Feeling of dry mouth in relation to whole and minor gland saliva secretion rate

Metabolomic insights into idiopathic xerostomia: The central role of caffeine metabolism in salivary biochemistry

OBJECTIVE

This study aims to delineate the salivary metabolomic profile of patients with idiopathic xerostomia using untargeted metabolomics techniques, with the goal of addressing the lack of clear diagnostic markers and providing insights into the pathophysiological mechanisms of the condition.

DESIGN

In this observational, cross-sectional study, saliva samples from 33 patients with idiopathic xerostomia and 34 healthy controls were analyzed using Ultra Performance Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry (UPLC-QTOF MS). Metabolomic profiling was complemented by multivariate statistical analysis to differentiate between affected individuals and controls.

RESULTS

Metabolomic analysis delineated a pronounced differentiation between patients with idiopathic xerostomia and healthy controls. A total of 195 metabolites displayed significant differential expression, each with a variable importance in projection (VIP) greater than 1 and a P-value less than 0.05. Pathway enrichment analysis, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG), identified 22 metabolites that participated in 18 distinct metabolic pathways. Among these, the caffeine metabolism pathway, characterized by notable alterations in impact values (VIP, P-value, Log2-fold change, Rich factor), emerged as the most significantly disrupted, underscoring its potential role in the pathophysiology of idiopathic xerostomia (P = 0.0000395).

CONCLUSIONS

The salivary metabolomic profiling revealed distinct alterations in idiopathic xerostomia, with a significant reduction in caffeine metabolism pathways, underscoring potential neuropathic involvement. This study advances our understanding of the metabolic alterations in xerostomia, suggesting that salivary metabolomics may offer viable biomarkers for diagnosing and understanding the etiology of idiopathic xerostomia. Future research should focus on therapeutic targeting of these metabolic disturbances and evaluating their reversibility with treatment.

Contribution of kelp dashi liquid to sustainable maintenance of taste sensation and promotion of healthy eating in older adults throughout the umami-taste salivary reflex

Introduction

Taste decline, including taste loss in older adults, leads to malnutrition and frailty. In a super-aging society, improving taste decline and maintaining taste sensation are crucial for the wellbeing of older adults. Hyposalivation frequently affects older individuals and is the leading cause of taste decline in older adults. Treating taste decline, including taste loss, in older adults presents challenges due to the limited sustainable methods for increasing saliva production, except for drug therapy, which may lead to adverse effects. Umami-taste stimulation results in a prolonged increase in both the whole salivary flow rate (WF), more than 90% of which is secreted from the major salivary glands, and the minor salivary gland flow rate (MF) in healthy volunteers through the umami-taste salivary reflex. We hypothesized that umami-rich kelp dashi liquid (KDL), commonly used in Japanese cuisine, may alleviate taste decline and sustain normal taste sensation in older adults with hyposalivation. This study investigated whether KDL stimulation could improve taste decline.

Materials and methods

A non-randomized controlled trial was conducted at the dental department of a university hospital, involving those who presented with dry mouth between May 2017 and December 2021. Before and after repeated KDL stimulation, characteristics like changes in WF and MF, the recognition thresholds (RTs) for five basic tastes, and subjective eating and swallowing difficulties were assessed. Statistical comparisons were performed between the values measured before and after KDL stimulation.

Result

A total of 35 older patients were included. Patients with reduced MF and with or without reduced WF exhibited umami-taste loss. Repeated stimulation with KDL increased MF and WF and improved taste loss, including umami, decreased RTs, and normalized each taste. Furthermore, subjective taste impairment, subjective eating and swallowing difficulties, and burning sensations in the oral mucosa were alleviated.

Conclusion

These findings indicate that KDL stimulation improved umami-taste loss and normalized each taste sensation, further alleviating eating difficulties via the umami-taste salivary reflex. Importantly, umami-taste loss was also observed in patients with normal WF but decreased MF, who are typically not diagnosed with hyposalivation. Therefore, KDL has the potential to sustain taste sensations and promote healthy eating habits in older individuals.

The changes on salivary flow rates, buffering capacity and chromogranin A levels in adults after bariatric surgery

OBJECTIVES

This study aimed to investigate changes in salivary flow rates, buffering capacity, and salivary chromogranin A (CHGA) levels in adults undergoing bariatric surgery (BS) compared with a non-obese control group.

MATERIALS AND METHODS

Salivary analyses were performed on 62 participants aged over 50 years, stratified into two groups matched for age and gender-individuals who had undergone bariatric surgery (BS) (n = 31) and a corresponding healthy control group (n = 31). Before saliva collection, participants completed a comprehensive 11-point visual numerical rating scale (NRS 0-10) xerostomia questionnaire, assessing subjective perceptions of two key aspects: dryness of the oral mucosa and resultant impact on oral functional ability. Three distinct saliva measurements were obtained: unstimulated whole saliva (UWS), stimulated whole saliva (SWS), and unstimulated upper labial saliva (ULS). The buffering capacity of unstimulated saliva was assessed using pH indicator strips, and concentrations of salivary Chromogranin A (CHGA) were quantified in stimulated saliva via enzyme-linked immunosorbent assay (ELISA).

