INBDE practice questions: FK6 — General and oral pathology

Answer C: The relationship runs both ways, so periodontal treatment is part of caring for his diabetes

The module states that the relationship between diabetes and periodontitis runs both ways: poor control brings dry mouth, candidiasis, burning mouth, delayed healing, and more severe and faster periodontal destruction, while severe periodontitis is associated with worse glycaemic control — so periodontal treatment is part of caring for the diabetic patient rather than an optional extra. A turns a laboratory value into a gate and leaves an active infection untreated; 6.5 % is a diagnostic threshold, not a permission line for treatment. B makes the relationship one-directional, which is exactly what the two-way finding denies, and would leave established destruction to resolve on its own. D asserts an effect of periodontal therapy that the module does not describe, and uses it to justify the same delay.

Common trap: Sequencing dental care behind a target number when the two conditions drive each other.

Source: Newman and Carranza's Clinical Periodontology and Implantology

Answer D: Treat on a non-dialysis day, keep cuffs off the fistula arm, and avoid NSAIDs entirely

The module's practical rules for chronic kidney disease are to avoid NSAIDs because they are nephrotoxic, to adjust or avoid renally cleared drugs, never to place a blood-pressure cuff or take blood from the arm carrying an arteriovenous fistula or graft, and to schedule a haemodialysis patient on a non-dialysis day — usually the day after — because heparin given during dialysis raises bleeding risk and the patient is fluid- and electrolyte-shifted immediately afterwards. A picks the single worst slot and then prescribes the drug class to avoid. B keeps the dialysis-day timing and uses the limb that must be left alone. C claims dialysis abolishes bleeding risk; uraemia impairs platelet function, so expect more oozing regardless.

Common trap: Timing treatment around the dialysis session for convenience rather than around the heparin.

Source: Little & Falace's Dental Management of the Medically Compromised Patient

Answer B: It has passed the threshold for status epilepticus, so activate emergency services

Status epilepticus is the point at which a seizure stops being self-limiting, and for convulsive seizures five minutes or more of continuous activity is the operational threshold for treating it as status; thirty minutes is the separate point beyond which long-term neurological consequences are expected. Repeated seizures without recovery of awareness between them count the same way, and the response is to activate emergency medical services. A confuses those two time points and would delay the call by nearly half an hour. C and D each do something the module forbids during a seizure: put nothing in the mouth and do not restrain the patient. Injuries — a tongue laceration, a luxated or avulsed tooth, a jaw injury — are checked for afterwards, during the confused post-ictal period.

Common trap: Remembering both time points but attaching the action to the wrong one.

Source: ILAE Task Force operational definition of status epilepticus

Answer A: Trigeminal neuralgia in the maxillary division, triggered by light touch and wind

Trigeminal neuralgia is brief, severe, electric-shock pain in the distribution of a trigeminal division — usually V2 or V3 and almost always unilateral — triggered by light touch, chewing or wind, with pain-free intervals between attacks. Her right cheek and upper teeth are the V2 distribution, and the teeth themselves are sound and vital. B is the classic and avoidable harm the module names, because irreversible treatment would be done on a sound tooth for pain the tooth is not producing. C describes a numbness or altered sensation following an injection she has not had. D is a diagnosis of exclusion presenting as burning, not as shocks. Carbamazepine is the conventional first-line drug, and imaging is warranted to exclude a structural cause.

Common trap: Answering the location of the pain instead of its character, and treating a sound tooth.

Source: Neville, Oral and Maxillofacial Pathology

Answer D: Pseudomembranous candidiasis; treat it and correct the unrinsed inhaler habit

The first question for any white lesion is whether it wipes off: if gauze removes it and leaves a red, sometimes bleeding base, it is pseudomembranous candidiasis — an infection, not a premalignancy. The second question is why, and inhaled corticosteroids used without rinsing sit at the top of that list alongside dry mouth, a denture worn overnight, poorly controlled diabetes, recent broad-spectrum antibiotics and immunosuppression. Treating the thrush without finding the reason guarantees recurrence. A applies a clinical label reserved for a fixed white plaque of equivocal risk once other diseases are excluded, and leukoplakia does not wipe off. B names a lateral-tongue, Epstein-Barr-driven lesion that also does not wipe off. C describes a chronic bilateral disease with lacy Wickham striae.

Common trap: Diagnosing a white lesion by colour and site before performing the wipe test.

