The short tandem repeat (STR) polymorphism of the lipoprotein lipase (LPL) locus was amplified by PCR and analyzed using denaturing polyacrylamide gel electrophoresis followed by silver staining. Among 158 DNA samples from the Japanese population, six alleles were observed. When the sequences of the allelic products were compared, each allelic segment contained 7 and 9-13 TTTA tetranucleotide repeat motifs. Genotypic distribution met Hardy-Weinberg expectations, and included heterozygosity was 48.8%. Most of the Japanese genotypes allele 10. When PCR amplification efficiency for the LPL locus from degraded DNA was compared with that for the D21S11 locus in terms of amplification size, increase in amplification size showed a considerable influence on amplification efficiency, producing inaccurate amplification, such as unbalanced amplification, or amplification of non-target PCR products. These results suggest that reduction in amplification size increases the accuracy and efficiency of PCR amplification from highly degraded DNA.

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The purpose of this study was to evaluate whether percentile curves for food acceptance response scores were useful in assessing oral and occlusal conditions. We used data obtained from Chiba City Patient Surveys (males: 1,276, females: 1,381, aged 20 to 64), which were conducted in 1998 and 1999. Subjects were assigned scores of between 1 and 4 for 31 different kinds of food based on their food acceptance responses. Occlusal conditions were measured with pressure-sensitive sheets. We calculated the percentile values from 5 to 95 at intervals of five years. We divided the subjects into two groups at the twenty-fifth percentile and statistically analyzed various oral conditions in the two groups. Significant differences were found between them in the mean numbers of present, sound, and missing teeth for almost all age groups. Moreover, there were significant differences in tooth-contact area and occlusal force between the two groups. The results of multiple regression analysis revealed that the scores had a stronger correlation with occlusal conditions than number of teeth in 55-year-olds, although the effect teeth-factors had on scores was more significant in 45- to 50-year-old males. Females' scores had a stronger correlation with occlusal conditions than number of teeth in all age groups. These results indicate that the questionnaire on the acceptance of 31 different kinds of food is useful in providing a basis for oral health instruction and dental treatment aimed at improving chewing ability in adults.

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We conducted oral examinations and dietary surveys on a total of 141 subjects with an average age of 80 years or more-specifically, seniors (S-group) living in a health service facility for the elderly and patients with mild dementia (SD-group) living in a special nursing home for the elderly. All were assumed to have a roughly uniform diet. We investigated which factors contributed to their dietary intake, and the relationship between dietary intake and number of present teeth (PT). Factors affecting total energy of the subjects and those in the S-group were body weight and number of PT. No factors were recognized as having a relationship with total energy in the SD-group. A significant difference was found in males in the S-group in that those in the “five PT or more” group had higher levels of carbohydrates and vitamin B₁ than those in the “four PT or less” group. However, significant differences were found in the SD-group in that subjects in the “five PT or more” group had higher levels of carbohydrates, calcium, iron, and vitamins A, B₁, B₂, and C than those in the “four PT or less” group. Significant differences were seen in both groups for female patients in the nursing home with regard to total energy, proteins, carbohydrates, iron, vitamin B₁, and fiber intake. No significant differences were recognized, however, for females in the SD-group. Reductions in dietary intake should be considered from the perspective of nutritional status, which is a problem that can be resolved through dental treatment. This study found that recovery of chewing ability in seniors was essential not only to maintain nutritional status, but also to fully bring out all the functions of the foods themselves.

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An unknown skeletonized body was identified by DNA analysis and dental information. The body had already been cremated when a candidate for the unknown body was proposed. Therefore, for DNA analysis we used teeth that had been kept for a long time after use for serological examination. We also used a chest X-ray photograph of the candidate and photographs of dentition, as well as dental X-ray photographs taken when the unknown body was found. Because DNA obtained from teeth was highly degraded, we amplified three PCR fragments to determine the 766 bp mitochondrial DNA (mtDNA) sequence including HV1 and HV2. Polymorphism of the ABO locus was also analyzed using small PCR fragments. Although the isolated DNA was contaminated, probably with DNA from a different individual, DNA polymorphisms of mtDNA and the ABO locus could be analyzed. We discuss the reliability of our conclusions from the point of view of the necessity of constructing an accurate mtDNA database. Although a dentist who had treated the teeth of the unknown body could not be found, a chest X-ray photograph for medical diagnosis was very useful in comparing dental characteristics, as it included an image of the frontal part of the lower jaw and upper teeth.

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