ABO ABO Retention and Stability 2

Question 1

Bonded retainers should be checked at recall visits primarily for:

Accepted Answer

Bond failures, wire distortion, and signs of plaque accumulation

Answer

Bonded retainer recall includes checking bond integrity, wire distortion, and periodontal health since fixed wires can accumulate plaque.

Question 2

Essix (vacuum-formed) retainers are contraindicated in patients who:

Accepted Answer

Exhibit bruxism or severe parafunction

Answer

Patients with bruxism can rapidly wear through or fracture vacuum-formed retainers, reducing their effectiveness and potentially damaging dentition.

Question 3

Long-term stability of corrected Class III malocclusion treated with growth modification is LEAST favorable in patients with:

Accepted Answer

Vertical mandibular growth pattern and strong Class III genetics

Answer

A vertical growth pattern combined with strong Class III genetic tendency produces the highest risk of relapse after orthopedic correction.

Question 4

The primary purpose of a positioner appliance at the end of fixed treatment is to:

Accepted Answer

Seat and refine the occlusion while providing initial retention

Answer

Positioners use a flexible rubber or silicone tray to detail and seat the occlusion while simultaneously acting as a short-term retainer.

Question 5

According to the ABO grading system, which OGS (Objective Grading System) criterion evaluates the axial inclination of posterior teeth?

Accepted Answer

Root angulation

Answer

The ABO OGS root angulation criterion evaluates whether roots are properly parallel and properly angulated on the final panoramic radiograph.

American Board of Orthodontics (ABO) Practice Test