Circuit 2, station 9

The oral complications of head and neck chemotherapy and radiotherapy are:

Oral Mucositis: One of the most prevalent complications of head and neck RT is oral mucositis, affecting up to 91% of patients. Additionally, chemotherapy contributes to its occurrence in 20 to 40% of cases. The basal layer of the oral epithelium, characterised by its heightened mitotic activity, renders it susceptible to radiation-induced injury, culminating in oral mucositis. Typically, symptoms emerge after the first week of RT initiation and may endure for several months. Clinical presentations encompass erythema, atrophy, swelling, and ulcerations, sometimes concealed by pseudomembranes. Patients contend with debilitating pain, loss of taste, eating and drinking challenges, and speech difficulties, occasionally necessitating parenteral nutrition. The interruption of radiation treatment may become necessary, exerting a profound impact on the overall prognosis of the malignancy. Fortunately, oral mucositis generally resolves within two to three weeks post-completion of radiotherapy.

2. Xerostomia: Xerostomia, characterised by dry mouth, emerges as an anticipated consequence of head and neck RT and may assume irreversible proportions in some cases. Salivary glands’ vulnerability to radiation, even at low doses, results in cell death and fibrosis, culminating in gland dysfunction. This damage leads to hyposalivation (reduced salivary flow) and thickening of saliva, manifesting as xerostomia. This condition poses significant challenges, including speech impairment, difficulty in eating and swallowing, and altered taste perception. Furthermore, reduced salivary flow heightens vulnerability to conditions such as candidiasis, gingivitis, and dental caries.
3. Oropharyngeal Candidiasis: Patients undergoing radiation therapy for head and neck cancer face an elevated risk of fungal infections, largely attributed to reduced salivary flow during radiation therapy and, potentially, a decline in the phagocytic activity of salivary granulocytes. Clinically, radiation-induced oropharyngeal candidiasis may manifest as pseudomembranous, erythematous, or angular cheilitis. Diagnosing the erythematous forms can be challenging, as they may mimic radiation-induced oral mucositis. Oral candidiasis typically presents as a scrapable white pseudomembrane or erythematous patch on the tongue, commissures, and palate. Patients often report a burning sensation in the mouth, dysgeusia (altered taste perception), and halitosis. The incidence of oral candidiasis is influenced by salivary flow rate, oral hygiene status, and the severity of concurrent oral mucositis.
4. Dysgeusia: Dysgeusia, characterised by an unpleasant or abnormal taste alteration, often described as metallic, is a recognized consequence of radiation therapy, alongside infections, head and neck trauma or surgery, and certain medications. This complication afflicts approximately 70% of patients receiving radiotherapy and is closely associated with a diminished appetite and weight loss. Dysgeusia typically emerges during the second or third week of treatment and generally subsides to normal taste perception within 60 to 120 days following the completion of radiotherapy.
5. Radiation-Related Caries: Radiation-related caries represents an aggressive form of tooth decay that affects dental surfaces typically resistant to caries. It predominantly targets the labial surfaces of the cervical areas, and extends to the lingual aspect of lower anterior teeth, which are not conventionally predisposed to caries. Although its precise aetiology remains elusive, it is believed to arise from reduced salivary flow during radiotherapy and direct radiation-induced damage to dental structures. These caries tend to manifest approximately six to twelve months post-head and neck radiation treatment, initially appearing as enamel cracks and fractures that progress into brown-black enamel discoloration. Untreated lesions can advance to incisal-cuspal wear and extensive cervical caries, often necessitating crown amputation.
6. Osteoradionecrosis (ORN): Osteoradionecrosis (ORN) emerges as a late complication of radiation therapy in the head and neck region. It is characterised by necrosis in irradiated bone that persists for a minimum of three months without evidence of tumour recurrence. ORN predominantly afflicts the mandible, with rare instances of occurrence in the maxilla. Risk factors encompass poor oral health and hygiene, pre-existing head and neck radiation surgery, dental procedures, and tobacco and alcohol consumption. The likelihood of ORN escalates with radiation doses exceeding 60 Gy. Clinically, ORN presents as exposed bone with or without mucosal dehiscence. As the condition progresses, intraoral and extraoral fistulae may develop, eventually culminating in pathological fractures.

As such an assessment of Oral and Dental Health is required before commencing cancer therapy, with a thorough assessment of oral and dental health, including radiographic evaluation. The specific objectives of this assessment encompass:

• Identification of pre-existing oral conditions and potential risks.
• Elimination of infectious dental and oral issues prior to initiating cancer therapy.
• Preparation of the patient for anticipated side effects of cancer treatment.
• Establishment of a baseline standard of oral hygiene to address the evolving challenges during cancer treatment.
• Formulation of a comprehensive plan for maintaining oral hygiene, delivering preventive care, completing oral rehabilitation, and establishing a follow-up regimen.
• Creation of the necessary collaborative framework within the cancer centre to mitigate oral symptoms and complications before, during, and after cancer therapy.

Chemotherapy and radiotherapy can give rise to both short-term and long-term oral complications. It is essential to provide practical preventive guidance, emphasising its role in preserving oral comfort during treatment and reducing complications.

Dietary Recommendations: Dietary advice should be provided in collaboration with a dietitian, with a focus on ensuring oral comfort during therapy.

Utilisation of Chlorhexidine: In cases of diagnosed gingival disease, oral hygiene practices can be supplemented with the use of alcohol-free chlorhexidine mouthwash or dental gel.

Periodontal Care: Professional removal of plaque and calculus deposits should be performed to stabilise periodontal disease.

Management of Dental Caries: Whenever possible, carious teeth should be definitively restored or stabilised with suitable dental restorations.

Addressing Dental Trauma: All sharp edges of teeth and restorations should be appropriately adjusted and polished.

Impressions: Mouth impressions are taken to create study casts for the construction of applicator trays and, when necessary, for planning intra-oral radiation stents and obturators.

Dentures and Obturators: Patients using removable prostheses should be educated about their care during cancer therapy. If feasible, patients should be advised not to wear their prostheses during treatment, particularly at night.

Dental Extractions: To the extent possible, teeth with uncertain prognoses should be extracted at least ten days before the initiation of cancer therapy.

Antibiotic Prophylaxis and Hematological Support: In cases of neutropenia (neutrophil count less than 2000/mm3), antibiotic prophylaxis before invasive oral procedures may be necessary, but close consultation with the oncologist and clinical judgement should guide this decision. Haematological support may also be required.

Orthodontic Care: Orthodontic treatment should be discontinued, and fixed appliances should be removed.