MJDF Human Disease — Questions and Answers
Question 1: A patient with rheumatic heart disease and a prosthetic mitral valve presents for dental treatment. What is the primary cardiac concern during dental procedures?
- Risk of myocardial infarction during treatment
- Risk of infective endocarditis from transient bacteraemia caused by invasive dental procedures, though NICE guidelines no longer recommend routine antibiotic prophylaxis in the UK (Correct answer)
- Risk of cardiac arrest from the local anaesthetic
- There are no cardiac concerns for patients with prosthetic heart valves
Correct answer: Risk of infective endocarditis from transient bacteraemia caused by invasive dental procedures, though NICE guidelines no longer recommend routine antibiotic prophylaxis in the UK
Patients with prosthetic heart valves are at the highest risk of infective endocarditis (IE), which can be caused by bacteraemia from invasive dental procedures (extractions, scaling, root canal treatment). Oral streptococci (especially Streptococcus mutans and S. sanguinis) can colonise damaged or prosthetic valves. However, NICE CG64 in the UK recommends AGAINST routine antibiotic prophylaxis for dental procedures, differing from AHA/ESC guidelines. Emphasis is placed on maintaining good oral health to reduce chronic bacteraemia. The dentist should document the discussion of risks with the patient and their cardiologist.
Question 2: What is the significance of a patient's ASA (American Society of Anesthesiologists) classification in dental practice?
- It determines the cost of dental treatment
- It classifies patients by their physical health status to assess fitness for treatment under sedation or general anaesthesia, ranging from ASA I (healthy) to ASA V (moribund); it guides the level of monitoring, setting, and modifications needed for safe dental care (Correct answer)
- It is only relevant for hospital-based treatment
- It classifies the type of dental restoration needed
Correct answer: It classifies patients by their physical health status to assess fitness for treatment under sedation or general anaesthesia, ranging from ASA I (healthy) to ASA V (moribund); it guides the level of monitoring, setting, and modifications needed for safe dental care
The ASA classification is widely used in dentistry to assess patient fitness: ASA I — normal healthy patient; ASA II — mild systemic disease (well-controlled hypertension, mild asthma, pregnancy); ASA III — severe systemic disease limiting activity (poorly controlled diabetes, stable angina, COPD); ASA IV — severe systemic disease that is a constant threat to life (recent MI, severe heart failure); ASA V — moribund patient. Most general dental practice treats ASA I-II patients. ASA III patients may require modifications (shorter appointments, stress reduction, medical liaison). ASA IV patients typically require hospital-based dental care.
Question 3: A patient presents with a history of adrenal insufficiency (Addison's disease) and takes daily prednisolone 10mg. What is the risk during a stressful dental procedure and how should it be managed?
- There is no additional risk for patients on corticosteroids
- The patient may develop an adrenal crisis (acute adrenal insufficiency) if the hypothalamic-pituitary-adrenal axis cannot mount an adequate cortisol response to stress; management depends on the procedure complexity — for minor procedures under LA, the usual dose is adequate; for more stressful procedures, supplementary corticosteroid cover may be needed (Correct answer)
- All dental treatment must be performed under general anaesthesia
- The prednisolone must be stopped 48 hours before dental treatment
Correct answer: The patient may develop an adrenal crisis (acute adrenal insufficiency) if the hypothalamic-pituitary-adrenal axis cannot mount an adequate cortisol response to stress; management depends on the procedure complexity — for minor procedures under LA, the usual dose is adequate; for more stressful procedures, supplementary corticosteroid cover may be needed
Patients with adrenal insufficiency on replacement corticosteroids may be unable to produce additional cortisol in response to physiological stress (surgical procedures, infections, trauma), risking adrenal crisis (hypotension, tachycardia, collapse). Current guidelines suggest: for minor procedures under LA with good anxiety management, the usual daily dose is typically sufficient; for surgical procedures or where significant stress is anticipated, doubling the usual dose on the day of the procedure is recommended. IV hydrocortisone 100mg should be available for emergencies. Never abruptly stop corticosteroid therapy.
Question 4: What are the dental implications of a patient undergoing head and neck radiotherapy?
