ORTHODONTICS NBDE EXAM
WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED
DETAILED RATIONALES ANSWERS
LATEST 2024 (NEWEST) ALREADY
GRADED A+
A 12-year-old boy was classified as having class II division 2 malocclusion. What
position would you suspect the patient's maxillary centrals and laterals are in?
A. Maxillary centrals tipped palatally and in retruded position; maxillary lateral
tipped
labially and mesially
B. Maxillary centrals tipped palatally and in retruded position; maxillary lateral
tipped
palatally
C. Maxillary centrals tipped labially and in protruded position; maxillary lateral
tipped
labially and mesially
D. Maxillary centrals tipped labially and in protruded position; maxillary lateral
tipped
palatally
The correct answer is A. In class II division 2, it is typical for maxillary centrals to have
linguoversion, whereas maxillary laterals are tipped in the labial mesial direction. Class
II division 1 typically has maxillary centrals tipped palatally and in a retruded position.
Maxillary laterals are also tipped palatally.
How would you classify the occlusion below?
A. Class III malocclusion, also known as distoclusion
B. Class II malocclusion, also known as mesioclusion
,C. Class III malocclusion, also known as mesioclusion
D. Class II malocclusion, also known as distoclusion
E. Class I malocclusion
The correct answer is C. The image shows a dentition in class III malocclusion, which is
known as mesioclusion. Class II, not class III, is known as distoclusion. While the
statement in answer choice D is true, to classify malocclusion as class II: the first
mandibular molar
needs to be distal to the first maxillary molar.Class I malocclusion has the mesiobuccal
cusp of the maxillary first molar inter digitating with the buccal groove of the first
mandibular molar
In a pseudo-class III malocclusion, the patient has the ability to:
A. Bring the mandible back with strain so that the mandibular incisors touch the
maxillary incisors
B. Bring the mandible forward without strain so that the mandibular incisors
touch the
maxillary incisors
C. Bring the mandible forward with strain so that the mandibular incisors touch
the maxillary incisors
D. Bring the mandible back without strain so that the mandibular incisors touch
the maxillary incisors
The correct answer is D. Pseudo-class III patients adopt a closed-jaw position that is
forward to normal and typically presents with an edge-to-edge bite. Bringing the
mandible back with strain so that the mandibular incisors touch the maxillary incisors
depicts a patient who has class III malocclusion. Bringing the mandible forward without
strain so that the mandibular incisors touch the maxillary incisors depicts a class I
malocclusion. Bringing the mandible forward with strain so that the mandibular incisors
touch the maxillary incisors depicts a class II malocclusion
This is the most innermost point on contour of mandible between incisor tooth
and bony chin. This landmark is known as:
A. #11—point B
B. #11—point A
,C. #10—point A
D. #13—pogonion
E. #12—menton
The correct answer is A. Point B is also known as supramentale; #10 is point A; #12 is
pogonion; #13 is menton.
When the lines connecting sella-nasion and gonion-menton meet, they create an
angle that helps to determine the malocclusion. What type of anterior vertical
dimension and malocclusion correlates with this steep angle?
A. Long anterior vertical dimension and a deep-bite malocclusion.
B. Short anterior vertical dimension and an open-bite malocclusion.
C. Short anterior vertical dimension and a deep-bite malocclusion.
D. Long anterior vertical dimension and an open bite malocclusion.
The correct answer is D. The mandibular plane angle is a line connecting gonion -
gnathion (menton), and the sella-nasion. Mandibular plane angle determines open- or
deep-bite malocclusion by its measurement.A steep angle signifies a long vertical
dimension with an open-bite malocclusion. A steep angle signifies a long vertical
dimension with an open-bite malocclusion, not deep-bite malocclusion. When the
mandibular plane angle is flat, it signifies a short vertical dimension with a deep-bite
malocclusion. Although answer choice C is a correct statement, the question was
asking for a steep angle.
A 35-year-old man presents for an evaluation.Upon examination, you notice that
the patient's buccal cusps of the lower posterior teeth occlude buccal to the
buccal cusps of the upper posterior teeth on the left and the right side.What
treatment should be rendered to correct this malocculsion?
