PIEZO1 activation may serve as an early tissue biomarker for the prediction of irradiation-induced salivary gland dysfunction.

Irradiation (IR)-induced xerostomia is the most common side effect of radiation therapy in patients with head and neck cancer (HNC). Xerostomia diagnosis is mainly based on the patient's medical history and symptoms. Currently, no direct biomarkers are available for the early prediction of IR-induced xerostomia. Here, we identified PIEZO1 as a novel predictive tissue biomarker for xerostomia. Our data demonstrate that PIEZO1 is significantly upregulated at the gene and protein levels during IR-induced salivary gland (SG) hypofunction. Notably, PIEZO1 upregulation coincided with that of inflammatory (F4/80) and fibrotic markers (fibronectin and collagen fibers accumulation). These findings suggest that PIEZO1 upregulation in SG tissue may serve as a novel predictive marker for IR-induced xerostomia.

Oral Candida in post-radiotherapy patients with xerostomia/hyposalivation: A narrative review.

OBJECTIVE: Head and Neck Cancer (HNC) patients receiving radiotherapy (RT) often suffer from xerostomia and/or hyposalivation. As saliva plays an important antimicrobial and cleansing roles, these patients are at higher risks of opportunistic infections. This narrative review aims to provide an overview of current evidence on oral Candida colonisation and infection in these patients. METHODS: A literature review of clinical studies on oral Candida colonisation and candidiasis in HNC patients receiving radiotherapy/chemoradiotherapy was conducted. RESULTS: Many clinical studies found high levels of Candida colonisation and a substantial proportion of post-RT HNC patients suffering from oropharyngeal candidiasis (OPC). Importantly, oral Candida could be a reservoir for life-threatening systemic infection in immunocompromised patients. The rising prevalence of non-albicans Candida species and drug-resistant infections has made identification of Candida species and antifungal susceptibility more important. Recent advances in oral microbiome and its interactions with Candida are discussed. This review also offers perspectives on limitations of current evidence and suggestions for future research. CONCLUSION: Further research to better understand Candida carriage, microbiome, OPC, and xerostomia/hyposalivation post-RT would aid in devising a more comprehensive long-term management plan and novel therapeutic approaches for HNC patients to achieve the full benefits of RT while minimising side effects.

Oral discomfort and health behavior of patients with typical vs. atypical antipsychotic drugs.

Introduction: Psychiatric patients suffer from oral diseases and side effects of antipsychotic medication. In particular, the typical antipsychotic drugs may cause severe hyposalivation with subsequent oral symptoms. We therefore aimed to compare oral health behavior and oral side effects of in-hospital patients taking typical vs. atypical antipsychotic drugs with the hypothesis that the former drugs cause more oral pain than the newer drugs. Methods: This cross-sectional questionnaire and interview study investigated subjective oral symptoms and their health behavior in 170 hospitalized psychiatric patients, comparing those taking typical vs. atypical antipsychotic drugs. Cross-tabulations and chi-square tests were used for analyses. Results: Persistent oral pain lasting throughout the day was reported by 46% in the typical, and 5% in the atypical antipsychotic group patients, respectively. In both groups, the pain was mainly in the tongue and buccal mucosa and was described as a burning sensation. A significantly higher prevalence of xerostomia was reported in the typical antipsychotic medication group (66%) compared with the atypical antipsychotic medication group (53%, p<0.01). Self-assessed dental health was assessed as poor by two-thirds of the patients of whom 69% reported toothbrushing once daily. Approximately half of them reported having had a visit to a dentist within the previous year. Of the women 28%, and of the men 17%, respectively, had received professional consultations for oral symptoms. Conclusion: The current results on psychiatrically hospitalized patients emphasize the need for awareness of oral discomfort and its subsequent effects on the quality of life in this challenging patient group. Focus should also be placed on a wide range of support encouraging the patients to maintain good daily oral hygiene and seek professional dental help when needed.

Periodontal status and mandibular biomechanics in rats subjected to hyposalivation and periodontitis.

