Studies on human minor salivary gland secretions using the Periotron method

Dysphagia and Oral Morbidities in Chemoradiation-Treated Head and Neck Cancer Patients

This study prospectively evaluated relationships between oral morbidities and swallowing ability in head/neck cancer patients following chemoradiation therapy (CRT) and at 3 months following CRT. Thirty patients with confirmed head/neck cancer undergoing chemoradiation were assessed with a battery of swallowing measures and measures of oral morbidities related to chemoradiation (xerostomia, mucositis, pain, taste/smell, oral moisture). All measures were completed at baseline (within the first week of CRT), at 6 weeks (end of treatment), and at 3 months following chemoradiation. Descriptive and univariate statistics were used to depict change over time in swallowing and each oral morbidity. Correlation analyses evaluated relationships between swallowing function and oral morbidities at each time point. Most measures demonstrated significant negative change at 6 weeks with incomplete recovery at 3 months. At 6 weeks, mucositis ratings, xerostomia, and retronasal smell intensity demonstrated significant inverse relationships with swallowing function. In addition, oral moisture levels demonstrated significant positive relationships with swallowing function. At 3 months, mucositis ratings maintained a significant, inverse relationship with swallow function. Taste and both orthonasal and retronasal smell intensity ratings demonstrated inverse relationships with measures of swallow function. Swallow functions and oral morbidities deteriorate significantly following CRT with incomplete recovery at 3 months post treatment. Furthermore, different patterns of relationships between swallow function measures and oral morbidities were obtained at the 6-week versus the 3-month assessment point suggesting that different mechanisms may contribute to the development versus the maintenance of dysphagia over the trajectory of treatment in these patients.

Oral Administration of Lactobacillus plantarum 299v Reduces Cortisol Levels in Human Saliva during Examination Induced Stress: A Randomized, Double-Blind Controlled Trial

Objective. To clarify the effect of Lactobacillus plantarum 299v on the salivary cortisol and salivary IgA levels in young adults under examination stress. Design. Forty-one students with an upcoming academic exam were included in a randomized double-blind, placebo-controlled study. The probiotic bacteria or the placebo product was administered in capsules once a day during 14 days. Saliva was collected and a perceived stress test was filled out at each sampling occasion. Saliva was collected for cortisol analysis by Electrochemiluminescence Immunoassay (ECLI) and salivary IgA was analysed by Enzyme-Linked Immunosorbent Assay (ELISA). Abundance of lactobacilli was evaluated by cultivation of saliva on selective medium and identification of L. plantarum 299v was done on randomly selected colonies by a random amplification of polymorphic DNA (RAPD) typing. Results. A significant difference in cortisol levels was found between the treatment group and the placebo group (P < 0.05), together with a significant increase in levels of lactobacilli in the treatment group compared with the placebo group (P < 0.001). No significant changes were found for salivary IgA. Conclusion. A probiotic bacterium with ability to reduce symptoms of irritable bowel syndrome (IBS) prohibited increased levels of the stress marker cortisol during the examination period. The registration number of the study is NCT02974894, and the study is registered at ClinicalTrials.gov.

Effect of 12-month weekly professional oral hygiene care on the composition of the oral flora in dentate, dependent elderly residents: A prospective study

OBJECTIVE

To study the effect of weekly professional oral hygiene care on the proportion of micro-organisms associated with good oral health, caries, and periodontal and soft tissue diseases in oral biofilms in dentate, dependent elderly residents.

BACKGROUND

Assisted oral hygiene care reduces the plaque score and number of micro-organisms in the oral biofilms in elderly residents. Less is known about the effect on the quality/composition of the remaining oral flora.

MATERIALS AND METHODS

Participants comprised 33 residents in the study and 35 in the control group. Dental status (≥10 natural teeth and no removable dentures to be included), plaque score, salivary secretion rate and prescription medicines were recorded. Duplicate samples, collected from supragingival plaque and tongue, were analysed using cultivation technique. Differences between and within groups were analysed using one-way and two-way ANOVA, respectively.

RESULTS

At the baseline, the number of teeth in the participants (mean age, 83.7 ± 7.4 years) was 22.0 ± 4.5. The number of prescription medicines was 9.4 ± 4.5. Seventy-six per cent had low salivary secretion rate. Fifty per cent had "visible thick" supragingival plaque. At the 12-month registration, "no visible" or "visible but thin" plaque was recorded in 92% in the study group. The proportions of bacteria associated with good oral health and periodontal diseases were decreased over time, while the frequency and proportions of micro-organisms associated with caries and soft tissue infection were unaffected or increased.

