The effect of ammonium glycopyrrolate (Robinul)-induced xerostomia on oral mucosal wetness and flow of gingival crevicular fluid in humans

Prospective assessment of gustatory function after radiotherapy for head and neck cancers

BACKGROUND

Taste disorders are major causes of morbidity in patients undergoing head and neck irradiation. We quantitatively assessed the gustatory function of patients with head and neck cancers who underwent radiotherapy using recently developed standardised tools for measuring taste.

METHODS

Twenty patients undergoing head and neck irradiation responded to a specific questionnaire and were assessed by olfactory and gustatory function tests. To assess changes over time, testing was performed before, immediately after, and at 2- and 4-week intervals following the start of radiotherapy. Concurrently, patients were evaluated for xerostomia from radiotherapy.

RESULTS

A decrease in the taste recognition threshold was observed in the second week after the beginning of radiotherapy. The taste detection threshold improved within the 14th-18th week. Most affected patients demonstrated that their gustatory function primarily decreased independent of the olfactory function. Disturbances in taste were exponentially worsened beyond an accumulated dose of 30 Gy and involved all tastants. According to a multivariate analysis, radiation-induced taste impairment was not influenced by the degree of xerostomia. However, there was an association between the dose of irradiation and the severity of taste disturbance.

CONCLUSIONS

In this preliminary study, we found that the taste function was worse 2 weeks after the start of radiotherapy and returned to pretreatment levels within 4.5 months. Taste disturbances were exponentially worse beyond an accumulated dose of 20 Gy. Taste dysfunction after radiotherapy was not influenced by the degree of xerostomia, whereas only the dose of irradiation was associated with the severity of taste dysfunction.

Microbial biogeography and ecology of the mouth and implications for periodontal diseases

In humans, the composition of microbial communities differs among body sites and between habitats within a single site. Patterns of variation in the distribution of organisms across time and space are referred to as "biogeography." The human oral cavity is a critical observatory for exploring microbial biogeography because it is spatially structured, easily accessible, and its microbiota has been linked to the promotion of both health and disease. The biogeographic features of microbial communities residing in spatially distinct, but ecologically similar, environments on the human body, including the subgingival crevice, have not yet been adequately explored. The purpose of this paper is twofold. First, we seek to provide the dental community with a primer on biogeographic theory, highlighting its relevance to the study of the human oral cavity. We summarize what is known about the biogeographic variation of dental caries and periodontitis and postulate that disease occurrence reflects spatial patterning in the composition and structure of oral microbial communities. Second, we present a number of methods that investigators can use to test specific hypotheses using biogeographic theory. To anchor our discussion, we apply each method to a case study and examine the spatial variation of the human subgingival microbiota in 2 individuals. Our case study suggests that the composition of subgingival communities may conform to an anterior-to-posterior gradient within the oral cavity. The gradient appears to be structured by both deterministic and nondeterministic processes, although additional work is needed to confirm these findings. A better understanding of biogeographic patterns and processes will lead to improved efficacy of dental interventions targeting the oral microbiota.

Change of saliva composition with radiotherapy

OBJECTIVE

The aim of this study was to analyze the physiological and microbiological changes of saliva from patients with head and neck cancer during and after intensity-modulated radiotherapy (IMRT).

DESIGN

In this prospective clinical trial saliva samples and oral candida swabs were collected from patients receiving IMRT due to head and neck cancer (examination group). The first measurement was scheduled before radiotherapy, the other measurements during and after radiotherapy up to a one year follow-up. Additionally samples from healthy controls were collected over six weeks. Salivary flow rate and pH were measured. Microbiological analysis of cariogenic and periodontopathogenic taxa was performed by fluorescence in situ hybridization and oral Candida spp occurrence was evaluated by swab tests.

RESULTS

11 patients and 19 controls were included. The salivary flow rate and the unstimulated pH of the examination group were significantly reduced during radiotherapy compared with the measurement before radiotherapy and to the control group. Total bacteria, streptococci and lactobacilli numbers slightly increased after radiotherapy, resuming baseline levels after one year. Mutans streptococci, Porphyromonas gingivalis and Treponema denticola were barely detectable, whereas Tannerella forsythia slightly increased following radiotherapy. No differences in Candida levels were observed in the study.

