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Geo-mapping of time trends in childhood caries risk a method for assessment of preventive care

Ulf Strömberg12*, Anders Holmn1, Kerstin Magnusson3 and Svante Twetman34

Author Affiliations

1 Department of Research and Development, Halland Hospital, SE-301 85, Halmstad, Sweden

2 Department of Occupational and Environmental Medicine, Lund University, SE-221 85, Lund, Sweden

3 Section of Community and Preventive Dentistry, Maxillofacial Unit, Halland Hospital, SE-301 85, Halmstad, Sweden

4 Department of Cariology, Endodontics, Pediatric Dentistry and Clinical Genetics, Institute of Dentistry, Faculty of Health and Medical Sciences, University of Copenhagen, Nrre All 20, 2200, Copenhagen N, Denmark

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BMC Oral Health 2012, 12:9  doi:10.1186/1472-6831-12-9

Published: 17 April 2012



Dental caries is unevenly distributed within populations with a higher burden in low socio-economy groups. Several attempts have been made to allocate resources to those that need them the most; there is a need for convenient approaches to population-based monitoring of caries risk over time. The aim of this study was to develop the geo-map concept, addressing time trends in caries risk, and demonstrate the novel approach by analyzing epidemiological data from preschool residents in the region of Halland, Sweden.


The study population consisted of 9,973 (2006) and 10,927 (2010) children between 3 to 6years of age (~77% of the eligible population) from whom caries data were obtained. Reported dmfs>0 for a child was considered as the primary caries outcome. Each study individual was geo-coded with respect to his/her residence parish (66 parishes in the region). Smoothed caries risk geo-maps, along with corresponding statistical certainty geo-maps, were produced by using the free software Rapid Inquiry Facility and the ESRI ArcGIS system. Parish-level socioeconomic data were available.


The overall proportion of caries-free (dmfs=0) children improved from 84.0% in 2006 to 88.6% in 2010. The ratio of maximum and minimum (parish-level) smoothed relative risks (SmRRs) increased from 1.76/0.44=4.0 in 2006 to 2.37/0.33=7.2 in 2010, which indicated an increased geographical polarization of early childhood caries in the population. Eight parishes showed evidential, positional changes in caries risk between 2006 and 2010; their corresponding SmRRs and statistical certainty ranks changed markedly. No considerable parallel changes in parish-level socioeconomic characteristics were seen during the same time period.


Geo-maps based on caries risk can be used to monitor changes in caries risk over time. Thus, geo-mapping offers a convenient tool for evaluating the effectiveness of tailored health promotion and preventive care in child populations.

Caries; Children; Prevention; Geo-mapping; Time trend