ABO Orthodontic Appliances and Mechanics Flashcards
6 cards from real ABO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ABO Orthodontic Appliances and Mechanics flashcards as text
Which factor most directly determines the center of rotation during tooth movement?
Answer: Moment-to-force (M/F) ratio
The moment-to-force ratio applied to a tooth determines where the center of rotation is located relative to the center of resistance.
Forsus Fatigue Resistant Device (FRD) is classified as which type of appliance?
Answer: Fixed functional appliance
The Forsus FRD is a fixed functional appliance that is attached to the orthodontic brackets and delivers a continuous corrective force.
The Herbst appliance corrects Class II malocclusion primarily through which mechanism?
Answer: Mandibular advancement and restraint of maxillary growth
The Herbst appliance postures the mandible forward continuously, stimulating mandibular growth and restraining maxillary forward development.
What is the recommended frequency of archwire changes when using superelastic NiTi wires?
Answer: Every 6–8 weeks
Superelastic NiTi wires deliver sustained forces over longer periods, so they are typically changed every 6–8 weeks.
A quad helix appliance is used primarily to achieve which treatment goal?
Answer: Maxillary transverse expansion and molar derotation
The quad helix is a fixed maxillary expander that widens the upper arch and derotates the upper molars.
Placing a reverse curve of Spee in the lower archwire is intended to:
Answer: Level the curve of Spee by extruding premolars and intruding incisors/molars
A reverse curve of Spee creates intrusive forces on the anteriors and molars while extruding the premolars to level a deep curve of Spee.