2. WHAT IS RESEARCH?
RESEARCH- “is the continual search for truth
using the scientific method”
ORAL HEALTH RESEARCH – “refers to
laboratory, clinical and field investigations
that lead to improvement in the control of
oral diseases and health care delivery”
3. WHY DO CLINICAL RESEARCH?
• To promote the oral health of the public
• To contribute new knowledge or reevaluate current
knowledge.
• To improve techniques and practices of identifying ,
preventing and treating oral diseases.
• To develop and test theories related to oral health
care.
• To solve problems in advancement , decision making
and change in oral health delivery.
4. 542-03-#4
CLASSIFICATION OF RESEARCH
STUDIES:
OBSERVATIONAL STUDIES:OBSERVATIONAL STUDIES:
• Groups are studied & contrasts made between groups
ANALYTIC STUDIES:ANALYTIC STUDIES:
• Study the impact of a certain therapy
CLINICAL TRIAL:CLINICAL TRIAL:
• Considered the “true” experimental study
• “Gold Standard” of clinical research
5. THE DIFFERENT STUDY DESIGNS
• Case-control • Cohort
• Case Reports • Survey Research:
Questionnaires
Polls
Surveys
• Meta Analyses
• Randomized Clinical Trial
6. BASIC RESEARCH TERMINOLOGY
• Case Control Study:Case Control Study: Persons w/ disease &
those w/out are compared
• Cohort Study:Cohort Study: Persons w/ and/or w/out
disease are followed over time
• Cross-sectional Study:Cross-sectional Study: Presence or
absence of exposure to possible risk
factor measured at one point in time.
7. • LoLongitudinal study :ngitudinal study : study that provides
data about events or changes during a
period of time.
• Prevalence:Prevalence: The # of new cases and
existing cases during specified time
period.
• Incidence:Incidence: The # of NEW cases per unit
of a population at risk for disease
occurring during stated time period.
9. GETTING STARTED
• FORMULATION AND SET FRAMEWORK OF
RESEARCH PROBLEM
• “A RESEARCHABLE PROBLEM IS A
STATEMENT OR QUESTION THAT POSES
AN UNKNOWN RELATIONSHIP BETWEEN
VARIABLES AND SERVES TO FOCUS
THE ENTIRE INVESTIGATION”
10. HYPOTHESIS
• HYPOTHESIS is defined as “a
tentative prediction or
explanation of the relationship
between two or more variables.”
• Hypothesis is the foundation on
top of which you build your thesis
11. REVIEW OF LITERATURE
The literature that is relevant to the problem
must be concisely reviewed
It can be
-Indices
-Computer based literature searches
- Bibliographies
12. ELIGIBILITY CRITERIA
Eligibility criteria are guidelines that describe
characteristics that must be minimally shared by all
participants. The criteria differ from study to study.
Criteria include:
• Age
• Gender
• Medical history
• Current health status
• Lab values
13. INCLUSION/EXCLUSION
CRITERIA
•Factors that allow someone to participate in
a clinical trial are "INCLUSION CRITERIA“
• Factors that exclude or do not allow
participation in a clinical trial are
"EXCLUSION CRITERIA“
14. SAMPLING
• What is your population of interest?
– To whom do you want to generalize your results?
SAMPLING
“Is the process or technique of selecting a
sample of appropriate Characteristics and
adequate size “
16. TYPES OF SAMPLES
• PROBABILITY (RANDOM) SAMPLES
– Simple random sample
– Systematic random sample
– Stratified random sample
– Cluster sample
• NON-PROBABILITY SAMPLES
– Convenience sample
– Purposive sample
– Quota
17. SAMPLE SIZE
•Bigger the sample higher will be the
precision of the estimates of the
sample .
•An optimum size of the sample is to
be considered.
18. INFORMED CONSENT
Informed consent is the process of providing
potential participants with important facts
about a clinical trial before they decide to
participate.
19. BIAS
SELECTION BIAS- occurs when a group studied does
not reflect the same distribution of characteristics like age,
sex, occupation , race etc. as occuring in general population.
