The mouth during cancer treatment: mucositis, dry mouth and osteonecrosis
- Mouth and systemic disease
Chemotherapy and head and neck radiotherapy damage the mouth. A dental check before treatment prevents many complications.
What it is
Chemotherapy and radiotherapy to the head and neck cause oral mucositis, painful ulceration that limits eating and can open the way to infection, usually starting a week or two into treatment. Radiotherapy also destroys salivary glands (often permanently), causes rampant «radiation caries», trismus from fibrosis, altered taste and, most seriously, osteoradionecrosis: dead bone in the irradiated jaw, usually the mandible, often after an extraction. Bone-modifying drugs used in cancer (high-dose bisphosphonates, denosumab) can cause medication-related osteonecrosis of the jaw. Neutropenia brings severe candidiasis, herpes and dental infections.
Oral findings
- Before treatment: dental assessment and removal of infected or hopeless teeth with time to heal.
- Mucositis: basic oral care, bland rinses, pain control; specialised measures per oncology protocols.
- After radiotherapy: lifelong high-fluoride toothpaste and frequent dental review.
- Osteoradionecrosis risk is lifelong; extractions in irradiated bone need specialist planning.
- Jaw exercises reduce radiation trismus.
What the doctor does
- Exposed bone in an irradiated jaw or in a patient on antiresorptives must not be treated by routine extraction.
- Candidiasis and herpes in neutropenic patients can spread systemically.
- Dry mouth after radiotherapy makes dentures hard to wear and caries progresses fast.
Next step / Initial management
- Refer every patient due for head and neck radiotherapy, high-dose antiresorptives or chemotherapy to the dentist before starting.
- During treatment: oral care plan with the oncology team; treat candidiasis and herpes promptly.
- Exposed bone, non-healing sockets, swelling or numbness in the jaw: refer to oral and maxillofacial surgery.
Test yourself
Think of the answer, then tap the question to see it.
What is osteoradionecrosis?
Death of irradiated bone, usually the mandible, that fails to heal and is exposed, often after an extraction.
Why is a dental assessment done before head and neck radiotherapy?
To remove infected or hopeless teeth while healing is still possible and reduce later osteoradionecrosis and infection.
What lifelong measure protects teeth after head and neck radiotherapy?
Daily high-fluoride toothpaste or gel and frequent dental review.
Elsewhere in DurgiPedia
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In Pharmacology4
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Oral Mucositis (StatPearls Publishing (NCBI Bookshelf), 2023); Oral Management of Patients Undergoing Radiation Therapy (StatPearls Publishing (NCBI Bookshelf), 2023); Mandible Osteoradionecrosis (StatPearls Publishing (NCBI Bookshelf), 2026); Bisphosphonate-Related Jaw Osteonecrosis (StatPearls Publishing (NCBI Bookshelf), 2023).
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Representative model, for educational purposes only.