Children who survived cancer are generally believed to be weaker than their healthy peers. It means that they are more likely to have health issues, including dental ones such as caries. In order to see whether having cancer in the past and suffering from caries are connected, professionals conducted several research studies. Still, there are only few of them, and their results are conflicting. Some professionals considered caries to be one of the long-term health consequences experienced after cancer while others do not support such idea.
The main purpose of this study was to “examine the risk of dental caries among children who have survived cancer” (Wogelius et al., 2008, p. 1221). The researchers focused on children who were 7-15 years old (being born in 1984-1988 and 1993–1997) and were mentioned in the records of the Danish Cancer Registry and the Danish Central Population Registry.
The primary exposure was the prevalence of dental caries among kids of the same age with and without previous experience of having cancer. Professionals received accurate data on the sample’s vital status from the Danish Central Population Registry, which provided them with the opportunity to maintain needed measurements. Cancer and tooth-surface-specific data were obtained.
Thus, the attention was paid to those cases when children who were 5-15 years old had CNS and non-CNS tumors as well leukemia/lymphoma. It was defined if their treatment consisted of radiation therapy also. As a result, the prevalence of primary and secondary caries in each case was determined, including the fillings and extractions maintained because of caries.
Wogelius et al. (2008) conducted a population-based observational study. The sample included children who were 7-15 years old (being born in 1984-1988 and 1993–1997). All in all, there were “299,426 7-yearold, 313,461 12-year-old, and 301,930 15-year-old children born between 1984 and 1988”, among them “288 7-year-old, 459 12-year-old, and 526 15-year-old” had cancer. This sample was selected randomly, and the researchers did not communicate with them, so the selection process is not likely to be biased.
The information that interested Wogelius et al. (2008) was collected from the authoritative sources, the records of the Danish Cancer Registry and the Danish Central Population Registry, in particular. The data was quantitative and did not include personal statements or analysis that is why it tends to be objective. Some bias may exist as it is not clear how the records were made but in general, the data was trustworthy.
To minimalize the influence on the analysis, the sample was divided into groups according to their age. The range of variables was limited so that the cases of particular cancer types were identified. No additional information about the children was taken into consideration. During the study, obtained numerical results were transformed in percentages, which allowed generalizing. Unfortunately, diet and actual dental hygiene were not taken into consideration during the measurement even though the authors mentioned them as confounding factors.
The mean annual number of new caries cases as well as cancer ones allows to measure association while P values and 95% confidence intervals were used to measure statistical stability.
The major results of the study revealed that no association between cancer and caries was found in children who had cancer before the age of 5 years. Still, those who were diagnosed being 5-6 years old “had an increased prevalence of severe caries” (Wogelius et al., 2008, p. 1221). However, this relationship was observed only at the age of 12 years and disappeared by age 15.
The results of the study may be affected by the data obtained for the study, as it is not clear how it was gathered. The fact that the prevalence of cancer disappeared proves that some environmental factors that were not discussed could influence the situation. In this way, the results of the study may be wrong.
There is a possibility that the variables were misclassified due some error. It is possible that healthcare professionals made a wrong diagnosis in some cases when identifying cancer and the severity of caries. In addition to that, some mistakes may be some when recording the information. Still, the sample was rather large and such biases are not likely to affect the results enormously.
The discussion section addresses the limitations of the study decently. Professionals mentioned that they lacked clinical details and did not discuss diet and actual dental hygiene. However, they should have also pointed out environmental issues, as even the creation of some soft drink or new toothpaste that were extremely popular at a particular period of time could affect the results greatly.
All in all, professionals concluded that cancer and its treatment increase the risks for caries among children. Such opinion is supported by the obtained results but only partially, as those who survived cancer before the age of 5 years did not face such issue.
The results of this study may be applied to a large population of children of the discussed age. Still, such generalization requires more thorough research, as people of other nationalities may have other tendencies. Unfortunately, the adult population cannot be discussed in this framework.
Reference
Wogelius, P., Dahllof, G., Gorst-Rasmussen, A., Sørensen, H., Rosthøj, S., & Poulsen, S. (2008). A Population-Based Observational Study of Dental Caries among Survivors of Childhood Cancer. Pediatric Blood & Cancer, 50(1), 1221-1226.