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.

Effect of continuous sweet gustatory stimulation on salivary flow rate over time

OBJECTIVE

This study aimed to determine changes in saliva secretion and subjective taste intensity during a sustained period with continuous gustatory stimulation.

DESIGN

Twenty-two healthy adults participated in this study. The selected taste solutions were aspartame, sucralose, and acesulfame potassium, which are nonnutritive sweeteners. The concentrations of sucralose1 and acesulfame potassium were set to show the same sweetness intensity as aspartame. Sucralose2 was twice the concentration of sucralose1. The solution was continuously fed into the oral cavity at a flow rate of 0.04 mL / min through a neck-worn precise infusion system. The salivary flow rate (g/min) after 10 min of intraoral water supply from the device was used as the baseline. Salivary flow rate, subjective taste intensity evaluated by the visual analog scale (VAS), and salivary flow rate relative to the baseline were recorded at 10, 30, 60, and 120 min after the start of the test.

RESULTS

In the aspartame, sucralose1, and sucralose2 groups, the salivary flow rate increased significantly from 10 min to 120 min after the start of the test when compared to the rate at baseline (p < 0.05). The relative salivary flow rate increased and the VAS value decreased significantly over time and were affected by the time factor (p < 0.001, p = 0.013, respectively) but not by the sweetener-group factor and the interaction effects.

CONCLUSIONS

Continuous gustatory stimulation may maintain increased salivary production for a sustained period.

酸刺激对腮腺和下颌下腺唾液流率及成分的影响

OBJECTIVE

To investigate the effect of acid stimulation on salivary flow rate and compositions of human parotid and submandibular glands, so as to provide basis for comprehensive evaluation of salivary gland function in both health and disease status.

METHODS

In the study, 210 healthy participants' whole saliva samples were collected under passive drooling, and their parotid gland and submandibular gland secretions were collected by negative pressure suction. 2% citric acid was dropped on the tip of tongue every 1 min for acid stimulation for a total of 5 times to collect stimulated whole saliva, parotid and submandibular gland saliva. The collected saliva was weighed and saliva flow rate was calculated. The K⁺, Na⁺, Cl^-, Ca²⁺, total protein, total phosphorus and α-amylase in saliva samples were detected by biochemical analyzer, and the changing features of flow rate and compositions of different kinds of saliva were compared and analyzed.

RESULTS

After acid stimulation, saliva flow rate significantly increased. The increase proportion of parotid gland saliva (10.7 folds) was much higher than that of submandibular gland saliva (2.9 folds). The concentrations of Na⁺, Cl^-, Ca²⁺, total protein and α-amylase in parotid gland saliva increased significantly (P < 0.05), but there was no significant difference in total phosphorus and K⁺ (P=0.89, P=0.34). The concentration of Na⁺ and Ca²⁺ in saliva of submandibular gland increased significantly(P < 0.05), the concentration of total phosphorus decreased significantly(P < 0.05), and the concentration of Cl^- increased, but the difference was not significant(P=0.068). There was no significant difference in total protein, K⁺ and α-amylase (P=0.85, P=0.07, P=0.95). The compound secretion rate of total phosphorus in saliva of submandibular gland remained unchanged(P=0.066), while the secretion rate of K⁺, Na⁺, Cl^-, Ca²⁺, total protein and α-amylase significantly increased(P < 0.01). The compound secretion rate of K⁺, Na⁺, Cl^-, Ca²⁺, total protein and total phosphorus and α-amylase in parotid gland saliva increased(P < 0.01). The concentrations of Na⁺, Cl^-, K⁺, total phosphorus, total protein and α-amylase in parotid were higher than those in submandibular gland (P < 0.01), and the concentration of Ca²⁺ in submandibular gland saliva was significantly higher than that in parotid (P < 0.001).

CONCLUSION

The response of parotid to acid stimulation is stronger, and the secretion of submandibular gland is more stable. Acid stimulation significantly influences the concentrations of electrolytes in saliva, and the composited secretion rate is an evaluation index to reflect both flow rate and composition concentration of saliva. The parotid gland plays an important role in the secretion of total protein, total phosphorus and α-amylase in saliva, and the submandibular gland is the main source of Ca²⁺ in saliva.

A novel histological grading system for minor salivary gland involvement in oral submucous fibrosis patients with clinico-pathological validation

BACKGROUND

The involvement of minor salivary glands (MSGs) with fibrosis in oral submucous fibrosis (OSMF) pathology is a quite conceivable fact. However, very little attention has been given to the status of MSGs in OSMF.

METHODOLOGY

Total 53 cases of OSMF were recruited and demographic details, mouth opening, clinical oral dryness score (CODS), and buccal mucosal MSG flow rate were determined. The fibrosis around MSGs is categorized into three grades and compared with relevant clinicopathological parameters.

