Discovery and Validation of Biomarkers for Periodontitis, Dental Caries and Oral Squamous Cell Carcinoma

The goal of this observational study is to develop better ways to detect and predict major oral diseases, including oral cancer, gum disease, and tooth decay. This study will collect detailed oral health information and biological samples from adults with different oral health conditions and healthy participants to identify markers that may help doctors detect diseases earlier and predict how diseases may change over time. The main questions this study aims to answer are whether biological markers from saliva, mouth rinse samples, blood, or oral tissue samples can help identify people with oral diseases, whether these markers can predict future disease changes such as worsening gum disease, new or progressing tooth decay, or recurrence and spread of oral cancer, and whether combining clinical information with biological markers can improve disease detection and risk prediction. Participants will receive a standard oral health examination, provide information about their health history and oral health behaviors, provide biological samples when appropriate, and be followed over time through clinical visits, questionnaires, and health information collection. Researchers will compare findings among people with different oral health conditions and healthy participants to better understand disease-related changes and develop tools for earlier detection and prediction of oral disease outcomes.

Inclusion Criteria: Participants must meet all of the following criteria: 1. Adults aged 18 years or older. 2. Able to understand the study information and provide written informed consent. 3. Meet the criteria for one of the study groups based on clinical evaluation and disease assessment, including: Oral squamous cell carcinoma (OSCC); Periodontal disease; Dental caries; Oral health without the corresponding diseases (healthy controls). Exclusion Criteria: Participants will be excluded if they meet any of the following criteria: 1. Edentulous individuals. 2. History of radiotherapy to the head and neck region. 3. Presence of immunodeficiency conditions (for example, human immunodeficiency virus infection). 4. Pregnancy.