RESULTS

After BS, more than 40% of BS group patients reported xerostomia, with 16.1% experiencing only mild symptoms without significant functional impact (p = 0.009). The prevalence of xerostomia and tongue dryness was higher in the BS group compared to the control group (p = 0.028 and p = 0.025, respectively). The comparative analysis unveiled no statistically significant differences in flow rates of unstimulated upper labial saliva (ULS), unstimulated whole saliva (UWS), and stimulated whole saliva (SWS) between the control group and patients who underwent bariatric surgery. However, in patients undergone BS with xerostomia, both ULS and UWS flow rates were significantly lower than in controls with xerostomia (p = 0.014 and p = 0.007, respectively). The buffering capacity was significantly lower in patients undergone BS than in controls (p = 0.009). No differences were found between groups regarding CHGA concentration and output values, nevertheless, higher values of CHGA concentrations were significantly correlated to lower flow rates.

CONCLUSION

According to the results, this study suggests that individuals undergoing BS may exhibit altered salivary buffering capacity and reduced unstimulated salivary flows in the presence of xerostomia. Additionally, the findings suggest that elevated concentration of salivary CHGA might be associated, in part, with salivary gland hypofunction.

CLINICAL RELEVANCE

The clinical significance of this study lies in highlighting the changes in salivary functions after BS. The identified salivary alterations might be attributed to adverse effects of BS such as vomiting, gastroesophageal reflux, and dehydration. Understanding these changes is crucial for healthcare professionals involved in the care of post-BS patients, as it sheds light on potential oral health challenges that may arise as a consequence of the surgical intervention. Monitoring and managing these salivary alterations can contribute to comprehensive patient care and enhance the overall postoperative experience for individuals undergoing BS.

Anticholinergic burden of medications is associated with dry mouth and reflected in minor labial gland secretion

OBJECTIVE

Medications with anticholinergic potential inhibit saliva secretion. Polypharmacy potentiates anticholinergic burden, causing dry mouth symptoms and chronic deterioration of oral health. Patients of any age can be affected by anticholinergic medication-triggered hyposalivation (the objective measure of dry mouth); therefore, seeking predictions of hyposalivation to screen dry mouth is needed.

DESIGN

In our prospective, cross-sectional clinical study, 55 middle-aged adult patients participated. We examined whether the anticholinergic burden calculated from anticholinergic medications (anticholinergic drug score; ADS) and blood serum anticholinergic activity (SAA; the gold standard measure of anticholinergic burden) is associated with hyposalivation. As no prior studies measured minor salivary glands regarding the quantifiable anticholinergic burden, we assessed hyposalivation by the minor saliva flow (MSF) and unstimulated whole saliva (UWS) secretion.

RESULTS

Our data showed a negative linear relationship between SAA and UWS (p < 0.05); when SAA increases by one pmol/ml unit, the saliva flow decreases by 0.058 ml/min. MSF showed a linear correlation (p < 0.005) with UWS. In a multivariate logistic regression model (including age, gender, race, smoking status, xerostomia severity, ADS, and BMI), we identified SAA and age as predictors of hyposalivation (p < 0.05).

CONCLUSIONS

We provide evidence for the significant relationship between measurable anticholinergic burden and saliva flow. The correlation between UWS and MSF suggests that both saliva flow rate measurement methods could reflect anticholinergics-induced changes in salivary health.

Eating and speech problems in oral and pharyngeal cancer survivors - Associations with treatment-related side-effects and time since diagnosis

AIMS

The aim of this cross-sectional study was to find factors associated with problems with the ability to eat and speak in oral and pharyngeal cancer (OPC) survivors and to evaluate if the panorama of oral problems varied with time since diagnosis.

METHODS AND RESULTS

A questionnaire assessing cancer diagnosis and treatment, oral health-related quality of life, and presence of treatment-related side-effects was sent to members of the Norwegian Head and Neck Cancer Association. Three-quarters (n = 117) of the respondents experienced xerostomia, and 51% (n = 79) had dysphagia. Prevalence of dysphagia, trismus, and dysphonia was lowest among respondents diagnosed within the last 5-10 years prior to the study. Eating problems were reported by 75% (n = 121) of the OPC survivors and were associated with xerostomia, dysphagia, trismus, having removed part of the tongue, cancer diagnosis within 5 years prior to the study and having little problems with caries and tooth fracture. Speaking problems were experienced by 60% (n = 93) of the OPC survivors, and were associated with dysphonia, dysphagia, and trismus.

CONCLUSION

Our study shows a high prevalence of oral problems among OPC survivors and points to targets for interventions for eating and speech impairments that may improve oral health-related quality of life.

Sialadenitis of the anterior mandibular vestibule: A subset of burning mouth syndrome

Burning Mouth syndrome (BMS) is a relatively common oral neurosensory disorder known for oral burning pain. In that there is a relative absence of oral clinical findings and systemic causation, the diagnosis of BMS is challenging. Sialadenitis of the anterior mandibular vestibule appears to be a subset of BMS. The lip component of chronic orofacial pain is potentially an important concern with regard to the diagnosis and treatment of chronic orofacial pain. Discussion regarding the etiology, diagnosis, and therapy of this condition is provided.