Xerostomia emerges as a consequence of salivary gland hypofunction, and seriously compromises the integrity of hard and soft oral tissues, whileperiodontitis is an infectious disease characterized by biofilm accumulation, inflammation and alveolar bone resorption. AIM: The aim this study was to compare the deleterious effects caused by experimental hyposalivation, periodontitis, and the combination of both on periodontal tissues and mandibular biomechanics in rats. MATERIALS AND METHOD: Hyposalivation (group H) was induced through bilateral submandibulectomy. Periodontitis (group EP) was induced by injecting LPS (1 mg/ml) into the gingiva of the first lower molars. A third group was subjected to both conditions (group H+EP). Alveolar bone loss was evaluated by micro-computed tomography and histomorphometric analysis, and gingival inflammatory mediators were assessed by specific techniques. Biomechanical properties were evaluated in mandible. RESULTS: Alveolar bone loss increased similarly in groups H, EP and H+EP compared to control. Metalloproteinase (MMP2 and MMP9) activity was similar in H and control, but higher in groups EP and H+EP (MMP2: C 9644+2214, EP 34441+3336, H 5818+1532, H+EP 42673+3184; MMP9: C 5792+961, EP 14807+861, H 9295+520, H+EP 4838+1531). The rest of the inflammatory mediators evaluated increased in groups H, EP and H+EP to a greater or lesser extent with respect to the control, although in most cases, they were higher in groups EP and H+EP than in group H. The biomechanical properties of the mandible increased in group H compared to the other three groups. CONCLUSIONS: Both hyposalivation and periodontitis cause periodontal damage, but hyposalivation also produces biomechanical alterations, causing more extensive deleterious effects than periodontitis.

La xerostomía surge como consecuencia de la hipofunción de las glándulas salivales y compromete seriamente la integridad de los tejidos orales duros y blandos, mientras que la periodontitis es una enfermedad infecciosa caracterizada por la acumulación de biofilm, inflamación y reabsorción ósea alveolar. OBJETIVO: El objetivo del presente estudio fue comparar los efectos deletéreos causados por la hiposalivación y la periodontitis experimental, y la combinación de ambas sobre los tejidos periodontales y la biomecánica mandibular en ratas. MATERIALES Y MÉTODOS: La hiposalivación (H) se indujo mediante una submandibulectomía bilateral. Por otra parte, la periodontitis (PE) se indujo mediante la inyección de LPS (1 mg/ml) en la encía de los primeros molares inferiores. Otro grupo se sometió a ambas condiciones (H+PE). La pérdida ósea alveolar se evaluó mediante tomografia microcomputarizada y análisis histomorfométrico, mientras que los mediadores inflamatorios gingivales fueron determinados mediante técnicas específicas. Se evaluaron las propiedades biomecánicas en la mandíbula. RESULTADOS: La hiposalivación aumentó la pérdida ósea alveolar en comparación con el control de forma similar a la PE y H+PE. La actividad de las metaloproteinasas (MMP2 y MMP9) fue similar en los grupos H y control, pero resultó mayor en los grupos PE y H+PE (MMP2: C 9644+2214, PE 34441+3336, H 5818+1532, H+PE 42673+3184; MMP9: C 5792+961, PE 14807+861, H 9295+520, H+PE 24838+1531). El resto de los mediadores inflamatorios evaluados aumentaron en mayor o menor medida en los grupos H, PE y H+PE respecto al control, aunque en la mayoría de los casos fueron superiores en los grupos PE y H+PE respecto al grupo H. Sin embargo, las propiedades biomecánicas de la mandíbula aumentaron en el grupo H con respecto a los otros grupos. CONCLUSIONES: Tanto la hiposalivación como la periodontitis causan daño periodontal, pero la hiposalivación también produce alteraciones biomecánicas, provocando efectos deletéreos más extensos que la periodontitis.

Interventional Prospective Studies on Xerostomia in Patients Undergoing Palliative and End-of-Life Care: A Scoping Review.

Patients undergoing palliative care often develop debilitating oral conditions, including xerostomia. These conditions may significantly impact patients' quality of life. Despite the high prevalence and adverse impact of xerostomia, effective management strategies remain unclear. This scoping review was performed to elucidate effective interventions for xerostomia in patients undergoing palliative and end-of-life care. A comprehensive search strategy was employed to identify relevant studies up to August 2023. Full-text primary articles focusing on xerostomia in patients receiving palliative care were included in the review. Eleven articles were selected for analysis, and data were extracted by six reviewers. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Among the 11 studies, interventions ranged from oral care to saliva substitutes and methods to stimulate saliva secretion. The primary method of assessing xerostomia was the performance of subjective evaluations using visual analog scale scores or numerical rating scale scores. Various interventions including oral care regimens, topical treatments, and mixed efficacy outcomes were reported. Notably, only one study directly measured the saliva volume, highlighting a reliance on subjective endpoints in most studies. Although no definitive conclusions can be drawn regarding the most effective intervention, oral care was a preferred option for managing xerostomia in patients undergoing palliative care. Additionally, adjunctive treatments such as ice cubes, saline, and moisturizers showed promise but require further investigation. Objective measures should be incorporated into future intervention trials to complement subjective assessments and provide a comprehensive evaluation of xerostomia management strategies in this patient population.

