History of head and neck radiation therapy

Oral health effects

• Jawbone breakdown after radiation (osteoradionecrosis, ORN) risk

  Exposed, non-healing irradiated bone (most often the mandible) is typically precipitated by extraction or trauma within the radiation field. Risk peaks around 3–12 and 24–60 months post-treatment but persists for decades.

  Mechanism: Radiation produces hypovascular, hypocellular, hypoxic bone with severely impaired healing capacity.

  Clinical management: Avoid elective extractions within the radiation field when possible; ideally extract non-restorable teeth before radiotherapy begins; coordinate any necessary extraction with radiation oncology/oral surgery.

• Severe, often permanent xerostomia

  Major salivary gland tissue is highly radiosensitive, and radiation-induced dry mouth is frequently severe and long-lasting.

  Clinical management: Aggressive fluoride therapy, saliva substitutes/stimulants, and frequent recall.

• Rapid tooth decay after radiation (radiation caries)

  Rapid-onset, often circumferential caries driven by xerostomia and dietary shifts during treatment.

  Clinical management: Daily high-fluoride trays and dietary counseling.

• Limited mouth opening (trismus)

  Progressive limitation of mouth opening from fibrosis of the masticatory muscles and TMJ within the radiation field.

  Clinical management: Early referral for jaw-stretching devices or physical therapy.

• Painful mouth sores during radiation (oral mucositis)

  Radiation inflames and ulcerates the mouth lining during treatment, peaking in the later weeks of therapy and usually healing within weeks after it ends; it is the most frequently reported oral complication of head and neck cancer treatment.

  Clinical management: For patients seen during or just after radiotherapy, use gentle instrumentation, avoid irritating products (alcohol mouthrinses, strong flavours), recommend bland rinses (saline/bicarbonate), coordinate with the oncology team on pain control and any photobiomodulation, and defer elective care while ulceration is active.

• Taste loss or changed taste (dysgeusia)

  Nearly all patients have taste disturbance during radiotherapy; most recover partially, but about a quarter have long-term taste dysfunction, which contributes to weight loss and poor diet choices.

  Clinical management: Ask about taste changes and appetite; reinforce that sugary or acidic foods used to compensate raise radiation-caries risk; give dietary counselling alongside daily high-fluoride use and refer to the dietitian/oncology team if weight loss is evident.

• Oral thrush and other fungal infections (oral candidiasis)

  Head and neck radiotherapy independently increases the risk of clinical oral fungal infection, which is common during and after treatment, especially with dry mouth and dentures.

  Clinical management: Check for white wipeable plaques, redness and angular cheilitis at each visit; have patients clean and remove dentures overnight; refer for antifungal therapy when infection is present.

• Swallowing difficulty (dysphagia)

  Fibrosis and nerve/muscle damage after radiation commonly impair swallowing, raising the risk of aspirating water, debris, and dental materials.

  Clinical management: Seat the patient more upright, use high-volume suction and minimal water spray, avoid letting irrigants pool, and ask whether they are under speech-language pathology care.