CONCLUSION

The results indicate that assisted oral hygiene care alone is not sufficient to regain an oral microbial flora associated with good oral health in dentate, dependent elderly residents.

Minor salivary glands function is decreased in hyposalivation-related diseases

OBJECTIVES

The aim of this cross-sectional study was to investigate the relationship between minor salivary gland (MSG) flow rates and oral dryness degrees in patients with xerostomia induced by primary Sjögren's syndrome (pSS), IgG4-related sialadenitis (IgG4-RS), radiation therapy-induced dry mouth (RTDM), or Steven-Johnson syndrome (SJS).

DESIGN

160 patients with pSS, IgG4-RS, RTDM, or SJS and their age- and sex-matched healthy control subjects were enrolled. The whole saliva flow rates and MSG flow rates were measured in four locations, including the upper labial, lower labial, buccal, and palatal mucosae. The degree of oral dryness was assessed in patient groups using the summated xerostomia inventory (SXI).

RESULTS

The flow rates of whole saliva and most MSGs in patient groups were significantly lower than the flow rates in healthy control groups (P<0.05). The mean relative percentage of decrease in saliva flow rates was smaller in MSGs than in whole saliva in patient groups (P<0.05), indicating that these disorders have less impact on MSGs. Among the four MSG locations (the upper labial, lower labial, buccal, and palatal), buccal glands showed the highest flow rates in patient groups (P<0.05). SXI scores were significantly higher in pSS and RTDM patients than in IgG4-RS and SJS patients (P<0.05). The degree of xerostomia varied among different patient groups (P<0.05) and there was no clear correlation between MSG flow rates and SXI scores (P>0.05).

CONCLUSIONS

MSG function is significantly reduced in pSS, RTDM, IgG4-RS, and SJS patients, but this reduction is more pronounced in the major salivary glands.

Effect of Caffeinated Soft Drinks on Salivary Flow

BACKGROUND

Soft drinks containing caffeine have been associated with more aggressive forms of dental decay. Cariogenicity of caffeinated soft drinks may be attributed to the effect of caffeine on salivary flow. This study assessed whether caffeinated soft drinks produced short-term oral dryness in healthy adults.

METHODS

The authors collected saliva on two separate days from 35 participants before and one hour after drinking a soft drink. On one of the days the soft drink was caffeinated and on the other day it was not. Saliva collection involved 15 minutes unstimulated whole saliva, 5 minutes paraffin-stimulated whole saliva, and 10 seconds labial minor salivary gland output.

RESULTS

Unstimulated and stimulated flow rates slightly increased and minor gland output slightly decreased one hour after the soft drink consumption regardless of caffeine content. These changes were not statistically significant (two-period two-treatment crossover trial using two-stage Grizzle model, p>0.05). A linear mixed model statistic did not show the caffeine effect on salivary flow rate.

CONCLUSIONS

Caffeinated soft drink consumption had no significant effect on salivary flow rate after one hour by any of the three measures employed in this study. Caffeine's contribution to the cariogenicity of soft drinks is likely by centrally-mediated effects on consumption patterns.

Sialometry of upper labial minor glands: a clinical approach by the use of weighing method Schirmer's test strips paper

Objectives. To establish referential values ranges of hyposalivation and normosalivation for the salivary flow rate (SFR) of upper labial (LS) and palatal (PS) mucosa using Schirmer's test strips paper and as a second goal to determine the values ranges of the SFR of palatal (PS) and upper labial (LS) mucosa in subjects with and without xerostomia. Methods. A cross-sectional study was conducted among subjects distributed in three groups according to their unstimulated and stimulated whole saliva. Results. 144 subjects were enrolled in groups as follows: severe hyposalivation (n = 24), mild hyposalivation (n = 78), and normosalivation (n = 42). The mean and the 95% confidence interval for the LS flow rate (μL/cm²/min) were 3.2 (2.46 to 3.94), 5.86 (4.96 to 6.75), and 9.08 (7.63 to 10.53) (P < 0.001) for each group, respectively. The PS results were 1.01 (0.68 to 1.34), 1.72 (1.31 to 2.13), and 2.44 (1.66 to 3.22) (P = 0.014). Xerostomia complainers presented lower rates of LS (5.17 (4.06 to 6.23)) than non-complainers (7.33 (6.4 to 8.27)) (P = 0.003). Conclusions. The test was reliable to provide referential values ranges for LS flow rate measurement and was shown to be valid to distinguish normosalivation from severe and mild hyposalivation and also to predict xerostomia.

