ABO Orthodontic Diagnosis and Treatment Planning 4

Question 1

The SNA angle primarily indicates the anteroposterior position of which structure?

Accepted Answer

Maxilla relative to cranial base

Answer

The SNA angle measures the anteroposterior position of the maxilla relative to the cranial base.

Question 2

A patient with a concave profile, protrusive lower lip, and negative overjet most likely has:

Accepted Answer

Skeletal Class III

Answer

A concave profile with negative overjet is typical of a skeletal Class III relationship.

Question 3

During treatment planning, the term 'anchorage' refers to:

Accepted Answer

Resistance to unwanted tooth movement

Answer

Anchorage is the resistance to reactive forces that prevents undesired movement of teeth used as a base.

Question 4

Which finding would most strongly favor a surgical rather than orthodontic-only approach in an adult?

Accepted Answer

Severe skeletal discrepancy beyond dental compensation

Answer

Severe skeletal discrepancies in non-growing adults typically require orthognathic surgery.

Question 5

The mixed dentition analysis is used to predict:

Accepted Answer

Size of unerupted permanent canines and premolars

Answer

Mixed dentition analysis estimates the space needed for unerupted canines and premolars.

American Board of Orthodontics (ABO) Practice Test