ABO Retention and Stability Flashcards

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

Answer: Late mandibular growth and forward drift of lower teeth

Late mandibular growth combined with anterior soft tissue pressure and mesial drift causes lower incisor crowding to recur after treatment.

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

Answer: Allows minor tooth movement and easy modification by the clinician

Hawley retainers have a labial bow that can be adjusted by the clinician, allowing minor tooth movement corrections during the retention phase.

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

Answer: Expansion of the lower intercanine width

Expansion of the lower intercanine width is highly unstable because it is strongly determined by the pre-treatment dimensions and muscular environment.

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

Answer: Maintaining lower incisor and canine alignment long-term

Bonded lingual retainers attached canine-to-canine are highly effective at preventing lower anterior crowding relapse.

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

Answer: Reduce relapse of rotational corrections by severing the supracrestal fibers

CSF severs the supracrestal gingival fibers that tend to pull rotated teeth back toward their original position after correction.

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

Answer: Skeletal discrepancy that was not fully corrected

When the underlying skeletal discrepancy is not fully corrected, continued jaw growth and soft tissue pressure tend to drive teeth back toward the original malocclusion.