Effect of 0.1% pilocarpine mouthwash on xerostomia: double-blind, randomised controlled trial

The objective of this study was to evaluate the effect of 0.1% pilocarpine mouthwash in xerostomic patients. Sixty volunteers were randomly allocated to two groups. The experimental group used 0.1% pilocarpine solution, and the control group used 0.9% saline. The short- and long-term effects of pilocarpine were investigated by measuring the severity of oral dryness, minor salivary flow rates and unstimulated whole salivary flow rate at predetermined times. The severity of oral dryness was decreased in both groups at 0, 30 and 60 min after mouthwashing, with no significant difference between the groups. Buccal and labial secretions were increased in both groups, but only the experimental group exhibited increased palatal secretion. Labial and palatal secretions, but not buccal secretion, differed between the groups. The unstimulated whole salivary flow rate was increased in the experimental group and differed from that in the control group. After 4 weeks, the severity of oral dryness was decreased in both groups and did not differ between them. The oral dryness at night or on awakening significantly decreased in both groups, with no significant difference between them, but the oral dryness at other times of the day and the difficulty in swallowing foods were not significantly changed in both groups. Minor salivary and unstimulated whole salivary flow rates did not increase in both groups. Until 1 h after mouthwashing, 0.1% pilocarpine mouthwash increased minor salivary and unstimulated whole salivary secretions, but was not superior compared with 0.9% saline at relieving subjective oral dryness.

Associations between labial and whole salivary flow rates, systemic diseases and medications in a sample of older people

OBJECTIVE

To investigate the associations between age, gender, systemic diseases, medications and labial and whole salivary flow rates in older people.

METHODS

Unstimulated labial (LS) and unstimulated (UWS) and chewing-stimulated (SWS) whole salivary flow rates were measured in 389 randomly selected community-dwelling Danish women and 279 men aged 65-97 years. Systemic diseases, medications (coded according to the Anatomical Therapeutic Chemical (ATC) Classification System), tobacco and alcohol consumption were registered.

RESULTS

The number of diseases and medications was higher and UWS lower in the older age groups. On average, women were slightly older, had more diseases, higher medication intake and lower UWS, SWS and LS than men. High number of diseases and medications was associated with low UWS, SWS and LS. In the healthy (14%) and nonmedicated (19%) participants, flow rates were not associated with age and gender, apart from SWS being lower in nonmedicated women. Low UWS were associated with psychiatric and respiratory disorders, type 2 diabetes and intake of psycholeptics, psychoanaleptics (especially SRRIs), respiratory agents, oral antidiabetics (particularly sulfonylureas), magnesium-hydroxide, cardiac agents, quinine, thiazides, calcium channel blockers, statins, urinary antispasmodics, glucosamine, NSAIDs, opioids and ophthalmologicals. SWS were lower in participants with ophthalmological disorders using ophthalmologicals (especially antiglaucoma agents and miotics), but also in those taking antidepressants, cardiac agents (mostly digitalis glycosides) and calcium channel blockers. Cardiovascular diseases and intake of anti-thrombotics (mainly low dose aspirins), calcium channel blockers and oral antidiabetics were associated with low LS.

CONCLUSIONS

In older people, low salivary flow rates are associated with specific and high number of diseases and medications, but neither with age and gender per se nor with tobacco and alcohol consumption. Low UWS are associated with more diseases and medications than SWS and LS, which were primarily associated with cardiovascular diseases and medications including preventive agents such as low-dose aspirins and statins. New insights into medications and their association with salivary gland function were achieved using the ATC classification system.

Investigating the relationship between hyposalivation and mucosal wetness

BACKGROUND

Mucosal wetness (MW) reflects the layer of residual saliva that covers the oral mucosal surfaces.

OBJECTIVES

The aim of this study was to determine MW at different oral mucosa sites and to investigate the relationship between MW, unstimulated whole salivary flow rates (UWS) and Clinical Oral Dryness Score (CODS).

METHOD

A total of 100 dry mouth patients and 50 healthy subjects participated in the study. MW was sampled with filter paper strips at four sites inside the mouth; anterior hard palate (AHP), buccal mucosa (BUC), anterior tongue (AT), lower lip (LL) and measured with a micro-moisture meter. Reproducibility was assessed by repeated sampling and diurnal variation was examined.

RESULTS

Mucosal wetness in healthy subjects differed according to site and means±SD were; AHP (11± 11.7μm), BUC (32±14.8μm), AT (65±17.2μm), and LL (25 ±13.5μm). Dry mouth patients with reduced UWS showed increased CODS. MW at all four sites was significantly reduced (P<0.05) in dry mouth patients compared with the healthy subjects. Reproducibility of MW measurement using the intra-class correlation coefficient showed agreement at different visits within subject. MW of the AT showed a positive correlation with UWS (P<0.05).

