Average Leeway Space

# The average "Leeway space" available in each half of the maxilla is approximately:
a) 0.9 mm
b) 4.0 mm
c) 2.9 mm
d) 6.9 mm 

The correct answer is A. 0.9 mm.

The combined mesiodistal width of the permanent canines and premolars is usually less than that of deciduous canines and molars and this difference is known as Leeway Space of Nance. This space is used by the permanent lower molars during late mesial shift from end-on occlusion to class-I relation. The amount ot leeway space is about 1.8 mm (0.9 mm on each side of arch) in maxillary arch and about 3.4 mm in mandibular arch (1. 7 mm on each side of arch). 

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Ugly duckling stage

# Ugly duckling stage affects:
a) Maxillary anterior teeth
b) Mandibular anterior teeth
c) Both Maxillary and mandibular teeth
d) Cause decrease in vertical height 

The correct answer is A. Maxillary anterior teeth. 

Ugly duckling stage is seen in maxillary central incisor region between 8 -9 years of age. This condition is seen during eruption of permanent canines. The developing canines displaces the roots of central and lateral incisors mesially and causes distal divergence of the crowns of the central incisors resulting in midline diastema. 

This type of malocclusion is not seen in lower arch because lower anteriors erupt almost simultaneously. Also, the path of eruption of mandibular canine is different from that of maxillary canines.

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Canine placement

# Canine placed anterior to the orbital plane:
a) Protraction
b) Abstraction
c) Attraction
d) Expansion

The correct answer is A. Protraction.

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ANB Angle Cephalogram

# An ANB angle 2 ° on the cephalogram usually indicates:
a) An unfavorable relationship of mandible to maxilla
b) A favorable relationship of maxillary alveolar base to mandibular alveolar base
c) Poor cranial growth with poor prognosis
d) Retruded maxillary incisor

The Correct answer is B. A favorable relationship of maxillary alveolar base to mandibular alveolar base.

SNA angle relates maxilla to the cranial base. The mean value is 82°. A Larger value indicates prognathic maxilla while a smaller value is suggestive of retrognathic maxilla.

SNB angle relates mandible to cranial base. Its average value is 80°. Larger values indicate prognathic mandible while smaller values indicates retrusive mandible.

AN B angle denotes the relative position of maxilla and mandible to each other. Mean value is 2° .

An increase in this angle indicates class-II skeletal tendency while an angle that is Less than normal or a negative angle is suggestive of a skeletal classIII relationship.

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Frankfort's horizontal plane

# Frankfort's horizontal plane is formed by joining:
a) Porion and Orbitale
c) Porion and sella
b) Nasion and se lla
d) Porion and Nasion

The correct answer is A. Porion and Orbitale.

FHP or Frankfort horizontal plane =  Formed by joining Porion and orbitale
SN plane or anterior cranial base = Formed by joining nasion and sella
Cranial base length = Nasion and Bolton line
Upper facial height = Nasion to ANS (anterior nasal spine)
Lower facial height = ANS to menton
Total facial height = Nasion to menton

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Prolonged retention of primary tooth

# Prolonged retention of primary tooth may lead to
a) Altered path of permanent tooth eruption
b) Root resorption of adjacent tooth
c) Ankylosis of permanent tooth
d) Warping of roots of adjacent teeth

The correct answer is A. Altered path of permanent tooth eruption.

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Diagnosis in Orthodontics

# In a patient with competent lips together at rest, the lip line is opposite the tips of the upper incisors. The lip line is then described as:
a) Average
b) High
c) Incomplete
d) Low

# Following are "essential diagnostic criteria" according to Graber except:
a) Case history
b) Facial photographs
c) Periapical x-rays
d) Lateral cephalograms

# Incompetent lips refer to:
a) Inability of the Lips to cover the incisors in the mandibular relaxed position
b) Inability of the lips to cover the incisors in occlusion
c) The lips come in between the upper and lower incisors
d) Tongue thrusts against the lips during swallowing

# Mentalis muscle contraction causes the lower lip to:
a) Retrude
b) Protrude
c) Inversion
d) Eversion

# Transposition of teeth refers to:
a) Bucco rotation of 120°
b) Hypodontia
c) Teeth erupted in unusual position i.e, one tooth erupts in place of another
d) Inverted supernumerary teeth

# Carpel radiograph is used for assessment of:
a) Bone condition
b) Chronological age
c) Treatment plan
d) Skeletal maturation