CONCLUSIONS

Salivary changes in quantitative, qualitative and microbial composition occur during and after radiotherapy, with resumption of the measurements towards baseline levels after one year. While low levels of cariogenic and periodontopathogenic species were detected, the lower pH and salivary flow combined with increased numbers of aciduric and acidogenic lactobacilli corroborates a higher risk for caries, necessitating prevention.

Update knowledge of dry mouth- A guideline for dentists

BACKGROUND

Dry mouth is usually caused by a reduced salivary flow or by changes in the biochemical composition of saliva.

OBJECTIVE

The aim of this paper is a review of the update literature of dry mouth.

METHODS

We search in pubmed in the past 10 years using the words «dry mouth», «causes», «symptoms», «treatment» and «dentistry». A large number of papers have been identified. Papers not relevant to the issue were removed reducing the entries to 56 only.

RESULTS

There are no clearly established protocols for the treatment of dry mouth in the literature. Most of identified papers were systematic reviews, non-systematic reviews, and observational studies. The most studied patients were Sjögren's syndrome and the irradiated patients. Treatments are focused on the etiology, prevention, symptomatic, local salivary stimulation and systemic treatments.

CONCLUSION

It can be concluded that there is no clear evidence for the causes and treatment of dry mouth, therefore the majority of the general dental practitioners refer most of the cases to appropriate specialist. Treatment must be individualized, salivary substitutes and mechanical stimulation techniques can be applied.

Analysis of factors influencing the development of xerostomia during intensity-modulated radiotherapy

OBJECTIVES

Factors influencing xerostomia during intensity-modulated radiation therapy (IMRT) were assessed.

METHODS

A 6-week study of 32 head and neck cancer (HNC) patients was performed. Subjects completed the Xerostomia Inventory (XI) and provided stimulated saliva (SS) at baseline, week 2 and at end of IMRT. Influence of SS flow rate (SSFR), calcium and mucin 5b (MUC5b) concentrations and radiation dose on xerostomia was determined.

RESULTS

HNC subjects experienced mean SSFR decline of 36% by visit 2 (N = 27; P = .012) and 57% by visit 3 (N = 20; P = .0004). Concentrations of calcium and MUC5b increased, but not significantly during IMRT (P > .05). Xerostomia correlated most with decreasing salivary flow rate as determined by Spearman correlations (P < .04) and linear mixed models (P < .0001).

CONCLUSIONS

Although IMRT is sparing to the parotid glands, it has an early effect on SSFR and the constituents in saliva in a manner that is associated with the perception of xerostomia.

The efficacy of a topical sialogogue spray containing 1% malic acid in patients with antidepressant-induced dry mouth: a double-blind, randomized clinical trial

BACKGROUND

One of the most important antidepressants side effects is dry mouth. The aim of this study was to evaluate the clinical efficacy of a topical sialogogue spray containing 1% malic acid on patients affected by dry mouth caused by antidepressants drug.

MATERIALS AND METHODS

This research took the form of a double-blind, randomized clinical trial at Faculty of Dentistry of University of Granada (Spain). Seventy participants with antidepressant-induced dry mouth were divided into two groups: for the first "intervention group" (35 subjects) a topical sialogogue spray (1% malic acid) was applied, while for the second "control group" (35 subjects), a placebo spray was applied; for both groups, the sprays were applied on demand during 2 weeks. The dry mouth questionnaire (DMQ) was used to evaluate dry mouth symptoms before and after product/placebo application. Unstimulated and stimulated salivary flows rates, before and after application, were measured.

RESULTS

Dry mouth symptoms improved after 1% malic acid topical spray application (p < .05). After 2 weeks of 1% malic acid application, unstimulated and stimulated salivary flows rates increased significantly (p < .05).

