ORE Part 1 Oral Biology & Pathology 2 — Questions and Answers
Question 1: What is 'reactive oxygen species' involvement in periodontal disease?
- Excessive ROS production by neutrophils during bacterial challenge damages host tissues (collagen, lipids, DNA), contributing to periodontal tissue destruction (Correct answer)
- ROS are beneficial antioxidants produced by the host
- ROS only cause systemic disease, not periodontal destruction
- ROS are produced by periodontal bacteria to destroy host defences
Correct answer: Excessive ROS production by neutrophils during bacterial challenge damages host tissues (collagen, lipids, DNA), contributing to periodontal tissue destruction
In periodontal disease, sustained neutrophil activation produces excessive ROS beyond what is needed for bacterial killing. This oxidative stress damages host collagen, lipids, and DNA, contributing to bone and soft tissue destruction.
Question 2: What is a 'dentigerous cyst' and what does it arise from?
- A developmental odontogenic cyst forming around the crown of an unerupted tooth by accumulation of fluid between the crown and the reduced enamel epithelium (Correct answer)
- An inflammatory cyst at the apex of a non-vital tooth
- A cyst arising from the rest of Malassez
- A traumatic cyst with no epithelial lining
Correct answer: A developmental odontogenic cyst forming around the crown of an unerupted tooth by accumulation of fluid between the crown and the reduced enamel epithelium
The dentigerous cyst is the most common developmental odontogenic cyst. It develops from fluid accumulation between the crown and the reduced enamel epithelium of an unerupted (often impacted) tooth.
Question 3: Which cell type is most numerous in the gingival connective tissue?
- Fibroblasts (Correct answer)
- Macrophages
- Neutrophils
- Osteoclasts
Correct answer: Fibroblasts
Fibroblasts are the dominant cell type in the gingival lamina propria. They produce and maintain the collagen fibres (principal and minor fibre groups), proteoglycans, and other extracellular matrix components.
Question 4: What is the histological definition of 'epithelial dysplasia'?
- Cellular and architectural abnormalities in the epithelium including loss of polarity, increased mitoses, and nuclear atypia — indicating potential for malignant transformation (Correct answer)
- Inflammation of the oral epithelium
- Benign overgrowth of epithelium without atypia
- Absence of the epithelium in an ulcer
Correct answer: Cellular and architectural abnormalities in the epithelium including loss of polarity, increased mitoses, and nuclear atypia — indicating potential for malignant transformation
Epithelial dysplasia describes pre-neoplastic changes: architectural disorganisation and cytological atypia. Severity grades (mild, moderate, severe) reflect the risk of malignant transformation to squamous cell carcinoma.
Question 5: What is 'Hutchinson's triad' and what condition does it indicate?
- Hutchinson's incisors (notched), interstitial keratitis, and nerve deafness — signs of congenital syphilis (Correct answer)
- A triad of TMJ symptoms
- Signs of ectodermal dysplasia
- Features of cretinism
Correct answer: Hutchinson's incisors (notched), interstitial keratitis, and nerve deafness — signs of congenital syphilis
Hutchinson's triad is pathognomonic of congenital syphilis: Hutchinson's incisors (barrel-shaped, notched), interstitial keratitis (corneal inflammation), and 8th nerve deafness (hearing loss).
Question 6: What is 'ghost teeth' (regional odontodysplasia)?
- A rare developmental defect where teeth have very thin enamel and dentine with large pulp chambers, giving a ghost-like radiographic appearance (Correct answer)
- A term for non-vital teeth with pulp necrosis
- Hypoplastic primary teeth following fluorosis
- Teeth with taurodontism
Correct answer: A rare developmental defect where teeth have very thin enamel and dentine with large pulp chambers, giving a ghost-like radiographic appearance
Regional odontodysplasia ('ghost teeth') is a rare developmental condition affecting multiple adjacent teeth. Severely defective enamel and dentine with enlarged pulp chambers give the pathognomonic 'ghost' radiographic appearance.
ORE Part 1 Oral Biology & Pathology 2
What is 'reactive oxygen species' involvement in periodontal disease?