Frequency of Oral Lesions, Olfactory, and Gustatory Disorders and Xerostomia in Patients with COVID-19.

COVID-19, a respiratory illness with a global impact on millions, has recently been linked to manifestations affecting various bodily systems, including the oral cavity. Studies highlight oral issues, like ulcers, blisters, and white patches, alongside olfactory and gustatory dysfunction, influencing an individual's quality of life. In this context, our study aimed to assess the frequency of oral lesions, olfactory and gustatory disorders, and xerostomia resulting from COVID-19. An observational study was conducted with 414 patients to evaluate the frequency of oral symptoms resulting from COVID-19. Patients were diagnosed with mild symptoms and evaluated through clinical examination of the oral cavity and a questionnaire to assess functional alterations. The findings showed that 139 out of 414 patients presented clinical manifestations, with oral lesions being the most prevalent (19.1%), followed by gustatory disorders (18.1%), xerostomia (14.2%), and olfactory dysfunction (14%). The most prevalent oral lesions were ulcerations (n = 51), candidiasis (n = 8), and erythema or red plaques (n = 7). Unfortunately, 50 (12.1%) patients died during this study. Therefore, oral lesions, olfactory and gustatory dysfunctions, and xerostomia are common symptoms associated with COVID-19.

Unlocking the Future: Bioprinting Salivary Glands-From Possibility to Reality.

Salivary gland biofabrication represents a promising avenue in regenerative medicine, aiming to address the challenges of salivary gland dysfunction caused by various factors such as autoimmune diseases and radiotherapy. This review examines the current state of bioprinting technology, biomaterials, and tissue engineering strategies in the context of creating functional, implantable salivary gland constructs. Key considerations include achieving vascularization for proper nutrient supply, maintaining cell viability and functionality during printing, and promoting tissue maturation and integration with surrounding tissues. Despite the existing challenges, recent advancements offer significant potential for the development of personalized therapeutic options to treat salivary gland disorders. Continued research and innovation in this field hold the potential to revolutionize the management of salivary gland conditions, improving patient outcomes and quality of life. This systematic review covers publications from 2018 to April 2024 and was conducted on four databases: Google Scholar, PubMed, EBSCOhost, and Web of Science. The key features necessary for the successful creation, implantation and functioning of bioprinted salivary glands are addressed.

Salivary buffering capacity is correlated with umami but not sour taste sensitivity in healthy adult Japanese subjects.

OBJECTIVE: Saliva serves multiple important functions crucial for maintaining a healthy oral and systemic environment. Among them, the pH buffering effect, which is primarily mediated by bicarbonate ions, helps maintain oral homeostasis by neutralizing acidity from ingested foods. Therefore, higher buffering capacity, reflecting the ability to neutralize oral acidity, may influence taste sensitivity, especially for sour taste since it involves sensing H+ ions. This study aims to explore the relationship between salivary buffering capacity and taste sensitivities to the five basic tastes in healthy adult humans. DESIGN: Eighty seven healthy adult students participated in this study. Resting saliva volume was measured using the spitting method. The liquid colorimetric test was used to assess salivary buffering capacity. The whole-mouth taste testing method was employed to determine the recognition threshold for each tastant (NaCl, sucrose, citric acid, quinine-HCl, monosodium glutamate). RESULTS: Taste recognition thresholds for sour taste as well as sweet, salty, and bitter tastes showed no correlation with salivary buffering capacity. Interestingly, a negative relationship was observed between recognition threshold for umami taste and salivary buffering capacity. Furthermore, a positive correlation between salivary buffering capacity and resting saliva volume was observed. CONCLUSIONS: Salivary buffering capacity primarily influences sensitivity to umami taste, but not sour and other tastes.

Influence of two paraffin wax chewing gums with different con-sistencies on the stimulated salivary flow rate.