CONCLUSIONS

A sialogogue spray containing 1% malic acid improved dry mouth feeling of the patients suffering antidepressant-induced dry mouth and increased unstimulated and stimulated salivary flows rates.

Evaluation of the efficacy of a topical sialogogue spray containing malic acid 1% in elderly people with xerostomia: a double-blind, randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the clinical efficacy of a topical sialogogue spray containing 1% malic acid for elderly people affected by xerostomia.

MATERIAL AND METHODS

This research took the form of a double-blind, randomized clinical trial. Forty-one individuals (mean age: 78.7 years) with xerostomia were divided into two groups: for the first 'intervention group' (21 subjects) a topical sialogogue spray (1% malic acid) was applied, while for the second 'control group' (20 subjects), a placebo spray was applied; for both groups, the sprays were applied on demand during 2 weeks. The Xerostomia Inventory (XI) was used to evaluate xerostomia levels before and after product/placebo application. Unstimulated and stimulated salivary flows rates, before and after spray application, were measured.

RESULTS

XI scores decreased significantly (clinically meaningful) from 36.4 ± 7.3 points to 29.1 ± 7.1 (p < 0.05) with an XI difference of 7.2 ± 6.1, after the combination among 1% malic acid with xylitol and fluoride application. After 2 weeks of 1% malic acid application, unstimulated and stimulated salivary flows rates increased significantly (p < 0.05).

CONCLUSION

A topical sialogogue spray containing 1% malic acid improved xerostomia in an elderly population and increased unstimulated and stimulated salivary flows rates.

Effectiveness of malic acid 1% in patients with xerostomia induced by antihypertensive drugs

Objectives: Assessing the clinical effectiveness of a topical sialogogue on spray (malic acid, 1%) in the treatment of xerostomia induced by antihypertensive drugs. Study Design: This research has been carried out through a randomized double-blind clinical trial. 45 patients suffering from hypertensive drugs-induced xerostomia were divided into 2 groups: the first group (25 patients) received a topical sialogogue on spray (malic acid, 1%) whereas the second group (20 patients) received a placebo. Both of them were administered on demand for 2 weeks. Dry Mouth Questionnaire (DMQ) was used in order to evaluate xerostomia levels before and after product/placebo application. Unstimulated and stimulated salivary flows rates, before and after application, were measured. All the statistical analyses were performed by using SPSS software v17.0. Different DMQ scores at the earliest and final stage of the trial were analysed by using Mann-Whitney U test, whereas Student’s T-test was used to analyse salivary flows. Critical p-value was established at p<0.05. Results: DMQ scores increased significantly (clinical recovery) from 1.21 to 3.36 points (p<0.05) after malic acid (1%) application whereas DMQ scores increased from 1.18 to 1.34 points (p>0.05) after placebo application. After two weeks of treatment with malic acid, unstimulated salivary flow increased from 0.17 to 0.242 mL/min whereas the stimulated one increased from 0.66 to 0.92 mL/min (p<0.05). After placebo application unstimulated flow ranged from 0.152 to 0.146 mL/min and stimulated flow increased from 0.67 to 0.70 mL/min (p>0.05). Conclusions: Malic acid 1% spray improved antihypertensive-induced xerostomia and stimulated the production of saliva.

Key words:Xerostomia, hyposialia, malic acid, antihypertensive drugs.

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.

Signs of oral dryness in relation to salivary flow rate, pH, buffering capacity and dry mouth complaints

Background

This study aimed to investigate the signs of oral dryness in relation to different salivary variables and to correlate subjective complaints of oral dryness with salivary flow rate.

Methods

312 unmedicated healthy individuals belonging to three age groups, (6–11, 12–17, and 18–40 years) were examined clinically for signs of oral dryness. Resting and stimulated saliva were collected to determine flow rate, pH and buffering capacity. A questionnaire was used to obtain information on subjective sensation of dry mouth.

