Dietary inflammatory index and number of functional teeth in middle-aged and older Japanese adults: A cross-sectional study using national survey data.

PURPOSE: To determine whether the number of functional teeth, including the remaining natural teeth and prosthetically restored missing teeth, is associated with the dietary inflammatory index (DII), a quantitative measure of the inflammatory potential of the overall diet, in middle-aged and older Japanese adults. METHODS: National survey data from a non-institutionalized Japanese population aged ≥45 years was analyzed. Multivariable linear regression analyses were performed to assess the association between the DII score, which was calculated based on dietary records, and the number of functional teeth, which was determined during dental examination. All regression analyses were stratified according to the age groups 45-64, 65-74, and ≥75 years. The association between functional tooth units (FTUs) and the DII was assessed using sensitivity analysis. RESULTS: In total, 2407 individuals (1053 men and 1354 women; mean age = 66.7 years) were included. Multivariable analysis revealed that the number of functional teeth was significantly inversely associated with the DII score among participants aged ≥75 years (regression coefficient per increase of one in the number of functional teeth = -0.050; 95% confidence interval = -0.089 to -0.010). The number of functional teeth was not associated with the DII score in younger age categories (i.e., those aged 45-74 years). As in the primary analysis, the number of FTUs was significantly inversely associated with the DII score only in the group aged ≥75 years. CONCLUSIONS: A greater number of functional teeth was associated with a lower DII (i.e., diet with greater anti-inflammatory potential) in Japanese adults aged ≥75 years.

Trends in Primary Tooth Emergence Pattern and Associated Factors in Japanese Infants.

OBJECTIVE: The purposes of this study were to analyse trends in primary tooth emergence patterns and to identify physical factors potentially associated with them. METHODS: The participants were 27,454 infants who underwent routine 18-month-old health examinations in Ebetsu City, Japan, between 1980 and 2012. This study was conducted using data from infants' 18-month-old health examinations over a 33-year period. The mean number of emerged primary teeth was analysed by sex using a general linear model. For logistic regression analysis, the proportion of infants with 16 emerged teeth or more at 18 months old was used as a dependent variable. Examination year; birth order; birth weight; weight, height, and chest girth at 18 months old; number of fused teeth; and mother's age were used as independent variables. RESULTS: The mean number of emerged primary teeth decreased over the 33-year period. Birth weight and weight and height at 18 months old decreased, and the proportion of low-birth-weight (<2500 g) infants increased over the 33-year period. On general linear model analysis, the yearly change in the mean number of emerged primary teeth was -0.0188 for boys and -0.0181 for girls. Birth weight and weight and height at 18 months old were significantly associated with the presence of 16 emerged primary teeth or more, according to the logistic regression analysis. CONCLUSIONS: The results demonstrated that, over the 33-year period examined, the mean number of emerged primary teeth decreased and birth weight and weight and height at 18 months old were associated with the pattern of tooth emergence.

Attachment formation after transplantation of teeth cultured with enamel matrix derivative in dogs.

BACKGROUND: Implantation of cultured cells may be applied for periodontal regeneration in the future. However, a donor is essential in each case and tooth extraction is required to obtain the periodontal ligament-derived cell. We developed a novel regenerative technique combining tissue culture and transplantation of teeth. The purpose of this study is to evaluate the effect of enamel matrix derivative (EMD) on periodontal healing using this technique in dogs. METHODS: A total of 32 incisors from seven beagle dogs were used. The periodontal ligament and cementum 5 mm from the coronal part of the roots were removed, whereas those in the apical part were preserved. Teeth were transplanted after the following treatments: 1) culture with application of EMD to the root surface for 6 weeks (n = 11); 2) culture without application of EMD for 6 weeks (n = 11); and 3) immediately transplanted without culture as control (n = 10). Eight weeks after transplantation, periodontal healing was analyzed. RESULTS: The downgrowth of junctional epithelium on the roots of the EMD and culture groups was significantly smaller than that in the control group (P <0.01). Most of the root-planed surfaces in the EMD group were covered with new cementum (72.2% ± 8.6%). This was significantly greater than that in the culture (29.1% ± 22.9%) and control groups (0.3% ± 1.1%). CONCLUSIONS: Transplantation of tissue-cultured teeth decreased epithelial downgrowth and increased connective tissue attachment on the root-planed surface. Furthermore, EMD could remarkably increase the new connective tissue attachment in this periodontal regenerative technique.

Prevalence of oral malodor and the relationship with habitual mouth breathing in children.

The prevalence of oral malodor and association of habitual mouth breathing with oral malodor were investigated in children residing in rural areas. One hundred and nineteen children participated in this study. A sulfide monitor and organoleptic method were used to evaluate oral malodor. About 8% of children had a sulfide level in mouth air above the socially acceptable limit (75 ppb). Habitual mouth breathing was a factor contributing to oral malodor. Oral malodor was not significantly correlated with plaque index, history of caries or frequency of toothbrushing.