World Workshop on Oral Medicine VIII: Development of a Core Outcome Set for Dry Mouth: A Systematic Review of Outcome Domains for Xerostomia

OBJECTIVE

The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth.

STUDY DESIGN

A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized.

RESULTS

From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains.

CONCLUSION

There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

Protease inhibitor concentrations in the saliva of individuals experiencing oral dryness

Background

Oral dryness is a common symptom that may interfere with swallowing, chewing, and taste. The most common reason for oral dryness is hyposalivation. Some individuals experiencing oral dryness do not have hyposalivation, however, and the reverse is also true. Here, we focused on healthy individuals with a lower salivary flow rate and evaluated the relationship between the perception of oral dryness and salivary parameters to clarify the cause underlying the perception of oral dryness.

Methods

A total of 59 participants were divided into 2 groups with a lower or higher salivary flow rate according to the median salivary flow rate. In participants with a lower salivary flow rate, we assessed salivary bacterial counts, protease activities, protein concentrations, oral parameters, and the subjective perception of oral dryness.

Results

Protease activities and concentrations of protease inhibitors such as cystatin-D and cystatin-SA in the saliva of participants experiencing oral dryness were significantly higher and lower, respectively, than in those not experiencing oral dryness, even though no difference in the salivary flow rate was detected. Salivary cystatin-D and cystatin-SA concentrations correlated negatively with salivary protease activities.

Conclusions

The composition of salivary protease inhibitors and increased protease activities affect the subjective perception of oral dryness.

Lubricating properties of chewing stimulated whole saliva from patients suffering from xerostomia

OBJECTIVES

The study aimed to quantify the lubricating properties of chewing stimulated whole saliva from healthy controls (n = 22), from patients suffering from primary Sjögren's syndrome (n = 37) and from patients undergoing head-and-neck radiotherapy (n = 34).

MATERIALS AND METHODS

All participants had to complete the Xerostomia Inventory questionnaire to score dry mouth sensation. Lubrication was measured using an ex vivo tongue-enamel friction system in terms of Relief and Relief period. MUC5b and total protein concentrations of the saliva samples were measured by an enzyme-linked immunosorbent assay and a bicinchoninic acid assay, respectively.

RESULTS

Relief of Sjögren's patients' saliva and post-irradiation patients' saliva was similar compared with healthy controls, but saliva from post-irradiation patients lubricated significantly better than saliva from Sjögren's patients. The Relief period was similar between the three groups. The Relief and Relief period were higher for saliva samples post-irradiation compared to pre-irradiation. MUC5b and total protein concentrations were comparable in all groups. MUC5b and total protein output were significantly lower in patients subjected to radiotherapy compared to saliva from healthy controls and pre-irradiation patients. MUC5b concentrations positively correlated with lubricating properties of post-irradiation patient saliva.

CONCLUSIONS

The lubricating properties of patient saliva were not any worse than healthy controls. Lower flow rate leads to lower availability of saliva in the oral cavity and decreases the overall output of protein and MUC5b, which might result in an insufficient replenishing of the mucosal salivary film.

CLINICAL RELEVANCE

An insufficient replenishing might underlie the sensation of a dry mouth and loss of oral function.

Candida Infection Associated with Salivary Gland-A Narrative Review

Candida species are common global opportunistic pathogens that could repeatedly and chronically cause oral mucosa infection and create an inflammatory environment, leading to organ dysfunction. Oral Candida infections may cause temporary or permanent damage to salivary glands, resulting in the destruction of acinar cells and the formation of scar tissue. Restricted function of the salivary glands leads to discomfort and diseases of the oral mucosa, such as dry mouth and associated infection. This narrative review attempts to summarize the anatomy and function of salivary glands, the associations between Candida and saliva, the effects of Candida infection on salivary glands, and the treatment strategies. Overall, clinicians should proactively manage Candida infections by educating patients on oral hygiene management for vulnerable populations, conducting frequent checks for a timely diagnosis, and providing an effective treatment plan.

Effectiveness of an intraoral thermoformed splint with magnet device in patients with xerostomia and hyposalivation: A pilot study

AIM

The aim of the study was to examine the effectiveness of intraoral thermoformed splint with a magnet device over a period of 3 months, that is, to assess acceptability of this method of treatment using both objective and self-reported measures.

MATERIALS AND METHODS

This study was designed as a prospective clinical pilot trial. 22 patients with xerostomia and hyposalivation were included. Xerostomia was assessed using a 4-question xerostomia questionnaire score and a test for unstimulated salivary flow rates. Evaluations were performed before the treatment and 3 months after the treatment using a thermoformed splint with a magnet device.

RESULTS

There was a significant reduction in subjective symptoms after using a thermoformed splint with a magnet device for 3 months. For all 4 scored items, there was a statistically significant difference (P < .001) in median VAS scores before and 3 months after treatment. There was also a statistically significant difference in USFR before (0,15 ± 0,04 ml/min) and after treatment (0,24 ± 0,03 mL/min).