RESULTS

Out of total 53 OSMF patients, there were 15 patients in grade I MSG involvement with fibrosis followed by 24 and 14 patients in grade II and grade III, respectively. Grade I MSG involvement showed maximum mouth opening (32 ± 3.87 mm) followed by Grade II (19.85 ± 4.31mm) and Grade III (11.42 ± 5.21mm) and the differences between them were statistically significant. The CODS score was more in grade III (5.5 ± 1.09 mm) as compared to Grade II (4.04 ± 0.62 mm) and Grade I (2.46 ± 0.74 mm) involvement of MSG. The flow rate was more in grade I (8.02 ± 2.99 mm) as compared to Grade II (3.97 ± 1.09 mm) and Grade III (3.4 ± 0.87 mm) involvement of MSG.

CONCLUSION

The fibrosis associated with OSMF can affect the MSGs located at mucosal and sub-mucosal levels. The clinical determinants such as mouth opening, salivary flow rate, and CODS corroborate with the grading of the degree of MSG involvement with fibrosis.

The relation between stimulated salivary flow and the temporal consumption experience of a liquid oral nutritional supplement

Use of oral nutritional supplements (ONS) in undernourished patients has proven clinical benefits, but this can be hampered by low adherence due to poor experience of palatability. Many patients, particularly older patients, experience hyposalivation which can cause taste changes and reduce the enjoyment of foods. The aim of this study was to investigate differences in the temporal consumption experience (comprising sensory perception, in-mouth aroma release and subjective appetite) of a clinically relevant portion of ONS, for groups differing in saliva flow rates (SFR). The SFR (mL/min) of thirty healthy individuals was measured on three occasions. This data was used to categorise individuals into three groups using quartile analysis: low flow (LF) (0.3–0.6 mL/min, n = 5), medium flow (MF) (0.7–1.2 mL/min, n = 16) and high flow (HF) (1.3–1.8 mL/min, n = 9). Over the consumption of eight 15 mL sips of ONS, individuals rated their sensory perception and subjective appetite perception using line scales. Additionally, in-mouth aroma release was measured for each sip, using atmospheric pressure chemical ionisation (APCI). Compared with the MF and HF group, the LF group reported a significantly greater increase of mouth-drying over increased sips (p = 0.02). The LF group also experienced significantly higher aftertaste perception (p < 0.001), and more intense in-mouth aroma release (p = 0.015), compared with the HF group. These findings occurred concurrently with relatively lower hunger sensations in the LF and MF group. Many patients who are prescribed ONS likely experience reduced salivary flow rates. The unique sensory experiences of these individuals should be considered in order to optimise palatability and nutritional intake.

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A full portion of ONS was evaluated by three groups differing in saliva flow rates.

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A sensory profiling method captured perceptual differences over repeated sips.

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Mouth-drying built up most significantly for the low saliva flow group.

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Intensity of aftertaste and aroma release was highest in the low saliva flow group.

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Sensorial intensity of ONS may be associated with greater feelings of satiation.

Efficacy of Stannous Ions on Enamel Demineralization under Normal and Hyposalivatory Conditions: A Controlled Randomized in situ Pilot Trial

The study aim was to investigate the effect of antierosive agents on enamel under normal and hyposalivatory conditions. This double-blind crossover in situ pilot study evaluated 4 toothpastes: placebo (0 ppm F), sodium fluoride (NaF, 1,450 ppm), stannous/sodium fluoride (SnF/NaF, 1,450 ppm F-, 1,090 ppm Sn2+), and sodium fluoride, stannous chloride and chitosan (NaF/Sn/Ch, 1,450 ppm F-, 3,500 ppm Sn2+, 0.5% Ch). Twenty participants were assigned to 2 groups (n = 10 each): normal and low salivary flow. Participants wore palatal appliances holding 4 bovine enamel specimens previously eroded in vitro (D1) for 20 min prior to an in situ phase after which they were eroded again (D2). Surface microhardness was determined at baseline (BL), after D1, in situ phase and D2 to assess hardness loss (%SMH), residual hardness loss (%RHL) and erosion resistance (%RER). Additional specimens were evaluated by scanning electron microscopy after the in situ phase. ANOVA and a factorial analysis for between-subject effects were performed. Sn-based toothpastes showed the best effects (p < 0.05). Under normal flow, SnF/NaF showed higher efficacy, with a significant difference compared to NaF/Sn/Ch, NaF, and placebo (p < 0.05). Under low flow, SnF/NaF and NaF/Sn/Ch were comparable (p > 0.05); NaF and placebo were statistically similar. Comparing salivary conditions, there were significant differences for SnF/NaF for %SMH after the in situ phase (%SMHtotal)), %RHL and for all toothpastes in case of %RER. Factorial analysis revealed interactions between toothpaste and saliva flow for %SMHtotal and %RHL. Salivary flow can influence the efficacy of the antierosive toothpastes; however, Sn2+ preparations show even under low salivary flow conditions the highest efficacy in the prevention of enamel erosion.

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.