Fundamental Oral Epidemiology

Question 0

Basic Oral Health Survey Methods

General Terms

1) Frequency
2) Means
3) Modes
4) Confidence levels (Statistical certainty)
5) The Null Hypothesis

Answer 0

5) Null Hypothesis
Where there is no statistical significance between a set of given observation. The Null Hypothesis attempts to show that no variation exist between the two variables or that a single variable is no different that zero. It is assumed true until statistical evidence nullifies it for an alternative hypothesis

Question 1

Basic Oral Health Survey Methods

What are requirements for survey methods?

Answer 1

• Clear protocol & purpose
  > What we want to measure?
  > What tools do we have?
  > What hypothesis we want to test?
• Well defined sampling & methodology
  > To eliminate bias via controls and etc
  > Randomized vs Selected vs Convenience
  > Calibration; ensure what you are measuring is the same as others
  > Standardisation
  > Consultation and biostatistician
• Consultation with biostatistician

Question 2

Basic Oral Health Survey Methods

Terms used when measuring Oral Disease & Disorders

1) Prevalence
2) Incidence
3) Severity
4) Rates

Answer 2

1) Prevalence
The total number of cases of the disease in a population at a given time, or the total number of cases in the population divided by the number of individuals

2) Incidence
A measure of the risk of developing some new condition within a specified period of time, or the of new cases during some time period.

3) Severity
A measure of development and advancement of a disease of condition.

4) Rates
A measure of the frequency of occurrence of a condition per nominated denominator.

Question 3

Basic Oral Health Survey Methods

Surveying Dental Caries

DMFT/DMFS
or dmft/dmfs for deciduous teeth

Answer 3

DMFT and DMFS are methods to described the accumulated severity of dental caries in an individual by numerically expressing caries severity by charting the:
D-Decayed
M-Missing
F-Filled
T-Teeth or S-Surfaces
These indices are usually given as mean scores for either each component or as a total index. Note that DMFS is more detailed as it looks at each different surface (posterior teeth = 5S, anterior teeth = 4S)

Question 4

Basic Oral Health Survey Methods

Surveying Dental Caries

Significant Caries Index

Answer 4

SIC or SIC^10

This is the mean DMFT for the top 30% or 10% of the population sampled.

Question 5

Basic Oral Health Survey Methods

Surveying Dental Caries

International Caries Detection & Assessment System - ICDAS Index

Answer 5

ICDAS index is a clinical scoring system for primary caries used in dental education, practice, research and epidemiology. It is an approach which is designed to provide better quality information to allow informed decisions about appropriate diagnosis, prognosis and clinical management.

Note: Table in slide 13 of 1. Fundamental Oral Epidemiology

Question 6

Basic Oral Health Survey Methods

Surveying Periodontal Disease

Measurement Tools and Criterias

Answer 6

• Russell’s PI
• Loe & Sillness GI, PI
• WHO - CPI (PRS) *
• Tissue Destruction

Question 7

Basic Oral Health Survey Methods

Surveying Periodontal Index

WHO - CPI

Answer 7

Scores:
0 = Health
1 = Bleeding on probing
2 = Supra/Sub-gingival calculus detected
3 = Pocket 4-5mm
4 = Pocket 6mm or more
X = Excluded sextant (when there are less than 2 teeth present)
9 = Not recorded

Question 8

p

Answer 8

o