Orthodontic Diagnosis and Treatment Planning Flashcards

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

Answer: Maxilla relative to cranial base

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

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

Answer: Skeletal Class III

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

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

Answer: Resistance to unwanted tooth movement

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

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

Answer: Severe skeletal discrepancy beyond dental compensation

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

The mixed dentition analysis is used to predict:

Answer: Size of unerupted permanent canines and premolars

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

A deep overbite with excessive curve of Spee is typically corrected by:

Answer: Extruding posterior teeth or intruding incisors to level the arch

Leveling the curve of Spee via incisor intrusion or molar extrusion reduces a deep overbite.

Which soft tissue analysis relates the lips to a line from the nose tip to the chin?

Answer: Steiner S-line / Ricketts E-line

The E-line (Ricketts) and S-line (Steiner) assess lip position relative to nose and chin references.