FREE NBDE Microbiology and Pathology Questions and Answers

Question 1

A 5-year-old child presents with a fever, sore throat, and small, painful ulcers primarily located on the soft palate and tonsillar pillars.
The child's hands and feet appear normal with no rash or lesions.
Based on these findings, what is the most likely diagnosis?

Accepted Answer

Herpangina

Answer

Primary Herpetic Gingivostomatitis

Answer

Hand, Foot, and Mouth Disease

Answer

Erythema Multiforme

Question 2

A patient presents with a chronic, non-healing, draining sinus tract on the skin of the jaw. A purulent discharge from the tract contains small, yellowish particles. Histopathological examination of these particles would most likely reveal tangled masses of filamentous bacteria. Which microorganism is the most probable causative agent?

Accepted Answer

Actinomyces israelii

Answer

Staphylococcus aureus

Answer

Mycobacterium tuberculosis

Answer

Treponema pallidum

Question 3

A routine radiographic examination reveals a well-demarcated, unilocular radiolucency surrounding the crown of an unerupted mandibular third molar. The tooth is asymptomatic. This radiographic finding is most characteristic of which of the following?

Accepted Answer

Dentigerous (Follicular) Cyst

Answer

Radicular (Periapical) Cyst

Answer

Odontogenic Keratocyst (OKC)

Answer

Ameloblastoma

Question 4

A middle-aged female patient complains of a burning sensation and soreness in her mouth. Clinical examination reveals bilateral, interlacing white lines (Wickham's striae) on the buccal mucosa. Some areas appear erythematous and eroded. This clinical presentation is most indicative of which condition?

Accepted Answer

Oral Lichen Planus

Answer

Oral Candidiasis

Answer

Pemphigus Vulgaris

Answer

Leukoplakia

Question 5

Which of the following bacteria is most strongly implicated as the primary initiator of enamel caries due to its ability to produce acid and synthesize extracellular polysaccharides from sucrose, which facilitates its adherence to the tooth surface?

Accepted Answer

Streptococcus mutans

Answer

Actinomyces naeslundii

Answer

Lactobacillus casei

Answer

Porphyromonas gingivalis

Question 6

A patient with a known autoimmune disorder presents with severe xerostomia and keratoconjunctivitis sicca. They report difficulty swallowing food without liquids and have a higher than normal incidence of dental caries. This combination of signs and symptoms is most characteristic of:

Accepted Answer

Sjögren's Syndrome

Answer

Pemphigus Vulgaris

Answer

Systemic Lupus Erythematosus

Answer

Crohn's Disease

A 5-year-old child presents with a fever, sore throat, and small, painful ulcers primarily located on the soft palate and tonsillar pillars.The child's hands and feet appear normal with no rash or lesions.Based on these findings, what is the most likely diagnosis?

A 5-year-old child presents with a fever, sore throat, and small, painful ulcers primarily located on the soft palate and tonsillar pillars.
The child's hands and feet appear normal with no rash or lesions.
Based on these findings, what is the most likely diagnosis?