ADC - Australian Dental Council Oral Medicine and Pathology Questions and Answers

Question 1

A 48-year-old female patient presents with asymptomatic, bilateral, white, lace-like lesions on her buccal mucosa. She has no other medical history of note. The lesions do not rub off on examination. What is the most likely diagnosis?

Accepted Answer

Reticular Oral Lichen Planus

Answer

The description of bilateral, asymptomatic, white, lace-like (reticular) striae on the buccal mucosa is the classic presentation of reticular oral lichen planus. Oral candidiasis typically presents as white plaques that can be wiped off, often leaving an erythematous base. Leukoplakia is a clinical term for a white patch that is not attributable to another disease and is typically unilateral. Linea alba is a benign frictional keratosis that corresponds precisely to the occlusal plane.

Question 2

A 62-year-old female patient complains of a persistent dry mouth and a 'gritty' sensation in her eyes for the past year. Clinical examination reveals a lobulated tongue with papillary atrophy and bilateral, firm, non-tender swelling of the parotid glands. She has a high caries rate despite good oral hygiene. Which systemic autoimmune condition is most likely responsible for these findings?

Accepted Answer

Sjögren's Syndrome

Answer

The combination of xerostomia (dry mouth) and xerophthalmia (dry eyes), known as sicca syndrome, along with bilateral salivary gland enlargement, is the hallmark of Sjögren's Syndrome. The resulting severe hyposalivation also explains the high caries rate. While patients with SLE or Rheumatoid Arthritis can have secondary Sjögren's, the primary presentation described points directly to this diagnosis. Sarcoidosis can cause parotid swelling, but the prominent sicca symptoms are more characteristic of Sjögren's.

Question 3

A large, multilocular radiolucency is noted in the posterior mandible of a 25-year-old male, extending into the ramus. A biopsy is performed. Which of the following histopathological features is most characteristic of an Odontogenic Keratocyst (OKC)?

Accepted Answer

A thin, uniform parakeratinised epithelial lining with a palisaded, hyperchromatic basal cell layer

Answer

The histopathological hallmark of an OKC is its unique epithelial lining. It is typically thin and uniform (around 5-8 cells thick), parakeratinised, and features a prominent, palisaded basal cell layer composed of hyperchromatic (darkly stained) columnar or cuboidal cells. Ghost cells are characteristic of Calcifying Odontogenic Cysts (Gorlin cyst). Mucous cells are found in Glandular Odontogenic Cysts or Mucoepidermoid Carcinomas. An inflamed capsule with arcading rete ridges is typical of an inflammatory cyst like a radicular cyst.

Question 4

In the context of developing oral squamous cell carcinoma (OSCC), what is the significance of a patient's combined heavy smoking and alcohol consumption habits?

Accepted Answer

They have a synergistic effect, significantly increasing the risk more than the sum of their individual effects.

Answer

Tobacco and alcohol are the two most significant risk factors for OSCC. Their combined use has a synergistic effect, meaning the total risk is much greater (up to 30-fold) than the additive risk of using either substance alone. Alcohol is thought to act as a solvent, increasing the permeability of the oral mucosa to the carcinogens found in tobacco smoke.

Question 5

A 65-year-old patient presents with painful, desquamating gingivitis and several intact bullae on the soft palate. Gentle lateral pressure on the clinically unaffected gingiva results in the formation of a new blister. What is this clinical sign called, and with which group of conditions is it most strongly associated?

Accepted Answer

Nikolsky's sign; Autoimmune blistering diseases

Answer

Nikolsky's sign is the clinical phenomenon where the epithelium dislodges from the underlying tissue with slight rubbing or pressure. It is a characteristic finding in autoimmune blistering (vesiculobullous) diseases such as Pemphigus Vulgaris and Mucous Membrane Pemphigoid. Auspitz's sign relates to psoriasis, Wickham's striae are pathognomonic for lichen planus, and Darier's sign is associated with mastocytosis.

ADC - Australian Dental Council Practice Test

ADC - Australian Dental Council Practice Test

ADC - Australian Dental Council Oral Medicine and Pathology Questions and Answers