This study investigated and compared the consistency and compressive strength of two commercially available paraffin wax chewing gums (Aurosan (AU) and GC Europe (GC)), as well as their impact on stimulated salivary flow rate. Instrumental texture analysis was uti-lized to assess the consistency and compressive strength of AU and GC during a 7-min chewing period. Subsequently, stimulated salivary flow rate (sSFR) was evaluated in healthy subjects using AU and GC over a 7-minute period. The compressive strengths from the pre-liminary test were compared over time with the sialometry data. Eighty-one test subjects, comprising 33 men and 48 women, participated. Over the 7-min measurement period, dif-ferences were observed in the total amount of saliva accumulated per minute. Direct com-parison of AU and GC revealed that regardless of age and gender, the amount of saliva formed after 1 min was 0.63 times less with AU than with GC (95% CI: 0.56 - 0.70; P < 0.001). The accumulated saliva volume with AU was also significantly lower than that with GC in the first 4 min (P = 0.016). However, from minute 5 onwards, the two products no longer showed statistical differences in the total amount of saliva. Comparison of the com-pressive strength of AU and GC showed that the values after 1 and 2 min were significantly higher for AU than for GC (P < 0.05); for all other time points, the compressive strength was higher for GC. In the mixed-effects model after log-transformation of compressive strength and saliva volume, GC exhibited decreasing saliva volumes with increasing compressive strength (P <0.001). Conversely, the opposite was observed for AU (P = 0.019). The study suggests that the consistency or compressive strength of paraffin wax chewing gums from different manufacturers could impact sSFR.

Enhancing Intraoral Fluoride Retention in Older Adults: A Randomized Crossover Study.

INTRODUCTION: Previous studies have shown that a calcium prerinse can increase intraoral fluoride retention from a fluoride rinse. To explore the potential of this approach to control root caries, we assessed intraoral fluoride bioavailability after a calcium prerinse in older adults with normal to low salivary flow rates. METHODS: In a 2-period crossover trial (NCT04239872), 20 participants (65-80 y old), with low or normal salivary flow rate, rinsed for 1 min with a 0.05% NaF mouth rinse (226 ppm F, F only) or with this rinse immediately after a 1-min rinse with 150 mM calcium lactate (Ca→F). Dental biofilm and saliva samples were collected before and up to 2 h after the rinse(s). Fluoride concentrations in saliva (whole and clarified) and dental biofilm (fluid and solid phases) were blindly determined. Data were statistically analyzed by a mixed-effects model for the effect of treatment, time, and their interaction (α = 5%). RESULTS: The Ca→F group resulted in significantly higher fluoride concentrations in all variables analyzed, for almost all of the collection time points. The effect was greater in the biofilm solids and whole saliva (compatible with the formation of calcium fluoride deposits) and still significant (P < 0.001) after 2 h in the biofilm fluid and clarified saliva, suggesting that fluoride stored in insoluble particles was released, increasing free fluoride. CONCLUSION: The use of a calcium prerinse before a fluoride rinse was able to prolong intraoral fluoride bioavailability in older adults. KNOWLEDGE TRANSFER STATEMENT: A calcium prerinse increased intraoral fluoride bioavailability in older individuals. This approach could be used to improve root caries control without the need to increase the fluoride concentration in dental products.

Application of anti-vascular endothelial growth factor antibody restores the function of saliva secretion in a type 2 diabetes mouse model.

OBJECTIVES: Xerostomia, a common complication of type 2 diabetes, leads to an increased risk of caries, dysphagia, and dysgeusia. Although anti-vascular endothelial growth factor (VEGF) antibodies, such as ranibizumab (RBZ), have been used to treat diabetic retinopathy, their effects on the salivary glands are unknown. This study evaluated the effects of RBZ on salivary glands to reduce inflammation and restore salivary function in a mouse model of type 2 diabetes. METHODS: Male KK-Ay mice with type 2 diabetes (10-12 weeks old) were used. The diabetes mellitus (DM) group received phosphate-buffered saline, while the DM + RBZ group received an intraperitoneal administration of RBZ (100 µg/kg) 24 h before the experiment. RESULTS: Ex vivo perfusion experiments showed a substantial increase in salivary secretion from the submandibular gland (SMG) in the DM + RBZ group. In addition, the mRNA expression levels of TNF-α and IL-1ß were considerably lower in this group. In contrast, those of aquaporin 5 were substantially higher in the DM + RBZ group, as revealed by quantitative reverse transcription PCR. Furthermore, the number of lymphocyte infiltration spots in the SMG was notably lower in the DM + RBZ group. Finally, intracellular Ca2+ signaling in acinar cells was considerably higher in the DM + RBZ group than that in the DM group. CONCLUSION: Treating a type 2 diabetic mouse model with RBZ restored salivary secretion through its anti-inflammatory effects.

