Association between Toothbrushing and Cancer Risk.

Background: Most cancers are lifestyle-related and are thus preventable. Lifestyle habits can be improved by individual efforts; for example, because oral health is suggested to play a preventive role in cancer risk, toothbrushing is considered a critical and fundamental measure for controlling oral health. This study aimed to investigate the association between toothbrushing and cancer risk. Methods: Cross-sectional data from the Japan COVID-19 and Society Internet Survey, a large-scale (n = 32,000) online survey conducted in 2022, were used. From September 12 to October 19, 2022, questionnaires were distributed to candidates selected by simple random sampling from a Japanese Internet research company's panelists to represent the Japanese population. The association between toothbrushing and cancer risk according to cancer prevalence was then analyzed. Results: Among all 32,000 participants, 2,495 (7.8%) who had any cancer previously were analyzed. Multivariable logistic regression analysis revealed a significant association between toothbrushing habit and cancer risk. Conclusion: The findings of this study suggest that daily toothbrushing is essential for maintaining oral health and preventing cancer.

Is discontinuation of dental treatment related to exacerbation of systemic medical diseases in Japan?

Aims Since it is known that oral problems affect various medical diseases, the effects of restrictions on visits for dental treatment on exacerbations of various systemic medical diseases were examined.Method and materials The data were used from the Japan COVID-19 and Society Internet Survey, a large-scale internet survey conducted in 2021 (n = 28,175). The questionnaires were distributed to 33,081 candidates who were selected to represent the Japanese population regarding age, sex and residential prefecture using a simple random sampling procedure. Patients currently undergoing treatment for diabetes mellitus, hypertension, asthma, cardiocerebrovascular disease, hyperlipidemia, atopic dermatitis, and mental illness, such as depression, were extracted from the total participants. Then, whether discontinuation of dental treatment affected the exacerbation of their systemic disease was examined.Results Overall, 50-60% of patients with each systemic disease had continued to receive dental treatment, and 4-8% of them had discontinued dental treatment. On univariate and multivariate analyses, discontinuation of dental treatment is a risk factor in the exacerbation of diabetes mellitus, hypertensive conditions, asthma, cardiocerebrovascular disease and hyperlipidemia.Conclusion The present epidemiological study showed the relationship between oral health and systemic health, which can provide meaningful insights regarding future medical-dental collaboration in Japan.

Dental Treatment and Risk of COVID-19 in Japan.

PURPOSE: During the Coronavirus Disease 2019 (COVID-19) pandemic, there has been concern about nosocomial infections acquired through dental practice, where machines - such as air turbines - that generate aerosols are used, and where there are many opportunities to come into contact with saliva and blood. Because there is no report to date on whether dental treatment is associated with a risk of SARS-CoV-2 infection in Japan, the aim of the present cross-sectional study was to examine the risk of SARS-CoV-2 infection associated with dental treatment. MATERIALS AND METHODS: Cross-sectional data were gathered from the Japan COVID-19 and Society Internet Survey (JACSIS), a large-scale internet survey conducted in 2021 (n=28,175). From September 27, 2021, to October 30, 2021, the questionnaires were distributed to candidates selected from the panelists of a Japanese Internet research company to represent the Japanese population regarding age, sex, and residential prefecture using a simple random sampling procedure. The risk of SARS-CoV-2 infection related to dental treatment was examined and analysed. RESULTS: Multivariable logistic regression analysis showed that younger age, male sex and living alone were statistically significant factors positively associated with SARS-CoV-2 infection, whereas the presence or absence of dental treatment was not statistically significantly correlated with SARS-CoV-2 infection. CONCLUSION: The present epidemiological study showed that dental treatment is not a positive risk factor for SARS-CoV-2 infection in Japan.

Automatic identification of individuals using deep learning method on panoramic radiographs.

Abstract Background/purpose: The dentition shows individual characteristics and dental structures are stable with respect to postmortem decomposition, allowing the dentition to be used as an effective tool in forensic dentistry. We developed an automatic identification system using panoramic radiographs (PRs) with a deep learning method. Materials and methods: In total, 4966 PRs from 1663 individuals with various changes in image characteristics due to various dental treatments were collected. In total, 3303 images were included in the data set used for model training. Vgg16, Vgg19, ResNet50, ResNet101, and EfficientNet models were applied for identification. The precision curves were evaluated. Results: The matching precision rates of all models (Vgg16, Vgg19, ResNet50, ResNet101, and EfficientNet) were examined. Vgg16 was the best model, with a precision of around 80-90% on 200 epochs, using the Top-N metrics concept with 5-15 candidate labels. The model can successfully identify the individual even with low quantities of dental features in 5-10 s. Conclusion: This identification system with PRs using a deep learning method appears useful. This identification system could prove useful not only for unidentified bodies, but also for unidentified wandering elderly people. This project will be beneficial for police departments and government offices and support disaster responses.

