Salivary Function Research Articles

Preservation of Salivary Function Following Extracapsular Dissection for Tumors of the Parotid Gland

This study evaluated salivary function after extracapsular dissection (ECD) compared with partial superficial parotidectomy (PSP) and classic superficial parotidectomy (CSP) of benign parotid gland tumors. The authors hypothesized that ECD would be superior to PSP and CSP in preserving postoperative salivary function. Retrospective analyses were performed for 43 consecutive patients who underwent parotidectomies of benign parotid tumors performed by a single experienced surgeon. Clinical data and pre- and postoperative whole salivary flow rates were compared among the operative procedures. Pearson χ2 and Fisher exact tests were used to compare categorical variables. Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests were used to compare means. A P value less than .05 was considered significant throughout the study. Tumor sizes did not differ among groups. Operative times, amounts of drainage, and hospital days for ECD were markedly decreased compared with CSP and tended to be decreased compared with PSP. Resection margins were exposed in 0, 12.5, and 6.7% of patients who underwent ECD, PSP, and CSP, respectively. Postoperative complications occurred less often (but not meaningfully) after ECD. Postoperative basal salivary flow rates in the ECD, PSP, and CSP groups were 0.39, 0.32, and 0.14mL/minute, respectively (P=.05). Stimulated salivary flow rates remained stable for the ECD and PSP groups but decreased in the CSP group. ECD is a safe and time-efficient surgical approach, offering early recovery from parotid tumors and better preservation of salivary function. ECD should be considered a surgical approach for parotid tumors, especially those in the parotid tail region, such as Warthin tumors.

Transoral Removal of aGiant Submandibular Sialolith: A Case Report

Submandibular salivary glands are commonly affected by sialolith (calculus),with patients suffering pain and swelling, especially at mealtime. Sialoliths and giant calculi larger than 15 mm are rarely reported. This case report presents a 28 mm sialolith which was removed successfully intraorally under local anesthesia (transoral approach; sialolithotomy). There were no complications either during the operation or postoperatively, and the salivary function of the gland remained normal.

Differences in salivary secretory function between patients with erosive esophagitis and those with nonerosive reflux disease

It has been speculated that impaired salivary flow contributes to abnormal acid clearance in patients with erosive esophagitis (EE). For easy and objective assessment of salivary function, we developed a salivary gland blood flow measurement technique using continuous-wave Doppler sonography. In the present study, we evaluated the salivary secretory function in patients with EE and those with nonerosive reflux disease (NERD) using this method. Doppler waveform analysis was performed on the facial artery to assess blood inflow to the submandibular gland of 30 healthy subjects (HS). Blood flow was compared before and after secretory stimulation with 1mL of lemon juice. Saliva was simultaneously collected and weighed before and after stimulation. Continuous-wave Doppler sonography was also performed in patients with EE and NERD. The size of the submandibular gland was compared in 26 patients with EE, 41 patients with NERD, and 86 HS. The submandibular gland blood flow increased after stimulation in all HS. Both within-day and day-to-day reproducibility were good. There was a significant correlation between the percent increase in the maximum velocity and the percent increase in salivary secretion. Although the size of the submandibular gland was not significantly different among the three groups, the percent increase in the maximum velocity in patients with EE was significantly smaller than that in HS. We have established an easy method of assessing salivary function in daily practice. This study revealed that a decrease in salivary secretory function is involved in the pathology of EE.

Evaluation of Salivary Gland Function Using Diffusion-Weighted Magnetic Resonance Imaging for Follow-Up of Radiation-Induced Xerostomia.