Investigation of Hydrocolloid Plant Polysaccharides as Potential Candidates to Mimic the Functions of MUC5B in Saliva.

The successful substitution of complex physiological fluids, such as human saliva, remains a major challenge in drug development. Although there are a large number of saliva substitutes on the market, their efficacy is often inadequate due to short residence time in the mouth, unpleasant mouthfeel, or insufficient protection of the teeth. Therefore, systems need to be identified that mimic the functions of saliva, in particular the salivary mucin MUC5B and the unique physiological properties of saliva. To this end, plant extracts known to contain hydrocolloid polysaccharides and to have mucus-forming properties were studied to evaluate their suitability as saliva substitutes. The aqueous plant extracts of Calendula officinalis, Fucus sp. thalli, and lichenan from Lichen islandicus were examined for composition using a range of techniques, including GC-MS, NMR, SEC, assessment of pH, osmolality, buffering capacity, viscoelasticity, viscoelastic interactions with human saliva, hydrocolloid network formation, and in vitro cell adhesion. For this purpose, a physiologically adapted adhesive test was developed using human buccal epithelial cells. The results show that lichenan is the most promising candidate to mimic the properties of MUC5B. By adjusting the pH, osmolality, and buffering capacity with K2HPO4, it was shown that lichenan exhibited high cell adhesion, with a maximum detachment force that was comparable to that of unstimulated whole mouth saliva.

Dry Mouth Dilemma: A Comprehensive Review of Xerostomia in Complete Denture Wearers.

Xerostomia, commonly known as dry mouth, presents a significant challenge for individuals wearing complete dentures, affecting their oral health and quality of life. This review explores the relationship between saliva and complete dentures, highlighting the varied management strategies for xerostomia. Saliva plays a critical role in denture retention, lubrication, and oral environment buffering. Complete denture wearers often experience reduced salivary flow, aggravating symptoms of xerostomia. Various management approaches are discussed, including general measures such as hydration and salivary stimulation techniques which aim to boost saliva production naturally. The use of salivary substitutes provides artificial lubrication and moisture to alleviate dry mouth discomfort. Oral lubricating devices, such as sprays, gels, and lozenges, offer relief by mimicking saliva's lubricating properties, thereby improving denture stability and comfort. This review addresses the etiology of xerostomia in complete denture wearers and explores preventive measures to reduce its impact. A comprehensive approach has been discussed for the management of xerostomia which will help to improve the oral health and well-being of complete denture wearers experiencing dry mouth.

Efficacy of Office-Based Salivary Ductal Steroid Irrigation for Managing Post-Irradiation Xerostomia in Head and Neck Cancer Patients: A Retrospective Study.

Post-irradiation xerostomia remains a significant quality of life concern for patients with head and neck cancers. Conventional therapies offer limited effectiveness. This study aims to investigate the therapeutic potential of office-based salivary ductal steroid irrigation in patients with post-irradiation xerostomia. This single-center observational study recruited 147 head and neck cancer patients suffering from post-irradiation xerostomia between November 2020 and October 2022. All included subjects received at least one round of successful salivary ductal cannulation and irrigation. The primary measure of efficacy was improvement in subjective xerostomia and objective salivary amylase levels. A logistic regression was employed to evaluate factors affecting treatment responsiveness. The response rate among nasopharyngeal cancer (NPC) patients was 74.8%, and that among non-NPC cancer was 65.6%, without significant intergroup differences. The statistical analysis revealed no significant influence of age, gender, or disease stage on treatment responsiveness. Post-treatment salivary amylase levels were significantly higher in responsive non-NPC patients. In conclusion, salivary ductal steroid irrigation emerged as a promising therapeutic modality for the management of post-irradiation xerostomia in head and neck cancer patients. While no explicit factors were predictive of responsiveness, the high rate of symptom improvement suggests that this therapy may be a viable alternative for patients that are refractory to standard treatments.

Chronic Phenotypes Underlying Radiation-Induced Salivary Gland Dysfunction.

