Self-reported periodontitis association with impaired smell and taste: A multicenter survey.

OBJECTIVES: To investigate the association between self-reported periodontitis and the senses of taste and smell among employees of one Danish and two American universities. MATERIALS AND METHODS: Data were collected through a digital survey. A total of 1239 individuals from Aarhus University - Denmark, the University of Iowa, and the University of Florida - USA were included. Self-reported periodontitis was the exposure. The perceived senses of taste and smell were the outcomes and were measured through a visual analog scale (VAS). Self-perceived halitosis was the mediator. Confounders were age, sex, income, education, xerostomia, COVID-19, smoking, body mass index, and diabetes. The total effect was decomposed into direct and indirect using a counterfactual approach. RESULTS: The total effect of periodontitis on an impaired sense of taste was OR 1.56 (95% CI [1.02, 2.09]), of which 23% was mediated by halitosis (OR 1.13; 95% CI [1.03, 1.22]). Additionally, individuals with self-reported periodontitis had a 53% higher chance of having impaired smell (OR 1.53; 95% CI [1.00, 2.04]), with halitosis mediating 21% of the total effect (OR 1.11; 95% CI [1.02, 1.20]). CONCLUSION: Our findings suggest that periodontitis is associated with distorted senses of taste and smell. Additionally, this association appears to be mediated by halitosis.

Chemosensory loss in COVID-19.

The COVID-19 pandemic caused by SARS-CoV-2 virus quickly spread globally, infecting over half a billion individuals, and killing over 6 million*. One of the more unusual symptoms was patients' complaints of sudden loss of smell and/or taste, a symptom that has become more apparent as the virus mutated into different variants. Anosmia and ageusia, the loss of smell and taste, respectively, seem to be transient for some individuals, but for others persists even after recovery from the infection. Causes for COVID-19-associated chemosensory loss have undergone several hypotheses. These include non-functional or destroyed olfactory neurons and gustatory receptors or of their supporting cells, disruption of the signaling protein Neuropilin-1, and disruption in the interaction with semaphorins, key molecules in the gustatory and olfactory axon guidance. The current paper will review these hypotheses and chart out potential therapeutic avenues.

Systematic review and meta-analysis of olfactory and gustatory dysfunction in COVID-19.

BACKGROUND: Chemosensory disorders associated with COVID-19 have been widely discussed during the pandemic. We performed a meta-analysis to assess the risk factors for olfactory and gustatory dysfunction in patients with COVID-19. METHODS: Three databases (PubMed, Embase, and Cochrane Library) were searched for studies published between December 1, 2019, and August 31, 2021. We selected random-effects model or fixed-effects model to pool data based on heterogeneity. The results were reported as odds ratios (ORs) or standardized mean differences (SMDs) and the corresponding 95% confidence intervals (CIs). Heterogeneity was reported as I2. RESULTS: Twenty-six studies with a total of 13,813 patients were included. The pooled data indicated that sex (OR 1.47; 95% CI 0.93-2.31), age (SMD -5.80; 95% CI -13.35 to 1.75), smoking (OR 2.04; 95% CI 0.72-5.79), and comorbidity (OR 1.21; 95% CI 0.58-2.53) of patients with COVID-19 had no effect on gustatory dysfunction. Olfactory dysfunction was more likely to occur in older patients with COVID-19 (SMD, -5.22; 95% CI, -8.28 to -2.16). Patients with COVID-19 with nasal congestion (OR 3.41; 95% CI 2.30-5.06) and rhinorrhea (OR 2.35; 95% CI 1.60-3.45) were more prone to olfactory dysfunction. CONCLUSION: These findings emphasize that older patients with COVID-19 are more likely to experience olfactory dysfunction. Symptoms of nasal congestion and rhinorrhea may affect the recognition of olfactory dysfunction.

Olfactory and Gustatory Dysfunction in COVID-19 Patients from Northern India: A Cross-Sectional Observational Study.

Olfactory dysfunction (OD) and gustatory dysfunction (GD) has been reported as one of the presenting symptoms amongst COVID-19 patients. However the literature available is disjunct on this aspect. This study is conducted to identify the prevalence of olfactory and/or gustatory dysfunction in patients with coronavirus disease in Northern part of India. It's a cross-sectional observation study, conducted over 387 COVID-19 positive patients, at ENT dept of tertiary care hospital. A retrospective survey was conducted using a pre designed questionnaire and details of Olfactory and Gustatory dysfunction was collected. The patient's demographic details, disease course and recovery time for olfactory (OD) and/or gustatory dysfunctions (GD) were collected. A total of 387 patients with COVID-19 completed the study. 228 (58.9%) patients suffered from influenza like illness (ILI) (fever, sore throat, dry cough, malaise, and myalgia). There was significant positive association seen between with ILI and OD and / or GD. 167/387 (43.15%) patients reported OD, and 153/387 (39.53%) reported GD. 43.71% and 50.3% patients had mild OD & GD respectively. Recovery rates for both OD and GD are high and almost similar, with 161 (96.4%) and 148 (96.73%) patients had complete recovery of smell and taste. Maximum recovery was noticed between 4 and 6 weeks. COVID-19 patients with habits have significantly high probability of developing OD &/or GD. There is a significant correlation between OD and GD and there is high probability that patients who reported to have OD will also have GD or vice versa. Prevalence of OD and GD in Indian population may not be as high as mentioned in western literature, however, both are frequent and early symptoms of COVID-19. Recent onset of these should be considered as red flag symptoms for COVID-19.