Päivi Hölttä

Disturbed root development of permanent teeth after pediatric stem cell transplantation. Dental root development after SCT

Deficient dental root development has been reported after conventional pediatric anticancer therapy, but less information is available on stem cell transplantation (SCT) recipients.

Agenesis and microdontia of permanent teeth as late adverse effects after stem cell transplantation in young children

The objective of the current study was to examine the occurrence of tooth agenesis and microdontia in pediatric stem cell transplantation (SCT) recipients.

The demonstration by ribotyping of the stability of oral Streptococcus mutans infection over 5 to 7 years in children

The distribution of serotypes and ribotypes of mutans streptococcal isolates obtained from seven unrelated children at 5 and at 10 or 12 yr of age was investigated. For ribotyping, chromosomal DNA from 5 to 13 isolates per subject was digested with restriction endonucleases EcoRI and HindIII. The DNA fragments were electrophoretically separated, blotted on to nylon membrane and hybridized to the plasmid pKK3535, which contains the rRNA operon of the Escherichia coli chromosome. The ribotypes were unique for each child. In five children only one ribotype and serotype (c, e or f) was found. In one child two serotypes (c and f) were found at baseline and only one (serotype c) in the follow-up sample. In one child the same serotype was not found in the baseline (serotype e) and in the follow-up (serotype c) samples. Every child except one had a ribotype that was identical to one found 5-7 yr later. The results suggest that, at the age of 5 yr, infection by Streptococcus mutans has already stabilized and the colonizing strain remains permanent.

Prevalence of short-root anomaly in healthy young adults

Short-root anomaly (SRA), occurring mostly in maxillary incisors, is defined as developmentally very short, blunt dental roots. The condition has a genetic background and is related to hypodontia. Earlier population studies have been based on schoolchildren with developing dentitions and have indicated prevalence figures between 1% and 10%. We studied a random sample of existing panoramic radiographs of 2000 university students for SRA. Roots as long as or shorter than the crowns in the incisors and visually evaluated as very short, blunt roots bilaterally in the posterior teeth were classified as SRA. The prevalence was 1.3%. According to anamnestic information, half the SRA patients had undergone orthodontic therapy, but pre-treatment radiographs were unavailable. In 70% of the SRA patients the short-rooted tooth pairs were upper incisors, but also involved were maxillary premolars, lateral incisors, and lower second premolars. Women were significantly more often affected. We discuss other factors known to cause short-rooted teeth and conclude that the population prevalence for genetic SRA in fully developed dentitions is close to our 1.3%.

Natal and Neonatal Teeth in Relation to Environmental Toxicants

Infants born to mothers heavily exposed to polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs) have earlier been reported to have increased prevalences of natal and neonatal teeth. Some tendency toward higher prevalence figures of natal and neonatal teeth can be seen in the literature in normal child populations during the last 40 y. We therefore decided to determine the present prevalence of these teeth in a Finnish population and to evaluate whether infants with natal and neonatal teeth are more exposed to PCBs, PCDFs, and polychlorinated dibenzo-p-dioxins (PCDDs) than infants on average. A total of 34,457 infants born in 1997–2000 in four hospitals in southern Finland were examined for natal and neonatal teeth. The exposure of the infant to PCBs and PCDD/Fs was evaluated by measuring the levels of 17 most toxic PCDD/F and 36 PCB congeners in his or her mothers milk sample when the child was 4–8 wk old. A total of 34 infants had one or two natal (29 infants) or neonatal teeth (five infants). The milk analyses showed that the median level of PCDD/Fs as toxic equivalent (World Health Organization–recommended 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent quantity for PCDD/Fs in fat) was 11.9 pg/g in fat, and that of PCBs (World Health Organization–recommended 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent quantity for PCBs) was 7.24 pg/g in fat. These levels corresponded to the prevailing levels. The results showed that the prevalence of natal and neonatal teeth was 1:1000. No association was found between pollutant levels and occurrence of natal and neonatal teeth, indicating that the prevailing levels of PCDD/Fs and PCBs are likely to be below the threshold to cause perinatal eruption of teeth.

Dental Caries is Common in Finnish Children Infected with Helicobacter pylori

Childhood factors such as low socioeconomic status are risk factors for Helicobacter pylori infection and Streptococcus mutans-related dental caries. We examined whether H. pylori infection and dental caries are present today in the same group of children examined previously. We reviewed the public dental health service files of 21 H. pylori-positive children (upper gastrointestinal endoscopy at a median age of 13.5 y) and 27 H. pylori-negative children (endoscopy at a median age of 12.5 y) examined during 1995-98 at the Helsinki University Central Hospital, Finland. All H. pylori-positive children had experienced dental caries in their primary or permanent teeth or in both whereas among H. pylori-negative children the respective proportion was 70% (p < 0.01). At the age of 7 y, 18% (3/17) of the H. pylori-positive children had experienced caries in permanent teeth as compared to 0% among H. pylori-negative children (0/24; p < 0.05). At the age of 12 y, H. pylori-positive children had more decayed, missing or filled permanent teeth than H. pylori-negative children (80% vs. 38%; p < 0.05). Although a causal relationship between H. pylori and dental caries is unlikely, it is possible that H. pylori-infected children have an increased risk of other health problems, such as dental caries, for which proper treatment is needed.Childhood factors such as low socioeconomic status are risk factors for Helicobacter pylori infection and Streptococcus mutans-related dental caries. We examined whether H. pylori infection and dental caries are present today in the same group of children examined previously. We reviewed the public dental health service files of 21 H. pylori-positive children (upper gastrointestinal endoscopy at a median age of 13.5 y) and 27 H. pylori-negative children (endoscopy at a median age of 12.5 y) examined during 1995-98 at the Helsinki University Central Hospital, Finland. All H. pylori-positive children had experienced dental caries in their primary or permanent teeth or in both whereas among H. pylori-negative children the respective proportion was 70% (p <0.01). At the age of 7 y, 18% (3/17) of the H. pylori-positive children had experienced caries in permanent teeth as compared to 0% among H. pylori-negative children (0/24; p < 0.05). At the age of 12 y, H. pylori-positive children had more decayed, missing or filled permanent teeth than H. pylori-negative children (80% vs. 38%; p <0.05). Although a causal relationship between H. pylori and dental caries is unlikely, it is possible that H. pylori-infected children have an increased risk of other health problems, such as dental caries, for which proper treatment is needed.