Source: Neville, Oral and Maxillofacial Pathology

Answer B: A non-homogeneous patch carries about four times the risk of a homogeneous one

Leukoplakia is a clinical term for a white plaque of equivocal risk once other known diseases and disorders have been excluded, and it says nothing about what the microscope will show, because it may be dysplastic or non-dysplastic. Its estimated prevalence is about 2 per cent, its collective annual malignant transformation rate about 1 per cent, and pooled transformation across large series about 9.8 per cent — with non-homogeneous forms, meaning verrucous, nodular or speckled, carrying roughly four times the risk of homogeneous ones. A inverts that relationship. C claims colour excludes dysplasia, which is precisely what a clinical diagnosis of exclusion cannot do. D delays: the short review interval belongs to a seemingly innocuous lesion with a removable cause, and he has none.

Common trap: Hearing "leukoplakia" as a reassuring label instead of an unresolved question needing tissue.

Source: AAOMS Position Paper — Oral Mucosal Dysplasia

Answer C: At least moderate or severe dysplasia, or carcinoma in situ already present

Erythroplakia is a fiery red patch that cannot be characterised clinically or pathologically as any other definable disease. It is far less common than leukoplakia — reported prevalence between about 0.02 and 0.83 per cent against roughly 2 per cent — and far more dangerous: histologically it typically shows at least moderate or severe dysplasia or carcinoma in situ, and the vast majority undergo malignant transformation. That is why prompt incisional biopsy is indicated rather than observation. A predicts the benign result the red colour argues against. B belongs to erythematous candidiasis, which tells a different story — denture stomatitis confined to the denture-bearing area, median rhomboid glossitis, angular cheilitis. D describes lichen planus, which presents with lacy white striae rather than an unexplained red patch.

Common trap: Expecting a red patch to be inflammatory because red usually means inflammation.

Source: AAOMS Position Paper — Oral Mucosal Dysplasia

Answer A: The lesion is vascular, so it should not be biopsied as though it were pigmented

Pressing the lesion is one of the two bedside tests that do most of the work with red, blue and pigmented lesions: a lesion that blanches under pressure is vascular — a haemangioma, a vascular malformation or a varix — and recognising that stops you from biopsying something that will bleed. B names a localised grey-blue macule near a restoration or an old extraction site, which does not empty under pressure and may show metal particles on a radiograph, the useful discriminator there. C names a small, flat, uniformly coloured and stable lesion, which likewise does not blanch. D names a red-purple macule or nodule of advanced HIV disease, often palatal or gingival; nothing in this history points there, and the blanching test identifies vascularity rather than naming a tumour.

Common trap: Reading blue as pigment and reaching for a biopsy before pressing the lesion.

Source: Neville, Oral and Maxillofacial Pathology

Answer C: Minor aphthous ulceration; antivirals do nothing, and recurrence warrants a work-up

Recurrent aphthous stomatitis sits on movable, non-keratinised mucosa — labial and buccal mucosa, floor of mouth, soft palate and ventral tongue — and minor aphthae are under 1 cm and heal in 7 to 14 days without scarring. They are not caused by herpes virus, so antivirals do nothing, and recurrent or severe disease justifies looking for iron, folate or B12 deficiency, coeliac disease, inflammatory bowel disease, HIV and Behçet disease. A puts recurrent herpes on the wrong tissue: it favours keratinised, bound-down mucosa such as the hard palate and attached gingiva. B describes a first-exposure illness, usually in a young child, with fever, malaise and fiery painful gingivitis. D is acute, with target-shaped skin lesions and haemorrhagic crusted lips.

Common trap: Letting a patient's analogy to cold sores decide the diagnosis instead of the tissue involved.

Source: Neville, Oral and Maxillofacial Pathology

Answer D: Perilesional tissue from beside an affected area, for direct immunofluorescence

Desquamative gingivitis is a sign, not a diagnosis; its usual causes are lichen planus, mucous membrane pemphigoid and pemphigus, and the way to tell them apart is a biopsy that includes perilesional tissue submitted for direct immunofluorescence, not a specimen taken from the ulcer floor. The distinction matters because pemphigus vulgaris is an intraepithelial suprabasilar split whose fragile blisters leave ragged erosions, while mucous membrane pemphigoid is a subepithelial split that can scar and whose ocular involvement can blind, so it needs ophthalmology referral. A is the named sampling error. B substitutes a smear for the immunofluorescence specimen the diagnosis depends on. C treats a mucocutaneous disease as a plaque problem, though her plaque control is already good.

Common trap: Sampling the most dramatic-looking tissue rather than the tissue the test requires.

Source: Neville, Oral and Maxillofacial Pathology