ABO ABO Retention and Stability 3

Question 1

The Ricketts analysis dimension most predictive of post-treatment lip stability is the:

Accepted Answer

E-line (esthetic plane) relationship of the lips

Answer

ANB angle

Answer

Mandibular plane angle

Answer

Interincisal angle

Question 2

Which statement about lower incisor position and long-term stability is most supported by orthodontic evidence?

Accepted Answer

Maintaining lower incisors near their pre-treatment position improves stability

Answer

Proclining lower incisors is highly stable

Answer

Lower incisor position has no effect on stability

Answer

Intruding lower incisors always causes relapse

Question 3

Nighttime-only retainer wear is typically appropriate beginning at which stage?

Accepted Answer

After approximately one year of full-time wear

Answer

Immediately after debonding

Answer

After three months

Answer

Never — full-time wear is always required

Question 4

Canine-to-canine intercanine width changes during orthodontic treatment have the highest relapse rate because:

Accepted Answer

The intercanine dimension is closely controlled by the surrounding musculature and pre-treatment anatomy

Answer

Canines have the shortest roots

Answer

Canine brackets always debond prematurely

Answer

Canines erupt last in the permanent dentition

Question 5

Which radiographic finding on the ABO case presentation may indicate a problem with long-term stability?

Accepted Answer

Significant root resorption of anterior teeth

Answer

Normal alveolar bone levels

Answer

Parallel roots on panoramic radiograph

Answer

Well-interdigitated posterior occlusion

Question 6

The term 'post-retention stability' in orthodontics refers to:

Accepted Answer

Long-term maintenance of corrected tooth positions after retainers are discontinued

Answer

Tooth position immediately after retainer insertion

Answer

Stability of retainer material

Answer

Bonding strength of fixed retainers