ABO ABO Orthodontic Appliances and Mechanics 3

Question 1

Which factor most directly determines the center of rotation during tooth movement?

Accepted Answer

Moment-to-force (M/F) ratio

Answer

Wire stiffness

Answer

Bracket width

Answer

Archwire cross-section

Question 2

Forsus Fatigue Resistant Device (FRD) is classified as which type of appliance?

Accepted Answer

Fixed functional appliance

Answer

Removable functional appliance

Answer

Extraoral appliance

Answer

Palatal expansion appliance

Question 3

The Herbst appliance corrects Class II malocclusion primarily through which mechanism?

Accepted Answer

Mandibular advancement and restraint of maxillary growth

Answer

Maxillary retraction only

Answer

Pure dental tipping

Answer

Molar intrusion

Question 4

What is the recommended frequency of archwire changes when using superelastic NiTi wires?

Accepted Answer

Every 6–8 weeks

Answer

Every 2 weeks

Answer

Every 3–4 weeks

Answer

Every 3–4 months

Question 5

A quad helix appliance is used primarily to achieve which treatment goal?

Accepted Answer

Maxillary transverse expansion and molar derotation

Answer

Mandibular sagittal advancement

Answer

Anterior bite opening

Answer

Lower incisor proclination

Question 6

Placing a reverse curve of Spee in the lower archwire is intended to:

Accepted Answer

Level the curve of Spee by extruding premolars and intruding incisors/molars

Answer

Increase overbite

Answer

Retract the lower anterior teeth

Answer

Expand the lower arch