Large lingual heterotopic gastrointestinal cyst in a newborn: A case report.

BACKGROUND: Heterotopic gastrointestinal cysts have gastrointestinal epithelium in the cyst wall and rarely occur in the oral cavity. Most are found in the neonatal period. However, heterotopic gastrointestinal cysts that are diagnosed as a congenital tongue cyst by routine ultrasonography are extremely rare. CASE SUMMARY: A 12-day-old female presented with swelling of the anterior tongue. The obstetrician had detected significant tongue swelling on fetal ultrasonography in the 35th gestational week. The female was born by cesarean delivery at gestational week 39. She soon became dyspneic, and the cyst was aspirated. After the aspiration, her breathing recovered and she started breastfeeding. The cyst was excised under general anesthesia on the 67th day. Histopathologic examination showed that that cyst wall consisted of a lining of columnar gastrointestinal-type epithelium and pseudostratified ciliated epithelium. The patient restarted breastfeeding 3 h after surgery. The postoperative course was uneventful. CONCLUSION: Airway distress and feeding difficulty were successfully avoided by cyst aspiration, and surgical resection was performed with no perioperative complications.

Salivary duct cyst of accessory parotid gland in contact with the temporomandibular joint.

A 60-year-old woman presented with a painless swelling in the right preauricular region. Physical examination revealed a soft, nontender, oval-shaped lump in this location. Computed tomography indicated an anterolateral cystic lesion that was attached to the condyle of the mandible and to the accessory parotid gland. Differential diagnoses included ganglion cyst, synovial cyst of the temporomandibular joint, and accessory parotid gland cyst. Surgical removal of the cyst was performed with the patient under general anesthesia. The specimen was 18 × 20 × 18 mm in size; it contained fluid that was clear, slightly yellow, and amylase positive. Hematoxylin and eosin staining revealed that a bilayer cuboidal epithelium lined the cyst wall. Immunohistochemical analyses of the cyst wall showed strong expression of cytokeratin and weak expression of vimentin. The final diagnosis was a salivary duct cyst. The postoperative course was uneventful except for a transient facial motor paresis.

Use of NRP1, a novel biomarker, along with VEGF-C, VEGFR-3, CCR7 and SEMA3E, to predict lymph node metastasis in squamous cell carcinoma of the tongue.

Lymph node (LN) metastasis has been suggested as a major prognostic factor for oral cancer. Knockdown of the growth factors and receptors involved in these metastatic mechanisms could significantly reduce LN metastasis and improve the survival of oral cancer patients after treatment. The present study, therefore, aimed to evaluate the expression levels of the following growth factors and receptors in squamous cell carcinoma (SCC) of the tongue: the vascular endothelial growth factor (VEGF)­C and VEGF­D, which bind to the cell surface tyrosine kinase receptor VEGF receptor­3 (VEGFR­3); C­C motif chemokine receptor 7 (CCR7); neuropilin (NRP)1 and NRP2; and semaphorin 3E (SEMA3E). Furthermore, we assessed microvessel density (MVD) and lymphatic vessel density (LVD) to demonstrate the correlation between these factors and regional LN metastasis, with respect to the clinicopathological features. Finally, we analyzed the correlation between these proteins and overall or disease­free survival, in order to demonstrate their prognostic value. Univariate analysis revealed a significant association between LN metastasis and the expression levels of VEGF­C, VEGFR­3, CCR7, NRP1, and SEMA3E, as well as LVD, in SCC cells. In contrast, multivariate analysis identified associations between LN metastasis and NRP1 expression, as well as between LN metastasis and LVD; however, no correlation was found between LN metastasis and the expression levels of the other proteins. The expression levels of VEGF­C, VEGFR­3, NRP1, and SEMA3E, as well as LVD, were correlated with disease­free survival time. These results indicate that LN metastasis is associated with poor survival in SCC. This study suggests that NRP1 expression and LVD are independent factors that are likely to predict the risk of LN metastasis in SCC of the tongue, whereas the expression of VEGF­C, VEGFR­3, CCR7, and SEMA3E are non­independent predictive factors.