ObjectiveTo investigate the value of diffusion-weighted magnetic resonance imaging (DW-MRI) as a noninvasive tool to assess salivary gland function for follow-up of patients with radiation-induced xerostomia.Materials and MethodsThis study included 23 patients with nasopharyngeal carcinoma who had been treated with parotid-sparing radiotherapy (RT). Salivary function was assessed by DW-MRI pre-treatment and one week and one year post-RT, respectively. The maximum apparent diffusion coefficient (ADC) of parotid glands (pADCmax) and the time to peak ADC of parotid glands (pTmax) during stimulation were obtained. Multivariate analysis was used to analyze factors correlated with the severity of radiation-induced xerostomia.ResultsThe ADCs of parotid and submandibular glands (1.26 ± 0.10 × 10−3 mm2/s and 1.32 ± 0.07 × 10−3 mm2/s pre-RT, respectively) both showed an increase in all patients at one week post-RT (1.75 ± 0.16 × 10−3 mm2/s, p < 0.001 and 1.70 ± 0.16 × 10−3 mm2/s, p < 0.001, respectively), followed by a decrease in parotid glands at one year post-RT(1.57 ± 0.15 × 10−3 mm2/s, p < 0.001) but not in submandibular glands (1.69 ± 0.18 × 10−3 mm2/s, p = 0.581). An improvement in xerostomia was found in 13 patients at one year post-RT. Multivariate analysis revealed 4 significant predictors for the improvement of xerostomia, including dose to parotid glands (p = 0.009, odds ratio [OR] = 0.639), the ADC of submandibular glands (p = 0.013, OR = 3.295), pADCmax (p = 0.024, OR = 0.474), and pTmax (p = 0.017, OR = 0.729) at one week post-RT.ConclusionThe ADC value is a sensitive indicator for salivary gland dysfunction. DW-MRI is potentially useful for noninvasively predicting the severity of radiation-induced xerostomia.

Saliva Dysfunction and Oral Microbial Changes among Systemic Lupus Erythematosus Patients with Dental Caries.

Systemic lupus erythematosus (SLE) is a chronic autoimmune and inflammatory disease affecting multiorgans of human body. Independent studies show that SLE patients had higher caries prevalence compared to non-SLE individuals. However, the underlying mechanisms remain unclear. In present study, we enrolled SLE patients to explore potential factors contributing to the susceptibility of SLE patients to dental caries (such as oral hygiene, salivary function, and oral microbial community). Dental examination confirmed SLE patients were more vulnerable to caries. Although subjects in both groups announced similar oral hygiene habits, more dental plaque was found on tooth surfaces of SLE patents as revealed by plaque index. In addition, the salivary function was impaired in SLE group as salivary flow rate, buffering capacity, and pH were lower among SLE subjects compared to healthy controls. Importantly, disturbed microbial community with lower richness and diversity was observed in SLE group, as well as disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal bacteria. Our data suggest that SLE increases patients' sensitivity to dental caries through imposing stress to both host and oral microbes.

Intragland Shh gene delivery mitigated irradiation-induced hyposalivation in a miniature pig model

Irreversible hypofunction of salivary glands is common in head and neck cancer survivors treated with radiotherapy and can only be temporarily relieved with current treatments. We found recently in mouse models that transient activation of Hedgehog pathway following irradiation rescued salivary gland function by preserving salivary stem/progenitor cells, parasympathetic innervation and microvessels. Due to huge differences between salivary glands of rodents and humans, to examine the translational potential of this approach, we evaluated effects of Shh gene transfer in a miniature pig model of irradiation-induced hyposalivation.Methods: The right parotid of each pig was irradiated with a single dose of 20 Gray. Shh and control GFP genes were delivered into irradiated parotid glands by noninvasive retrograde ductal instillation of corresponding adenoviral vectors 4 or 16 weeks after irradiation. Parotid saliva was collected every two weeks. Parotid glands were collected 5 or 20 weeks after irradiation for histology, Western blot and qRT-PCR assays.Results: Shh gene delivery 4 weeks after irradiation significantly improved stimulated saliva secretion and local blood supply up to 20 weeks, preserved saliva-producing acinar cells, parasympathetic innervation and microvessels as found in mouse models, and also activated autophagy and inhibited fibrogenesis in irradiated glands.Conclusion: These data indicate the translational potential of transient activation of Hedgehog pathway to preserve salivary function following irradiation.