CONCLUSION

Our findings indicate that the use of this device alleviated oral dryness and stimulated the function of the submandibular salivary gland. An intraoral thermoformed splint with a magnet device is safe, physiologically indifferent, useful, and effective in treating xerostomia and hyposalivation.

Expression of aquaporin 5 during murine palatine glands development: a light and electron microscopic immunocytochemical study

Although aquaporin 5 (AQP5) seems to play a role in cytodifferentiation and cell proliferation during the development of salivary glands, its distribution during minor salivary glands development has been scarcely reported. This study examined the temporal-spatial distribution of AQP5 in the developing rat palatine glands using light and electron microscopy. At embryonic (E) age E18, AQP5 labeling was observed on the cell membranes of some terminal bulb cells. After lumenization at E20, AQP5 labeled the apical membrane in acini where a lumen existed, in addition to displaying positive diffuse cytoplasmic and cell membrane staining. At the electron microscopic level, AQP5 labeled the supranuclear cytoplasm and the luminal microvilli along the apical membrane. At birth, AQP5 was also localized to the lateral membranes associated ultrastructurally with the microvilli of intercellular canaliculi. After postnatal (PN) day PN7, mucous acini and serous demilunes showed reactivity. AQP5 reached peak reactivity around PN13 with a similar staining pattern in all acini, but had reduced dramatically by PN21. Thereafter, AQP5 reactivity was mainly associated with serous cells in adults. In conclusion, the transitory expression of AQP5 during palatine glands development may reflect changing physiological functions of the secretory cells and/or AQP5 throughout the maturation of the glands.

Aberrant MUC1 accumulation in salivary glands of Sjögren’s syndrome patients is reversed by TUDCA in vitro

Objectives

Xerostomia in SS patients has been associated with low quality and quantity of salivary mucins, which are fundamental for the hydration and protection of the oral mucosa. The aim of this study was to evaluate if cytokines induce aberrant mucin expression and whether tauroursodeoxycholic acid (TUDCA) is able to counteract such an anomaly.

Methods

Labial salivary glands from 16 SS patients and 15 control subjects, as well as 3D acini or human submandibular gland cells stimulated with TNF-α or IFN-γ and co-incubated with TUDCA, were analysed. mRNA and protein levels of Mucin 1 (MUC1) and MUC7 were determined by RT-qPCR and western blot, respectively. Co-immunoprecipitation and immunofluorescence assays for mucins and GRP78 [an endoplasmic reticulum (ER)-resident protein] were also performed. mRNA levels of RelA/p65 (nuclear factor-κB subunit), TNF-α, IL-1β, IL-6, SEL1L and EDEM1 were determined by RT-qPCR, and RelA/p65 localization was evaluated by immunofluorescence.

Results

MUC1 is overexpressed and accumulated in the ER of labial salivary gland from SS patients, while MUC7 accumulates throughout the cytoplasm of acinar cells; however, MUC1, but not MUC7, co-precipitated with GRP78. TUDCA diminished the overexpression and aberrant accumulation of MUC1 induced by TNF-α and IFN-γ, as well as the nuclear translocation of RelA/p65, together with the expression of inflammatory and ER stress markers in 3D acini.

Conclusion

Chronic inflammation alters the secretory process of MUC1, inducing ER stress and affecting the quality of saliva in SS patients. TUDCA showed anti-inflammatory properties decreasing aberrant MUC1 accumulation. Further studies are necessary to evaluate the potential therapeutic effect of TUDCA in restoring glandular homeostasis in SS patients.

Salivary flow and xerostomia in patients with type 2 diabetes

BACKGROUND

Saliva is secreted by the major and minor salivary glands. There are a number of physiological factors that can reduce this secretion such as age, sex, body weight, number of teeth present in the mouth or time of day. This decrease may also be caused by the use of certain drugs, radiotherapy for head and neck cancer, chronic rheumatic diseases such as Sjögren's syndrome and other systemic disorders such as diabetes mellitus (DM). Objective of this study was to investigate the effect of type 2 DM on salivary secretion and its relation to the sensation of xerostomia.

METHODS

Forty-seven patients with type 2 DM and 46 healthy individuals, aged 40-80, participated in the study. Samples of saliva were collected, at rest and after stimulation, at baseline and after the administration of a meal. A questionnaire of 10 items was used to define the patients' sensations of xerostomia. For statistical analysis, the Mann-Whitney test was used to assess the difference in salivary flow between the two groups and the relationship between the response to each of the questions and salivary flow levels. The degree of the patients' sensation of xerostomia was analysed by the Fisher test.

RESULTS AND CONCLUSIONS

There was a significant decrease in total saliva levels at rest in patients with type 2 DM compared to the control group. The study group also experienced higher levels of dryness at night and on waking as well as a greater sensation of lingual burning compared to the control group.

Distribution of nerve fibers during the development of palatine glands in rats

BACKGROUND

Salivary gland maturation and function are modulated by the nervous system. Nevertheless, little is known about salivary gland innervation during development, particularly minor salivary glands. This study investigated the development of the innervation of the palatine glands of rat.

