Dental Braces Orthodontic Appliances and Accessories 2 — Questions and Answers
Question 1: What is the primary purpose of a transpalatal arch (TPA)?
- To expand the upper jaw by widening the palate
- To correct tongue-thrusting habits
- To connect upper molars and maintain their width and position (Correct answer)
- To hold front teeth in alignment while back teeth are moved
Correct answer: To connect upper molars and maintain their width and position
A transpalatal arch connects upper first molars across the roof of the mouth to stabilize their position and prevent unwanted lateral movement during treatment.
Question 2: What is the main purpose of a Nance appliance?
- To correct crossbites in the front teeth
- To prevent upper molars from moving forward into extraction spaces (Correct answer)
- To hold the palate in place during jaw surgery
- To expand the lower dental arch
Correct answer: To prevent upper molars from moving forward into extraction spaces
A Nance appliance anchors upper molars using an acrylic button pressed against the palate, preventing them from drifting forward after teeth are extracted.
Question 3: What are orthodontic coil springs used for?
- To hold the archwire in curved positions
- To connect headgear to molar bands
- To hold the palatal expander key in place
- To open or close spaces between teeth (Correct answer)
Correct answer: To open or close spaces between teeth
Open coil springs push teeth apart to create space, while closed coil springs pull teeth together to close gaps, both working via the archwire.
Question 4: What is the function of a bite plate or bite turbo?
- To hold retainers in place during sleep
- To prevent the upper and lower teeth from fully occluding so bite correction can proceed (Correct answer)
- To prevent thumb-sucking habits
- To align the midline of the upper and lower teeth
Correct answer: To prevent the upper and lower teeth from fully occluding so bite correction can proceed
Bite plates and bite turbos create a temporary open bite by preventing teeth from fully touching, which allows orthodontic forces to correct the bite without interference.
Question 5: What best describes a Forsus appliance?
- A removable device worn only at night to advance the lower jaw
- A type of clear aligner used for minor bite corrections
- A fixed spring mechanism attached to braces that continuously corrects overbites by advancing the lower jaw (Correct answer)
- An appliance that holds extraction sites open to prevent space closure
Correct answer: A fixed spring mechanism attached to braces that continuously corrects overbites by advancing the lower jaw
The Forsus appliance is a fixed spring attached to the upper and lower braces that constantly pushes the lower jaw forward to correct overbites, replacing the need for headgear or rubber bands.
Question 6: What is the main purpose of a lower lingual arch?
- To maintain space in the lower arch and prevent molars from moving forward (Correct answer)
- To correct tongue-thrusting habits in children
- To create space between lower front teeth
- To hold the lower jaw in a retracted position
Correct answer: To maintain space in the lower arch and prevent molars from moving forward
A lower lingual arch is a space maintainer that runs along the inside of the lower teeth between molars, preventing them from drifting forward after primary teeth are lost early.
Question 7: What is the function of orthodontic ligature ties?
- To connect upper and lower jaw appliances together
- To connect rubber bands to hooks on the brackets
- To secure the archwire into each bracket slot (Correct answer)
- To hold palatal expanders in position
Correct answer: To secure the archwire into each bracket slot
Ligature ties — either tiny elastic rings or thin metal wires — wrap around each bracket to hold the archwire securely in the bracket slot so forces are transmitted to the teeth.
Dental Braces Orthodontic Appliances and Accessories 2
What is the primary purpose of a transpalatal arch (TPA)?