Clinically, early-stage oral cancers are difficult to distinguish from oral potentially malignant disorders (OPMDs), and invasive tissue biopsy should be performed to determine a treatment strategy. Previously, we focused on gargle fluid as a noninvasive testing method and reported aberrant methylation in gargle fluid in patients with oral cancer. This study aimed to distinguish early-stage oral cancer from clinically diagnosed OPMDs using gargle fluid samples. We collected gargle fluid samples from 40 patients who were clinically diagnosed with OPMDs in the training set; among them, 9 patients were pathologically diagnosed with oral cancer. Methylation levels of 25 tumor suppressor genes were analyzed using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) method. We found that a combination of six genes (TP73, CASP8, RARB, KLLN, GSTP1, and CHFR) could distinguish oral cancer from clinically diagnosed OPMDs with high diagnostic performance (area under the curve [AUC], 0.885; sensitivity, 77.8%; and specificity, 87.1%). Additionally, the panel comprised of the six methylated genes was validated in the test set. Furthermore, when compared with cytology testing, the panel could accurately detect oral cancer. The present methylated gene panel may serve as a novel biomarker for oral cancer.

Background/Objectives: The population of Japan has a high life expectancy, but there is room for improvement in terms of the country’s healthy life expectancy. The long period of care dependency among Japan’s elderly is also a major economic health challenge. Dementia is a major factor in the need for care, and its prevention is a crucial and urgent challenge. There are recent reports of a possible association between changes in oral function and cognitive impairment, but the details of this association remain unclear. To clarify the relationship between poor oral function and cognitive impairment, we conducted an exploratory investigation using a cognitive function assessment (Mini-Cog) administered in a large-scale study and its relevance to oral function. Methods: The study population was 678 community-dwelling individuals aged ≥65 years living in Tarumizu city, Japan, in 2019. Cognitive function was assessed using the Mini-Cog test, and the oral survey was a modification of the content of the Oral Hypofunction Examination as defined by the Japanese Society of Gerodontology. Results: The participants’ median age was 73 years. The oral function results revealed median scores below the oral hypofunction criterion for occlusal force, tongue pressure, oral diadochokinesis, and swallowing function. The results of a binomial logistic regression analysis indicated that tongue–lip motor function was independently associated with oral function in relation to cognitive impairment. Conclusions: The oral function associated with cognitive impairment in this study was tongue–lip motor function. Aiming to improve this function may prevent the exacerbation of cognitive impairment.