DMFT and DMFS along with dmft and dmfs INDEX property explained
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DECAYED , MISSING , FILLED TOOTH INDEX & DECAYED MISSING FILLED SURFACES INDEX By Dr Nishant Singh Department of Public Health Dentistry
WHAT IS AN INDEX ? “A numerical value describing the relative status of a population, on a graduated scale with definite upper and lower limits designed to permit and facilitate comparison with other populations classified by the same criteria and methods. Russel A.L
Epidemiological indices are attempt to quantitate clinical condition on a graduated scale , thereby facilitating comparison among populations examined by the same criteria and methods. --- Irving Glickman WHAT IS AN INDEX ?
CLASSIFICATION OF INDICES Based on the direction which it can fluctuate . Upon the extent which the areas of oral cavity are examined. According to the entity they measure General indices
Based on the direction which it can fluctuate Reversible Index : Measure condition that can be changed, e.g Periodontal Index Irreversible Index : Index that measure conditions that will not change , e.g Caries Index
TYPES OF CARIES INDEX Permanent Teeth DMFT DMFS DMFSS Primary Teeth Dft Dfs Dfss
Mixed Dentition (dft) & ( DMFT) (dfs) & ( DMFS) Other Indices Stone’s Index Czechoslovakian Caries Index Modified DMFT Index TYPES OF CARIES INDEX
DECAYED MISSING FILLED TOOTH INDEX
DECAYED, MISSING, FILLED, TEETH INDEX (DMFT Index) It was proposed by Henry T . Klein , Carrol E. Palmer & Knutson JW in 1938. Developed to determine the prevalence of Coronal Caries Is a simple rapid versatile, universally accepted and widely used index for several decades .
It is used to determine total dental caries experience past and previous . The DMFT is a irreversible Index (meaning it measures total life time caries experience The tooth either remains decayed or if it is treated it is extracted or filled. DECAYED, MISSING, FILLED, TEETH INDEX (DMFT Index)
INSTRUMENTS Favorable lighting condition A No 3 plain mirror A fine pointed pig tail explorer
INSTRUMENTS
No tooth must be counted more than once i.e. it is either decayed , missing , filled or sound. Decayed , Missing , and Filled teeth should be recorded separately since the component of DMF are of great interest . When counting decayed teeth, also include teeth which have restorations with recurrent decay. PRINCIPLES AND RULES WHILE RECORDING DMFT
Care must be taken to list as missing only those teeth which have been lost due to decay Also included should be those teeth which are so badly decayed that they are indicated for extraction The following should not be counted as missing Unerupted Tooth Missing Tooth due to extraction Congenitally missing tooth Teeth extracted for orthodontic purpose PRINCIPLES AND RULES WHILE RECORDING DMFT
A tooth may have several restorations but it should be counted as one tooth. Deciduous teeth are not included in DMF are included in dmf A tooth is considered as erupted when the occlusal surface or incisal edge is totally exposed or can be exposed gently by reflecting the overlying gingival tissue with the mirror or explorer. A tooth is considered to be present even though the crown has been destroyed and only the roots are left. PRINCIPLES AND RULES WHILE RECORDING DMFT
CODDING CRITERIA FOR DMF INDEX : CODE E Excluded tooth or tooth space 1 Sound permanent teeth 2 Filled permanent teeth 3 Decayed permanent teeth
CALCULATION OF INDEX INDIVIDUAL DMFT TOTAL D+M+F= DMF GROUP AVERAGE TOTAL DMF/ TOTAL NO OF SUBJECTS EXAMINED PERCENT NEEDING CARE TOTAL NUMBER OF DECAYED TOOTH/ TOTAL NUMBER EXAMINED PERCENTAGE OF TEETH LOST TOTAL NUMBER OF TEETH LOST / TOTAL NUMBER EXAMINED PERCENTAGE OF FILLED TEETH TOTAL NUMBER OF FILLED TEETH/ TOTAL DMF MISSING PERMANENT TEETH/100 TOTAL NUMBER OF MISSING TEETH * 100 /TOTAL NUMBER EXAMINED
The maximum possible DMFT Score is 32 (if third molars included ) DMFT Score is 28 ( if third molars are not included) CALCULATION OF INDEX
Advantages of DMFT Because of its wide spread use world wide over the past 60 Years , it provides a reasonable accurate historical account of changes in prevalence of dental caries
Limitations of DMFT DMFT values are not related to the number of tooth at risk. DMFT Index can be invalid in older adult as because teeth can be lost due to other than carries . DMFT can be misleading in children whose teeth have been lost due to the orthodontic reason.
