Background/Objectives: A retrospective study was conducted to clarify the clinical characteristics of taste disorder cases at the Department of Oral Medicine of Hokkaido University Hospital. The subjects were 322 taste disorder patients (86 male, 236 female, average age: 66 (13.1) years, mean duration of disorder: 15.2 (20.0) months) who were treated at our department from 2007 to 2018. Methods: Associations between symptoms and classification were examined. Results: When looking at the taste symptoms, 154 cases of quantitative taste disorder were observed as taste loss, abscission, and dissociative taste disorder, and 168 cases of qualitative taste disorder were observed as spontaneous abnormal taste, dysgeusia, and maltaste. There was no relationship between sex and quantitative/qualitative taste disorders at V = 0.08. When looking at the causes of taste disorders, the majority were psychogenic, idiopathic, and oral diseases. Conclusions: Approximately 20% of taste disorders are caused by oral diseases, so it should be noted that oral diseases such as oral candidiasis and xerostomia can cause taste disorders and that many of them can be improved with oral treatment.

Background The activity level of alkaline phosphatase, a zinc-requiring enzyme in the serum, is used to indicate zinc nutritional status; however, it does not correlate with serum zinc levels or subjective symptoms of taste disorder in many cases. Hence, this study focused on the total activity of alkaline phosphatase, a zinc-requiring enzyme. The total alkaline phosphatasa activity level in the saliva was measured before and after zinc supplementation, and the results were compared with serum zinc levels.Case presentation This study included patients with hypozincemia, specifically a patient with zinc-deficient taste disorder (patient 1: a 69-year-old Japanese woman) and a patient with glossodynia with zinc deficiency (patient 2: an 82-year-old Japanese woman). Saliva samples were collected, and blood tests were performed before and after zinc supplementation. Subjective symptoms and serum zinc levels were simultaneously evaluated. Zinc supplementation was performed using zinc acetate hydrate or Polaprezinc.Conclusions Total alkaline phosphatase activity levels were found to be associated with serum zinc levels and subjective symptoms. A further study with a higher number of patients is necessary to confirm whether total alkaline phosphatase activity levels more accurately reflect the amounts of zinc in the body than serum zinc levels.

Background: Burning mouth syndrome (BMS) is a chronic orofacial pain disorder. The etiology and pathophysiology of BMS remain unclear; multiple factors may interact in complex ways. There is a need for simpler and more cost-effective BMS evaluation criteria. This study aimed to evaluate the reliability and validity of the Short Form McGill Pain Questionnaire version 2 (SF-MPQ-2) in patients with BMS and develop a subscale based on factor analysis of the results to classify patients per their symptoms. Methods: Several factors such as patient characteristics (age, sex, smoking habit, and medical history), the SF-MPQ-2 (original: eleven-point rating scale and modified: four-point rating scale), and the numerical rating scale (NRS) of BMS were examined and analyzed. Results: In total, 38 patients were enrolled. Cronbach’s alpha was 0.93 (0.88–0.96) and 0.83 (0.74–0.90) for the SF-MPQ-2 (original) and SF-MPQ-2 (Modified), respectively. Only the correlation between the NRS and the SF-MPQ-2 (Modified) reached statistical significance. These results showed that the SF-MPQ-2 (Modified) were more reliable than the SF-MPQ-2 (Original). Factor analysis led to classification into three new factors. Conclusions: SF-MPQ-2 was useful for BMS. In current clinical practice, the modified questionnaire may yield similar or better results, and a more precise treatment strategy can be pursued by classifying responses according to the proposed subscales and examining treatment effects.

Burning mouth syndrome (BMS) is a chronic oral pain disorder. There is a theory that BMS is a form of nociplastic pain. A standard treatment for BMS has not yet been established. Kampo medicine is a traditional oriental medicine. The purpose of this study is to evaluate the effectiveness of Rikkosan—a traditional Japanese herbal medicine (Kampo)—in the treatment of BMS. A single-center retrospective study was conducted on 20 patients who were diagnosed with BMS and treated with Rikkosan alone (total daily dose; 7.5 g) three times daily for approximately 4 weeks (29.5 ± 6.5 days). Rikkosan was dissolved in hot water and taken internally. They had an average age of 63 years, and 90% were being treated for other illnesses, but their medication status was the same during this study period, except for Rikkosan. No adverse events were observed in patients. Numerical rating scale (NRS) or visual analog scale (VAS)/10 scores decreased significantly between the time of the initiation of Rikkosan and one month after (−2.1 ± 1.2, p < 0.05). Rikkosan has a short-term effect of reducing NRS by two levels in BMS patients.

The relationships among bacterial flora, diseases, and diet have been described by many authors. An operational taxonomic units (OTUs) are the result of clustering the 16S rRNA gene sequences at a certain cutoff value, and they are considered compositional data. As Pearson’s correlation coefficient is difficult to interpret, Aitchison’s ratio analysis was used to develop a method to handle compositional data. Multivariate analysis was developed because univariate analysis can be subject to large biases. Simulations regarding absolute abundance based on certain assumptions and some analyses, such as nonparametric multidimensional scaling (NMDS), principal component analysis (PCA), and ratio analysis, were conducted in this study. The same content as a 100% stacked bar graph could be expressed in low dimensions using PCA. However, the relative diversity was not reproducible with NMDS. Various assumptions were made regarding absolute abundance based on the relative abundance. However, which assumptions are true could not be determined. In summary, ratio analysis and PCA are useful for analyzing compositional data and the gut microbiota.

Our understanding of the relationship between oral Candida and systemic conditions has significantly increased recently, which this study aims to extend further by investigating the risks of oral candidiasis. A total of 314 patients were involved in this study and underwent an oral swab test at the Department of Oral Medicine, Hokkaido University Hospital, between January and December 2021. Data were collected on age, sex, white and red blood cell counts, Hb, total protein, vitamin B12, as well as serum albumin, iron, copper, and zinc levels. The clinical fungus samples were swabbed to identify those with Candida species using a MALDI Biotyper, then applied analysis of covariance and multivariant logistic regression analysis. It was possible to assess the oral swab test results without considering the difference between sex (p = 0.946). The oral swab test results were associated with aging (odds ratio: 1.03) and serum albumin levels (odds ratio: 0.32). In summary, the results of our study suggest a relationship between aging and oral candidiasis and offer in-depth insights into how to prevent or treat oral candidiasis onset.