Head and neck cancer (HNC) is the sixth most diagnosed cancer, and treatment typically consists of surgical removal of the tumor followed by ionizing radiation (IR). While excellent at controlling tumor growth, IR often damages salivary glands due to their proximity to common tumor sites. Radiation damage to salivary glands results in loss of secretory function, causing severe and chronic reductions in salivary flow. This leads to the patient-reported sensation of dry mouth, termed xerostomia, which significantly reduces quality of life for HNC patients and survivors. The mechanisms underlying salivary gland damage remain elusive, and therefore, treatment options are scarce. Available therapies provide temporary symptom relief, but there is no standard of care for permanent restoration of function. There is a significant gap in understanding the chronic mechanistic responses to radiation as well as treatments that can be given in the months to years following cessation of treatment. HNC cases are steadily rising; particularly, the number of young patients diagnosed with nonfatal human papillomavirus + HNC continues to increase. The growing number of HNC diagnoses and improved prognoses results in more people living with xerostomia, which highlights the mounting need for restorative treatments. Mechanisms underlying chronic damage include decreases in acinar differentiation markers, increases in acinar cell proliferation, immune and inflammatory dysregulation, and metabolic changes including increases in amino acids and reductions in glycolysis and oxidative phosphorylation, fibrosis, and dysregulated neuronal responses. Currently, promising treatment options include adenoviral gene transfers and stem cell therapy. Thus, this review describes in depth known mechanisms contributing to chronic damage and discusses therapeutic advances in treating chronically damaged glands. Understanding the chronic response to radiation offers potential in development of new therapeutics to reverse salivary gland damage and improve the quality of life of HNC survivors.

Long-term follow-up of protective effects on salivary and swallowing structures and improvement of late xerostomia and dysphagia by level IIb optimisation in clinical target volume of nasopharyngeal carcinoma.

BACKGROUND: This study aimed to assess the long-term effect of level IIb clinical target volume (CTV) optimisation on survival, xerostomia, and dysphagia in patients with nasopharyngeal carcinoma (NPC). METHODS: Clinical data of 415 patients with NPC treated with intensity-modulated radiotherapy between December 2014 and October 2018 were retrospectively analysed. The patients were categorised into modified and comparison groups. Late xerostomia and dysphagia were evaluated using Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer scoring. Survival analysis was performed using the Kaplan-Meier method. Differences in late toxicity and dose parameters between both groups were compared. Prognostic factors for survival and late toxicity were assessed using regression analyses. RESULTS: Patients in the modified group developed late xerostomia and dysphagia less frequently than those in the comparison group did (P < 0.001). The mean dose (Dmean) and V26 of parotid glands; Dmean and V39 of submandibular glands; and Dmean of sublingual glands, oral cavity, larynx, and superior, middle, and lower pharyngeal constrictor muscles were lower in the modified group than those in the comparison group (all P < 0.001). Both groups had no significant differences in overall, local recurrence-free, distant metastasis-free, or progression-free survival. The Dmean of the parotid and sublingual glands was a risk factor for xerostomia. The Dmean of the parotid and sublingual glands and middle pharyngeal constrictor muscle was a risk factor for dysphagia. CONCLUSIONS: Level IIb optimisation in NPC patients who meet certain criteria specially the exclusion of positive retropharyngeal nodes treated with intensity-modulated radiotherapy has the potential to better protect the salivary and swallowing structures, decreasing the development of late radiation-induced xerostomia and dysphagia while maintaining long-term survival.

Potential predictive value of IVIM MR for xerostomia in nasopharyngeal carcinoma.

BACKGROUND AND PURPOSE: Xerostomia, caused by radiation-induced parotid damage, is the most commonly reported radiotherapy (RT) complication for nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the value of intravoxel incoherent motion (IVIM) MR in monitoring radiation-induced parotid gland damage and predicting the risk of xerostomia. METHODS: Fifty-four NPC patients were enrolled and underwent at least three IVIM MR scans: before (pre-RT), after 5 fractions of (5th-RT), halfway through (mid-RT), and after RT (post-RT). The degree of xerostomia patients was assessed before each MR examination. Furthermore, the time when patients first reported xerostomia symptoms was recorded. The changes in IVIM parameters throughout RT, as well as the relationships between IVIM parameters and xerostomia, were analysed. RESULT: All IVIM parameters increased significantly from pre-RT to post-RT (p < 0.001). The rates of D, D* and f increase increased significantly from pre-RT to mid-RT (p < 0.001), indicating that cell necrosis mainly occurs in the first half of RT. In multivariate analysis, N3 (p = 0.014), pre-D (p = 0.007) and pre-D* (p = 0.003) were independent factors influencing xerostomia. D and f were significantly higher at 5th-RT than at pre-RT (both p < 0.05). IVIM detected parotid gland injury at 5th-RT at an average scanning time of 6.18 ± 1.07 days, earlier than the 11.94 ± 2.61 days when the patient first complained of xerostomia according to the RTOG scale (p < 0.001). CONCLUSIONS: IVIM MR can dynamically monitor radiation-induced parotid gland damage and assess it earlier and more objectively than RTOG toxicity. Moreover, IVIM can screen people at risk of more severe xerostomia early.