DMFT Index can over estimate caries experience in teeth which “ preventive fillings” have been placed. DMFT Index is of little use in studies of root caries Limitations of DMFT
WHO MODIFICATIONS OF DMFT 1986 All third molars are included Temporary restorations are considered as decayed Only, carious cavities are considered as ‘D’. The DMF index can be applied to denote the number of affected teeth (DMFT) or to measure the surfaces affected by dental caries (DMFS).
Other Methods of DMF Examination Short Hand Method Intended for use in surveys basic prevalence is assessed. Based on examination of selected teeth only Objective is to decrease the time taken for each examination and still provide valid DATA.
WHO has defined short hand method as Recommends the use of “half-mouth” DMF in its basic survey techniques. Objective is to obtain caries prevalence in a population which has not been surveyed previously. Half the upper arch is only scored. Then the lateral lower half arch and then the result is doubled . It is quicker and easier than full mouth DMF INDEX.
DECAYED FILED MISSING SURFACE INDEX
DECAYED – MISSING – FILLED TOOTH SURFACE INDEX (DMFS) Presented by Henry T. Klein , Carrole. E. Palmer & Knutson J.W in 1938 . It is more sensitive. Usually the index of choice in a clinical trial of carries preventive agent .
Used to determine the total dental caries experience past and present by recording tooth surface involved in place of teeth. DECAYED – MISSING – FILLED TOOTH SURFACE INDEX (DMFS)
PROCEDURE DMFS INDEX D Decayed Surface M Missing Surface F Filled Surface
DMFS INDEX – THE INDEX OF CHOICE This is because relative incidence is more likely to be detected over the limited time period of a clinical trail. But DMFS takes longer time and may sometimes produce inconsistency in diagnosis and may require the use of radiographs to be fully accurate .
DMFS is a more detailed index than DMFT by summing the total number of decayed missing and filled permanent tooth surfaces . As in case of the DMFS Index is simple versatile and more sensitive , has practically , universal acceptance , is one of the best known dental indices today. DMFS INDEX – THE INDEX OF CHOICE
CALCULATION OF DMFS INDEX 1. INDIVIDUAL DMFS INDEX DMFS SCORE = D+M+F 2. TOTAL SURFACE CPUNT FOR A DMFS INDEX ( If 28 teeth are examined) 16 POSTERIOR TEETH (16*5=80) 12 ANTERIOR TEETH (12*4=48) TOTAL =128 SURFACES 3. TOTAL SURFACE COUNT FOR DMFS INDEX ( If 32 teeth are examined) IF THIRD MOLARS ARE INCLUDED (4*5)=20 TOTAL = 148 SURFACES
For Posterior teeth : Five Surfaces Examined & Recorded ( Facial, Lingual, ,Mesial ,Distal, Occlusal) For Anterior teeth : Four Surfaces Examined & Recorded (Facial, Lingual, Mesial, Distal)
Disadvantage DMFS examination takes longer time is more likely to produce inconsistencies in diagnosis and may require the use of radiographs to be fully accurate. To save time in larger surveys DMFS can be used half mouth , applied to opposite diagonal quadrants and score doubled. This is based on the assumption that caries incidence is bilateral.
A tooth scores exactly same under extremes of clinical condition ; a tooth with small restoration in one pit rates as the same as a tooth that has been extracted . Provide little or no additional information in prevalence studies where the extent of caries is being compared between the groups . Has a wide range of of possible value hence larger standard deviation and standard error. Disadvantage
One of the difficulties encountered in use of this surface index is that the score allotted to the teeth that is indicated for extraction, which may have been attacked one surface only, although its extraction results in the loss of four or five surfaces , according to the tooth. Disadvantage
Another difficulty is the score to be given to two surfaces fillings in posterior teeth, where the initial attack was probably on one proximal surface and the occlusal surface was involved latter , to provide adequate Class II type cavity restoration. Disadvantage
Established Modification : Procedural modifications can be made to the DMFS index allow for factors such as secondary caries , crowned teeth , bridge pontics, and any other particular attribute required for study. To save time in large surveys, the DMFS can be used half-mouth , applied to opposite diagonal quadrants and score doubled an approach that assume that caries incidence is bilateral.