A. Surgery
B. Rapid maxillary expander
C. Quad helix expander
D. W-arch
E. Do nothing, it will eventually rectify by itself
The correct answer is A. The patient presented with a bilateral posterior crossbite, and
since the patient is 35 years of age, the sutures have closed and the maxilla and
, mandible stopped growing. Surgery is one of the best treatment options to correct a
crossbite. A rapid maxillary expander is an appliance that is used for a skeletal
expansion of the upper arch in the primary or mixed dentition,in cases where the upper
arch is very narrow and/or crossbite exists.The quad helix expander is a fixed, spring
loaded orthodontic appliance that uses four helical springs and is used primarily to
expand the maxillary dental arch, in cases where it is very narrow and/or crossbite
exists. It is utilized at an early stage of development to guide growth. The W-arch is a
fixed appliance constructed of steel wire soldered to molar bands. The W arch is a form
of rapid palatal expander (RPE)that is used for a skeletal expansion of the upper
arch in the primary or very early mixed dentition,in cases where the upper arch is very
narrow and/or crossbite exists. It is utilized at an early stage of development to guide
growth. Bilateral posterior crossbite is corrected only with orthodontic intervention.
This has been adapted as the best horizontal orientation that assesses lateral
representation of the skull. Which of the following cephalometric landmarks make
up this plane when a line is drawn to connect them?
A. Sella and nasion
B. Gonion and gnathion
C. Porion and orbitale
D. Spheno-occipital synchondrosis and anterior nasal spine (ANS)
The correct answer is C. This plane is known as the Frankfort-horizontal plane, which is
constructed by drawing a line connecting porion and orbitale. Sella-nasion line makes
the mandibular plane angle when intersected with the mandibular plane and is also
used to establish the vertical position of the mandible. Gonion and gnathion lines create
the mandibular plane. There is no plane connecting the spheno-occipital synchondrosis
and anterior nasal spine (ANS).
A 37-year-old Caucasian man has SNA angle of 88 degrees. What does SNA angle
of 88 degrees indicate regarding the patient's occlusion?
A. Maxillary retrusion
B. Maxillary protrusion
C. Class I skeletal pattern
WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED
DETAILED RATIONALES ANSWERS
LATEST 2024 (NEWEST) ALREADY
GRADED A+
A 12-year-old boy was classified as having class II division 2 malocclusion. What
position would you suspect the patient's maxillary centrals and laterals are in?
A. Maxillary centrals tipped palatally and in retruded position; maxillary lateral
tipped
labially and mesially
B. Maxillary centrals tipped palatally and in retruded position; maxillary lateral
tipped
palatally
C. Maxillary centrals tipped labially and in protruded position; maxillary lateral
tipped
labially and mesially
D. Maxillary centrals tipped labially and in protruded position; maxillary lateral
tipped
palatally
The correct answer is A. In class II division 2, it is typical for maxillary centrals to have
linguoversion, whereas maxillary laterals are tipped in the labial mesial direction. Class
II division 1 typically has maxillary centrals tipped palatally and in a retruded position.
Maxillary laterals are also tipped palatally.
How would you classify the occlusion below?
A. Class III malocclusion, also known as distoclusion
B. Class II malocclusion, also known as mesioclusion
,C. Class III malocclusion, also known as mesioclusion
D. Class II malocclusion, also known as distoclusion
E. Class I malocclusion
The correct answer is C. The image shows a dentition in class III malocclusion, which is
known as mesioclusion. Class II, not class III, is known as distoclusion. While the
statement in answer choice D is true, to classify malocclusion as class II: the first
mandibular molar
needs to be distal to the first maxillary molar.Class I malocclusion has the mesiobuccal
cusp of the maxillary first molar inter digitating with the buccal groove of the first
mandibular molar
In a pseudo-class III malocclusion, the patient has the ability to:
A. Bring the mandible back with strain so that the mandibular incisors touch the
maxillary incisors
B. Bring the mandible forward without strain so that the mandibular incisors
touch the
maxillary incisors
C. Bring the mandible forward with strain so that the mandibular incisors touch
the maxillary incisors
D. Bring the mandible back without strain so that the mandibular incisors touch
the maxillary incisors
The correct answer is D. Pseudo-class III patients adopt a closed-jaw position that is
forward to normal and typically presents with an edge-to-edge bite. Bringing the
mandible back with strain so that the mandibular incisors touch the maxillary incisors
depicts a patient who has class III malocclusion. Bringing the mandible forward without
strain so that the mandibular incisors touch the maxillary incisors depicts a class I
malocclusion. Bringing the mandible forward with strain so that the mandibular incisors
touch the maxillary incisors depicts a class II malocclusion
This is the most innermost point on contour of mandible between incisor tooth
and bony chin. This landmark is known as:
A. #11—point B
B. #11—point A
,C. #10—point A
D. #13—pogonion
E. #12—menton
The correct answer is A. Point B is also known as supramentale; #10 is point A; #12 is
pogonion; #13 is menton.