Primary Sj\xf6gren\u2019s syndrome with polymyositis, a rare amalgamation

Sjögren’s syndrome is characterized by diminished lacrimal and salivary gland secretory function. This disorder is not strictly confined to the exocrine glands and its manifestations may extend to extraglandular sites, such as the lungs, kidneys, reticuloendothelial system, and the musculoskeletal system. Although muscular manifestations are very common with Sjögren’s syndrome, true myopathy is very rare. Here, we report a case of a 45-year-old woman who presented with complaints of bilateral progressive weakness of upper and lower limbs associated with difficulty in neck holding with a history of dryness of the mouth and the eyes. The diagnosis of polymyositis associated with Sjögren’s syndrome was established on the basis of clinical picture and diagnostic tests. True polymyositis is very rare in primary Sjögren syndrome and there are scarcely any cases of primary Sjögren’s syndrome with polymyositis reported in the literature.

Delivery of Sonic Hedgehog Gene Repressed Irradiation-induced Cellular Senescence in Salivary Glands by Promoting DNA Repair and Reducing Oxidative Stress.

Rationale: Irreversible hypofunction of salivary glands or xerostomia is common in head and neck cancer survivors treated with radiotherapy even when various new techniques are applied to minimize the irradiation (IR) damage. This condition severely impairs the quality of life of patients and can only be temporarily relieved with current treatments. We found recently that transient expression of Sonic Hedgehog (Shh) in salivary glands after IR rescued salivary function, but the underlying mechanisms are not totally clear.Methods: We generated a mouse model of IR-induced hyposalivation, and delivered adenoviral vectors carrying Shh or control GFP gene into submandibular glands (SMGs) via retrograde ductal instillation 3 days after IR. The cellular senescence was evaluated by senescence-associated beta-galactosidase assay and the expression of senescence markers. The underlying mechanisms were explored by examining DNA damage, oxidative stress, and the expression of related genes by qRT-PCR, Western blot and immunofluorescent staining.Results: Shh gene transfer repressed IR-induced cellular senescence by promoting DNA repair and decreasing oxidative stress, which is mediated through upregulating expression of genes related to DNA repair such as survivin and miR-21 and repressing expression of pro-senescence gene Gdf15 likely downstream of miR-21.Conclusion: Repressing cellular senescence contributes to the rescue of IR-induced hyposalivation by transient activation of Hh signaling, which is related to enhanced DNA repair and decreased oxidative stress in SMGs.

Current State of Knowledge on Salivary Gland Cancers.

Salivary gland cancers (SGCs), categorized as head and neck cancers (HNCs), constitute about 6% of head and neck cancer diagnoses based on estimate by American Head and Neck Society. Salivary gland tumors originate from different glandular cell types and are thus morphologically diverse. These tumors arise from any of the three major and various minor salivary glands. The incidence of SGCs has slowly increased during the last four decades. The etiology of SGCs is mostly unknown; however, specific gene mutations are associated with certain types of salivary tumors. Treatment options include surgical resection, radiation therapy (RT), chemotherapy, and multimodality therapy. HNC patients treated with RT often develop xerostomia and salivary hypofunction due to damaged salivary glands. In this review, we discuss etiology of SGCs, present findings on the role of autophagy in salivary tumorigenesis, review adverse effects of radiation treatment, and examine remedies for restoration of salivary function.

Saliva and Oral Health in Attention Deficit Hyperactivity Disorder (ADHD)

Purpose: It’s estimated that 9% of children in the United States have been diagnosed with attention deficit hyperactivity disorder (ADHD) and many take medications to control their disease. Since the results of clinical studies on the oral health of ADHD patients have been inconclusive, we compared salivary function and oral health in medicated and non-medicated ADHD and healthy subjects. Methods: Fifty (50) children (6-17 y; female/ male: 1:1.8) were recruited. Group 1 subjects were diagnosed with ADHD and medicated (n=16), Group 2 had ADHD and not medicated (n=17), and Group 3 were healthy (n=17). Whole saliva was collected and flow rate, pH, buffering capacity, and level of secretory Immunoglobulin A (sIgA), cortisol and total protein determined. Nonparametric statistics were used. Results: ADHD children taking medication did not show any significant change in salivary flow rate, pH, buffering capacity, and level of salivary total protein, sIgA, and cortisol compared to non-medicated ADHD and healthy subjects (P>0.5). Streptococcus mutans (S.mutans) has been correlated with caries risk, but in these subjects there was no significant difference between groups. Conclusion: Our results suggest that medicated and non-medicated ADHD patients (6-17 y) have no additional risk for oral diseases or salivary dysfunction compared to healthy controls.

