Oral health of children

This section provides the latest information about oral health of children living in fluoridated and non-fluoridated areas in New Zealand. Fluoride in drinking-water helps to prevent and reduce tooth decay.

Two measures of children's oral health are:

  • percentage of children who are caries-free
  • the lifetime experience of dental decay - measured as the number of decayed, missing or filled teeth, in primary teeth (dmft) or permanent teeth (DMFT).

Children with fluoridated water supplies continued to have better oral health than those without fluoridated supplies

The percentage of caries-free children was higher in areas with access to fluoridated drinking-water supplies for children in school-year 8. In 2018, 68.5% of children in school-year 8 who lived in fluoridated areas were caries-free, compared to 63.3% in non-fluoridated areas (Figure 1).

There was no difference in caries-free percentage by fluoridation status for 5-year-old children in 2018. In 2018, 59.7% of 5-year-old children living in fluoridated areas were caries-free, compared to 59.8% in non-fluoridated areas (Figure 2). 

Māori and Pacific children in both age groups had lower caries-free percentages compared to other ethnicities (Figure 1, Figure 2).

Figure 1: Percent of Year 8 children who are caries-free, by ethnic group and water fluoridation status, 2018 (%)

Figure 2: Percent of 5-year olds who are caries-free, by ethnic group and water fluoridation status, 2018 (%)

 Among all ethnicities and both age groups, the mean number of decayed, missing or filled teeth (dmft/DMFT) was lower in fluoridated areas compared to non-fluoridated areas (Figure 3, Figure 4).

Māori and Pacific had higher mean dmft scores among 5-year-old children and children in school-year 8 compared to other ethnicities. This difference was larger among 5-year-old children. Pacific children aged 5-years-old had a mean of 3.3 dmft and Māori a mean of 2.9 dmft. This compares to just 1.3 dmft for Other 5-year-old children (Figure 4).

Figure 3: Mean number of decayed, missing or filled teeth of Year 8 children, by ethnic group and water fluoridation status, 2018

Figure 4: Mean number of decayed, missing or filled teeth of 5-year old children, by ethnic group and water fluoridation status, 2018

Oral health status differs by region

In 2018, the District Health Boards (DHBs) with the lowest caries-free percentages for 5-year-old children were Northland, Counties Manukau, Tairāwhiti, Lakes and Bay of Plenty. For children in school-year 8 the DHBs with the lowest caries-free percentages were Northland and Bay of Plenty (Figure 5).

The DHB with the highest dmft for 5-year-old children was Northland. The DHBs with the highest DMFT for children in school-year 8 were Northland and Bay of Plenty (Figure 6).

Figure 5: Percentage of children in school-year 8 and 5-year old children that were caries-free, by District Health Board, in 2018.


 

Figure 6: DMFT (children in school-year 8) and dmft (5-year-old children), by District Health Board, in 2018 


Oral Health continues to improve

Overall, oral health in 5-year-old children and children in school-year 8 has improved between 2000 and 2018. The largest improvement in oral health is in children in school-year 8 and non-fluoridated areas.

Between 2000 and 2018, the level of children in school-year 8 that were caries-free (ie have no past or current experience of dental decay), increased from 42% to 66%. In the same timeframe, the level of 5-year-old children that were caries-free increased from 52% to 59%.
From 2000 to 2018, the difference in caries-free levels between fluoridated and non-fluoridated areas has generally decreased in both age groups.

Between 2000 and 2018, the mean number of DMFT (decayed missing and filled permanent teeth) of children in school-year 8 dropped from 1.6 to 0.7. This means that on average, children in school-year 8 had less than half as many decayed, missing or filled permanent teeth in 2018 compared to 2000.

Five-year-old children had, on average, 1.8 dmft (decayed missing and filled deciduous teeth) in 2018.
The overall mean dmft increased between 2000 and 2007 but decreased from 2008 to 2018. It is now at the same level as in 2000.

In New Zealand, the community oral health service collects oral health data for 5-year-old children and children in school-year 8 (12–13-year-olds) [1]. 

For more data, visit the  Ministry of Health 's oral health data and stats webpage

 

References

  1. Ministry of Health. (2019). Oral health data and stats 2018. URL: http://www.health.govt.nz/nz-health-statistics/health-statistics-and-data-sets/oral-health-data-and-stats/age-5-and-year-8-oral-health-data-community-oral-health-service (accessed February 2020).
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