When the lines connecting sella-nasion and gonion-menton meet, they create an
angle that helps to determine the malocclusion. What type of anterior vertical
dimension and malocclusion correlates with this steep angle?
A. Long anterior vertical dimension and a deep-bite malocclusion.
B. Short anterior vertical dimension and an open-bite malocclusion.
C. Short anterior vertical dimension and a deep-bite malocclusion.
D. Long anterior vertical dimension and an open bite malocclusion.
The correct answer is D. The mandibular plane angle is a line connecting gonion -
gnathion (menton), and the sella-nasion. Mandibular plane angle determines open- or
deep-bite malocclusion by its measurement.A steep angle signifies a long vertical
dimension with an open-bite malocclusion. A steep angle signifies a long vertical
dimension with an open-bite malocclusion, not deep-bite malocclusion. When the
mandibular plane angle is flat, it signifies a short vertical dimension with a deep-bite
malocclusion. Although answer choice C is a correct statement, the question was
asking for a steep angle.
A 35-year-old man presents for an evaluation.Upon examination, you notice that
the patient's buccal cusps of the lower posterior teeth occlude buccal to the
buccal cusps of the upper posterior teeth on the left and the right side.What
treatment should be rendered to correct this malocculsion?
A. Surgery
B. Rapid maxillary expander
C. Quad helix expander
D. W-arch
E. Do nothing, it will eventually rectify by itself
The correct answer is A. The patient presented with a bilateral posterior crossbite, and
since the patient is 35 years of age, the sutures have closed and the maxilla and
, mandible stopped growing. Surgery is one of the best treatment options to correct a
crossbite. A rapid maxillary expander is an appliance that is used for a skeletal
expansion of the upper arch in the primary or mixed dentition,in cases where the upper
arch is very narrow and/or crossbite exists.The quad helix expander is a fixed, spring
loaded orthodontic appliance that uses four helical springs and is used primarily to
expand the maxillary dental arch, in cases where it is very narrow and/or crossbite
exists. It is utilized at an early stage of development to guide growth. The W-arch is a
fixed appliance constructed of steel wire soldered to molar bands. The W arch is a form
of rapid palatal expander (RPE)that is used for a skeletal expansion of the upper
arch in the primary or very early mixed dentition,in cases where the upper arch is very
narrow and/or crossbite exists. It is utilized at an early stage of development to guide
growth. Bilateral posterior crossbite is corrected only with orthodontic intervention.
This has been adapted as the best horizontal orientation that assesses lateral
representation of the skull. Which of the following cephalometric landmarks make
up this plane when a line is drawn to connect them?
A. Sella and nasion
B. Gonion and gnathion
C. Porion and orbitale
D. Spheno-occipital synchondrosis and anterior nasal spine (ANS)
The correct answer is C. This plane is known as the Frankfort-horizontal plane, which is
constructed by drawing a line connecting porion and orbitale. Sella-nasion line makes
the mandibular plane angle when intersected with the mandibular plane and is also
used to establish the vertical position of the mandible. Gonion and gnathion lines create
the mandibular plane. There is no plane connecting the spheno-occipital synchondrosis
and anterior nasal spine (ANS).
A 37-year-old Caucasian man has SNA angle of 88 degrees. What does SNA angle
of 88 degrees indicate regarding the patient's occlusion?
A. Maxillary retrusion
B. Maxillary protrusion
C. Class I skeletal pattern