Prevalence and Predictors of Sjögren's Syndrome in Patients with Burning Mouth Symptoms.

To investigate the prevalence and predictive factors of Sjögren's syndrome (SS) in a cohort of patients with burning mouth symptoms. A total of 125 patients with burning mouth symptoms were enrolled in a prospective study and assessed for the presence of SS. The severity of oral symptoms was evaluated by using questionnaires. Salivary flow rates and salivary scintigraphy were used to evaluate salivary function. Patient laboratory work-ups were reviewed, and SS was diagnosed by a rheumatologist based on the American-European Consensus Group criteria. The differences between the SS patient group and the non-SS patient group were analyzed with chi-square test or t test. A total of 12 of the 125 enrolled patients (9.5%) had a positive autoimmune antibody test, and 6 (4.8% of the entire cohort) had SS (4 [3.2%] primary and 2 [1.6%] secondary). Patients with SS exhibited significantly decreased hemoglobin levels, an increased erythrocyte sedimentation rate, and an increased prevalence of autoantibody positive results compared to non-SS patients. Salivary scintigraphy showed that the uptake ratio of the submandibular gland in SS patients was decreased significantly. The prevalence of SS in patients with burning mouth symptoms was 4.8%. Therefore, clinicians who treat patients with burning mouth symptoms should evaluate laboratory findings and salivary functions to identify patients with SS.

Effects of standardized isopropanolic black cohosh and estrogen on salivary function in ovariectomized rats

Oral dryness is a common feature in menopausal women. Estrogen therapy can relieve this symptom; however, the underlying mechanism was not clear. Standardized isopropanolic black cohosh (Actaea racemosa; Remifemin) can also relieve menopausal symptoms, such as hot flashes and sweating. Our previous study showed that standardized isopropanolic black cohosh could protect the submandibular gland structure. To investigate the effects and possible mechanisms of action of estrogen and standardized isopropanolic black cohosh on submandibular gland function in ovariectomized (OVX) rats, we measured body weight, daily water consumption, and blood flow in the submandibular glands. Immunohistochemistry and western blotting were used to detect the expression of muscarinic acetylcholine receptors 1 (M1) and 3 (M3), and aquaporin 5 (AQP5) in the submandibular gland. OVX increased daily water consumption and reduced vasodilation in the submandibular gland. It suggested that ovariectomy could damage the salviary function. Moreover, the expression of M1 and M3 receptors decreased, whereas that of AQP5 increased. These changes may explain the dysfunction of saliva secretion in menopause. Estrogen and standardized isopropanolic black cohosh treatment had the same effect on daily water consumption and vasodilation in the submandibular gland. It indicated that estrogen and standardized isopropanolic black cohosh could relieve oral dryness in menopause. However, the mechanism of the two treatments may differ because standardized isopropanolic black cohosh only protected against changes in M1 expression, whereas estrogen protected against variations in M1, M3, and AQP5 expression.

Salivary evaluation in radioactive I131 treated patients with thyroid carcinoma

Background and objective: radioiodine treatment (I131) used to treat thyroid carcinomas produces side effects (sialadenitis, xerostomia, dysphagia and caries susceptibility) reflecting in a poor patient quality of life. This study aimed to evaluate the effect of I131 on salivary function and possible oral impairment.Material and methods: Thirty-seven patients undergoing I131 were submitted to oral examination, answer questions regarding xerostomia/hyposalivation and collect saliva at three moments (M1: 30–45 days before I131, M2: 1–2 days after I131 and M3: 7–10 days after treatment). Saliva was assayed for flow rate and calcium/phosphate concentrations.Results and conclusions: significant difference in calcium/phosphate concentration was shown between M1 and M2, with evident decrease at M2. Flow rate reduced right after treatment with 41% of patients returning to previous rate at M3 (no statistical difference). A higher number of patients related xerostomia and difficulty in swallowing food at M2. The results showed that xerostomia/hyposalivation, dysphagia and calcium/phosphate concentration decrease may be considered early radioiodine side effects.

