Classification of Malocclusion

# In Angle's classification for malocclusion, the key tooth is:
A. Mesiobuccal cusp of permanent maxillary forst molar
B. Distobuccal cusp of permanent maxillary first molar
C. Mesiobuccal cusp of permanent maxillary second molar
D. Mesiobuccal cusp of permanent mandibular first molar

# Andrew's 5th Key of occlusion is:
A. Curve of Spee
B. Rotation absent
C. Tight contact
D. Bolton's ratio

# Zygoma or Key ridge corresponds to:
A. Mesiobuccal root of upper first molar
B. Mesiobuccal root of upper second molar
C. Distobuccal cusp of upper first molar
D. Distobuccal cusp of second molar

  

# Angles line of occlusion are seen in which plane?
A. Sagittal
B. Vertical
C. Transverse
D. Transverse and vertical

# When Angle's classification system is used then displacement occurs in which direction?
A. Vertical
B. Transverse
C. Sagittal
D. Sagittal and transverse

# The following features are noted in a patient. The mesiobuccal cusp of right upper first molar is aligning in the mesiobuccal groove of right lower first molar. The distobuccal cusp of left upper first molar is aligning in the mesiobuccal groove of left lower first molar. The upper incisors are retroclined. You would like to classify it as:
A. Angle's class I div I subdivision
B. Angle's class II div I subdivision
C. Angle's class II div II subdivision
D. Angle's class III div I subdivision

# A patient is having edge to edge or end on relation of first molar in permanent dentition with retroclination of incisors. The malocclusion according to Angle's classification is:
A. Class I
B. Class II Div I
C. Class II Div II
D. Class III

# Anterior crossbites according to Dewey are classified in Angle's class I as:
A. Type I
B. Type II
C. Type III
D. Type IV

# Who has classified malocclusion based on etiology?
A. Angle
B. Lischer
C. Benett
D. Dewey

# Classification for skeletal malocclusion was given by:
A. Kartz
B. Salzman
C. Angle
D. Kingsley

# Transposition of teeth refers to:
A. Buccorotation of 120 degrees
B. Hypodontia
C. Teeth erupted in unusual position
D. Inverted supernumerary teeth

# Transposition of teeth is most commonly seen in the region of:
A. Maxillary central and lateral incisors
B. Mandibular canine and first premolar
C. Maxillary lateral incisor, canine and premolar
D. Mandibular first and second premolars

# The term torsiversion refers to the:
A. Impaction of the maxillary canines
B. Interchange of position of teeth
C. Rotation of teeth in their long axis
D. None of the above

# Postnormal occlusion is:
A. Class I with anterior crowding
B. Class II malocclusion
C. Class III malocclusion
D. Bimaxillary protrusion

# If the tooth has not erupted to the line of occlusion, it is called:
A. Supraversion
B. Torsiversion
C. Rotated
D. Infraversion

# The skeletal classification of malocclusion is given by:
A. Calvin Case
B. Martin Dewey
C. Paul Simon
D. Edward H. Angle

# If maxillary canines are placed forward to orbital plane, they are said to be in:
A. Protraction
B. Retraction
C. Abstraction
D. Contraction

# Which of the following system of classification gives a complete picture of malocclusion in a patient?
A. Simon
B. Ackerman
C. Dewey
D. Angle

# In Ackerman-Profitt classification, outer envelope represents:
A. Alignment
B. Profile
C. Transverse relation
D. Vertical relation

# In classifying molar relation in patient with premature loss of molar, additional relation to be noted is:
A. Incisor relation
B. Canine relation
C. Midline relation
D. Premolar relation

# Canine class I relation is:
A. Distal inclines of lower cuspid contact with mesial inclines of upper cuspid
B. Distal inclines of lower cuspid in line with distal inclines of upper cuspid
C. Mesial inclines of lower cuspid in contact with distal inclines of upper cuspid
D. Mesial inclines of lower cuspid in line with mesial inclines of upper cuspid

# Katz classification is based on:
A. Incisor
B. Canine
C. Premolar
D. Molar

# A bimax protrusion is:
A. Splitting and protrusion of maxilla into two halves
B. Forward placed upper and lower dental arches on normal skeletal bases
C. Forward placed upper dental arch and skeletal base
D. Forward placed lower dental arch and skeletal base

# The term surtrusion refers to the:
A. Backward movement of the condyle
B. Downward movement of the centric position
C. Lateral movement away from the midline
D. Upward movement of the working condyle as it moves away

Pioneer in the treatment of cleft palate

# Who among the following is named as the pioneer in the treatment of cleft palate and related problems?

A. Norman Kingsley

B. Edward H. Angle

C. Graber

D. Nance

The correct answer is A. Norman Kingsley.

Kingsley, was among the first to use extraoral force to correct protruding teeth. He was also a pioneer in the treatment of cleft palate and related problems. 

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First Orthodontic Appliance was developed by:

 # Who among the following developed the first orthodontic appliance?

A. Pierre Fauchard

B. Norman Kingsley

C. Emerson C. Angell

D. Edward H. Angle

The correct answer is A. Pierre Fauchard.