- Radiotherapy to the head and neck has no effect on the oral cavity
- Complications include mucositis, xerostomia (permanent if salivary glands are in the radiation field), radiation caries, osteoradionecrosis of the jaws, trismus from fibrosis of muscles of mastication, altered taste, and candidiasis; pre-radiotherapy dental assessment and extractions of poor-prognosis teeth are essential (Correct answer)
- Only mucositis occurs and it resolves immediately after treatment
- Dental treatment is permanently contraindicated after radiotherapy
Correct answer: Complications include mucositis, xerostomia (permanent if salivary glands are in the radiation field), radiation caries, osteoradionecrosis of the jaws, trismus from fibrosis of muscles of mastication, altered taste, and candidiasis; pre-radiotherapy dental assessment and extractions of poor-prognosis teeth are essential
Head and neck radiotherapy (typically 50-70 Gy) causes multiple oral complications: acute mucositis (within 1-2 weeks), xerostomia (may be permanent if major salivary glands receive >30 Gy), radiation caries (rampant cervical caries due to xerostomia and altered flora), osteoradionecrosis (ORN — avascular necrosis of irradiated bone, risk highest in mandible), trismus (from fibrosis of masticatory muscles), dysgeusia, and candidiasis. Pre-radiotherapy dental management includes extracting teeth with poor prognosis at least 2-3 weeks before radiotherapy, fluoride tray fabrication, and oral hygiene optimization. Post-radiotherapy extractions must be avoided if possible or performed with hyperbaric oxygen/pentoxifylline-tocopherol protocols to reduce ORN risk.
Question 5: A patient with liver cirrhosis presents for dental treatment. What are the key medical considerations?
- Liver disease has no relevance to dental treatment
- Impaired coagulation (reduced clotting factor synthesis), altered drug metabolism (prolonged action of hepatically-metabolised drugs), increased infection risk, and potential for excessive bleeding requiring pre-treatment coagulation screen (INR, platelet count) and possible liaison with hepatologist (Correct answer)
- Only the choice of local anaesthetic is affected
- The patient cannot receive any dental treatment
Correct answer: Impaired coagulation (reduced clotting factor synthesis), altered drug metabolism (prolonged action of hepatically-metabolised drugs), increased infection risk, and potential for excessive bleeding requiring pre-treatment coagulation screen (INR, platelet count) and possible liaison with hepatologist
Liver cirrhosis has multiple dental implications: impaired synthesis of clotting factors (II, V, VII, IX, X) causing coagulopathy (check INR, platelet count, bleeding time); altered metabolism of drugs cleared by the liver (avoid or reduce doses of paracetamol, diazepam, lidocaine); thrombocytopenia from portal hypertension/splenism; increased infection susceptibility; potential hepatitis B/C co-infection requiring infection control measures; and alcohol-related cirrhosis may indicate oral cancer risk. Pre-treatment assessment should include recent blood tests, medical liaison, and consideration of local haemostatic measures for surgical procedures.
Question 6: What is the dental significance of a patient having a history of organ transplantation and taking immunosuppressive medication?
- Transplant patients require no special consideration for dental treatment
- Immunosuppressive drugs (ciclosporin, tacrolimus, mycophenolate, corticosteroids) increase susceptibility to oral infections (candidiasis, herpes reactivation), impair healing, and ciclosporin causes gingival overgrowth; dental treatment should be coordinated with the transplant team, and prophylactic antibiotics may be needed for invasive procedures (Correct answer)
- Only dental X-rays should be avoided
- Immunosuppressive medication protects against dental disease
Correct answer: Immunosuppressive drugs (ciclosporin, tacrolimus, mycophenolate, corticosteroids) increase susceptibility to oral infections (candidiasis, herpes reactivation), impair healing, and ciclosporin causes gingival overgrowth; dental treatment should be coordinated with the transplant team, and prophylactic antibiotics may be needed for invasive procedures
Organ transplant recipients on lifelong immunosuppression present several dental challenges: increased susceptibility to opportunistic infections (oral candidiasis, HSV reactivation, bacterial infections); ciclosporin-induced gingival overgrowth (up to 70% of patients, worsened by nifedipine co-prescription); increased risk of oral squamous cell carcinoma and lymphoma (post-transplant lymphoproliferative disorder); impaired wound healing; drug interactions (azole antifungals increase ciclosporin/tacrolimus levels); and adrenal suppression from corticosteroid component. Treatment planning requires medical liaison, meticulous infection control, and vigilance for malignancy.
MJDF Human Disease
A patient with rheumatic heart disease and a prosthetic mitral valve presents for dental treatment.
What is the primary cardiac concern during dental procedures?