NBDE Part 2 – Orthodontics Exam Questions and
Answers
Indirect bonding technique bonding requires - Answers--more complex
-technique sensitive
-extra precautions
.indirect bonding - Answers-1. accurate impression with alignate is taken and poured up
with orthodontic model stone
2. vertical lines are drawn on the teeth to lay brackets
3. brackets are loaded with a filled resin paste and cured
4. individual positioning of tray with silicone is prepared by applying it over the bracket
teeth on plaster model
5. place in warm water to dissolve the separating media
6. silicone tray is then removed from the plaster model with brackets embedded in it
7. brackets are cleaned under running water to make sure that pads have cured resin
8. enamel is etched, conditioned and unfilled resin is applied
9. silicone tray with embedded brackets is then positioned on teeth and bonded
.types of appliances - Answers-equal and opposite forces: elastic band stretched
between two brackets produces equal and opposite forces
one couple appliance: inserted into a bracket at one end and tied as a point contact at
the other.
two couple appliances: inserted into a bracket at each end. both a couple and a force
are produced at each end. The magnitude of the couple is largest at the end closer to
the bend in the wire.
All the sum of the forces are 0.
.functional appliances examples - Answers-Tissue borne: frankel functional appliance is
the only tissue borne functional appliance, which serves to expand the arch by
"padding" against the pressure of the lips and cheeks on the teeth and postures the
mandible forward and downward
toothborne:
-activator: advances the madible to an edge to edge position to induce mandibular
growth for the correction of class 2 malocclusion. Maxillary teeth are prevented from
erupting by the acrylic shelf while mandibular posterior teeth are free to erupt. This
improves the deep bite seen in class 2.
-bionator: similar to the activator in function but its design is trimmed down version of
the activator to make it more comfortable to wear
, -herbst: fixed or removable. metal rod and tube telescopic apparatus is attached
bilaterally to the maxillary first molars and mandibular first premolars. This helps to
posture the mandibule forward and induce growth.
-twin block appliance: 2 piece acrylic appliance postures the mandible forward with help
of occlusally inclined guiding planes and bite blocks. the vertical seperation of the jaws
is also configued by the height of the bite block. It postures the mandibular forward to
induce growth.
.functional appliances - Answers-changes the posture of the mandible, holding it open
or open and forward. strech of the muscles and soft tissues creates pressures
transmitted to the dental and skeletal structures, moving teeth and modifying growth.
they are used to treat class 2 malocclusion
.quad helix - Answers-fixed appliance that consists of 4 helix (2 anterior, 2 posterior),
used for posterior cross bite with digital sucking habit
.lip bumper - Answers--removable
-placed on the molars to move them more distal
-maintain space
-removes the pressure from the mandibular lip (allow for less crowding)
.anchorage used to - Answers-maintain space
.traction is used to - Answers-create space
.headgear is an orthopedic appliance that allows ortho to - Answers--control growth of
facial structures
-various designs
-growing patients
.greatest advantage of using extraoral anchorage - Answers-permits posterior
movement of teeth in one arch without adversely disturbing the opposite arch
.ideal wire material - Answers-1. high strength
2. low stiffness
3. high working range
4. high formability
.stainless steel wires - Answers--excellent corrosion resistance
-low cost
-18% chromium and 8% nickel
-Highest modulus of elasticity (stiffness) and lowest springback
.NiTi - Answers-highly desirable combinatin of low modulus of elasticity and wide
working range
Answers
Indirect bonding technique bonding requires - Answers--more complex
-technique sensitive
-extra precautions
.indirect bonding - Answers-1. accurate impression with alignate is taken and poured up
with orthodontic model stone
2. vertical lines are drawn on the teeth to lay brackets
3. brackets are loaded with a filled resin paste and cured
4. individual positioning of tray with silicone is prepared by applying it over the bracket
teeth on plaster model
5. place in warm water to dissolve the separating media
6. silicone tray is then removed from the plaster model with brackets embedded in it
7. brackets are cleaned under running water to make sure that pads have cured resin
8. enamel is etched, conditioned and unfilled resin is applied
9. silicone tray with embedded brackets is then positioned on teeth and bonded
.types of appliances - Answers-equal and opposite forces: elastic band stretched
between two brackets produces equal and opposite forces
one couple appliance: inserted into a bracket at one end and tied as a point contact at
the other.
two couple appliances: inserted into a bracket at each end. both a couple and a force
are produced at each end. The magnitude of the couple is largest at the end closer to
the bend in the wire.
All the sum of the forces are 0.
.functional appliances examples - Answers-Tissue borne: frankel functional appliance is
the only tissue borne functional appliance, which serves to expand the arch by
"padding" against the pressure of the lips and cheeks on the teeth and postures the
mandible forward and downward
toothborne:
-activator: advances the madible to an edge to edge position to induce mandibular
growth for the correction of class 2 malocclusion. Maxillary teeth are prevented from
erupting by the acrylic shelf while mandibular posterior teeth are free to erupt. This
improves the deep bite seen in class 2.
-bionator: similar to the activator in function but its design is trimmed down version of
the activator to make it more comfortable to wear
, -herbst: fixed or removable. metal rod and tube telescopic apparatus is attached
bilaterally to the maxillary first molars and mandibular first premolars. This helps to
posture the mandibule forward and induce growth.
-twin block appliance: 2 piece acrylic appliance postures the mandible forward with help
of occlusally inclined guiding planes and bite blocks. the vertical seperation of the jaws
is also configued by the height of the bite block. It postures the mandibular forward to
induce growth.
.functional appliances - Answers-changes the posture of the mandible, holding it open
or open and forward. strech of the muscles and soft tissues creates pressures
transmitted to the dental and skeletal structures, moving teeth and modifying growth.
they are used to treat class 2 malocclusion
.quad helix - Answers-fixed appliance that consists of 4 helix (2 anterior, 2 posterior),
used for posterior cross bite with digital sucking habit
.lip bumper - Answers--removable
-placed on the molars to move them more distal
-maintain space
-removes the pressure from the mandibular lip (allow for less crowding)
.anchorage used to - Answers-maintain space
.traction is used to - Answers-create space
.headgear is an orthopedic appliance that allows ortho to - Answers--control growth of
facial structures
-various designs
-growing patients
.greatest advantage of using extraoral anchorage - Answers-permits posterior
movement of teeth in one arch without adversely disturbing the opposite arch
.ideal wire material - Answers-1. high strength
2. low stiffness
3. high working range
4. high formability
.stainless steel wires - Answers--excellent corrosion resistance
-low cost
-18% chromium and 8% nickel
-Highest modulus of elasticity (stiffness) and lowest springback
.NiTi - Answers-highly desirable combinatin of low modulus of elasticity and wide
working range
