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

Oral diseases, including oral squamous cell carcinoma (OSCC), periodontal disease, and dental caries, are common conditions that can significantly affect oral health and quality of life. Early identification of individuals at risk and accurate prediction of disease progression are important for improving prevention, treatment planning, and long-term outcomes. However, current approaches mainly rely on clinical signs and symptoms, and there is still a need for reliable biological markers that can support earlier detection and better prediction of disease changes over time.

This observational cohort study aims to establish a comprehensive clinical and biological resource for the discovery and evaluation of markers associated with major oral diseases. The study will combine standardized oral examinations, health information collection, biological sample collection, and long-term follow-up to investigate factors associated with disease presence, severity, progression, and treatment outcomes.

Participants will undergo standardized oral health examinations and provide information related to their general health, oral health behaviors, and medical history. Biological samples, including saliva and mouth rinse samples, will be collected from participants to study changes associated with oral diseases. Additional samples, including blood samples, may be collected when appropriate. Oral lesion-related samples will only be collected from participants with oral squamous cell carcinoma (OSCC) when clinically indicated as part of their routine diagnostic or treatment procedures. Participants without OSCC, including those with periodontal disease, dental caries, or healthy oral conditions, will not undergo oral tissue biopsy for this study.

Participants will be followed over time to collect information on changes in oral health status and clinically relevant outcomes. Follow-up assessments may include repeated clinical examinations, questionnaires, and biological sample collection according to the study plan. The collected clinical information and biological samples will be analyzed to identify markers that may help improve early detection, disease risk assessment, and prediction of future disease progression.

The long-term goal of this study is to support the development of improved approaches for early detection and personalized risk assessment of major oral diseases. The clinical data and biological sample resources generated from this cohort may also support future research into the mechanisms underlying oral disease development and response to treatment.

• Step 1 and 2 periodontal therapy according to the EFP clinical practice guidelines (Procedure): Standard of care treatment
• Dental filling with or without root canal treatment (Procedure): Standard of care treatment with a composite filling material
• Oral cancer surgical resection including extension, dissection and reconstruction with adjunctive radiation, chemotherapy and/or biological treatments per international guidelines, (Procedure): All the necessary surgical procedures to remove the primary oral cancer tumour from the oral cavity, including the necessary dissection and plastic reconstructive surgery. All necessary adjunctive treatments, including radiation, chemotherapy and/or biological therapies.

Primary outcomes

• Diagnostic accuracy to detect oral diseases [At baseline assessment]: The diagnostic accuracy will be measured as the area under the receiver operating characteristic curve (AUC). Clinical diagnosis will be the reference standard and will be performed by calibrated examiners in accordance with international case-definition standards.

Secondary outcomes

• Sensitivity to detect oral diseases [At baseline assessment]: Sensitivity will be calculated using clinical diagnosis as the reference standard as defined by calibrated examiners in accordance with international case-definition standards
• Specificity to detect oral diseases [At baseline assessment]: Specificity will be reported as the proportion of participants without oral diseases correctly classified by the test. The reference standard will be clinical diagnosis performed by calibrated examiners in accordance with international case definition standards.
• Hazard ratio of oral disease progression [up to 48 months of follow-up]: The hazard ratio (HR) for oral disease progression will be estimated using survival analysis methods. The progression of oral disease will be assessed using longitudinal changes in standardized clinical parameters and tooth loss. The reference standard will be clinical diagnosis performed by calibrated examiners in accordance with international case definition standards.
• Hazard ratio of oral squamous cell carcinoma metastasis [up to 48 months of follow-up]: The hazard ratio (HR) for oral squamous cell carcinoma (OSCC) metastasis will be estimated using survival analysis methods. Metastasis will be assessed based on clinical and imaging evaluations during follow-up by calibrated examiners and following international standards.

Sex: All, ages: 18 Years to any, accepts healthy volunteers

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.