CONCLUSION

Mucosal wetness is a reliable measure of oral dryness and had a positive correlation with UWS.

An update on minor salivary gland secretions

In this article, the literature on minor salivary gland secretion rates, composition, and function is reviewed. Measurements of the minor salivary gland secretion rates and composition are complicated, and the secretions display large biological variability. Despite this, some characteristics of these secretions have been found repeatedly in independent investigations. Minor gland saliva varies between different oral sites. Buccal saliva flow is higher than labial saliva flow, which in turn is usually higher than the palatal gland secretion rate. It is generally agreed that minor gland saliva is important for the whole saliva composition, and especially for the secretory immunoglobulin A and mucins. The secretion from these glands seems also important for subjective feelings of dry mouth and general wellbeing. Further research is essential for understanding the role of these secretions for oral, as well as for general, health.

Minor salivary gland secretion rates and immunoglobulin A in adults and the elderly

Previously published data are conflicting about the effect of various factors on secretions from minor salivary glands. The aim of the present study was to investigate the secretion rate from palatal, buccal, and labial glands, and to analyze the immunoglobulin A (IgA) concentrations in relation to age, gender, circulatory disease, diabetes, medication, smoking, and pregnancy. Resting and stimulated whole-saliva secretion rates, as well as IgA concentration in stimulated whole saliva, were also examined. One-hundred and forty two individuals (96 women and 46 men), 18-82 yr of age, participated. The results did not suggest any effect of aging on the secretion capacity of minor salivary glands, but the IgA concentration seemed to increase with age. Women had lower buccal and labial saliva secretion rates, and lower levels of IgA in buccal saliva, than men. For whole saliva, resting, but not stimulated, saliva secretion rates were reduced with age, and the secretion rate of stimulated whole saliva was lower in women than in men. The IgA concentration in buccal saliva showed a positive correlation with IgA in stimulated whole saliva, and the IgA concentration decreased with increased flow rate in both salivas.

The distribution of oral mucosal pH values in healthy saliva secretors

OBJECTIVES

To establish the normal range of oral mucosal pH and to correlate these measurements to salivary flow rate in healthy individuals according to age and gender.

SUBJECTS AND METHODS

Measurements of pH levels using a flat pH meter and salivary secretion rates were established in eight mucosal sites from a total of 50 healthy individuals.

RESULTS

The mean pH (+/-s.d.) of all sites was 6.78 +/- 0.04 with significant differences between mean pH values in the palate (7.34 +/- 0.38), the floor of the mouth (6.5 +/- 0.3), the buccal mucosa (6.28 +/- 0.36) and the tongue (6.8 +/- 0.26). A significant correlation was found between age and pH at palatal and tongue sites but no gender effects were noted.

CONCLUSIONS

This method is easy and relatively quick to manipulate, and may offer many diagnostic possibilities for oral related diseases and disorders such as oral malodour, mouth breathing, dysgeusia, acidic diet consumption and gastrointestinal disorders affecting the mouth.

Physical and physiological consequences of passive intra-oral shimming

Imaging the human orbitofrontal cortex (OFC) with fMRI is problematic due to the proximity of this region to the air-filled sinuses, which causes susceptibility artifacts. Placing a strongly diamagnetic material into the mouth ('mouthshim') of a human volunteer can significantly reduce the artifacts in this region. Using the same combined olfactory and visual fMRI paradigm, we compared brain activation and static B0 field maps of participants being scanned both with and without the 'mouthshim'. Results demonstrate that the device improves the B0 field homogeneity within OFC, resulting in significantly stronger BOLD activation in this region. However, the device also caused both increased head motion and reduced activation in insular cortices due to more frequent swallowing and tactile stimulation of the tongue. The 'mouthshim' should only, therefore, be used where sensitivity in OFC regions is paramount.