Optimal timing and frequency of bone marrow soup therapy for functional restoration of salivary glands injured by single-dose or fractionated irradiation.

Injections of bone marrow (BM) cell extract, known as 'BM soup', were previously reported to mitigate ionizing radiation (IR) injury to salivary glands (SGs). However, the optimal starting time and frequency to maintain BM soup therapeutic efficacy remains unknown. This study tested the optimal starting time and frequency of BM soup injections in mice radiated with either a single dose or a fractionated dose. First, BM soup treatment was started at 1, 3 or 7 weeks post-IR; positive (non-IR) and negative (IR) control mice received injections of saline (vehicle control). Second, BM soup-treated mice received injections at different frequencies (1, 2, 3 and 5 weekly injections). Third, a 'fractionated-dose radiation' model to injure mouse SGs was developed (5 Gy × 5 days) and compared with the single high dose radiation model. All mice (n = 65) were followed for 16 weeks post-IR. The results showed that starting injections of BM soup between 1 and 3 weeks mitigated the effect of IR-induced injury to SGs and improved the restoration of salivary function. Although the therapeutic effect of BM soup lessens after 8 weeks, it can be sustained by increasing the frequency of weekly injections. Moreover, both single-dose and fractionated-dose radiation models are efficient and comparable in inducing SG injury and BM soup treatments are effective in restoring salivary function in both radiation models. In conclusion, starting injections of BM soup within 3 weeks post-radiation, with 5 weekly injections, maintains 90-100% of saliva flow in radiated mice.

The influence of polishing techniques on pre-polymerized CAD\CAM acrylic resin denture bases.

BackgroundLately, computer-aided design and computer-aided manufacturing (CAD/CAM) has broadly been successfully employed in dentistry. The CAD/CAM systems have recently become commercially available for fabrication of complete dentures, and are considered as an alternative technique to conventionally processed acrylic resin bases. However, they have not yet been fully investigated.ObjectiveThe purpose of this study was to inspect the effects of mechanical polishing and chemical polishing on the surface roughness (Ra) and contact angle (wettability) of heat-cured, auto-cured and CAD/CAM denture base acrylic resins.MethodsThis study was conducted at the Advanced Dental Research Laboratory Center of King Abdulaziz University from March to June 2017. Three denture base materials were selected: heat cure poly-methylmethacrylate resin, thermoplastic (polyamide resin) and (CAD\\CAM) denture base resin. Sixty specimens were prepared and divided into three groups, twenty in each. Each group was divided according to the polishing techniques into (Mech P) and (Chem P), ten specimens in each; surface roughness and wettability were investigated. Data were analyzed by SPSS version 22, using one-way ANOVA and Pearson coefficient.ResultsOne-way analysis of variance (ANOVA) and post hoc tests were used for comparing the surface roughness values between three groups which revealed a statistical significant difference between them (p1<0.001). Heat-cured denture base material of (Group I) in both methods, showed the highest mean surface roughness value (2.44±0.07, 2.72±0.09, Mech P and Chem P respectively); while CAD\\CAM denture base material (group III) showed the least mean values (1.08±0.23, 1.39±0.31, Mech P and Chem P respectively). CAD/CAM showed the least contact angle in both polishing methods, which were statistically significant at 5% level (p=0.034 and p<0.001).ConclusionMechanical polishing produced lower surface roughness of CAD\\CAM denture base resin with superior smooth surface compared to chemical polishing. Mechanical polishing is considered the best effective polishing technique. CAD/CAM denture base material should be considered as the material of choice for complete denture construction in the near future, especially for older dental patients with changed salivary functions, because of its wettability.

