Cancer treatment therapies administered before stem cell transplantation often damage children’s permanent teeth, said researchers in the April issue of the journal Cancer.
A research team led by Dr. Päivi Hölttä (Institute of Dentistry, University of Helsinki) studied 52 children treated for cancer or aplastic anemia, who had received stem cell transplantation preceded by high-dose anticancer chemotherapy and, in most cases, with total body irradiation at 1 to 9.4 years of age. Researchers wanted to determine how many of these children lacked permanent teeth or had microdontia, as well as the frequency of poorly developed dental roots.
They assessed root:crown ratios of fully developed permanent teeth using panoramic radiographs. They found that 31 percent of the subjects lacked permanent teeth (versus 8 percent of the Finnish population), after excluding third molars. Lack of permanent teeth was most frequent among subjects who were younger than 3 years at the time of stem cell transplantation. The highest number of missing teeth among these subjects was 12. Subjects older than 5 years at the time of stem cell transplantation lacked only third molars.
Researchers also found that subjects who received high-dose anticancer chemotherapy alone lacked permanent teeth nearly as often as subjects who received the therapy in combination with total body irradiation. Subjects who had received total body irradiation, however, had a slightly increased number of missing teeth.
The subjects also had a high frequency of microdontia (44 percent versus 2 percent of the Finnish population). Microdontia was common among subjects younger than 5 years at the time of stem cell transplantation. All subjects who received high-dose anti-cancer chemotherapy when they were younger than 3 years had microdontia. Total body irradiation did not appear to have an effect on the number of subjects with microdontia.
Researchers found developmental aberrations in dental roots of all the subjects. Some had minor changes visible in only a few teeth, while others had severe damage in all teeth. Total body irradiation increased the number of damaged roots. Subjects who had received only high-dose anticancer chemotherapy had root damage in more than one-half of their teeth, but the damage was not as severe as in subjects who also had received total body irradiation.
"We still don’t know about the long-term consequences of the treatments, which is why the monitoring of the patients should be continuous and centralized," said Dr. Hölttä.
