ABO ABO Retention and Stability

Question 1

Which factor is most commonly cited as a cause of post-treatment lower incisor crowding recurrence?

Accepted Answer

Late mandibular growth and forward drift of lower teeth

Answer

Excessive torque applied during treatment

Answer

Use of full-coverage retainers

Answer

Expansion of the upper arch

Question 2

A Hawley retainer differs from a clear vacuum-formed retainer primarily in that it:

Accepted Answer

Allows minor tooth movement and easy modification by the clinician

Answer

Cannot be adjusted after delivery

Answer

Covers the occlusal surfaces completely

Answer

Is bonded to the teeth

Question 3

Which type of teeth movement has the LEAST long-term stability after orthodontic treatment?

Accepted Answer

Expansion of the lower intercanine width

Answer

Molar intrusion

Answer

Upper incisor retraction

Answer

Molar distalization with headgear

Question 4

A fixed lingual retainer bonded from canine to canine on the lower arch is most effective for:

Accepted Answer

Maintaining lower incisor and canine alignment long-term

Answer

Preventing molar rotation

Answer

Retaining expanded arch width

Answer

Preventing deep bite relapse

Question 5

The fibrotomy (circumferential supracrestal fiberotomy, CSF) procedure is performed to:

Accepted Answer

Reduce relapse of rotational corrections by severing the supracrestal fibers

Answer

Accelerate tooth movement

Answer

Increase alveolar bone density

Answer

Improve periodontal health

Question 6

Which patient characteristic is associated with the GREATEST risk of orthodontic relapse?

Accepted Answer

Skeletal discrepancy that was not fully corrected

Answer

Adult age at treatment start

Answer

Mild crowding prior to treatment

Answer

Extraction of all four premolars