Minor gland saliva flow rate and proteins in subjects with hyposalivation due to Sjögren's syndrome and radiation therapy

In this study, the secretion rate and IgA, albumin and lactoferrin concentrations in minor labial and buccal gland saliva were investigated in individuals with hyposalivation due to primary Sjogren's syndrome (pSS; 10 subjects) or head and neck radiation therapy (RT; 10 subjects) and in their matched controls. Whole saliva was similarly examined. The minor gland saliva flow was measured using the Periotron method. IgA, albumin and lactoferrin concentrations were analysed by ELISA techniques. A general finding was that the flow rate and protein concentrations were lower in labial than in buccal gland saliva. In both hyposalivation groups, the labial minor gland saliva secretion rate was lowered compared to their respective controls. The buccal gland saliva flow rate was significantly reduced in the RT group only. IgA and albumin concentrations were not different from the controls in the labial secretions. The concentration of lactoferrin was increased in the RT group. In buccal saliva, the concentrations of all proteins examined but pSS IgA, were increased compared to the controls. Reduced flow rate and increased protein concentrations were seen for whole saliva where the lactoferrin concentration was higher in RT than in pSS subjects. Thus, our findings suggested that minor gland saliva flow rate and protein concentrations are affected in RT and pSS subjects and to highest extent in the former.

Human palatal saliva: adsorption behaviour and the role of low-molecular weight proteins

In situ ellipsometry was employed to study adsorption from human palatal saliva (HPalS) in terms of dependence on surface wettability and saliva concentration (<or=1%). Adsorbed amounts, kinetics, and elutability with buffer and sodium dodecyl sulphate (SDS) were determined. The low-molecular weight protein content of bulk HPalS was also investigated using two-dimensional gel electrophoresis, and this revealed the presence of a large group of proteins<100 kDa in size. Adsorption to pure (hydrophilic) and methylated (hydrophobized) silica surfaces revealed that the total adsorbed amounts were greater on hydrophobized silica. Below concentrations of 0.5 and 0.25% saliva, adsorption was concentration dependent on hydrophobized and hydrophilic surfaces, respectively. The initial adsorption (<or=30 min) was faster on hydrophobized surfaces. Addition of SDS removed more material than buffer rinsing on both surfaces. Analysis of the adsorption kinetics indicated that the presence of low-molecular weight proteins plays a role in adsorption from HPalS.

Human minor and major gland saliva proteins and ability to mediate Actinomyces naeslundii adherence

Bacteria-binding components and the ability to mediate bacterial adhesion to the tooth surface have been thoroughly studied in major salivary gland secretions. Our knowledge on the bacteria binding activity in minor gland saliva is, however, limited. In this study, proteins were examined in parallel in minor (palatal, buccal and labial) and major (parotid and submandibular/sublingual) salivary gland secretions in one subject using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The adherence of early colonizing Actinomyces naeslundii to pellicles formed from the secretions on hydroxyapatite beads was also examined. Amylase, IgA, proline-rich proteins and the high-molecular-weight glycoproteins, agglutinins, were detected in all saliva tested. Carbohydrate-reactive antibodies recognized the low-molecular weight mucin, MUC 7 in submandibular/sublingual saliva only. A. naeslundii strain 12104 adhered to all pellicles and especially to the buccal gland saliva pellicles. Strain LY7 adhered in highest numbers to the submandibular/sublingual saliva pellicles. It also bound in considerable numbers to parotid and palatal saliva pellicles but not to the ones formed from buccal and labial gland saliva. Our findings indicate that several bacteria-binding components are secreted in both minor and major gland saliva. The adherence-promoting ability of the various gland secretions differs, however.

A simple, yet accurate method for detecting and quantifying secretions from human minor salivary glands using the iodine-starch reaction

The lack of published information about the minor salivary glands is due in part to the difficulties experienced in collecting and quantifying their secretions. In fact, no method exists for measuring their secretions that is both simple and accurate. This investigation examined the accuracy of our newly developed method (which simply employs the iodine-starch reaction) in 10 healthy non-medicated adults. A strip painted with a solution of iodine in absolute alcohol then with a fine starch powder mixed with castor oil was placed at a designated location on the lower-lip mucosa for 2 min to collect saliva. Black-stained spots of various sizes corresponding to the individual glands could be accurately visualized. After removal of the strip, the total stained area (mm2) was calculated by digitizing the spot areas using a computer system. The correlation coefficient (r) between known volumes of saliva and stain size was 0.995, indicating a close correlation. The correlation coefficient (r) between area values obtained in the first trial in each subject (Y) and the second (X; 10 min later) was 0.963, and the simple regression equation was close to Y=X, indicating good reproducibility. The mean flow rate microl/cm2 per min) obtained by converting mean total area to volume and thence to flow rate was 0.49+/-0.26, in good agreement with published values obtained by others. These results suggest that our newly developed method allows both the distribution and secretion rate of the minor salivary glands to be observed, and that it should be of practical value due to its simplicity, accuracy, and reproducibility.