# A reliable indicator of pubertal growth spurt on hand wrist films is sought as:
a) Ossification of adductor sessamoid
b) Appearance of hook of hamate
c) Ossification of all the carpal bones
d) Ossification of pisiform

# Dolicocephalic facial pattern is associated with:
a) Broad dental arch
b) Long and narrow dental arch
c) Paraboloid dental arch
d) Square dental arch

# Broad and short type of face is known as:
a) Mesoprosopic
b) Euryprosopic
c) Leptoprosopic
d) None of above

# Convex profile is seen in:
a) Class I
b) Class II
c) Class III
d) None of above

#  Facial divergence is:
a) Anterior placement of the midface
b) Inclination of the lower third of the face in relation to the forehead
c) Inclination of the upper third of the face to the middle third of the face
d) None of the above

# Fishman's index is used in relation with:
a) Population
b) Hand wrist radiographs
c) Cephalograms
d) Periodontal disease

# Brachy cephalic individual usually has:
a) Narrow dental arches
b) Broad dental arches
c) Normal dental arches
d) B or C

# The lip is supported by:
a) Relation of lip edge and facial surfaces of teeth
b) Labial sulcus between teeth and lip
c) Relationship of tongue and teeth
d) None

# Pletoric individual will have:
a) Tall and thin physique
b) Short and obese physique
c) Average physique
d) None of above

# Normal nasolabial angle:
a) 80°
c) 70°
b) 110°
d) 140°

# Hyperactive mentalis activity is seen in:
a) Class I
b) Class II division 1
c) Class II division 2
d) Class III

# Blanch test is used in diagnosis of:
a) Abnormal frenal attachments
b) Pseudo class III
c) Tongue thrusting
d) Tnumb sucking

# Backward path of mandibular closure is seen is:
a) Class II division 2
b) Class I
c) Pseudo class III
d) Class III

# Which of the following tests are employed to diagnose the mode of respiration?
a) Mirror test
c) Water test
b) Cotton test
d) All of the above

# The normal interincisal distance is:
a) 40 - 45 mm
b) 30 - 35 mm
c) 20 - 30 mm
d) 55 - 65 mm

# In gnathostatic models:
a) Maxillary cast is parallel to mandible cast
b) Maxillary cast is parallel to FH plane
c) Mandibular cast is parallel to FH plane
d) Both casts are parallel to FH plane

# Xeroradiography was invented by:
a) Chester F. Carlson in 1937
b) Simon
c) Hudson Kampula and Dickson in 1957
d) Hofrath and broad bent in 1934

# Ectomorphic, mesomorphic and endomorphic classification of body physique was given by:
a) Sheldon
b) Angle
c) LE Fouloun
d) Kielgren

# The Moyer's analyses requires the measurement of the:
a) Mesiodistal of the erupted permanent mandibular centrals and Laterals
b) Space available in the maxillary and mandibular posterior quadrants
c) Mesiodistal diameter of the unerupted premolars
d) Mesiodistal diameter of the unerupted maxillary and mandibular permanent cuspids and premolars

# Ashley-Howe model analysis is used to predict:
a) Tooth material excess
b) Maxillo-mandibular relationships
c) Basal bone-transverse relationship
d) Growth prediction

# Study models are used:
a) As references in orthodontic cases
b) To show shape, size and position of teeth
c) As an aid in treatment planning
d) All of the above

# Arch length analysis of a dentition shows a discrepancy of more than 10 mm. This indicates:
a) No extraction required if treated at an early age
b) No extraction required
c) Extraction of posterior teeth
d) Proximal stripping

# There are difference in completing a Hixon-Old father and Moyer's analysis. Of the following which would not be correct?
a) The Moyer's analysis requires the eruption of the mandibular permanent centrals and Laterals
b) The Hixon-Old father requires the eruption of the mandibular permanent centrals and laterals
c) The Hixon-Old father analysis requires the measured space available in all four posterior quadrants
d) The Moyer's analysis requires the measurement of the space available in the four posterior quadrants

# In which one of the following mixed dentition analysis of deciduous dentition there is no use of radiographs?
a) Carey's analysis
b) Moyer's analysis
c) Nance Carey's analysis
d) Pont's index


# The following is one of the mixed dentition analysis:
a) Tanaka Johnson
b) Counterpart analysis
c) Bjork analysis
d) Plaster cast analysis

# Which of the following analysis helps in determining the disproportion in the size between maxillary and mandibular teeth?
a) Pont's analysis
b) Bolton's analysis
c) Peck and Peck analysis
d) Carey's analysis

