A patient has hypoplasia, microdontia, hypodontia, multiple unerupted teeth, numbness in oral cavity, peripheral paresthesia. This is most likely due to:

 # A patient has hypoplasia, microdontia, hypodontia, multiple unerupted teeth, numbness in oral cavity, peripheral paresthesia. This is most likely due to:

A. Hyperparathyroidism

B. Hypoparathyroidism

C. Hyperthyroidism

D. Hypothyroidism

The correct answer is:

B. Hypoparathyroidism

Explanation:
Hypoparathyroidism can cause a range of dental and neurological symptoms, including:

• Dental manifestations: Hypoplasia, microdontia, hypodontia, delayed eruption, and multiple unerupted teeth are associated with impaired calcium metabolism.
• Neurological symptoms: Numbness in the oral cavity and peripheral paresthesia occur due to hypocalcemia, which leads to increased neuromuscular excitability.

Other options explained:

• A. Hyperparathyroidism: May cause brown tumors, loss of lamina dura, and tooth mobility due to increased bone resorption, but not hypoplasia or unerupted teeth.
• C. Hyperthyroidism: Can lead to accelerated dental development but does not cause hypoplasia or hypodontia.
• D. Hypothyroidism: May cause delayed eruption and macroglossia but does not typically result in hypoplasia or paresthesia. 

The most well recognized technique for orthodontic bonding to porcelain surfaces is:

 # The most well recognized technique for orthodontic bonding to porcelain surfaces is:

A. Traditional acid-etch technique with phosphoric acid.

B. Chemical retention using 4-META coupling agent.

C. Chemical and micro-mechanical retention using hydrofluoric acid and a silane coupling agent.

D. Chemical retention using hydrofluoric acid only.

The correct answer is C. Chemical and micro-mechanical retention using hydrofluoric acid and a silane coupling agent

Explanation:
The most effective and well-recognized technique for bonding to porcelain involves etching the porcelain surface with hydrofluoric acid to create micro-mechanical retention, followed by the application of a silane coupling agent to enhance chemical adhesion. This combination ensures a strong bond between the orthodontic bracket and the porcelain surface.

• A: Phosphoric acid etching is effective for enamel but not adequate for porcelain bonding.
• B: 4-META is less commonly used for porcelain.
• D: Hydrofluoric acid alone provides micro-mechanical retention but lacks the chemical bond achieved with silane.

How many hours after appliance placement does orthodontic pain peak?

 # How many hours after appliance placement does orthodontic pain peak?

A. 10 minutes.

B. 1 hour.

C. 24 hours.

D. 48 hours.

The correct answer is C. 24 hours.

It is generally considered that orthodontic pain starts at around 2 hours after appliance placement, with some studies reporting that this is the case for between 91% and 97% of orthodontic patients. It then usually peaks at 24 hours before gradually subsiding over the next 5 to 7 days. Interestingly, it would seem that up to 25% of orthodontic patients report experiencing pain for longer than 7 days.

In pain pathways the smaller primary unmyelinated fibres are called:

 # In pain pathways the smaller primary unmyelinated fibres are called:

 A. A fibres. 

B. B fibres. 

C. C fibres. 

D. D fibres.

The correct answer is:

C. C fibres

Explanation: C fibres are small, unmyelinated nerve fibers that conduct pain signals slowly. They are primarily responsible for transmitting dull, burning, or aching pain (slow pain) and are involved in the prolonged, less localized pain sensation.

A fibres: Include A-delta fibers, which are myelinated and transmit sharp, localized pain quickly (fast pain).

B fibres: Small, myelinated fibers mainly involved in autonomic functions.

D fibres: This category does not exist in standard nomenclature for nerve fibers.