Minor gland and whole saliva in postmenopausal women using a low potency oestrogen (oestriol)

Many women undergo hormone replacement therapy in order to relieve menopausal and postmenopausal symptoms. Oral discomfort is common among these symptoms and studies have shown that the stimulated whole saliva flow rate is increased after combined oestradiol and progesterone replacement therapy. There is, however, no data regarding the effect of other oestrogens or of oestrogen alone on whole and minor gland saliva. In the present study, the flow rate from minor salivary glands (buccal, labial and palatal) and the secretion rate and buffer capacity of whole saliva was examined in 18 postmenopausal women (61-76 years) prior to, and during 1 year of a low potency oestrogen (oestriol) use. The ability of whole saliva to aggregate and mediate bacterial adherence as well as subjective feelings of dry mouth was also examined. For comparison, the same variables were examined in nine peri- and postmenopausal, non-medicated women (reference group, 53-61 years). During hormone treatment, the labial saliva flow was significantly increased and the complaints of dry mouth reduced. Increased stimulated whole saliva flow was seen in both the hormone and reference groups. This was also true for the stimulated whole saliva buffer capacity, which was increased parallel to the flow rate. The secretion rates were generally lower in the hormone group compared to the reference group throughout the study period. Except for stimulated whole saliva, statistical analysis at baseline revealed no age-related reduction of the saliva flow rates. The ability of whole saliva to mediate aggregation of Actinomyces naeslundii was significantly decreased after hormone treatment. Thus, the present findings indicate that a low dose oestrogen (oestriol) may affect the flow rate of labial salivary glands and the bacterial aggregation activity of whole saliva.

Minor salivary gland secretion in children and adults

The minor salivary glands are of great importance in the physiology and pathology of the oral cavity. So far, studies of the minor glands have concentrated on adults. In the present study, minor salivary gland secretion was studied in the buccal and labial mucosa of 3-year-old children, adolescents and young adults. In addition, the number of glands per surface area was assessed in the labial mucosa. A total of 90 individuals were included, 30 in each age-group. Saliva was collected on filter paper discs and the salivary secretion rate was measured using a Periotron 8000. The number of secreting labial glands was assessed on PAS-stained filter paper discs under a microscope. Salivary secretion in the buccal mucosa was found to be age-related, with a statistically significant lower rate of secretion (P=0.003) in the 3-year-olds (mean 7.7 microl x cm(-2) x min(-1)) compared with the young adults (11.9 microl x cm(-2) x min(-1)). No significant differences between the sexes were noted. For the labial glands, no age- or sex-related differences were found. In all age-groups, salivary secretion was significantly higher in the buccal than in the labial mucosal area. A statistically significant difference in number of secreting glands was found between all age-groups, with a decreasing number of glands per surface unit with age. The number of glands was significantly lower in males compared with females in the group of adults. The lower rate of buccal salivary secretion in the young children may imply that the oral mucosa is more vulnerable to external injury and that caries protection on the buccal molar surfaces is lower. Previous studies indicate that adults with a reduced rate of minor salivary gland secretion are more susceptible to caries.

Optimisation of conformal radiation therapy by intensity modulation: cancer of the larynx and salivary gland function

PURPOSE

Prevention of damage to critical normal tissues is of paramount importance for the quality of life of patients irradiated for cancers in the head and neck. The purpose of this paper was to evaluate the parotid gland sparing 3D conformal radiation therapy technique (3DCRT) in a prospective study in node negative cancer of the larynx.

MATERIALS AND METHODS

Twenty-six patients with node negative squamous cell cancer of the larynx were irradiated by a 3DCRT technique (class solution) to both sides of the neck (elective dose 46 Gy to levels II, III and IV) and primary tumour (70 Gy). Dose distributions of the major salivary glands were correlated with objective (stimulated whole saliva flow, WS) and subjective (questionnaire; visual analogue scale, VAS) salivary gland function. Apart from the clinically used 3DCRT technique, in order to optimise 3DCRT dose distributions, intensity modulated (IMRT) treatment plans were generated for the same patient population. Dose-volume histograms of 3DCRT and IMRT treatment plans were analysed and compared.

RESULTS

For the 26 patients irradiated with the 3DCRT class solution technique: VAS scores and questionnaires reached their nadir 3 months post-radiotherapy; WS reached its nadir 6 months post-radiotherapy. WS flow rates improved significantly, but never normalised; 2 years post-treatment WS measurements were 48% of the pre-treatment values. VAS scores deteriorated during ERT from 0 pre-treatment to 6.1 immediately post-treatment. Compared to pre-treatment, questionnaires were answered affirmative by increasing numbers of patients. For all patients, IMRT treatment plans resulted in a significant reduction of the dose delivered to the parotid glands compared to the 3DCRT-treatment technique.