MATERIALS AND METHODS

Frozen sections of rat palatine glands at different stages were immunohistochemically labeled for detection of the general nerve markers protein gene product 9.5 (PGP 9.5) and growth associated protein 43 (GAP-43), and the autonomic nerve markers calcitonin gene-related peptide (CGRP) and neuropeptide Y (NPY).

RESULTS

PGP 9.5 and GAP-43-immunoreactive fibers (IRF) were present in the mesenchyme and in association with developing acini, ducts and blood vessels. GAP-43-IRF were more abundant and diffuse than PGP 9.5-IRF at early stages, but showed similar distribution with growth, ramifying out from thick bundles in connective tissues until encircling the secretory units observed around postnatal day 21 (PN21). CGRP-IRF were detected in the mesenchyme at embryonic day 20 (E20) and PN0. CGRP-IRF became numerous around PN7 and PN10. They then decreased to the adult level at PN21, mainly located around ducts and infrequently blood vessels. NPY-IRF were sparsely detected in the mesenchyme at E20, then detected in close proximity to acini in addition to blood vessels at PN3. NPY-IRF increased till reaching the adult stage, and were mainly associated with blood vessels and around mucous cells and some serous demilunes.

CONCLUSION

The findings indicated a developmental modification of the sensory and autonomic innervation which may play a role in the functional maturation of the palatine salivary glands.

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.

Reduced Mucin-7 (Muc7) Sialylation and Altered Saliva Rheology in Sjögren's Syndrome Associated Oral Dryness

Sjögren's syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration and hypofunction of salivary and lacrimal glands. This loss of salivary function leads to oral dryness, impaired swallowing and speech, and increased infection and is associated with other autoimmune diseases and an increased risk of certain cancers. Despite the implications of this prevalent disease, diagnosis currently takes years, partly due to the diversity in patient presentation. Saliva is a complicated biological fluid with major constituents, including heavily glycosylated mucins MUC5B and MUC7, important for its viscoelastic and hydrating and lubricating properties. This study investigated Sjögren's patient's perception of dryness (bother index questionnaires) along with the rheological, protein composition, and glycan analysis of whole mouth saliva and the saliva on the mucosal surface (residual mucosal saliva) to understand the properties that most affect patient wellbeing. Sjögren's patients exhibited a statistically significant reduction in residual mucosal saliva, salivary flow rate, and extensional rheology, spinnbarkeit (stringiness). Although the concentration of mucins MUC5B and MUC7 were similar between patients and controls, a comparison of protein Western blotting and glycan staining identified a reduction in mucin glycosylation in Sjögren's, particularly on MUC7. LC-MS/MS analysis of O-glycans released from MUC7 by β-elimination revealed that although patients had an increase in core 1 sulfation, the even larger reduction in sialylation resulted in a global decline of charged glycans. This was primarily due to the loss of the extended core 2 disialylated structure, with and without fucosylation. A decrease in the extended, fucosylated core 2 disialylated structure on MUC7, residual mucosal wetness, and whole mouth saliva flow rate appeared to have a negative and cumulative effect on the perception of oral dryness. The observed changes in MUC7 glycosylation could be a potential diagnostic tool for saliva quality and taken into consideration for future therapies for this multifactorial syndrome.

Changes in Saliva Rheological Properties and Mucin Glycosylation in Dry Mouth

Saliva is vital for the maintenance of normal oral physiology and mucosal health. The loss of salivary function can have far-reaching consequences, as observed with dry mouth, which is associated with increased orodental disease, speech impairment, dysphagia, and a significant negative effect on quality of life. The timely diagnosis of oral dryness is vital for the management of orodental disease and any associated often-undiagnosed systemic disease (e.g., Sjögren syndrome). Our aim was to investigate differences in mucin glycoproteins and saliva rheological properties between sufferers and nonsufferers of dry mouth in order to understand the relationship between saliva composition, rheological properties, and dryness perception and provide additional potential diagnostic markers. All patients exhibited objective and subjective oral dryness, irrespective of etiology. Over half of the patients ( n = 20, 58.8%) had a saliva secretion rate above the gland dysfunction cutoff of 0.1 mL/min. Mucin (MUC5B and MUC7) concentrations were generally similar or higher in patients. Despite the abundance of these moisture-retaining proteins, patients exhibited reduced mucosal hydration (wetness) and significantly lower saliva spinnbarkeit (stringiness), suggesting a loss of the lubricating and retention/adhesion properties of saliva, which, at least partially, are associated with mucin glycoproteins. Over 90% of patients with dry mouth (DMPs) consistently had unstimulated whole mouth saliva (UWMS) spinnbarkeit below the proposed normal cutoff (10 mm). Further analysis of mucins revealed the reduced glycosylation of mucins in DMPs compared to healthy controls. Our data indicate that UWMS mucin concentrations are not reduced in dry mouth but that the mucin structure (glycosylation) is altered. UWMS from DMPs had reduced spinnbarkeit, the assessment of which, in conjunction with sialometry, could improve sensitivity for the diagnosis of dry mouth. Additionally, it may be useful to take into consideration the altered mucin glycosylation and saliva rheological properties when designing synthetic or purified mucins for saliva substitutes and dry mouth therapy.