# Four dentists did study model analysis by Johnson and Tanaka; Moyer's, Stanley and Kerber, Wits analysis. Which one will give the best results:
a) Johnson and Tanaka
b) Moyer's
c) Stanley and Kerber
d) Wits

# Mixed dentition analysis was described by
a) Graber
b) Angle
c) Tweed
d) Moyer's

# In mixed dentition analysis, which tooth is used for classification:
a) Primary 1st molar
b) Primary 2nd molar
c) Permanent lst molar
d) B or C

#  Arch perimeter can be measured with:
a) Cephalogram
b) Brass wire
c) Vernier calipers
d) Occlusal radiograph

# Bolton analysis is used to determine
a) Arch length - tooth size discrepancy
b) Apical base length to arch perimeter
c) Tooth size ratio in the maxilla
d) Upper teeth to Lower teeth size ratio

#  In Pont's analysis
a) The width of 4 maxillary incisors is calculated
b) The width of 4 mandibular incisors is calculated
c) The width of 10 teeth anterior to first molars is calculated
d) The width of 12 teeth anterior to second permanent molars is calculated
e) The mesiodistal width and faciolingual width of mandibular centrals and laterals are taken individually

# The number of sites examined to assess the stages of bone maturation in Fishman's skeletal maturation index are:
a) 4
b) 5
c) 6
d) 7

#  SVED type of tooth plane is an example of:
a) Simple anchorage
b) Reciprocal anchorage
c) Extra oral anchorage
d) Reinforced anchorage


# In Peck and Peck index, mesiodistal and buccolingual measurements of which of the following tooth is taken:
a) Maxillary central incisor
b) Mandibular central incisor
c) Maxillary premolars
d) Mandibular molars

# Andrew's 5th key of occlusion is:
a) Curve of spee
b) Rotation absent
c) Tight contacts
d) Bolton's ratio

#  Lisping is associated commonly with which of the following malocclusions:
a) Anterior deepbite
b) Anterior crowding
c) Anterior open bite
d) Anterior retroclination

# The SCAN index is generally used as a :
a) Malocclusion index
b) Treatment need index
c) Treatment change index
d) Treatment of priority index

# According to American Board of Orthodontics recommendation for colour coding of sequential tracing, end treatment ceph tracing is done in:
a) Black
b) Blue
c) Red
d) Green

# Which of the following is not a type of mouth breathing?
a) Obstructing
b) Anatomical
c) Physiological
d) Habitual

# Tooth Loss that causes the patient to bite in an abnormal relation of maxilla to mandible, in order to obtain better function during mastication is termed:
a) Convenience bite
b) Dramatic bite
c) Temporary bite
d) Squashed bite

# The term applied when it is doubtful, according to mixed dentition analysis whether there will be space for all the teeth:
a) Space maintenance
b) Space regaining
c) Space supervision
d) None of the above

# For class II div 1 malocclusion of 14 years old boy, which analysis is indicated to detect the tooth extraction:
a) Bolton's analysis
b) Pont's analysis
c) Peck & peck analysis
d) Ashley & Howe's analysis

# A lingually erupting maxillary lateral incisor:
a) Is always indicative of arch length deficiency
b) Can be corrected by using a tongue blade if sufficient space exists in the arch
c) Is a self-correcting anomaly
d) Is to be extracted as early as possible to avoid a reflective pathway of the mandible

# The orthodontic diagnosis focuses on:
a) Full smile
b) Emotional smile
c) Social smile
d) Gummy smile only

# Fishman index is used for:
a) Skeletal growth maturation index
b) Dental growth maturation index
c) Arch length discrepancy
d) Prognathism of maxilla

# Which of the following is NOT a type of mixed dentition analysis?
a) Moyer's
b) Tanaka Johnston
c) Pont & Linderharth
d) Hixon old Father

# In a perfect smile, the ratio of width to height of maxillary incisor is?
a) 8:10
b) 6:8
c) 10:14
d) 20:25

# Study model with mounted base and trimmed height is:
a) 55 mm
b) 70 mm
c) 60 mm
d) 90 mm

# Three quarter profile photograph is used to detect:
a) Lip incompetence
b) Mandibular asymmetry
c) Midline
d) Midface deformity

# Which of the following is used to measure the mineral bone density of mandible?
a) Micro radiography
b) Auto radiography
c) Finite element modeling
d) Nuclear volume morphometry