The purpose of this study was to explore the level to which dental caries impacts the oral health-related quality of life (OHRQoL) in a sample of preschool children in Kisarawe Tanzania.
This is one of the first population-based studies to systematically investigate the correlates of dental caries and oral health-related quality of life of preschool children in Kisarawe, Tanzania. Thus, this study provides information about preschool children that have not been well-covered by the national oral health survey in Tanzania. Information about the prevalence of dental caries in preschool children in sub-Saharan Africa is scarce, and the Kisarawe district has been surveyed to a very limited extent. There is a large body of literature that highlighted the role that individual macro factors such as socioeconomic and contextual factors such as ability to access, affordability and use of oral health services and proximal factors such as eating high sugar sugary food and beverages play a vital role on determinants of oral health1, 33, 36. Therefore individual macro factors, the contextual factors and proximal factors such as consumption of sugary foods and beverages were not evaluated in this study. Other limitation factors on this study relate to the sample size and these results cannot be extrapolated to represent data for the whole population. This is due to the sample calculation being drawn from a specific population (preschool children enrolled in public schools). High response rates and a limited number of missing items in the interview, however, suggest that the study group, for whom there are complete data, reflects preschool children (4–6 yrs.) living in the catchment areas of the public schools in Kisarawe districts.
In terms of child-attributed factors, the prevalence of preschooler dental caries was associated with age and oral hygiene. A tendency was found regarding a greater prevalence of preschooler dental caries associated with an increase in age, and with caries being more common among the six-year-olds, in agreement with findings reported in previous studies1, 2, 3. This result can be explained that dental caries is a multifactorial chronic condition that requires time to develop and to be clinically detectable. So, the increase in the burden of dental caries disease due to age may be due by this and also, change in the dietary habits and hygiene practices in older children1, 2.
Dental caries is highlighted as one of the most common diseases in children and adults and a serious public health problem. The identification of groups at risk for disease development therefore presents fundamental importance for its prevention and early treatment. In the present study, a percentage of caries-free preschool children of 69.8 % was found; this result was similar to the observed 59% among preschool children in Abu Dhabi, United Arab Emirates19 and 51% among preschool children in Hong Kong20. However, the results found in this research were higher than the 80% of children who are caries-free children reported in Mbeya Tanzania15. Differences in the reported prevalence of dental caries could be caused by the materials and methods employed in the different researches, study age groups or it could be a fact that preschool dental caries was prevalent in this study population.
Poor oral hygiene is one of the risk factors of preschooler’s dental caries1, 3. The access of preschool children to different kind of toothbrushes (modern and traditional such as miswaki) and also, the use of fluoridated toothpaste were not evaluated in this study. The majority of the children in the present study exhibited poor oral hygiene, characterized by the presence of clinically visible plaque [93.2% (n=1031)]. Studies have documented an association between dental caries and tooth brushing supervision, and concluded that preschoolers do not yet have the manual dexterity needed for the maintenance of adequate oral hygiene1, 2, 3. Consistent with international evidence, the present study demonstrated that preschoolers who had absent visible plaque were less likely to develop dental caries [Adjusted OR=0.21, (95% CI=0.09-0.45)]. As mothers or caregivers’ supervision during tooth brushing of preschoolers was not part of the present study, the high prevalence of unsatisfactory oral hygiene may be explained by a lack of supervision of mothers or caregivers during tooth brushing, or else a lack of knowledge among parents regarding adequate oral hygiene practices2, 3.
Several instruments have been proposed to measure children’s quality of life and should be selected depending on the desired outcome and characteristics of the target population. These instruments should be easy to understand, have questions that are short, clear, simple, relevant to the objectives of the study, and previously validated and it should be noted that quality of life is a construct and cannot be directly measured8. They include the Child Perceptions Questionnaire21, the Child Oral Impacts on Daily Performances Index22, the Child Oral Health Impact Profile23, the Early Child Oral Health Impact Scale10 and the Scale of Oral Health Outcomes for 5-year-old children24, the Michigan Oral Health-Related Quality of Life scale9 and the Pediatric Oral Health Related Quality of Life Measure25. All but the Michigan Oral Health-Related Quality of Life scale9 and Early Child Oral Health Impact Scale10 were designed for self-report. The Michigan Oral Health-Related Quality of Life scale, MOHRQoL9 was chosen as the objectives of this study were to assess the effects of dental caries on oral health-related quality of life as reported by the children themselves of 4 years and above.
Studies have documented that, when possible, both child and parents should be asked to provide ratings of OHRQoL in an effort to provide a more well-rounded depiction of the child’s oral health care needs and quality of life issues26. Even if child’s opinion is the most valuable, there are certain factors which may compromise the reliability and validity of a child’s OHRQoL responses. Some of these factors include: short-term memory, a strong influence of recent incidents, lack of a fully developed long-term perspective, language problems during interviews, and reading problems when completing a written questionnaire26.
In contrast to findings from this study that found fewer children with dental caries reported to be in pain, other studies report that the severity of dental caries has a negative influence on a child’s OHRQoL27. This could be due to the fact that the acute stage in caries is cyclic in nature as a carious tooth may have become necrotic or created a fistula through the bone relieving the pressure and pain. It is also possible that these children have experienced chronic pain and may describe a tooth that is only slightly uncomfortable as not painful or that their tolerance to pain is high.
Similar to findings of this study, the most frequently reported impacts were ‘pain in the teeth, mouth, or jaws’28 and the associated pain from dental caries has a negative impact on children’s emotional status, sleep patterns, and ability to learn or perform their usual activities2. Another study conducted among children and adolescents found a high dental caries experience and that dental caries had a negative impact on OHRQoL29. From the child’s perspective, the sequela of dental caries could have been transient and that on the day of the interview the tooth no longer hurt. Or it is possible that the child felt that a tooth that spontaneously hurts throughout the day and/or night was worse than eating. The reported pain to the different questions indicates that dental caries goes through different stages.
Contrastingly to findings from this study other studies observed that the prevalence of having an impact of dental caries was almost three times higher for children with dental caries with negative impacts on items related to pain, and to difficulty drinking and eating some foods30. In addition, another study found that an increase in the severity of early childhood caries resulted in the child’s having an impaired quality of life31. The relatively low number of OHRQoL impacts found in this study can be attributed to the sample's community‐based nature and young age. To our knowledge in Tanzania, only the Masumo and colleagues10 has examined OHRQoL using Early Child Oral Health Impact Scale (ECOHIS) among infants and toddlers to‐date. Taking OHRQoL impacts into account, however, can differentiate needs and help prioritize care for vulnerable populations22. This information is important as most studies indicate a modest yet significant correlation between unmet needs like dental decay and children’s OHRQoL.