Orthodontics truly began developing in the 18th and 19th centuries. In 1728, French dentist Pierre Fauchard, who is often credited with inventing modern orthodontics, published a book entitled "The Surgeon Dentist" on methods of straightening teeth. Fauchard, in his practice, used a device called a "Bandeau", a horseshoe-shaped piece of iron that helped expand the palate. In 1754, another French dentist, Louis Bourdet, dentist to the King of France, followed Fauchard's book with The Dentist's Art, which also dedicated a chapter to tooth alignment and application. He perfected the "Bandeau" and was the first dentist on record to recommend extraction of the premolar teeth to alleviate crowding and to improve jaw growth.

Pierre Fauchard, 'Father of modern dentistry', as early as 1723, developed first orthodontic appliance.

Norman Kingsley, the first to use extraoral force on teeth. He is also considered to be the first person to use orthopedic force to correct protruding teeth.

Bunon- first to use the term 'orthopedic appliances'

Emerson C. Angell - founder of 'rapid maxillary expansion'

William E. Magill - First person to band teeth for active tooth movement. 

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Jackson's Triad in Orthodontics

 # Which of the following is a component of Jackson’s triad?

A. Functional efficiency

B. Structural balance

C. Aesthetic harmony

D. All of the above

The correct answer is D. All of the above.

The aims and objectives of orthodontic treatment have been summarized by Jackson as the 'Jackson's triad'. The three main objectives of orthodontic treatment are:

- Functional efficiency

- Structural balance

- Aesthetic harmony

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# The term ‘Orthodontics’ was coined by:

 # The term ‘Orthodontics’ was coined by:

A. Le Foulon

B. Hunter

C. Carabelli

D. Norman Kingsley

The correct answer is A. Le Foulon.

The term orthodontics was apparently used first by the Frenchman Le Foulon in 1839.

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The occipital condyle is represented by the following cephalometric point:

 # The occipital condyle is represented by the following cephalometric point:

A. Bolton’s point

B. Broadbent registration point

C. Basion

D. Articulare

The correct answer is A. Bolton's point.

Bolton's point: The highest point at the post-condylar notch of occipital bone

Few other cephalometric landmarks are:

1. Glabella: It is the most prominent point on the forehead in the mid-sagittal plane.

2. Nasion: The most anterior point midway between the frontal and nasal bone on the frontonasal suture.

3. Orbitale: The lowest point on the inferior bony margin of the orbit.

4. Porion: The highest bony point on the upper margin of external auditory meatus.

5. Sella: This point represents the mid point of the pituitary fossa or sella-turcica.

6. Basion: It is median point of the anterior margin of the foramen magnum

7. Anterior nasal spine: It is the anterior tip of the sharp bony process of the maxilla in the midline of the lower margin of anterior nasal spine.

8. Point A: It is a deepest point in the midline between the anterior nasal spine and alveolar crest between the two central incisors. It is also called as " subspinale".

9. Prosthion: The lowest and the most anterior point on the alveolar bone in the midline between the upper central incisors. It is also called as " supradentale".

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10. The key ridge: The lower most point on the contour of anterior wall of the infra-temporal fossa.

11. Posterior nasal spine: The intersection of a continuation of the the anterior wall of the pterygopalatine fossa and the floor of the nose, marking the distal limit of the maxilla.

12. Broadbent registration point: It is the midpoint of the perpendicular from the centre of the sella turcica to the Bolton point. 

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13 PTM point: It is the intersection of the inferior border of foramen rotundum with posterior wall of the pterygo maxillary fissure.

14. Chelion: It is the lateral terminus of the oral slit on the slit on the outer corner of the mouth.

15. Subnasal: The point where the lowest border of the nose meets the outer contour of the upper lip. 

16. Point B: It is the deepest point in the midline between the alveolar crest of mandible and the mental process. Also called as " submentale".

17. Gonion: It is a constructed point at the junction of ramal plane and the mandibular plane.

18. Pogonion: It is the most anterior point of the bony chin in the median plane.

19. Menton: It is the most inferior midline point on the mandibular symphysis.

20. Gnathion: It is the most antero-inferior point on the symphysis of the chin. It is constructed on the symphysis of the chin, by intersecting a line drawn perpendicular to the line connecting menton and pogonion.

21. Articulare: It is a point at the junction of the posterior border of ramus and the inferior border of the basilar part of the occipital bone.

22. Condylion: The most superior point on the head of the condyles.

23. Infradentale: The highest and the most anterior point on the alveolar process, in the median plane between the mandibular incisors.

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Termination of skeletal maturity - Indicator

 # Which of the following bone indicates the termination of skeletal maturity?

A. Presence of Sesamoid

B. Appearance of pisiformis

C. Appearance of calcification of hook of hamate

D. Union of diaphysis and epiphysis on radius

The correct answer is D. Union of diaphysis and epiphysis on radius.

Some other important tips:

 * Absence of hamate and pisiform - Still 1 year for prepubertal growth spurt

* Presence of hamular process of the hamate, pisiform and sesamoid- Beginning of  growth spurt

* Initial ossification of  sesamoid - Peak pubertal growth spurt

* The epiphysis and diaphysis fusion/ ossification of sesamoid completed - Prepubertal growth spurt completed

* The epiphysis and diaphysis fusion on radius and ulna- Active growth completed

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