2.2 Immunocompromised, Transplants & Oncology Patients

2.2 Immunocompromised, Transplants & Oncology Patients

Dental management of patients receiving oncology treatments, organ transplants, or potent immunosuppressive regimens presents complex clinical challenges. Oral complications in these cohorts can quickly escalate into systemic, life-threatening infections or permanent skeletal destruction.

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Head & Neck Oncology & Radiotherapy

Radiotherapy to the head and neck region induces microvascular damage and cellular depletion in irradiated bone tissue. This leads to the classic triad of radiation injury described by Marx: hypoxia, hypovascularity, and hypocellularity.

Osteoradionecrosis (ORN)

Osteoradionecrosis (ORN) is defined as exposed, irradiated bone that fails to heal over a 3-month period without evidence of tumor recurrence. The risk of ORN increases exponentially when total radiation dose to the jawbone exceeds 60 Gray (Gy). The mandible is significantly more vulnerable than the maxilla due to its dense hypovascular cortical structure and single terminal blood supply from the inferior alveolar artery.

Pre-Radiotherapy Dental Protocol

Every patient scheduled for head and neck radiotherapy must undergo a comprehensive dental evaluation prior to treatment:

1. Timing of Extractions: All non-restorable, periodontally hopeless, or questionable teeth within the planned radiation beam field must be extracted at least 14 to 21 days (ideally 3 weeks) before radiotherapy commences. This allows sufficient time for re-epithelialization and initial osteogenesis.
2. Preventive Restorative Care: Smooth sharp cusps, restore active carious lesions, remove hopeless fixed prostheses, and construct custom vinyl fluoride gel trays.
3. Fluoride Therapy: Prescribe daily high-dose fluoride toothpaste (5,000 ppm sodium fluoride, 0.11% F) to prevent rampant radiation-induced caries ("radiation caries") resulting from permanent salivary gland destruction (radiation xerostomia).

Post-Radiotherapy Dental Management

Post-radiotherapy dental extractions in areas exposed to >60 Gy should be avoided. Endodontic therapy (including decoronation of teeth leaving root stumps covered by mucosa) is strongly preferred over extractions. If extractions are unavoidable, treatment should occur in secondary care using hyperbaric oxygen (HBO) therapy or prophylactic prescription of the PENTO protocol (Pentoxifylline 400 mg BD combined with Tocopherol/Vitamin E 400 IU BD) for 8 weeks pre- and post-extraction.

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Medication-Related Osteonecrosis of the Jaw (MRONJ)

According to SDCEP Guidance, Medication-Related Osteonecrosis of the Jaw (MRONJ) is diagnosed when all three criteria are met:

1. Exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region persisting for more than 8 weeks.
2. Current or previous treatment with antiresorptive agents (bisphosphonates, Denosumab) or anti-angiogenic targeted therapies.
3. No history of radiation therapy to the jawbones or obvious metastatic disease of the jaws.

Drug Classes & Indication Risk Stratification

MRONJ risk varies dramatically depending on whether antiresorptive drugs are prescribed for osteoporosis or oncology (bone metastases, multiple myeloma):

Clinical Management Rules for MRONJ Risk

• Do NOT stop antiresorptive therapy prior to dental procedures without explicit instruction from the treating oncologist/rheumatologist. Drug holidays for bisphosphonates do not reduce short-term MRONJ risk due to decades-long skeletal binding.
• Atraumatic Technique: When extractions are mandatory, raise a minimal mucoperiosteal flap, avoid periosteal scoring, smooth sharp bony spicules, achieve primary wound closure, and prescribe 0.2% chlorhexidine mouthwash.
• Review extraction sites at 8 weeks post-op to confirm complete mucosal healing.

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Chemotherapy & Haematological Compromise

Cytotoxic chemotherapy suppresses bone marrow activity, resulting in severe pancytopenia (neutropenia, thrombocytopenia, anaemia).

Haematological Thresholds for Dental Treatment

Prior to performing dental treatment on a patient undergoing active chemotherapy, a full blood count (FBC) must be evaluated:

• Absolute Neutrophil Count (ANC):
  • Normal Range: 2.0 – 7.5 × 10^9/L
  • ANC 1.0 – 2.0 × 10^9/L (Moderate Risk): Elective care with caution; prophylactic broad-spectrum antibiotics may be indicated for invasive procedures.
  • ANC < 1.0 × 10^9/L (Severe Neutropenia): Elective dental treatment is strictly contraindicated. Emergency care requires hospital admission, prophylactic broad-spectrum IV antibiotics, and haematologist liaison.
• Platelet Count:
  • Normal Range: 150 – 400 × 10^9/L
  • 50 – 100 × 10^9/L: Minor oral surgery permitted with local haemostatic measures.
  • < 50 × 10^9/L: Invasive surgical procedures contraindicated due to severe bleeding risk.
  • < 20 × 10^9/L: High risk of spontaneous oral mucosal haemorrhage; requires emergency platelet transfusion prior to any intervention.

Oral Mucositis & Opportunistic Infections

Oral Mucositis is a debilitating toxicity of chemotherapy, graded from 1 (erythema) to 4 (ulceration preventing oral intake). Management involves sodium bicarbonate rinses, benzydamine hydrochloride 0.15% (Difflam) mouthwash, and topical barrier gels. Opportunistic infections must be treated promptly:

• Oral Candidiasis: Treated with topical Nystatin suspension (100,000 units/ml QDS) or Miconazole 2% oral gel (note: Miconazole is contraindicated in patients taking Warfarin due to severe interaction causing lethal INR elevation). Systemic Fluconazole (50–100 mg daily) is used in severe immunosuppression.
• Herpes Simplex Virus (HSV): Treated with oral Aciclovir (200–400 mg 5 times daily for 5 days).

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Solid Organ Transplants & Immunosuppressive Therapy

Organ transplant recipients (kidney, liver, heart) receive lifelong immunosuppressive therapy to prevent graft rejection. Management is divided into three distinct post-transplant phases:

1. Pre-Transplant Phase: Complete comprehensive dental clearance. Extract all hopeless, infected, or deeply carious teeth to eliminate potential septic foci.
2. Immediate Post-Transplant Phase (0–6 Months): Period of maximal immunosuppression. Elective dental treatment is strictly avoided. Only emergency dental care is provided under hospital protocols.
3. Stable Post-Transplant Phase (>6 Months): Elective dental care can proceed under local anaesthesia with strict aseptic technique and liaison with the transplant team.

Immunosuppressive Drug Side Effects

• Cyclosporine: Induces Gingival Overgrowth in 30–50% of patients. Fibrotic tissue enlargement is exacerbated by poor oral hygiene. Management includes non-surgical periodontal therapy, oral hygiene optimization, or consultation with the transplant physician to substitute Cyclosporine with Tacrolimus (which carries a significantly lower incidence of gingival enlargement).
• Tacrolimus & Mycophenolate Mofetil: Associated with oral ulceration, lichenoid reactions, and delayed wound healing.
• Corticosteroids: Increase risk of oral candidiasis and adrenal insufficiency.