CONCLUSIONS

The class solution for the 3DCRT salivary gland sparing technique is inadequate for fully preserving salivary gland function, given the dose distributions (DVHs) as well as the subjective- and objective salivary gland function assessments. The results can be optimised in the future, that is a further reduction of xerostomia can be achieved, by using IMRT techniques focused at sparing major and minor salivary glands.

Patients with head and neck cancer cured by radiation therapy: a survey of the dry mouth syndrome in long-term survivors

BACKGROUND

Xerostomia can have a significant impact on the quality of life of patients treated by radiation therapy (RT) for cancer in the head and neck. The first aim of the study was to evaluate the degree of xerostomia in 39 long-term survivors treated between 1965-1995 by conventional two-dimensional radiation therapy and currently without evidence of disease. The second aim was to develop a concise instrument to evaluate the subjective aspects of xerostomia.

METHODS

A newly developed questionnaire and a visual analog scale (VAS) were used in analyzing the degree of dry mouth and xerostomia-related problems. The radiation dose received by the major salivary glands was estimated by analyzing two-dimensional simulation films.

RESULTS

Sixty-four percent of the patients experienced a moderate to severe degree of xerostomia. In the multivariate analysis, three questions regarding dry mouth, eating, and speech were particularly discriminatory for establishing the degree of xerostomia as expressed by the VAS score.

CONCLUSIONS

In this survey, 64% of the long-term survivors, after treatment by conventional two-dimensional radiation therapy for a malignancy in the head and neck region, still experienced a moderate to severe degree of permanent xerostomia. A simplified instrument to evaluate xerostomia subjectively can consist of the VAS score and three graded questions.

Stimulation of minor salivary glands by intraoral treatment with the cholinesterase inhibitor physostigmine in man

A large number of the population, especially the elderly, suffers from dry mouth. The aim of the present investigation was to stimulate the minor salivary glands by the topical application of the cholinesterase inhibitor physostigmine. In eight healthy subjects. 100 microl of the substance, in the concentration interval 2-8 mg/ml, was applied locally to the inside of the lower lip for 1 min. In a separate study comprising 12 dry-mouth patients. 10 ml of 0.4 1.6 mg/ml physostigmine was administered as a mouth rinse solution for 2 min. Secretion from the labial glands. assessed using the Periotron method, increased in a dose-dependent manner in response to physostigmine in both groups. Average peak secretion exceeded baseline by more than 50% throughout the 30- to 45-min observation period; from 1.71 to 2.62 microl cm(-2) min(-1) among the healthy subjects and from 1.17 to 1.84 microl cm 2 min among the dry mouth patients. No systemic effects were registered as reflected by ECG, heart rate or blood pressure. It is assumed that intraorally applied physostigmine diffuses through the oral mucosa and acts by preserving acetylcholine released from the cholinergic, parasympathetic nerves that innervate the minor salivary glands. The topical application of physostigmine to the oral mucosa may, therefore, be an interesting approach for the treatment of dry mouth.

Analysis of residual saliva and minor salivary gland secretions

Residual saliva and minor salivary gland secretions are important for the maintenance of oral mucosal wetness. Salivary proteins and glycoproteins are the major components of the oral mucosal film, which functions as a moisture retainer and a protective barrier. Here, the correlations between the amounts of residual saliva and minor salivary gland secretions and their protein concentrations were investigated in 30 normal healthy individuals. The thickness of the mucosal film was measured at six mucosal surfaces and minor salivary gland secretion rate was measured at two mucosal surfaces. The thickness of residual saliva was determined by placing filter-paper strips against the mucosa at each site for 5 s and then measuring the volume electronically with a Periotron 8000 micro-moisture meter. The unstimulated rate of minor salivary gland secretion was measured for 30 s by the same method. Unstimulated whole salivary flow rate was measured with the spitting method. The total protein concentration of all salivary samples was measured by bicinchoninic acid assay. Before the experiment, the intra-/inter-examiner reliability of the method using the Periotron and the filter-paper strips was investigated. With a range of 0.4256-0.8846, the intraclass correlation coefficient, measured within and between examiners, was indicative of good reliability. The oral mucosal site with the thinnest coat of residual saliva was the anterior hard palate. Mucosal wetness on the hard palate and buccal mucosa showed significant positive correlations with the unstimulated whole salivary flow rate and significant negative correlations with the total protein concentration of residual saliva. Mucosal wetness on the upper and lower labial mucosa also showed significant negative correlations with the total protein concentration of residual saliva. Mucosal wetness on the soft palate was correlated with the minor salivary gland secretion rate (r=0.477, P<0.01). Among the minor salivary glands, the secretion rate of soft palate glands in females showed a significant correlation with the unstimulated whole salivary flow rate (r=0.563, P<0.05) and a significant negative correlation with its total protein concentration (r=-0.525, P<0.05). These data suggested that oral mucosal wetness and minor salivary gland secretions could be influenced by various factors differently according to mucosal sites.

