia nervosa

Our aim was to study if bulimia nervosa (BN) has an impact on salivary gland function and if such changes are related to dental erosion. Twenty women with BN and twenty age- and gender-matched controls participated. Flow rate and composition of whole and glandular saliva, as well as feeling of oral dryness were measured. Dental erosion was measured on casts. Compared with control subjects, unstimulated whole saliva (UWS) flow rate was reduced in persons with BN, primarily owing to intake of medication (P = .007). No major compositional salivary changes were found. In the BN group, the dental erosion score was highest and complaints of oral dryness were more frequent. The BN persons had impaired UWS, mainly owing to medication; increased feeling of oral dryness; and more dental erosion. Dental erosion was related to the duration of eating disorder, whereas no effect of vomiting frequency or intake of acidic drinks on reduced UWS was observed.

The effects of high frequency, low intensity ultrasound therapy on parotid flow rates

Saliva plays a critical role in maintaining oral health and comfort. Development of a single device capable of simulating salivary flow with no taste or adverse side effects is desirable. This clinical investigation on 23 healthy volunteers with no dry mouth complaints evaluated the effectiveness of ultrasonic therapy in mechanical stimulation of the parotid gland to increase saliva flow. Stimulated and unstimulated parotid saliva was collected. Differences in mean salivary flow rates and affects of age and ethnicity were measured. The mean difference between stimulated and unstimulated saliva flow rates was 0.009 mL/min +/- SD = 0.042, t (df = 22) = 1.27 with P = .31. There were no significant differences of age (P = .26), gender (P = .38), or race/ethnicity (P = .58) for the difference of stimulated and unstimulated conditions. Results indicate that high-frequency low-intensity ultrasound therapy is not effective in stimulating salivary flow rates.