This prospective observational study evaluates how head and neck radiotherapy affects oral health over time. Patients with head and neck cancer undergoing standard radiotherapy are followed from before treatment through multiple post-treatment visits. Changes in periodontal health, dental status, salivary function, and patient-reported oral health quality of life are assessed. The study aims to better understand the long-term oral complications of radiotherapy and to support improved preventive and supportive dental care for cancer patients.

This prospective longitudinal cohort study investigates the effects of head and neck radiotherapy on periodontal health, dental outcomes, salivary gland function, and oral health-related quality of life.

Adult patients with histologically confirmed head and neck malignancies scheduled to receive external beam radiotherapy are enrolled and followed longitudinally. Clinical assessments are conducted at baseline prior to radiotherapy, at the end of radiotherapy, and at 3, 6, and 12 months post-treatment.

Periodontal evaluation includes clinical attachment level, probing pocket depth, plaque index, gingival index, and bleeding on probing, recorded at six sites per tooth using standardized periodontal examination protocols. Dental outcomes include decayed, missing, and filled teeth index, radiation-associated caries incidence, and tooth mobility. Salivary gland function is assessed using unstimulated whole saliva collection. Patient-reported outcomes include xerostomia severity and oral health-related quality of life using validated questionnaires.

Radiotherapy characteristics including technique, total dose, fractionation schedule, mandibular field involvement, and concurrent chemotherapy are recorded. Longitudinal changes in oral health outcomes are analyzed to identify patterns of disease progression and potential predictors of radiotherapy-related oral complications.

This study aims to generate clinical evidence to improve preventive strategies, early detection, and supportive oral care protocols for patients receiving head and neck radiotherapy.

Inclusion Criteria:

• Age ≥18 years
• Histologically confirmed head and neck malignancy
• Planned radiotherapy dose ≥50 Gy
• Presence of at least 20 natural teeth
• No periodontal treatment during the preceding 6 months
• Ability to comply with the scheduled follow-up visits

Exclusion Criteria:

• Previous head and neck radiotherapy
• Autoimmune salivary gland disorders
• Current bisphosphonate or anti-resorptive therapy
• Pregnancy
• Uncontrolled systemic disease (HbA1c >9% for diabetic patients)
• Severe periodontal destruction requiring immediate surgical intervention

Adult patients with head and neck cancer receiving external beam radiotherapy at a tertiary referral hospital who are followed longitudinally for oral and periodontal health outcomes.