Minor salivary gland secretion in the elderly

OBJECTIVE

Very little information exists on minor salivary gland output (MSGO) in health and disease. We investigated the minor salivary gland output of elderly subjects with different medical backgrounds and the relationship of that output with life practices, demographic variables, complaints of dry mouth, medication usage, functional status, medical treatments, and dental and medical variables.

STUDY DESIGN

MSGO was measured with a special moisture-detecting paper on the lip, cheek, and palate, which comprised the total MSGO. A parsimonious linear regression model was developed to determine which of the many measured variables influenced the MSGO.

RESULTS

There were significant differences in MSGO between the recruitment sites, with the non-Veteran Affairs (VA) Independent Living participants having significantly lower MSGO than the VA groups. A secretion rate for MSGO based on median values from all subjects of <4.6 microL/min was categorized as being low, whereas a secretion rate for MSGO >/=4.6 microL/min was categorized as high. A regression model was used to examine variables that could be associated with MSGO variability. The results show that being older, a woman, a current smoker, and having a complaint of dry mouth were associated with lower MSGO rates.

CONCLUSIONS

An association between subjective complaints of dry mouth and a decrease in MSGO measured objectively was demonstrated in this elderly population. Furthermore, age and sex effects on MSGO were also demonstrated.

Saliva in health and disease: an appraisal and update

Saliva plays an important role in oral health monitoring, regulating and maintaining the integrity of the oral hard tissues and some soft tissues. This paper reviews the role of saliva, the prevalence of oral dryness and the consequent importance of salivary flow as well as the relationship between xerostomia and salivary gland hypofunction amongst the causes of oral dryness. Other aspects of oral conditions associated with saliva are also reviewed including Sjögren's Syndrome and oesophageal function. Finally, knowledge, and the current use of salivary tests and the utilisation of saliva as a diagnostic fluid are surveyed.

Medication and dry mouth: findings from a cohort study of older people

OBJECTIVES

The aim of this study was to examine the association between medication exposure and (1) unstimulated whole-salivary flow rate and (2) the severity of xerostomia among older people while adjusting for multiple medication use.

METHODS

Data were obtained from participants remaining at the five-year follow-up phase of a cohort study of community-dwelling older South Australians. Medication exposure information was available at baseline and at five years, enabling examination of the effects on dry mouth of long-term exposure to medications. At the five-year follow-up, unstimulated salivary flow was estimated using the spit method, and xerostomia severity was estimated using the 11-item Xerostomia Inventory. Because of the potential difficulties posed by polypharmacy, a two-stage analytical approach was employed: (1) Classification and Regression Tree (CART) analysis was used as an exploratory device to elucidate the relationships among the dependent and independent variables, and (2) linear regression analysis was used as a complementary procedure.

RESULTS

Unstimulated flow rate was lower among individuals who were female or taking antidepressants at both baseline and five years, and higher among smokers or people who were taking hypolipidemic drugs. Xerostomia severity was higher among females, or individuals taking: (1) an anginal at baseline and five years, (2) an anginal without a concomitant betablocker at five years, (3) thyroxine and a diuretic at five years, or (4) antidepressants or antiasthma drugs at both baseline and at five years.

CONCLUSIONS

These results suggest that polypharmacy can be accounted for to a certain extent by using CART analysis in conjunction with more conventional approaches; and that the relationship between medications and dry mouth is a complex one, and differs according to which aspect of dry mouth is being examined.

The flow rate and composition of human labial gland saliva

Since the flow rate of saliva from human labial salivary glands has usually been measured as the secretion from an area of labial mucosa as 0.05-4.8 microl/cm2/min. The only data for single glands gives a comparable figure of 0.1 microl/min/gland. There is no consensus on the effects of gustatory stimulation, gender or ageing, although most reports suggest that flow rate is not related to gender and ageing up to age 60. The main differences in composition between labial gland saliva and that from the major glands are the higher and variable sodium concentration, the very low phosphate and hydrogen carbonate concentrations, and the higher protein concentration despite low concentrations of amylase. The concentrations of IgA and blood group substances are notably higher in labial gland saliva. In Sjogren's syndrome and cystic fibrosis flow rates are decreased. Low rates of flow have been associated with a higher incidence of dental caries.