INFORMATION BIAS-occurs when there is an error in
the classification of individuals with respect to the outcome
variable. This may result from measurement errors, imprecise
measurements and misdiagnosis of cases.
CONFOUNDING BIAS – confounding occurs when
other factors that are associated with the outcome and
exposure variables do not have the same distribution in the
exposed and unexposed groups.
20. BLINDING
A)Single blind trial : the trial is so planned that the participant is
not aware whether he belongs to the study group or control
group.
B)Double blind trail: The trial is so planned that neither the
investigator nor the participant is aware of the group allocation
and the treatment received.
c)Triple blind trial : The participant , the investigator and the
person analyzing the data are all blind.
21. EPIDEMIOLOGY VS RCT
• Epidemiology allows the study of the real
world and the development of hypothesis
regarding disease states
• Randomized, controlled trials allow the
rigorous testing of hypothesis in a well
characterized manner that is less real world in
nature
22. CASE CONTROL STUDY
• The same problem could also be studied in a
case-control study. A case-control study
begins with the selection of cases (people
with a disease) and controls (people without
the disease). The controls should represent
people who would have been study cases if
they had developed the disease (population
at risk).
23. COHORT STUDY
• Cohort studies begin with a group of people
(a cohort) free of disease. The people in the
cohort are grouped by whether or not they
are exposed to a potential cause of disease.
The whole cohort is followed over time to
see if the development of new cases of the
disease (or other outcome) differs between
the groups with and without exposure.
25. ETHICS OF CLINICAL TRIALS:
PROTECTION OF PARTICIPANTS
3 ethical principles guide clinical research:
• Respect for Persons:Respect for Persons: Treatment of person
as autonomous
• Beneficence:Beneficence: Issue re: potential conflict
between good of society vs. individual
• Justice:Justice: Treatment of all fairly & all equally
share benefits & risks
26. DATA
• Data are the facts you measure
• They should be carefully recorded in an
unbiased manner
• They should be measured in a manner that
minimizes random variation
• They should be derived from the operational
definitions you have developed
27. COLLECTION OF DATA
Qualitative data: when the data is collected on the basis of
attributes or qualities like age , sex etc., it is called qualitative data.
Quantitative data: When the data is collected through
measurement example – LA drug dose ,
SOURCE OF DATA
Primary source – Data obtained by the researcher
himself. This is first hand information.
Secondary source – The data already recorded
is utilized to serve the purpose of the objective of the
study. Eg . The records of the OPD of dental clinics
28. METHODS OF DATA COLLECTION
INTERVIEWS QUESTIONNAIRES ORAL
EXAMINATION
29. ANALYSIS AND INTERPRETATION
•Analysis and interpretation is done using biostatistics
•BiostatisticsBiostatistics- is that branch of
statistics concerned with
mathematical facts and data
related to biological events.
30. RELIABILITY AND VALIDITY
• RELIABILITY
– The extent to which a test is repeatable and yields
consistent scores
– Affected by random error/bias
• VALIDITY
– The extent to which a test measures what it is supposed to
measure
– A subjective judgment made on the basis of experience
and empirical indicators
– Affected by systematic error/bias
31. WRITING IT UP
• If you don’t write it, then it didn’t happen
• Order of writing:
– Title
– Abstract
– Introduction
– Aims and objectives
– Methods
– Results
– Discussion
– Conclusion
– References
32. SENDING IT IN
• When writing the paper, have the
journal you will submit to in mind
• Pick journals that will match your
paper’s topic and the quality and
importance of your work.
33. PRESENTING THE RESEARCH
• Scientific writing
– Original / full research reports
– Short communications
– Case stories
– Systematic reviews / meta-analysis
– Books or book chapters
– Academic thesis
– Conference abstracts
35. EVIDENCEEVIDENCE BBASEDASED DDENTISTRYENTISTRY
Evidence-based dentistry is the practice ofEvidence-based dentistry is the practice of
dentistry that integrates the bestdentistry that integrates the best
available evidence with clinicalavailable evidence with clinical
experience and patient preference inexperience and patient preference in
making clinical decisions.making clinical decisions.
