Periodontics · patient case with 2 questions
Painful gums and a foul odour
Patient: Male, 24 years old
Chief Complaint: “My gums are killing me and my breath is terrible.”
Background: University finals week. Smokes half a pack a day, sleeping four hours a night, eating poorly. Reports a sore throat two weeks ago.
Vital Signs: BP 124/78 mmHg · HR 88 bpm · T 99.6°F
Findings: Cratered, punched-out interdental papillae in the mandibular anterior region covered by a greyish pseudomembrane. Spontaneous bleeding on gentle retraction. Marked fetor oris. Submandibular lymphadenopathy. Generalised plaque and calculus; dry mucosa.
Question 1
What is the most likely diagnosis?
Show answer and explanation
Correct answer: C. Necrotising ulcerative gingivitis
- A. Primary herpetic gingivostomatitis is a childhood illness with high fever, malaise and vesicles that ulcerate across ALL mucosal surfaces, including non-keratinised tissue. It does not selectively crater the papillae.
- B. Plaque-induced gingivitis gives erythema, oedema and bleeding on probing, but no necrosis, no pseudomembrane and no characteristic odour.
- C. CORRECT. The diagnostic triad is PAIN, spontaneous BLEEDING and NECROSIS of the interdental papillae, which is what gives the cratered or punched-out appearance. Add the grey pseudomembrane, the distinctive fetid odour and the classic predisposing background — stress, smoking, sleep deprivation, poor nutrition — and the diagnosis is necrotising ulcerative gingivitis. Fusiform bacteria and spirochaetes predominate.
- D. Desquamative gingivitis is a clinical description, not a diagnosis — diffuse erythema with epithelial sloughing, usually from lichen planus or mucous membrane pemphigoid. There is no papillary necrosis or fetor.
Question 2
Each of the following is contributing to this patient's halitosis EXCEPT one. Which is the EXCEPTION?
Show answer and explanation
Correct answer: C. The calculus deposits themselves
- A. The posterior dorsum of the tongue is the single largest reservoir of odour-producing anaerobes in the mouth; a coated tongue with poor hygiene is the commonest cause of halitosis overall.
- B. Saliva clears bacteria and substrate and buffers the mouth. When flow drops, anaerobic proteolysis accelerates and volatile sulphur compounds accumulate — the mechanism behind morning breath.
- C. CORRECT as the exception. Calculus is a mineralised, essentially inert deposit. It contributes to halitosis only INDIRECTLY, by providing a rough retentive surface for the living biofilm that actually produces the odour. The calculus itself is not a source of volatile sulphur compounds.
- D. The necrotic tissue in NUG is a potent direct source of volatile sulphur compounds — hydrogen sulphide and methyl mercaptan — which is why the odour of NUG is so characteristic that experienced clinicians recognise it before looking.
Note: The recall listed the options confusingly and appended a separate note about calculus. Reconstructed here as the version the examiner was most likely testing: calculus is a retentive factor, not a direct odour source.