Kiyoko Tamura

Distribution of 10 periodontal bacterial species in children and adolescents over a 7-year period

OBJECTIVE There is scant information available regarding the distribution of periodontal bacterial species in children and adolescents over an extended period. The purpose of this study was to compare bacterial profiles in the same individuals over a period of 7 years. SUBJECT AND METHODS Twenty-six children and adolescents from whom dental plaque and saliva specimens were obtained during both the first (1999-2000) and second (2006-2007) periods, were analyzed. Bacterial DNA was extracted from each specimen and the presence of 10 periodontal bacterial species was determined using a PCR method, with a focus on the red complex species of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. RESULTS Subjects with red complex species in saliva specimens obtained during the second collection possessed a significantly higher number of total bacterial species than those without. The detection rate of the red complex species in the second collection period samples was significantly greater in subjects who had two or more species detected in samples taken during the first collection compared with the other subjects. CONCLUSION Subjects possessing red complex species may be at possible risk for infection with a high number of periodontal bacterial species during adolescent and younger adult years.

Clinical and microbiological evaluations of acute periodontitis in areas of teeth applied with orthodontic bands

Two cases with severe periodontal inflammation in areas of teeth applied with orthodontic bands are presented. Both were diagnosed as acute periodontitis, and removal of the orthodontic bands followed by professional oral hygiene procedures resulted in the recovery to the normal level of periodontal condition. The presence of 10 targeted species of Gram-negative periodontal bacteria in subgingival plaque samples taken from the corresponding teeth, which were not detected in either patient during the period of severe periodontal inflammation, was assessed several times using a polymerase chain reaction method. As the periodontal conditions of the patients improved, these bacteria were identified during the follow-up examination periods. Our results suggest that none of the 10 Gram-negative periodontal bacteria were associated the acute periodontitis at the teeth applied with orthodontic bands.

A comparative study of X-ray diffraction and infrared absorption properties and amino-acid analysis of bovine enamel

Abstract The physico-chemical changes of inorganic and organic matrix components from the coronal, intermediate and cervical parts of developing enamel have been investigated by X-ray diffraction, i.r. absorption spectroscopy and amino acid analysis. 1. (1) The initial stages of maturation were characterized mainly by growth of the apatite crystals and the later stages by removal of imperfections or strain from the crystals without much further growth. 2. (2) Changes in the i.r. spectra between the immature and the adult enamels were observed in the region of 1650 cm −1 . Although the immature enamels showed medium absorption, the adult one showed only traces of the band. 3. (3) The proportion of arginine, lysine and NH 3 increased in the highly mineralized cuspal parts and glycine, proline, glutamic acid and leucine showed a high value in the cervical parts of the enamel. Hydroxyproline was absent from bovine enamel. The changes in amino-acid composition during enamel maturation are consistent with the removal of organic matrix in the enamel.

Oral findings and microbiological evaluation in a case of triple-X syndrome

We present a case of a triple-X syndrome in a Japanese girl who was treated from 5Y9M to 14Y6M of age at the Pedodontic Clinic of Osaka University Dental Hospital. At the first examination, multiple dental caries were identified, and a pulpectomy and extraction of the affected teeth were carried out. There were no congenitally absent teeth, including third molars, though the development of permanent teeth was approximately 2 years behind chronological age. At 14Y6M, a PCR analysis of 10 putative periodontopathic bacteria was performed, and all 10 species were found in saliva samples. At the same time, an oral examination revealed that the gingival tissues were highly inflamed with an extremely large amount of calculus, suggesting a risk for the early onset of periodontitis.

Clinical and microbiological evaluations of children with hypophosphatasia affected by periodontitis

Abstract Four patients with hypophosphatasia, including twin brothers and younger and older sisters, were analyzed longitudinally. Ten periodontitisrelated bacterial species in dental plaque were detected using a Polymerase chain reaction (PCR) method with species-specific sets of primers. Further, clinical parameters related to periodontal conditions were recorded at each visit. One of the twins, who had experienced early exfoliation of the primary teeth, had a greater number of bacterial species than his brother, who had no alveolar bone loss. Both of the sisters experienced early exfoliation of their primary teeth, and the average numbers of tested bacterial species were higher in other subjects of the same age. Our results indicate that impaired cementum tissue caused by hypophosphatasia may produce favorable sites for colonization of periodontitis-related bacteria.

Clinical and microbiological evaluations of gingival fibromatosis in children: Report of two cases

Abstract Gingival fibromatosis is a rare clinical finding of non-inflammatory gingival overgrowth. Here we present 2 cases of children with gingival fibromatosis and provide a longitudinal analysis of the correlation between the presence of periodontal bacteria and clinical condition. The first case, a boy treated from age 2 to 6, showed periodontitis in the lower anterior region, which recovered to a good periodontal condition by a professional therapeutic approach. The second case is a girl, treated for 2 years from age 10, who presented with extremely enlarged gingiva and severe gingivitis, and a gingivectomy was carried out to eliminate the dental plaque accumulation. In both cases, periodontal bacteria were assessed periodically using PCR (Polymerase Chain Reaction) method, and the results compared with the clinical conditions. In both cases, increased numbers of periodontal bacteria were detected during the bad gingival condition period. In addition, Prevotella nigrescens and Prevotella intermedia were especially detected. Clinical condition seems to be influenced by the number of the periodontal bacteria present, which indicates that an effective monitoring of such bacteria would be beneficial for not only evaluating the current periodontal condition, but also for making an appropriate prognosis of a lesion.