Antiseptic mouthwashes could worsen xerostomia in patients taking polypharmacy

OBJECTIVE

Polypharmacy is a common cause of xerostomia. This study aimed to investigate whether xerostomia could be an adverse drug event of mouthwashes, when they are used for longer than 2 weeks by patients taking polypharmacy.

MATERIALS AND METHODS

This cross-sectional observational study included 120 hospitalized patients (60 middle-aged and 60 elderly patients), taking polypharmacy (≥4 drugs daily) and at risk of drug-induced xerostomia. Xerostomia was assessed by questioning participants.

RESULTS

A total of 62.5% of patients complained of xerostomia. In the middle-aged group (mean age=44.0 (8.7) years; 35.0% women) xerostomia seemed independently associated to mouthwashes, at the limit of significance (OR=5.00, 95% CI=0.99-25.3, p=0.052). Active principles in mouthwashes were mainly quaternary ammonium compounds (91.9%). Mouthwashes may disturb the healthy balance of the biofilm moisturizing the oral mucosa. The biofilm contains mucins, salivary glycoproteins with oligosaccharides side chains able to sequester water and endogenous bacteria surrounded by a glycocalyx. Oral bacteria are fully susceptible to quaternary ammonium (chlorhexidine, hexetidine, cetylpyridinium chloride) and to other antiseptics used in mouthwashes, such as betain, resorcin, triclosan, essential oils and alcohol. However, caregivers currently recommend such dental plaque control products to patients suffering from xerostomia in order to reduce the risk of caries and periodontitis.

CONCLUSION

This study is the first report that use of antiseptic mouthwashes for more than 2 weeks could worsen xerostomia in patients taking polypharmacy. Oral care protocols should avoid this iatrogenic practice, particularly when xerostomia alters the quality-of-life and worsens malnutrition.

Characteristics of the saliva flow rates of minor salivary glands in healthy people

OBJECTIVES

To investigate the normal range and characteristics of saliva secretion in the minor salivary glands (MSGs).

DESIGN

The flow rates of MSGs were measured in 4 anatomical locations of oral mucosa, and the relationship between MSG flow rates and whole saliva flow rates were assessed in 300 healthy subjects stratified by age and sex. An additional 30 young females were further evaluated for flow symmetry, effects of stimulation, circadian effects in MSGs, and the relationship with the flow rates of major salivary glands.

RESULTS

(1) The mean saliva flow rates were 2.10 ± 0.66 (lower labial glands), 2.14 ± 0.62 (upper labial glands), 2.88 ± 0.72 (buccal glands) and 2.15 ± 0.51 (palatal glands) μl/min/cm(2), respectively. The flow rate of buccal glands was significantly higher than the rates of SMGs in other locations (P < 0.01). (2) 5-year-old children had the lowest MSG flow rates (P < 0.0001) while the 10-14-year-old group had the highest (P < 0.001). (3) MSG flow rates were independent of sex (P > 0.05), right vs. left (P > 0.05), and citric acid (2.5%) stimulation (P > 0.05). (4) Only labial MSG displayed a significant secretory circadian rhythm with the highest rate in the evening (P < 0.05). (5) A weak correlation was found between the flow rate of palatal glands and that of unstimulated whole saliva (r = 0.195, P = 0.007).

CONCLUSIONS

Our findings provide a reference for functional evaluation of MSGs and for donor site selection of MSG transplantation for treatment of severe dry eye syndrome.

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.

Oral health and menopause: a comprehensive review on current knowledge and associated dental management

The menopause is physiological changes in women that give rise to adaptive changes at both systemic and oral level. As we all begin to reach an older age, dental health and hygiene becomes a major concern. The dentist is often the first person to appreciate numerous changes that are experienced throughout the body during menopause. The teeth and gums are extremely susceptible to any hormonal changes that take place just before menopause and readily decrease body's ability to fight off minor infections or maintain a healthy balance of useful and harmful bacteria within the oral environment. This review aimed to develop better understanding for major oro-dental complications observed in women during menopause, and schematic approach towards the different dental management protocols used during these periods. Various internets based popular search engines were used to explore related data from literature, which includes PubMed, PubMed Central, Cochrane, Google, Medknow, Ebsco, Science Direct, and IndMed. Upon compilation of relevant data, it was observed that periodontal health is most severely affected (up to 60%) followed by dry mouth (25%) and burning mouth (glossodynia; 15%) which, in turn, may increase the occurrence of oral mucosal and dental diseases, such as candidiasis. Though, the usage of hormone replacement therapy is effective but it does not necessarily prevent or help women with oral symptoms. Therefore, well controlled long-term randomized studies are needed to establish more authentic clinical guidelines for successful management of such conditions.

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.

