Community Dentistry
Lec.5
Dental Indices
By Dr. Lamya Alazzawi
A requirement for any epidemiology investigation is the ability to quantify the occurrence and severity of the disease.
Measurement is a process of assigning value to characteristics per set of rules this is facilitate through indices, certain methodology and criteria.
• A dental Index is an abbreviated measurement of a mount or condition of oral disease in a population.
• An index is based on graduated numeric scale with defined upper and lower limits.
Objectives of Indices
• To increase our understanding of the disease process, thus helping in control and prevention.
• To discover population at risk and define the specific problem under investigation
Attributed of Good Index
• Valid
• Reliable
• Clear, simple, and objective
• Sensitive to shift in disease
• Acceptable to the participation involved
• Amenable to statistical analysis
Validity.
? The index should measure what it is intended to measure.
? It should correspond with clinical stages of disease under study at each point.
Reliability.
The index should measure consistently at different times and under a variety of condition.
Clarity, Simplicity, and Objectivity
The index should be reasonably easy to apply so that there is no undue time lost during field examination.
Sensitivity.
To detect reasonably small shits of disease in either direction.
Acceptability.
The use of the index should not be painful to subject.
Analysis amenable to statistical analysis.
The index should be amenable to statistical analysis, so that a number that corresponds to a relative position on a scale from zero to upper limit can express the status of a group.
Classification of Indices
Based upon the direction in which their scores can fluctuate
• Irreversible index measures condition that will not change
E.g. index measuring dental caries (DMF)
• Reversible index measures condition that can be changed
E.g. Indices that measure gingival condition.
Depending upon the extent to which the oral cavity is measured
• Full mouth index measure the entire periodontium or dentition
E.g. Russell’s Periodontal Index(PI)
• Simplified Index measure only a representative sample of the dentition
E.g. Green and Vermilion’s Oral Hygiene Index –Simplified (OHI-S)
According to the entity which they measure
• Disease index for e.g.(Decay) portion of the DMF index
• Symptom index e.g. Gingival index.
• Treatment index e.g. F(filling)portion of the DMF index
Indices used for assessment of oral disease
DMFT was introduced by Henry Klein,Carrole E.Plamer and Knutson J.W.in 1938 to determine the prevalence of coronal caries and it is the most universally employed index for measuring dental caries, which is
Simple, rapid, useful and since dental hard tissue is not self-healing established caries leaves scar.
So, that the tooth either remains, decayed, extracted, or filled, therefore the DMF index is an irreversible index (measure life time dental caries)
Procedure Methodology
• DMF index for permanent teeth, which is composed of components:
• D describe decay teeth
• M describe missing teeth due to caries only
• F describe teeth that have been previously filled because of caries involvement.
•
• All the 28 permanent teeth are examined except
• Third molars
Un erupted teeth
• Congenitally missing and supernumerary teeth.
• Teeth removed for reason other than dental caries (orthodontic treatment or impaction)
• Teeth filled for other reason (fracture, cosmetic purpose, or bridge abutment)
• Primary teeth are retained with permanent successor erupted, the permanent teeth are evaluated and the primary teeth is never included in this index.
Identification of dental caries.
• the tip of explorer can penetrate deep into soft yielding material
• 2.Discoloration or loss of translucency or demineralized enamel
• 3. There is a softness at the base of the cavity.
Examination method for DMF
• D A tooth can only be counted once, if it there is defect filling or secondary caries counted as decayed.
• M indicates the number of missing permanent teeth due to decay only
• F Indicates the number of restored permanent teeth that have been attacked by caries. A tooth with several fillings counted as one tooth.
Index calculation
• DMFT for permanent teeth (decayed, missing, filled teeth)
• Individual DMFT D+M+F=DMF
• Group average Total DMF
Total number of subjects examined
The maximum DMFT score is 32 (range from 0-32)
DMFS (Decay, Missing, Filled, surfaces), which is employed to assess each individual surface of each tooth. The principles ,rules and criteria of DMFS is the same as DMFT index only the difference is all the surfaces are counted.
Examination of surfaces
• Anterior teeth four surfaces are examined (facial, lingual, mesial, and distal)
• Posterior teeth five surfaces are examined occlusal, buccal, lingual, mesial, and distal)
• Total surfaces count for DMFS index if 28 teeth are examined
• Anterior teeth 12(12X4) =48 surfaces.
• Posterior teeth 16(16X5) =80 surfaces
Caries for Primary teeth
Gruebbel was described (def) as equivalent index to DMF index for measuring dental caries in primary teeth.
• d= decayed deciduous teeth
• e= deciduous teeth indicated for extraction due to dental caries
• f= restored deciduous teeth which have been decayed without any recurrent decay.
dmf index
• It is modified of (def index) include dmft index (d= decayed, m= missing, and f=filling)
df index in this index missing teeth are ignored to getting around the exfoliation problems, so the index applied to whole teeth as decayed –filled tooth) dft and decayed –filled surfaces dfs index.
Mixed dentition
• DMFT/DMFS and dmft/ dmfs are never added together so that each one is given separated index one for permanent and another for primary.
Index for Root Surface Caries
• Root caries index was developed by Katz 1979, which is used to count root surfaces caries
RCI is based on the requirement that gingival recession must occur before root caries surface lesion begin, therefore only teeth with gum recession are examined.
• 4 surfaces of root are examined (mesial, distal, lingual, and buccal or labial)
• A judgment of no gum recession is made if CEJ (cement enamel junction) cannot be visualized.
The root caries index is calculated for an individual using the formula
• RCI= (R-D) +(R-F) x 100
(R-D) +(R-F) +(R-N)
R-N =Recession present surface normal or sound
R-D =Recession present with decay root surface
R-F= Recession present with a filled root surface.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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