MCQs on Etiology of Malocclusion - Orthodontics

# Malocclusion can be progressive in:
A. Class I
B. Class II
C. Class III
D. Combination of both class I and Class III

# Retained mandibular deciduous central incisors will result in:
A. Lingual eruption of mandibular permanent incisors
B. Labial eruption of mandibular permanent incisors
C. Impaction of mandibular permanent incisors
D. Ankylosis of mandibular permanent incisors

# The most common local cause of malocclusion is:
A. Premature exfoliation of deciduous maxillary central incisors
B. Prolonged retention of primary teeth
C. Ankylosis of permanent teeth
D. Impaction of permanent teeth

# The most common cause of maxillary central incisor to be in cross bite is:
A. Premature exfoliation of deciduous maxillary central incisors
B. Prolonged retention of deciduous maxillary central incisors
C. High labial frenum
D. Early loss of deciduous mandibular

# Tooth in the mandibular arch which is most likely to be displaced due to arch size discrepancy is:
A. First molar
B. Second molar
C. First premolar
D. Second premolar

# Which of the following has maximum familial tendency ?
A. Protruded maxillary incisors
B. Open bite
C. Deep bite
D. Upper and lower cross bite

# The cause of Pseudo class III malocclusion is:
A. Developmental deficiency
B. Increased mandibular growth
C. Functional abnormality
D. Hormonal disturbance

# Mouth breathing with enlarged addenoids and tonsils may be best described as:
A. Anatomic
B. Obstructive
C. Psysiologic
D. Habitual

# A child who had a congenital defect of cleft lip and cleft palate is most likely to suffer from which type of malocclusion ?
A. Bilateral posterior cross bite
B. A collapsed anterior mandibular arch
C. Protrusion and spacing of maxillary anterior teeth
D. class II division I malocclusion

# Acromegaly is associated with:
A. Class I malocclusion
B. Class I cross bite
C. Class II malocclusion
D. Class III malocclusion

# Abnormally thick maxillary labial frenum results in:
A. maxillary midline diastema
B. Imbrication of incisors
C. labial inclination of incisors
D. anterior deep bite

# The abnormal swallowing pattern with the poorest prognosis is:
A. simple tongue thrust
B. complex tongue thrust
C. infantile swallow
D. retained infantile swallow

# Treatment of diastema because of thick labial frenum is done:
A. after frenectomy
B. before eruption of canines
C. after eruption of canines
D. before frenectomy

# The most probable cause of crowding in lower anterior region is:
A. Prologed retention of lower primary incisors
B. Premature exfoliation of lower primary incisors
C. Presence of supernumerary teeth
D. Tooth-size-arch length discrepancy

# Prologed 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

# A malocclusion is characterized by protrusion of maxilla, labioversion of maxillary incisors, deep overbite and overjet. These are typical characteristic of which malocclusion?
A. Class I
B. Class II Div I
C. Class II Div II
D. Class III

# A child is brought to clinic with complaint of irregular teeth. The maxillary central incisor is rotated in an otherwise normal occlusion. What should the next step be ?
A. check for supernumerary teeth
B. resection of supracrestal fibers
C. exert a couple on tooth
D. fixed orthodontic appliances given

# A 9 year old patient exhibits left maxillary central incisor in cross bite. Supporting bone is in harmony with tooth size. The most probable cause is:
A. Premature extraction of primary right central incisor
B. prolonged retention of primary left central incisor
C. absence of mandibular left central incisor
D. all of the above

# The most common cause of class II malocclusion is:
A. Sleeping habits
B. Growth discrepancy
C. Thumb and tongue thrusting
D. Tooth to jaw size discrepancy

# Bruxism bears which one of the following relationships to malocclusion ?
A. Malocclusion is only cause of bruxism
B. Malocclusion may be the cause of bruxism
C. Correction of occlusal discrepancy always eliminate bruxism
D. None of the above

# A 10 year old child wwith class II relationship stops thumb sucking:
A. Overjet will decrease
B. Upper incisors will become up right
C. There will be crowding of the lower incisors
D. Both A and B

# Which of the following is not a feature of simple tongue thrust swallowing ?
A. Contraction of facial muscle
B. Contraction of mandibular elevators
C. Teeth apart swallow
D. Anterior open bite

# The oral drive theory to explain thumb sucking habit was given by:
A. Benjamin
B. Sears and Wise
C. Sigmund Freud
D. Scheldon

