Count (Indices)

This indicator belongs to a set of indicators whose purpose is to measure the dental caries situation/status. Oral health is essential to general health and quality of life. Oral diseases including dental caries (tooth cavity) limit an individual’s capacity to bite, chew, smile and speak, and affect psychosocial wellbeing. The Global Burden of Disease Study estimated that oral diseases affected at least 3.58 billion people worldwide in 2016, ranking first for dental caries (decay) of permanent teeth (2.4 billion people) and 17th for dental caries of deciduous teeth (486 million children).

DMFT is the sum of the number of Decayed, Missing due to caries, and Filled Teeth in the permanent teeth. The mean number of DMFT is the sum of individual DMFT values divided by the sum of the population. The 12-year-old is one of the WHO indicator age groups.

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An examination for dental caries in permanent teeth means examining 32 teeth (i.e. all permanent teeth including wisdom teeth) with a metallic periodontal probe (Community Periodontal Index (CPI) probe) and a plane mouth mirror. The permanent dentition status of each tooth (crown and root) is recorded as a score from 0 to 9. 0: Sound - A crown/root is coded as sound if it shows no evidence of treated or untreated clinical caries. The stages of caries that precede cavitation, as well as other conditions similar to the early stages of caries, are excluded because they cannot be reliably identified in most field conditions in which epidemiological surveys are conducted. 1: Carious crown - Caries is recorded as present when a lesion in a pit or fissure, or on a smooth tooth surface, has an unmistakable cavity, undermined enamel, or a detectably softened floor or wall. Carious root - Caries is recorded as present when a lesion feels soft or leathery on probing with the CPI probe. 2: Filled crown, with caries - A crown is considered filled, with caries, when it has one or more permanent restorations and one or more areas that are decayed. Filled root, with caries - A root is considered filled, with caries, when it has one or more permanent restorations and one or more areas that are decayed. 3: Filled crown, with no caries - A crown is considered filled, without caries, when one or more permanent restorations are present and there are no caries anywhere on the crown. Filled root, with no caries - A root is considered filled, without caries, when one or more permanent restorations are present and there are no caries anywhere on the root. 4: Missing tooth, due to caries - This code is used for permanent teeth that have been extracted because of caries and are recorded under coronal status. 5: Permanent tooth missing due to any other reason - This code is used for permanent teeth deemed to be absent congenitally, or extracted for orthodontic reasons or because of periodontal disease, trauma, etc. 6: Fissure sealant - This code is used for teeth in which a fissure sealant has been placed on the occlusal surface or, in a pit or for teeth in which the occlusal fissure has been enlarged with a rounded or “flame-shaped” bur, and a composite material has been placed. 7: Fixed dental prosthesis abutment, special crown or veneer - This code is used under coronal status to indicate that the tooth forms part of a fixed bridge abutment. This code can also be used for crowns placed for reasons other than caries and for veneers or laminates covering the labial surface of a tooth, on which there is no evidence of caries or a restoration. 8: Unerupted tooth (crown) - This classification is used only for a tooth space with an unerupted permanent tooth. 9: Not recorded - This code is used for an erupted permanent tooth that cannot be examined for any reason such as orthodontic bands, severe hypoplasia, etc. Individual DMFT value is the sum of the number of D (Decayed), M (Missing) due to caries, and F (Filled) teeth in the permanent teeth. The D component includes all teeth with codes 1 or 2. The M component comprises teeth coded 4 in subjects under 30 years of age, and teeth coded 4 or 5 in subjects 30 years and older, i.e. missing tooth due to caries or for any other reason. The F component includes only teeth with code 3. Teeth coded 6 (fissure sealant) or 7 (fixed dental prosthesis/bridge abutment, special crown or veneer/implant) are not included in calculations of DMFT.

Impact

The mean number of DMFT (equal to the sum of individual DMFT values divided by the sum of the population) among the 12-year-old age group are extracted from the Oral Health database CAPP (Country/Area Profile Project) maintained by the WHO Collaborating Centre, Malmö University, Sweden. CAPP presents country oral diseases surveillance, which are based on national oral health surveys, annual publications from national health bulletins, and data retrieved from PubMed, Google and personal communications. Commonly used search words for PubMed and other sources are “caries epidemiology”, “caries prevalence” and “oral health”. The data presented in the database follow the WHO Oral Health Survey Basic Methods and criteria. Exceptions are made for those countries that have no data, in which case, data that may not conform to the WHO guidance may be presented in the CAPP database.

WHO suggests that clinical oral health surveys should be conducted regularly every five to six years in the same community or setting.

As mentioned above, the data presented in the database follow the WHO Oral Health Survey Basic Methods and criteria. Exceptions are made for those countries that have no data, in which case data that may not conform to the WHO guidelines may be presented in the database. Therefore, some data are not representative data which may lead to difficulty in comparison of percentages of population affected with dental caries globally. Generally national surveys are recommended to be conducted about every 5 to 6 years. But this also depends on the oral health status as well as on the change in the economical situation, the perceived change of oral health status, and the occurrence of human made crisis and natural disasters.

Dr Benoit Varenne