Community dentistry exam bcqs.

Community Dentistry Key Points
1) Which behavior management technique uses animated movies to distract patient from
painful procedure?
a) Impulsion therapy
b) Coping
c) Biofeedback
d) Hypnosis

EXPLANATION:
 Impulsion therapy: also known as aversion therapy is a form of behavior in which the
undesirable behavior is paired with an aversive stimulus to reduce the frequency of
behavior
In this the patient is exposed to the stimulus while simultaneously being subjected to some
form of discomfort: e.g. used in alcoholic patient (alcohol is paired with emetic drug by these
drug when the patient drink alcohol, he become and develop nausea and vomiting, over the
time he does not want to drink alcohol anymore)
 Coping:
 Biofeedback: Biofeedback is a mind-body technique that involves using visual or auditory
feedback to teach people to recognize the physical signs and symptoms of stress and
anxiety,
 Hypnosis:

2) The following sample data of the number of communications are taken from logs of
communication with distance education students: 5, 9, 5, 23, 55, 34, 7, 30, 15, 22, 60, 14,
52, 297, 8, 51, 15, 51, 35, 15, 39, 137, 43, 38, 14, 93, 7. Find range of this data set?
a) 291
b) 293
c) 292
d) 290

EXPLANATION:
Range: The difference between the largest number and the smallest number

Largest number = 297
Smallest number = 5
Range = 297-5 = 292

3) Find the mode of the following data set: 2, 3, 4, 2, 5, 2, 6, 8, 2, 3, 8, 4, 2, 3, 7, 2, 4

,a) 2
b) 4
c) 3
d) 5

EXPLANATION:
Mode: The number that appears the most
 2 repeated six times
 4 repeated three times
 3 repeated three times
 5 appear only one time

Mean: The total of the numbers divided my how many numbers there are
First sum of the numbers 2+3+4+2+5+2+6+8+2+3+8+4+2+3+7+2+4= 67
Total number = 17

MEAN = = 3.9

Median: The number which is in the middle
First arrange the number in sequence:
2,2,2,2,2,2,3,3,3,4,4,4,5,6,7,8,8
So median is 3


4) Which of the following is proposed explanation or supposition for phenomena or theory?
a) Hypothesis
b) Variable
c) Experiment
d) Protocol

EXPLANATION:
 Hypothesis: Based on supposition like chocolate may cause pimples
On the bases of limited evidence as a starting point for further investigation, it is tentative
or testable statement.
 Variable: It is a characteristics or properties of objects, events, or individuals that has or
can be assigned a numerical value e.g. Age, Education level, brushing habit
A factors that change during experiment
 Experiment: A scientific test in which you perform a series of action and carefully observe
their effects in order to learn about something

,  Protocol: A set of predetermined criteria that define appropriate nursing interventions

5) The students of 4th year BDS class visited a school the numbers of students per class from
class I to IX were as follows: 27, 23, 15, 18, 30, 24, 8, 12, 16. The median of this series will
be?
a) 12
b) 23
c) 16
d) 18

EXPLANATION:
Median: The number which is in the middle
First arrange the number in sequence:
8, 12, 15, 16, 18, 23, 24, 27, 30
So median is 18
Mode: The number that appears the most
Not any number repeat more than one time

Mean: The total of the numbers divided my how many numbers there are
First sum of the numbers 8+12+15+16+18+23+24+27+30= 173
Total number = 9

MEAN = = 19.2


6) A technique that is used when desired sample characteristics is rare, therefore it has to rely
on referrals from initial subjects to generate sample size:
a) Convenience sampling
b) Snowball sampling
c) Quota sampling
d) Judgmental sampling

EXPLANATION:
 Convenience sampling: Participants are selected on the basis of their availability
 Snowball sampling: Use when you do not have access to sufficient people with the
characteristics you are seeking. Find the people to study and ask them to refer you other people
Repeat this method of requesting referrals until you have studied enough people
 Quota sampling: Strata are identified and researchers determine proportions of elements
needed from various segments.

, Sample for various groups is decided by the researcher for a pre-determined purpose
 Judgmental sampling: Sampling done on basis of some predetermined idea (clinical
consideration)

7) Which teeth are most commonly involved in early childhood caries?
a) Mandibular incisors
b) Maxillary molars
c) Maxillary incisors
d) Mandibular molars

REMEMBER:
IF asked which teeth are speared in early childhood caries > Mandibular incisor

8) Limitations of DMF index include which one of the following?
a) DMF index gives equal weight to missing, untreated decayed and well restored teeth
b) DMF index is valid when teeth have been lost for reasons other than caries restorations
c) DMF index cannot estimate caries experience in teeth with preventive ds
d) DMF data are of great importance in estimating treatment needs

EXPLANATION:
 It is invalid when teeth have been lost for reasons other than caries restorations
 DMF index is useful to estimate caries experience in teeth with preventive ds
 It is not useful for estimating treatment needs

9) A dentist in his clinic facility is attempting to check the severity of dental caries in a patient
according to Dichotomous scale and he observes, the loss of tooth substance in pits and
fissure but no softened floor or undermined enamel, he will classify the lesion as
a) D2-Enamel caries
b) D1-Initial caries
c) D4-Pulpal caries
d) D3-Dentinal caries

EXPLANATION:
 0= Surface Sound= No evidence of treated or untreated clinical caries.
 D1 (Initial Caries) = No clinically detectable tooth substance loss from pits and fissures
but significant staining, rough surface and discoloration in the enamel and opaque areas
with loss of luster in smooth surfaces.
 D2 (Enamel Caries) = Demonstrable loss of tooth substance in pits, fissure or smooth
surfaces. No softened floor, wall or smooth surfaced enamel. Texture of material in the
cavity might be chalky or crumbly but no evident dentinal penetration.