FAGD EXAM – ORTHODONTICS
QUESTIONS AND ANSWERS
Maxillary fixed bilateral space maintainer is also known as? - Correct Answers -Nance
appliance
If both primary canines were present, what appliance could be used in place of a Nance
appliance (maxillary fixed bilateral space maintainer)? - Correct Answers -Band and
loop (bilateral)
What situation is a Nance appliance appropriate for? - Correct Answers -Premature
bilateral loss of maxillary primary teeth
What are the 4 properties of ideal wire material? - Correct Answers -1. High strength
2. Low stiffness
3. High working range
4. High formability
Stainless steel wire characteristics - Correct Answers -- good mechanical properties
- excellent corrosion resistance
- low cost
- highest modulus of elasticity
- lowest spring back
- 18% chromium, 8% nickel
Stainless steel vs nickel titanium orthodontic wires - Correct Answers -Stainless steel
has a high modulus of elasticity and a lower resilience
NiTi orthodontic wire characteristics - Correct Answers -Offer a highly desirable
combination of low modulus of elasticity and extremely wide working range
Benefits of the Hawley retainer? - Correct Answers -- palatal coverage makes it possible
to incorporate a bite plant lingual to the upper incisors to control bite depth
-
What is the major source of anchorage in a Hawley appliance? - Correct Answers -
Palatal coverage
, What does a steep mandibular plane correlate with? - Correct Answers -- long anterior
facial vertical dimension
- anterior open bite
- greater maxillary/mandibular plane angle
Generally, a long face predisposes the patient to ___? - Correct Answers -Class II
malocclusion
Generally, a short face predisposes a patient to ___? - Correct Answers -Class III
malocclusion
Prior to direct bonding, ________ is used as an etching agent. Prior to placing bands,
________ is used as an etching agent? - Correct Answers -35-50% unbuffered
phosphoric acid
Nothing
Indications for using bands instead of banded brackets? (4) - Correct Answers -1. To
provide better anchorage for greater tooth movement
2. For teeth that will need both lingual and labial attachment
3. Teeth with short clinical crowns
4 Tooth surfaces that are incompatible with successful bonding
What is the "anchorage value" of any tooth? - Correct Answers -It is roughly equivalent
to its root surface area (the same as the periodontal ligament area)
What are the 5 anchorage types? - Correct Answers -1. Reciprocal tooth movement: is
produced when two teeth or resistance units of equal size are moved against each other
and move the same amount toward or away from each other.
2. Reinforced anchorage: is accomplished by adding additional teeth to the unit to
distribute the force over a larger root surface area in the anchorage unit. Note: Another
method for reinforcing anchorage would be to add an extraoral force such as headgear
or interarch elastics.
3. Stationary anchorage: displacement of anchor teeth can be minimized by arranging
the force system so that anchor teeth must move bodily (translation) if at all, while
movement teeth are allowed to tip. This approach is called "stationary anchorage."
4. Cortical anchorage: anchor teeth roots are moved into cortical bone which resorbs
more slowly than does medullary bone. This situation may be encountered at an old
extraction site, it can be almost impossible to close such an extraction site, because
tooth movement is slowed to a minimum as the roots encounter cortical bone along the
resorbed alveolar ridge.
5. Implants for anchorage: implants can serve as anchorage for holding or moving teeth.
The implant (if stable) will not move because it has no PDL
QUESTIONS AND ANSWERS
Maxillary fixed bilateral space maintainer is also known as? - Correct Answers -Nance
appliance
If both primary canines were present, what appliance could be used in place of a Nance
appliance (maxillary fixed bilateral space maintainer)? - Correct Answers -Band and
loop (bilateral)
What situation is a Nance appliance appropriate for? - Correct Answers -Premature
bilateral loss of maxillary primary teeth
What are the 4 properties of ideal wire material? - Correct Answers -1. High strength
2. Low stiffness
3. High working range
4. High formability
Stainless steel wire characteristics - Correct Answers -- good mechanical properties
- excellent corrosion resistance
- low cost
- highest modulus of elasticity
- lowest spring back
- 18% chromium, 8% nickel
Stainless steel vs nickel titanium orthodontic wires - Correct Answers -Stainless steel
has a high modulus of elasticity and a lower resilience
NiTi orthodontic wire characteristics - Correct Answers -Offer a highly desirable
combination of low modulus of elasticity and extremely wide working range
Benefits of the Hawley retainer? - Correct Answers -- palatal coverage makes it possible
to incorporate a bite plant lingual to the upper incisors to control bite depth
-
What is the major source of anchorage in a Hawley appliance? - Correct Answers -
Palatal coverage
, What does a steep mandibular plane correlate with? - Correct Answers -- long anterior
facial vertical dimension
- anterior open bite
- greater maxillary/mandibular plane angle
Generally, a long face predisposes the patient to ___? - Correct Answers -Class II
malocclusion
Generally, a short face predisposes a patient to ___? - Correct Answers -Class III
malocclusion
Prior to direct bonding, ________ is used as an etching agent. Prior to placing bands,
________ is used as an etching agent? - Correct Answers -35-50% unbuffered
phosphoric acid
Nothing
Indications for using bands instead of banded brackets? (4) - Correct Answers -1. To
provide better anchorage for greater tooth movement
2. For teeth that will need both lingual and labial attachment
3. Teeth with short clinical crowns
4 Tooth surfaces that are incompatible with successful bonding
What is the "anchorage value" of any tooth? - Correct Answers -It is roughly equivalent
to its root surface area (the same as the periodontal ligament area)
What are the 5 anchorage types? - Correct Answers -1. Reciprocal tooth movement: is
produced when two teeth or resistance units of equal size are moved against each other
and move the same amount toward or away from each other.
2. Reinforced anchorage: is accomplished by adding additional teeth to the unit to
distribute the force over a larger root surface area in the anchorage unit. Note: Another
method for reinforcing anchorage would be to add an extraoral force such as headgear
or interarch elastics.
3. Stationary anchorage: displacement of anchor teeth can be minimized by arranging
the force system so that anchor teeth must move bodily (translation) if at all, while
movement teeth are allowed to tip. This approach is called "stationary anchorage."
4. Cortical anchorage: anchor teeth roots are moved into cortical bone which resorbs
more slowly than does medullary bone. This situation may be encountered at an old
extraction site, it can be almost impossible to close such an extraction site, because
tooth movement is slowed to a minimum as the roots encounter cortical bone along the
resorbed alveolar ridge.
5. Implants for anchorage: implants can serve as anchorage for holding or moving teeth.
The implant (if stable) will not move because it has no PDL