Scintigraphic Evaluation of Salivary Function after Intensity Modulated Radiotherapy for Head and Neck Cancer

Xerostomia is a common complication in patients treated for head and neck cancers (HNC). Highly conformal radiotherapy (RT) techniques, such as intensity modulated radiotherapy (IMRT), result in better normal tissue sparing in comparison to 3-dimensional conformal radiotherapy. We investigated salivary function using quantitative scintigraphy and aimed to identify associations between dosimetric parameters of the parotid glands and quality of life (QoL) for HNC patients receiving IMRT. Thirty patients treated for HNC were prospectively recruited. Salivary excretion function (SEF) was measured by 99mTc pertechnetate scintigraphy prior to RT and then 1 and 12 months after its completion. The recovery of parotid gland excretion function was expressed as the ratio of post- and pre-treatment SEF. Patient-reported QoL was evaluated by the EORTC QLQ-C30 and H&N35 questionnaires. The mean SEF before RT was 49.2±14.8%. In the univariate analysis we found that older age (r=-0.29, p=0.049) and localization of tumour in oral cavity or oropharynx (comparing to larynx/hypopharynx, p=0.030) affected recovery of salivary flow 12 months after RT. Mean parotid dose was significantly correlated with recovery of salivary flow 12 months after RT (r=-0.46, p=0.001). In the multivariate analysis all aforementioned factors were found to be significantly associated with salivary flow 12 months after RT - age (β=-0.39, p=0.002), tumour localized in oral cavity or oropharynx (β =-0.36, p=0.004), mean parotid dose (β=-0.44, p<0.001). Self-reported grade ≥3 xerostomia was more often in patients with tumour localized in oral cavity or oropharynx (p=0.027). It was also more common in patients who received higher mean dose for both parotids and in patients with worse recovery of salivary flow 12 months after RT. However these results were not statistically significant (p=0.104 and p=0.089, respectively). The results of scintigraphic evaluation of salivary function are strongly correlated with the mean parotid dose. However, this objective method is only partially associated with patients’ self-reported outcomes. The possible reason for that phenomenon is the fact that xerostomia is highly subjective and several factors, not just simply salivary flow, may be involved in its perception. This may be particularly important in older patients who were found to have the worst recovery of salivary flow.

Herbal Medicine for Xerostomia in Cancer Patients: A Systematic Review of Randomized Controlled Trials.

Background: Xerostomia (dry mouth) causes many clinical problems, including oral infections, speech difficulties, and impaired chewing and swallowing of food. Many cancer patients have complained of xerostomia induced by cancer therapy. Objective: The aim of this systematic review is to assess the efficacy of herbal medicine for the treatment of xerostomia in cancer patients. Materials and Methods: Randomized controlled trials investigating the use of herbal medicines to treat xerostomia in cancer patients were included. We searched the following 12 databases without restrictions on time or language. The risk of bias was assessed using the Cochrane Risk of Bias Tool. Results: Twenty-five randomized controlled trials involving 1586 patients met the inclusion criteria. A total of 24 formulas were examined in the included trials. Most of the included trials were insufficiently reported in the methodology section. Five formulas were shown to significantly improve the salivary flow rate compared to comparators. Regarding the grade of xerostomia, all formulas with the exception of a Dark Plum gargle solution with normal saline were significantly effective in reducing the severity of dry mouth. Adverse events were reported in 4 trials, and adverse effects of herbal medicine were reported in 3 trials. Conclusions: We found herbal medicines had potential benefits for improving salivary function and reducing the severity of dry mouth in cancer patients. However, methodological limitations and a relatively small sample size reduced the strength of the evidence. More high-quality trials reporting sufficient methodological data are warranted to enforce the strength of evidence regarding the effectiveness of herbal medicines.