Results

Dry lip and dry mucosa were present in 37.5% and 3.2% of the sample respectively. The proportion of subjects who complained of oral dryness (19%) showed a stimulated salivary flow rate significantly lower than non complainers. Dry lip was significantly related to low resting flow rate but pH and buffering capacity did not show any significant relation to dry lip. Dry mucosa was not related to any of the above mentioned parameters.

Conclusion

The finding that the stimulated salivary flow rate was reduced in subjects complaining of dry mouth is of great clinical relevance, since the reduction is expected to be reflected in compromising various salivary functions.

Sugammadex: a novel agent for the reversal of neuromuscular blockade

To achieve spontaneous ventilation after completion of surgery, the nondepolarizing effects on skeletal muscle relaxation are often reversed by administration of an acetylcholinesterase inhibitor. However, these agents increase acetylcholine at both the neuromuscular junction and the muscarinic receptors. Therefore, coadministration of an anticholinergic agent is required to prevent parasympathetic adverse effects. In addition, a relative pharmacologic ceiling effect is seen with inhibition of acetylcholinesterase, necessitating some recovery of neuromuscular function before an acetylcholinesterase inhibitor is administered. Sugammadex is a new modified gamma-cyclodextrin compound under clinical investigation in the United States. It does not interact with cholinergic mechanisms to elicit reversal. Instead, it is a selective relaxant binding agent and acts by forming a 1:1 complex with steroidal nondepolarizing neuromuscular blockers in the plasma, lowering the effective concentration available at the receptor. Due to its selectivity, sugammadex does not inhibit the effects of nondepolarizing agents of the benzylisoquinolinium class. In contrast to acetylcholinesterase inhibition, sugammadex is effective even when administered during profound blockade, and it does not require coadministration of an anticholinergic agent. It provides a novel mechanism of action for reversal of the neuromuscular block induced by nondepolarizing aminosteroidal agents.

Glycopyrrolate does not reduce the incidence of perioperative adverse events in children with upper respiratory tract infections

Two recent studies have identified copious secretions as an independent risk factor for perioperative adverse events in children who present for elective surgery in the presence of an upper respiratory tract infection (URI). We designed this study, therefore, to determine whether the administration of the anticholinergic drug, glycopyrrolate, to children with URIs would reduce the incidence of adverse perioperative respiratory events. One hundred thirty children (1 mo to 18 yr of age) who presented for elective surgery with a URI were randomized to receive either 0.01 mg/kg glycopyrrolate or placebo and were followed for the appearance and severity of any perioperative respiratory adverse events. The two groups were similar with respect to demographics, presenting URI symptoms, anesthetic management, and surgical procedure. In the intention-to-treat analysis, there were no statistical differences in the incidence or severity of perioperative respiratory adverse events between the glycopyrrolate and placebo groups (45.2% vs 37.5% respectively, P = NS). Furthermore, there were no differences in outcome between the two groups when children with congestion and secretions were analyzed separately (45.0% vs 37.0%, respectively). However, compared with the placebo group, children in the glycopyrrolate group had significantly shorter discharge times (83.9 min vs 111.4 min, P = 0.024), and significantly less postoperative nausea and vomiting (10.7% vs 33.3%, P = 0.005). These results suggest that glycopyrrolate, administered after induction of anesthesia to children with URIs, does not reduce the incidence of perioperative respiratory adverse events, and thus may not be clinically indicated for routine use in this population.

Injectable Polysaccharide Microcapsules for Prolonged Release of Minocycline for the Treatment of Periodontitis

Injectable polysaccharide microcapsules holding minocycline were fabricated from alginate and chitosan for the treatment of periodontitis. The microcapsules were examined for the release and degradation of minocycline, as well as antimicrobial activity. The microcapsules were biodegradable and released minocycline between 10 and 1000 microg ml(-1), which was higher than the usual therapeutic concentration (1-5 microg ml(-1)), for up to 7 days. These microcapsules showed a statistically significant suppression of pathogenic bacteria, such as Prevotella intermedia causing periodontitis. The microcapsules are thus potentially useful for drug delivery for the treatment of periodontitis.

