MJDF Orthodontics 2

Question 1

Which type of orthodontic tooth movement involves the entire tooth, including the root apex, moving in the same direction without tipping?

Accepted Answer

Bodily (translation) movement

Answer

Bodily movement (translation) requires the crown and root apex to move equally in the same direction, requiring a force couple and being the most demanding biomechanically.

Question 2

Current best evidence regarding the duration of orthodontic retention after fixed appliance therapy recommends:

Accepted Answer

Indefinite retention

Answer

Current evidence supports indefinite retention, as relapse can occur many years post-treatment and no predictable safe end-point for cessation has been established.

Question 3

Which force type is considered optimal for efficient orthodontic tooth movement with minimal tissue damage?

Accepted Answer

Light continuous force

Answer

Light continuous forces optimise bone remodelling via sustained periodontal ligament stimulation without causing hyalinisation or undermining resorption.

Question 4

The Hawley retainer is best classified as which type of orthodontic appliance?

Accepted Answer

Removable retainer

Answer

The Hawley retainer is a removable appliance comprising an acrylic baseplate and labial bow, widely used for post-treatment retention.

Question 5

Extraoral anchorage in orthodontics refers to:

Accepted Answer

Using structures outside the oral cavity such as the head or neck to reinforce anchorage

Answer

Extraoral anchorage involves headgear attached to the head or neck to provide force resistance or to redirect growth, supplementing intraoral anchorage.

MJDF Part 1 Practice Test

MJDF Part 1 Practice Test

MJDF Orthodontics 2