Analysis of the Parotid Glands on an Energy Spectrum CT Iodine Map to Evaluate Irradiation-Induced Acute Xerostomia in Patients With Nasopharyngeal Carcinoma.

Objective: This prospective study aims to evaluate acute irradiation-induced xerostomia during radiotherapy by utilizing the normalized iodine concentration (NIC) derived from energy spectrum computed tomography (CT) iodine maps. Methods: In this prospective study, we evaluated 28 patients diagnosed with nasopharyngeal carcinoma. At 4 distinct stages of radiotherapy (0, 10, 20, and 30 fractions), each patient underwent CT scans to generate iodine maps. The NIC of both the left and right parotid glands was obtained, with the NIC at the 0-fraction stage serving as the baseline measurement. After statistically comparing the NIC obtained in the arterial phase, early venous phase, late venous phase, and delayed phase, we chose the late venous iodine concentration as the NIC and proceeded to analyze the variations in NIC at each radiotherapy interval. Using the series of NIC values, we conducted hypothesis tests to evaluate the extent of change in NIC within the parotid gland across different stages. Furthermore, we identified the specific time point at which the NIC decay exhibited the most statistically significant results. In addition, we evaluated the xerostomia grades of the patients at these 4 stages, following the radiation therapy oncology group (RTOG) xerostomia evaluation standard, to draw comparisons with the changes observed in NIC. Results: The NIC in the late venous phase exhibited the highest level of statistical significance (P < .001). There was a noticeable attenuation in NIC as the RTOG dry mouth grade increased. Particularly, at the 20 fraction, the NIC experienced the most substantial attenuation (P < .001), a significant negative correlation was observed between the NIC of the left, right, and both parotid glands, and the RTOG evaluation grade of acute irradiation-induced xerostomia (P < .001, r = -0.46; P < .001, r = -0.45; P < .001, r = -0.47). The critical NIC values for the left, right, and both parotid glands when acute xerostomia occurred were 0.175, 0.185, and 0.345 mg/ml, respectively, with AUC = 0.73, AUC = 0.75, and AUC = 0.75. Conclusion: The NIC may be used to evaluate changes in parotid gland function during radiotherapy and acute irradiation-induced xerostomia.

Parkinson's disease - The dentist's role as part of the healthcare team.

Parkinson's disease is a neurodegenerative disease that results in patients exhibiting uncontrolled movements, changes in saliva production, and difficulty in swallowing and speech. Understanding the staging of the disease and the available therapies allows dentists to treat these patients safely and with compassion to meet their oral health care needs for an optimal quality of life. This appraisal discusses Parkinson's disease as it relates to clinically relevant facts to manage and treat the oral health care needs of these patients in the short and long term including general dental care recommendations. Important observations related to Parkinson's disease include disease causation,; stages, pharmacologic treatment, the effects on saliva, mastication, dysphagia, and aspiration pneumonia. Dental recommendations are made for the dentate, the partially edentulous, and the completely edentulous Parkinson's patients with a focus on late-stage concerns. Optimizing dental health will help maintain the quality of life as the disease progresses. In late stages of Parkinson's disease, dental treatment should focus on keeping the patient comfortable and out of pain.  While benign neglect is an often-used term, compassionate therapy in the late stages of Parkinson's disease is a more compelling term for defining the patient's needs.  Since dysphagia in Parkinson's patients has been underdiagnosed, neurologists must be aware of the important part that dentists play in the early diagnosis for these patients.  Early referral to a dentist is vital to mitigate the unfortunate consequence of the need for extensive dental care in late-stage patients.