Xerostomia in hereditary gelsolin amyloidosis

Hereditary gelsolin amyloidosis (AGel amyloidosis) is a rare, dominantly inherited systemic disease with worldwide distribution, caused by c.654G > A or c.654G > T gelsolin gene mutation. The disease mainly manifests with late-onset dystrophy of the cornea, laxity of the skin and dysfunction of the cranial nerves whereas the oral manifestations have remained less-studied. To examine if AGel amyloidosis also affects salivary gland function, we studied 27 patients. In a questionnaire, 89% of them reported oral dryness, and 74% oral and ocular dryness. Unstimulated (UWS) and stimulated whole salivary flow (SWS) rates were measured, and salivary proteins were analyzed in the patients and controls. Hyposalivation according to UWS was detected in 67% of the patients, while decreased SWS occurred in 63% of the patients and 19% of the controls (p = 0.001). The secretion rates of salivary total protein and IgA were significantly lower in patients than controls. Histopathological analyses of labial salivary gland biopsies showed deposition of gelsolin amyloid, atrophy and inflammation. This study showed that AGel amyloidosis belongs to the differential diagnostic choices to be kept in mind in the patients presenting with xerostomia, low secretion rates of salivary total protein and IgA and/or deposition of amyloid in the minor salivary glands. AGel amyloidosis patients should be advised for efficient dental care.

Histochemical analyses of glycoconjugates and antimicrobial substances in goat labial glands

Saliva is known to protect the oral cavity and contains glycoproteins and antimicrobial substances. The distribution of these salivary secretions was studied in the labial glands of the Japanese miniature (Shiba) goat using lectin histochemical and immunohistochemical methods. The mucous acinar cells of the labial glands exhibited glycoconjugates with different saccharide residues, such as GalNAcα1-3GalNAc, Galβ1-4GalNAc, β-D-GlcNAc and sialic acid linked to α2-6Gal/GalNAc. Furthermore, α-D-Man, α-L-Fuc, α-D-GalNAc, β-D-Gal and sialic acid residues were present, in particular, in the serous demilunar cells. Antimicrobial substances (lysozyme, IgA, lactoferrin and β-defensin) were shown to be mainly immunolocalized in the serous demilunes and duct cells. The results obtained are discussed with regard to the functional role of labial glands. The secretory compounds demonstrated may play an important role in the maintenance of oral health with regard to saliva.

Diagnostic performance of labial minor salivary gland flow measurement for assessment of xerostomia

OBJECTIVE

Minor salivary gland flow rate (MF) has been proposed as a key feature of xerostomia (subjective feeling of dry mouth). To assess its diagnostic performance, MF was compared in xerostomia and control subjects.

DESIGN

Sixty-six subjects with xerostomia and 30 controls were enrolled. MF was measured in the lower labial mucosa using the iodine-starch filter paper method. Stimulated whole salivary flow rates were also measured using the gum test (stimulated-WF).

RESULTS

Both labial-MF and stimulated-WF were significantly lower in xerostomia subjects than in controls. There was a positive correlation between labial-MF and stimulated-WF in control but not xerostomia subjects. In xerostomia subjects compared to controls, there was a significantly larger reduction in labial-MF than in stimulated-WF. Xerostomia was most accurately diagnosed using a labial-MF cutoff value of 0.25 μL/cm(2)/min. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at this cutoff value were 1.00, 0.87, 0.93, 1.00, and 0.96, respectively. Compared to respective values of 0.64, 1.00, 1.00, 0.56, and 0.75 for stimulated-WF at the traditional cutoff of 1.0 mL/min, these data indicate the higher sensitivity, negative predictive value, and diagnostic accuracy of labial-MF.

CONCLUSIONS

Xerostomia was more strongly related to reduction of labial-MF than to that of stimulated-WF. Xerostomia was most likely triggered at a labial-MF cut-off value of 0.25 μL/cm(2)/min based on results from the iodine-starch method.

Efficacy and safety of an intraoral electrostimulation device for xerostomia relief: a multicenter, randomized trial

OBJECTIVE

To evaluate the efficacy and safety of an intraoral electrostimulation device, consisting of stimulating electrodes, an electronic circuit, and a power source, in treating xerostomia. The device delivers electrostimulation through the oral mucosa to the lingual nerve in order to enhance the salivary reflex.

METHODS

The device was tested on a sample of patients with xerostomia due to Sjögren's syndrome and other sicca conditions in a 2-stage prospective, randomized, multicenter trial. Stage I was a double-blind, crossover stage designed to compare the effects of the electrically active device with the sham device, each used for 1 month, and stage II was a 3-month open-label stage designed to assess the long-term effects of the active device. Improvement in xerostomia severity from baseline was the primary outcome measure.

RESULTS

A total of 114 patients were randomized. In stage I, the active device performed better than the sham device for patient-reported xerostomia severity (P<0.002), xerostomia frequency (P<0.05), quality of life impairment (P<0.01), and swallowing difficulty (P<0.02). At the end of stage II, statistically significant improvements were verified for patient-reported xerostomia severity (P<0.0001), xerostomia frequency (P<0.0001), oral discomfort (P<0.001), speech difficulty (P<0.02), sleeping difficulty (P<0.001), and resting salivary flow rate (P<0.01).