36. THE STAGES IN EVIDENCE-BASED PRACTICETHE STAGES IN EVIDENCE-BASED PRACTICE
Identify Clinical ProblemIdentify Clinical Problem
Produce a Focused Clinical QuestionProduce a Focused Clinical Question
Search for EvidenceSearch for Evidence
Evaluate the EvidenceEvaluate the Evidence
Incorporate Evidence into PracticeIncorporate Evidence into Practice
Evaluate the Impact on PracticeEvaluate the Impact on Practice
37. META-ANALYSISMETA-ANALYSIS
• Meta-analysisMeta-analysis is a review that uses
quantitative methods to combine the
statistical measures from two or more
studies and generates a weighted average of
the effect of an intervention, degree of
association between risk factor and a
disease, or accuracy of a diagnostic test.
39. RESEARCH ADVANCES IN OMFS
LABORATORY RESEARCH
• Bone tissue engineering with human serum
• Gene Expression Profiling of the “Field of Injury” in Head and
Neck Cancer
• CASE CONTROL STUDIES
• Open vs. closed treatment of bilateral mandibular condyle
and anterior mandibular fractures:
• CLINICAL TRIALS
Temporomandibular Joint - Clinical Trials
Orthognathic Surgery – Relapse
Implants
40. TEMPOROMANDIBULAR JOINT –
ANIMAL MODEL
- SEVERAL MODELS OF INTERNAL DERRANGEMENT ,
OSTEOARTHRITIS AND ANKYLOSIS HAVE BEEN
DEVELOPED.
-THESE MODELS ARE USED TO UNDERSTAND
PATHOPHYSIOLOGY OF CONDITIONS.
-TO EVALUATION VARIOUS MEANS OF SURGICAL
RECONSTUCTION
41. TEMPOROMANDIBULAR JOINT -
CLINICAL TRIALS
A NUMBER OF PROSPECTIVE TRIALS OF
VARIOUS TREATMENT METHODS ARE IN
PROGRESS. THESE INCLUDE
-ARTHROSCOPY
-TEMPORALIS MUSCLE
RECONSTRUCTION
-OPEN REDUCTION OF FRACTURE
DISLOCATIONS
-TMJ IMPLANTS.
43. CLEFT LIP AND CLEFT PALATE
• MAXILLARY ADVANCEMENT WITH
CONVENTIONAL ORTHOGNATHIC SURGERY
• STUDY OF OPERATIVE OR ANATOMIC
FACTORS AFFECTING DENTAL ARCH
DEVELOPMENT.
44. ORAL CANCER
• UNDERSTANDING MOLECULAR BIOLOGY OF
ORAL CANCINOGENESIS.
• CREATION OF A TUMOUR PROGRESSION
MODEL
• ASSESSMENT OF QUALITY OF LIFE IN PATIENTS
WHO HAVE UNDERGONE SURGERY FOR ORAL
CANCER.
46. “To do successful research, you
don't need to know everything,
you just need to know of one
thing that isn't known.”
Notes de l'éditeur
How do we determine our population of interest? Administrators can tell us We notice anecdotally or through qualitative research that a particular subgroup of students is experiencing higher risk We decide to do everyone and go from there 3 factors that influence sample representativeness Sampling procedure Sample size Participation (response) When might you sample the entire population? When your population is very small When you have extensive resources When you don’t expect a very high response
Picture of sampling breakdown
Two general approaches to sampling are used in social science research. With probability sampling , all elements (e.g., persons, households) in the population have some opportunity of being included in the sample, and the mathematical probability that any one of them will be selected can be calculated. With nonprobability sampling , in contrast, population elements are selected on the basis of their availability (e.g., because they volunteered) or because of the researcher's personal judgment that they are representative. The consequence is that an unknown portion of the population is excluded (e.g., those who did not volunteer). One of the most common types of nonprobability sample is called a convenience sample – not because such samples are necessarily easy to recruit, but because the researcher uses whatever individuals are available rather than selecting from the entire population. Because some members of the population have no chance of being sampled, the extent to which a convenience sample – regardless of its size – actually represents the entire population cannot be known