Comparative evaluation of the doses received by the parotid glands as predictors of xerostomia be 3D-CRT, IMRT and VMAT irradiation techniques in local advanced nasopharynx cancer

Xerostomia is commonly associated with the radio-chemotherapy treatment of the head and neck cancers. The risk increases with increasing doses received by the parotid. Severe xerostomia (defined as long-term salivary function of < 25% of baseline) may be avoided if at least one parotid gland receives less than 20 Gy. The combined treatment with cisplatin regarded as bringing a significant benefit in survival with concurrent radiotherapy is associated with increased risk of late toxicity. Intensity-modulated radiotherapy (IMRT) is considered the radio-therapeutic standard in the management of head and neck cancer. Purpose: to evaluate the possibility of modern techniques to reduce radiation doses to parotid glands compared to conventional 3D-CRT radiotherapy even if the parotid glands are not delineated as organs at risk (OAR) and dosimetric constraints are not applied. Methods: For 10 locally advanced nasopharyngeal cancer cases treated by radiotherapy with curative intent using 3D-CRT technique, alternative IMRT and VMAT plans were proposed without applying dosimetric constraints for parotid glands. Results: IMRT and VMAT techniques reduce the maximum dose (Dmax) and the mean dose (Dmean) for both parotid glands compared to the 3D-CRT technique. The treatment plans were comparatively analyzed in terms of doses received by both parotid glands. Conclusions: Modern radiotherapy techniques implementation can reduce the dose received by the parotids even in the absence of contouring them as organs at risk, reducing xerostomia and ensuring a better quality of life for the nasopharynx cancer radio-treated patients.

Association between Salivary Hypofunction and Food Consumption in the Elderlies. A Systematic Literature Review.

This systematic literature review aims to summarize the existing scientific evidence about the association between a reduced salivary function and food consumption in elderly people. A validated search strategy in two databases (PubMed and ISI Web of Knowledge) was carried out and retrieved papers together with their reference lists were screened by two independent reviewers. The quality of the included studies was critically appraised via the Quality Assessment Criteria for Evaluating Primary Research Papers. From the originally identified studies (n=391), only 15 articles (all cross-sectional studies) met the pre-fixed inclusion/exclusion criteria. The methodological quality of the included studies was in general good, although only 3 from 15 obtained the maximum score. The control of confounding factors was the quality variable more poorly rated in the selected studies. Salivary hypofunction was associated with a decrease of the objective chewing and swallowing abilities and taste perception. Moreover, most of the selected studies showed a relationship between salivary hypofunction and food consumption (in terms of appetite loss, unbalanced dietary intake and malnutrition), although no causality could be established. This study highlights the fact that salivary hypofunction definition and measurements are different across the studies. Therefore, future research efforts should focus on establishing a gold standard to define and identify salivary hypofunction throughout life and on performing longitudinal studies controlling for confounding factors to establish causality.

Quantification of the salivary volume flow rate in the parotid duct using the time-spatial labeling inversion pulse (Time-SLIP) technique at MRI: A feasibility study.

We developed a method to quantify the volume flow rate (VFR) using the time-spatial labeling inversion pulse (Time-SLIP) technique to evaluate salivary function. To investigate the accuracy of quantification of the salivary VFR using the Time-SLIP technique in phantoms and to examine the feasibility of its use in human subjects. This was a prospective phantom and volunteer study. A phantom and 23 normal volunteers who fasted at least 2 hours study was performed. Flow images of the phantom and the parotid duct of 23 volunteers were acquired on a 3T-MRI scanner using the Time-SLIP technique. Hypothesizing that flow aggregates in the conducting duct, we measured the VFR on flow images. In the phantom study, the actual VFR (slow, medium, fast flow) was controlled by an automatic pump system and the measured VFR was compared with the actual VFR on flow images. In the human study we injected citric acid into the mouth of healthy volunteers to stimulate saliva secretion and recorded the VFR. As this study was a feasibility study, statistical tests were not performed. In the phantom study, the VFR at slow, medium, and fast flow was 5.7 ± 0.4 (SD), 8.4 ± 0.3, and 12.2 ± 1.1 mm3 /sec, respectively. The error between the measured and actual VFR values was 2.8-3.7%. Salivary flow in the parotid duct was visualized in 22 of the 23 volunteers. The mean VFR was 8760 mm3 /10 min. When salivary flow was stimulated with citric acid in normal volunteers, the salivary VFR could be obtained using the Time-SLIP technique. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:928-935.