CONCLUSION

Our findings indicate that daily use of the device alleviated oral dryness, discomfort, and some complications of xerostomia, such as speech and sleeping difficulties, and increased salivary output. The results show a cumulative positive effect of the device over the period of the study, from baseline to the end of the trial.

Associations between oral and ocular dryness, 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, labial and whole salivary flow rates and oral and ocular dryness in older people.

METHODS

Symptoms of oral and ocular dryness, systemic diseases, medications (coded according to the Anatomical therapeutic chemical (ATC) classification system), tobacco and alcohol consumption were registered, and unstimulated labial (LS) and unstimulated (UWS) and chewing-stimulated (SWS) whole salivary flow rates were measured in 668 randomly selected community-dwelling elderly aged 65-95.

RESULTS

Presence of oral (12%) and ocular (11%) dryness was positively correlated. Oral dryness was associated with low UWS, SWS and LS, and ocular dryness with low UWS and SWS. Oral and ocular dryness was related to female gender, but not to age. Only four persons in the healthy and nonmedicated subgroups reported oral and ocular dryness. The numbers of diseases and medications were higher in the older age groups and associated with oral and ocular dryness, low UWS, SWS and LS. On average, women were slightly older, reported more oral and ocular dryness and had lower UWS, SWS, LS and higher numbers of diseases and medications. High prevalence and odds ratios for oral dryness were associated with metabolic, respiratory and neurological diseases and intake of thyroid hormones, respiratory agents (primarily glucocorticoids), psycholeptics and/or psychoanaleptics, antineoplastics, proton pump inhibitors, antidiabetics, loop diuretics, antispasmodics, quinine and bisphosphonates. Ocular dryness was especially associated with neurological diseases and intake of psycholeptics and/or psychoanaleptics. Intake of magnesium hydroxide, antithrombotics, cardiac agents, thiazides, beta-blockers, calcium channel blockers, ACE inhibitors/angiotensin II antagonists, statins, glucosamine, paracetamol/opioids, ophthalmologicals and certain combination therapies was related to oral and ocular dryness.

CONCLUSIONS

In older people, oral and ocular dryness are associated with low salivary flow rates, specific as well as high number of diseases and medications, but neither with age and gender per se nor with tobacco and alcohol consumption. New detailed information concerning associations between medications and oral and ocular dryness has been obtained using the ATC classification system.

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.

The diagnostic suitability of a xerostomia questionnaire and the association between xerostomia, hyposalivation and medication use in a group of nursing home residents

The study objective was to explore the diagnostic suitability of the Xerostomia Inventory and the association between xerostomia, hyposalivation and medication use in a group of nursing home residents. A cross-sectional study was carried out in 50 physically impaired nursing home residents (20 men) with a mean age of 78.1 years (range, 53–98) in The Netherlands. The Xerostomia Inventory-Dutch version was completed for all residents and the data were subjected to exploratory factor analysis to determine the diagnostic suitability. Residents’ data on xerostomia, whole saliva secretion rates and hyposalivation-related medications used were collected and statistically analyzed. The diagnostic suitability of the Xerostomia Inventory-Dutch version appeared restricted. The prevalence of xerostomia was 52%, without gender and age difference. The prevalence of hyposalivation was 24% for resting, 60% for chewing-stimulated and 18% for acid-stimulated whole saliva. All whole saliva secretion rates were significantly lower in women than in men and in older than in younger residents. Forty-four percent of all medications used were hyposalivation-related and women used significantly more medications than men. Xerostomia was significantly negatively correlated with the resting whole saliva secretion rate. The number of hyposalivation-related medications used was not significantly correlated with the various whole saliva secretion rates. In nursing home residents, xerostomia, hyposalivation and using hyposalivation-related medications seem common and partially associated features.

Usefulness of labial salivary gland biopsy in familial amyloid polyneuropathy Portuguese type

BACKGROUND

The diagnosis of amyloidosis of all types is definitively made by demonstration of Congo red binding material in the affected tissues. Nerve biopsy was classically used to diagnose amyloid polyneuropathy but less invasive alternative types of biopsies have been proposed including labial salivary gland (LSG) biopsy, a minimally invasive procedure.

METHOD

LSG biopsies were done in 87 subjects with molecular diagnosis of TTRVal30Met mutation. The group includes 76 patients in different stages of familial amyloid polyneuropathy and 11 asymptomatic carriers. They were all submitted to a stomatological and a neurological observation to evaluate oral health problems and to determine the neurological stage of the disease. No major oral health problems were found. Mean age of onset of the symptomatic disease was 32.8 years (+/-9.69 SD).

CONCLUSIONS

No significant side effects occurred after the surgical procedure, and adequate material for pathological analysis was always obtained. Amyloid deposition was found in 91% of the patients. Patients with negative biopsies (N = 7) were all in the earlier stage of the disease. Two asymptomatic carriers had biopsies with amyloid deposition. We conclude that LSG biopsy is a useful, sensitive and minimal invasive method to detect amyloid deposition.