# Abnormal muscle activity results in:
A. Bruxism
B. Nail biting
C. Tongue thrusting
D. Thumb sucking

# In adenoid facies, the facial profile is:
A. long and wide
B. long and narrow
C. short and wide
D. short and narrow

# Which is false ?
A. Heredity plays an important role in the development of normal occlusion
B. A tongue thrusting habit may cause an open bite
C. Mouth breathing is recognized contributing cause of malocclusion
D. The cuspids are the most useful teeth for the anchorage of appliances

# In the pre school stage, what percentage of children show thumb sucking ?
A. less than 10 %
B. 10 - 20 %
C. More than 50 %
D. almost all children

# Rooting reflex disappears in normal infants by the age of:
A. 4 months after birth
B. 7 months after birth
C. 9 months after birth
D. 12 months after birth

# Earnest Klein has classified habits into :
A. Compulsive and non compulsive habits
B. Intentional and non intentional habits
C. Primary and secondary habits
D. pressure and non pressure habits

# Breathing is termed anatomic mouth breathing if:
A. Short upper lip
B. Enlarged adenoid
C. Enlarged tonsil
D. Both A and B

# The positioning of tongue in infantile swallowing is:
A. Posterior
B. Medial
C. Lateral
D. Anterior

# The patients with class II division I malocclusion have:
A. Hypertonic lower lip
B. Hypotonic lower lip
C. Hypertonic upper lip
D. Hypotonic upper lip

# In thumb sucking habit, posterior cross bite occurs due to:
A. Loss of normal outward thrust of the tongue
B. Negative pressure within the oral cavity, which causes buccinator to force the maxillary molar palatally
C. Both A and B
D. Loss of oral seal

# Billy, a 13 year old child has a severe thumb sucking habit. On examination, he has a class II malocclusion, anteoior open bite with an overjet of 12 mm. His cephalogram will show:
A. Normal anterior and posterior facial heights
B. Increased anterior facial height and normal posterior facial height
C. Increased posterior facial height and normal anterior facial height
D. Increased anterior and posterior facial heights

# The effect of enlarged adenoids on the maxillary growth is by:
A. narrowing of maxilla
B. widening of maxilla
C. palatal plane tipped upwards at PNS
D. Palate descends down

# Which of the following cephalometric parameter is used to diagnose a long face syndrome patient ?
A. ANB angle
B. SNA angle
C. Jaraback ratio
D. Saddle angle

# More than 80 % cephalic index of a patient indicates:
A. Brachycephalic
B. Mesocephalic
C. Dolichocephalic
D. Depends upon age

# Soft tissue profile of a thumbsucking patient is:
A. Convex
B. Concave
C. Normal
D. Anterior divergent

# Relative to a heterogeneous population, the incidence of malocclusion in a homogeneous population generally is:
A. lower
B. slightly higher
C. significantly higher
D. about the same

# The supervision of a child's development of occlusion is most critical at ages:
A. 3-6 years
B. 7-10 years
C. 11-14 years
D. 14-17 years

# Anterior open bite and maxillary constriction is caused by:
A. Thumb sucking
B. Nail biting
C. Bruxism
D. Lip biting

# The most common variant of malocclusion seen is:
A. Angle's class I occlusion with anterior crowding
B. Angle's class I occlusion with posterior crowding
C. Angle's class II div I
D. Angle's class II div II

# A patient is involved in chronic mouth breathing. The clinical examination of the patient reveals:
A. Convex profile, long face, narrow arches
B. Concave profile, long face, broad arches
C. Convex profile, short face, broad arches
D. concave profile, short face narrow arches

# Which of the following is the most common orofacial malformation that produces malocclusion ?
A. Cleft lip and palate
B. Ectodermal dysplasia
C. Pierre Robin Syndrome
D. Osteogenesis imperfecta

# Which of the following are NOT associated with complex tongue thrusting activity ?
A. Naso-respiratory distress
B. Contraction of the temporalis muscle
C. Contraction of the mentalis and lower lip during swallow
D. Absence of contact of teeth during swallow

# Profile due to chronic thumb sucking is:
A. concave and narrow
B. wide and concave
C. narrow and convex
D. convex and wide

# In a child, diagnosis of tongue thrusting is made by:
A. observing digits of patient
B. lower lip is held lightly by thumb and finger and asked to swallow water
C. holding paper in between lips
D. paper wick test (holding a piece of paper in front of nose)

# The suckling reflex and infantile swallow normally disappear by the age:
A. First year
B. Second year
C. Sixth year
D. Eight year

# Clinical feature of mouth breathing is:
A. Pigeon face appearance
B. Proclined mandibular anteriors
C. Shallow and flat maxillary arch
D. Retroclined maxillary anteriors