Influence of the time of measurement of unstimulated human whole saliva on the diagnosis of hyposalivation

OBJECTIVE

An unstimulated whole saliva flow rate (UWSFR) of less than 0.1 mL/min is often related to symptoms of dry mouth. It is also used as a diagnostic criterion for Sjogren's syndrome, and for assessment of hyposalivation as a caries risk factor. The main hypothesis was that the circadian rhythm of salivary flow affects this diagnosis if saliva is collected at different morning time-points.

DESIGN

UWSFR was tested at 7:30 and 11:30 a.m. in 108 individuals, age 15-46 years (mean 33+/-9). The participants were allocated to one of three groups (very low< or =0. 1/min, low 0.1-0.2 mL/min and normal>0.2 mL/min) based on the UWSFR at 7:30 a.m. Different aspects of the perception of oral dryness were rated using Visual Analog Scales.

RESULTS

All three groups displayed a statistically significant increase in UWSFR at 11:30 a.m. compared with 7:30 a.m., all of similar magnitude (0.08-0.09 mL/min). In the group with very low UWSFR, 70% at 11:30 a.m. exceeded the 0.1 mL/min limit. There were significant difference in perception of oral dryness between the normal group and both the low and the very low groups. Only the subjects in the groups with a low or very low UWSFR perceived an increase in oral wetness at 11:30 a.m.

CONCLUSIONS

It was concluded that the time of measurement strongly influences the diagnosis of hyposalivation. To control the influence of variations in the time of saliva collection, we suggest that unstimulated whole saliva tests are performed at a fixed time-point or in a limited time interval early in the morning.

How much saliva is enough for avoidance of xerostomia?

Xerostomia, the subjective sensation of dry mouth, occurs when the salivary flow rate is less than the rate of fluid loss from the mouth by evaporation and by absorption of water through the oral mucosa. Evaporation can only occur during mouth-breathing but could reach a maximum rate of about 0.21 ml/min at rest, although normally it would be much less. Water absorption through the mucosa can occur because saliva has one sixth the osmotic pressure of extracellular fluid, thus creating a water gradient across the mucosa. The maximum absorption rate is calculated to be about 0.19 ml/min, declining to zero as the saliva reaches isotonicity. A recent study found the residual saliva volume, the volume of saliva left in the mouth after swallowing, to be 71% of normal in patients with severe hyposalivation and whose mouths felt very dry. Saliva in the residual volume is present as a thin film which varies in thickness with site. The hard palate has the thinnest film and when this is <10 microm thick, evaporation during mouth-breathing and/or fluid absorption may rapidly decrease it to zero, resulting in xerostomia. This is also generally associated with reduced secretion from the soft palate minor glands, which may contribute to the film on the hard palate. Thus, xerostomia appears to be due, not to a complete absence of oral fluid, but to localized areas of mucosal dryness, notably in the palate. Unstimulated salivary flow rates >0.1-0.3 ml/min may be necessary for this condition to be avoided.

Role of saliva in oral dryness, oral feel and oral malodour

Patients who believe they have oral malodour often have a dry mouth condition instead. Here we have examined its relation to oral malodour, real or perceived. A direct relationship between the thickness of the film of residual saliva on mucosal surfaces throughout the mouth and perception of a dry mouth was observed. On the hard palate, the thickness of this film proved to be diagnostic for a dry mouth and corresponded to lower resting saliva flow and pH levels (P< 0.001). Intra-muscular administration of the anti-sialogogue, Robinul, accurately produced the dry mouth condition. Using a sulphide monitor, loss of volatile sulphur compounds into mouth air progressively occurred as the mouth became drier. Mouth pH and Eh on the dorsum of the tongue correspondingly fell. Mouth breathing led to tongue and palate moisture loss thus enabling escape of malodour volatiles into mouth air. Measurement of oral dryness should make it possible to differentiate genuine malodour from dry mouth related pseudo-malodour subjects, and in turn, the latter from patients that are halitophobic. This should facilitate identification of such patients and avoid error in their clinical management.