Examination Practice Questions And

Illinois Orthodontic Assistant Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Q1. What is the primary purpose of orthodontic treatment?

• Improve speech only
• Enhance facial aesthetics only
• Restore missing teeth
• Correct malocclusion to improve oral function and aesthetics

Rationale: Orthodontics corrects malocclusions that affect function,

alignment, and facial balance.

Q2. Which index is most commonly used to assess orthodontic treatment need? 1 / 4

• DMFT index
• PAR index
• CPI index
• Bartlett index

Rationale: The Peer Assessment Rating (PAR) index measures severity and

improvement.

Q3. What is the ideal age for the first orthodontic evaluation according to the AAO?

• 3 years
• 5 years
• 7 years
• 12 years

Rationale: At age 7, mixed dentition allows recognition of growth issues

early.

Q4. What is the main function of a bracket in fixed orthodontics?

• Retain elastics
• Provide anchorage
• Replace a missing tooth
• Hold the archwire to transmit corrective forces

Rationale: Brackets guide and hold the wire to apply forces on teeth. 2 / 4

Q5. What is the purpose of an archwire?

• To retain elastics
• Move teeth through controlled forces
• Stabilize appliances
• Seal pits and fissures

Rationale: Archwires deliver the mechanical force that shifts tooth

position.

Q6. Stainless steel archwires are known for:

• High elasticity only
• High strength and low flexibility
• Being more aesthetic
• Rapid deterioration

Rationale: Stainless steel is strong, rigid, and commonly used in later

treatment stages.

Q7. Nickel-titanium archwires are chosen for:

• Finishing stages
• Initial alignment due to superelasticity
• Providing heavy forces
• Long-term retention 3 / 4

Rationale: NiTi wires deliver light, continuous forces ideal for early

alignment.

Q8. Which appliance is commonly used to expand the maxillary arch?

• Nance appliance
• Herbst appliance
• Rapid palatal expander
• Lingual arch

Rationale: RPE widens the maxilla by applying transverse forces.

Q9. A space maintainer is used to:

• Align teeth
• Correct overjet
• Prevent space loss after premature tooth loss
• Reduce plaque

Rationale: It preserves arch space so permanent teeth erupt correctly.

Q10. What malocclusion involves a retrusive mandible and excessive overjet?

• Class I
• Class II
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