EFDA Orthodontic Procedures & Appliances 2 â Questions and Answers
Question 1: What does a rapid palatal expander (RPE) accomplish in orthodontic treatment?
- It retracts the maxillary arch posteriorly to correct Class III relationships
- It holds the mandible in a forward protrusive position during growth
- It widens the maxillary arch by gradually separating the midpalatal suture (Correct answer)
- It intrudes the maxillary molars to correct a deep overbite
Correct answer: It widens the maxillary arch by gradually separating the midpalatal suture
The RPE is activated incrementally, applying lateral force to the palatal shelves that separates the unfused midpalatal suture, increasing the width of the maxillary arch to treat constriction or posterior crossbite.
Question 2: Why are superelastic nickel-titanium archwires preferred for the initial stage of orthodontic treatment?
- They are the stiffest wires and generate the highest corrective forces
- They have the largest diameter available, providing maximum torque control
- They deliver light, continuous forces and can engage severely malpositioned brackets (Correct answer)
- They are the least costly archwire option for routine use
Correct answer: They deliver light, continuous forces and can engage severely malpositioned brackets
Superelastic NiTi wires have shape memory and low load-deflection, meaning they apply gentle, sustained forces even when deflected significantly to engage brackets on extremely misaligned teeth.
Question 3: What type of force does an orthodontic headgear primarily apply?
- Intrusive force directed apically to depress maxillary molars
- Lateral force across the palate to widen the maxillary arch
- Extraoral force to restrict maxillary forward growth or retract maxillary teeth (Correct answer)
- Rotational force to correct individually tipped teeth
Correct answer: Extraoral force to restrict maxillary forward growth or retract maxillary teeth
Headgear uses an external facebow inserted into molar tubes connected by straps to a cervical pad or headcap, applying extraoral orthopedic or orthodontic force to the maxilla.
Question 4: If a patient calls to report a broken or loose bracket between appointments, what is the most appropriate advice?
- Instruct the patient to reattach the bracket using household adhesive until the appointment
- Schedule a prompt repair appointment and advise the patient to avoid hard, crunchy, or sticky foods (Correct answer)
- Tell the patient the bracket is not urgent and can wait until the next regularly scheduled visit
- Advise the patient to cut the arch wire adjacent to the broken bracket at home
Correct answer: Schedule a prompt repair appointment and advise the patient to avoid hard, crunchy, or sticky foods
A broken bracket should be repaired promptly to avoid delaying treatment progress; avoiding hard foods prevents further breakage while the patient waits for the repair appointment.
Question 5: What is the purpose of interarch elastics (rubber bands) that orthodontic patients wear between upper and lower brackets?
- To tie the arch wire into the bracket slots on each tooth
- To keep the palatal expander activated between appointments
- To apply forces between the upper and lower arches to correct jaw and bite relationships (Correct answer)
- To hold a removable retainer securely in the mouth during sleep
Correct answer: To apply forces between the upper and lower arches to correct jaw and bite relationships
Interarch elastics run from hooks on upper brackets or bands to hooks on lower brackets, generating forces that correct anteroposterior, vertical, or transverse discrepancies between the arches.
Question 6: In orthodontics, the term 'debonding' refers to which procedure?
- Activating the palatal expander screw at each appointment visit
- Removing directly bonded brackets from tooth surfaces at the conclusion of treatment (Correct answer)
- Applying acid etchant to enamel before attaching a new bracket
- Cutting the arch wire during a routine adjustment appointment
Correct answer: Removing directly bonded brackets from tooth surfaces at the conclusion of treatment
Debonding uses bracket-removing pliers to fracture the adhesive bond between the bracket base and enamel, followed by cleanup of residual adhesive and polishing of the tooth surface.
Question 7: What is the typical interval between orthodontic adjustment appointments during active treatment?
- Every 1 to 2 days
- Every 2 to 3 weeks
- Every 4 to 8 weeks (Correct answer)
- Every 3 to 6 months
Correct answer: Every 4 to 8 weeks
Most patients are scheduled every 4 to 8 weeks to allow sufficient biologic tooth movement and bone remodeling in response to the applied forces before wire changes or adjustments are made.
EFDA Orthodontic Procedures & Appliances 2
What does a rapid palatal expander (RPE) accomplish in orthodontic treatment?