ABSTRACT
The proposed device considerably reduces the measuring time of important microscopic features of tooth crown surfaces. The instrumentation is accompanied by a computer program to analyse the results. Tooth enamel is formed by ameloblasts, which demonstrate daily secretory rhythms developing tissue-specific structures known as cross striations, and longer period markings that are referred as striae of Retzius. These striae correspond to linear structures on the enamel surface. This newly developed optical measuring instrument can automatically, precisely and accurately record the number and periodicity of perikymata on the dental crown. Furthermore it can characterize the variability in periodicity of perikymata in hominids. The depth of field can be extended as desired by taking several images with different focus positions and combining them into a single composite image that contains all regions fully focused.
ABSTRACT
A cross-sectional study of 130 Bengalee Hindu men (mean age = 50.3 years; SD = 10.5 years) was undertaken to investigate the relationship of body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR) with total cholesterol (TC), high density (HDL-C), low density (LDL-C) and very low-density (VLDL-C) lipoprotein cholesterol, fasting plasma glucose (FPG) and triglycerides (FTG). Correlation studies revealed that WHR was significantly correlated (r = 0.245, p < 0.01) with TC. WC and WHR had significant correlations with VLDL-C, FPG and FTG. All subjects were further divided into two groups based on WHR < or = 0.95 (centrally non-obese, CNO) and WHR > 0.95 (centrally obese, CO) following the US Joint National Committee (JNC) guidelines. Students' t-test revealed that CO subjects (n = 83) had a significantly higher mean TC (p < 0.05), VLDL (p < 0.05), FPG (p < 0.01) and FTG (p < 0.05) compared with CNO individuals (n = 47). Results of analysis of variance (ANOVA) of central obesity status (CNO = no, CO = yes) and BMI (BMI tertiles used as a categorical variable) with these metabolic variables revealed that CO status had a significant effect (p < 0.05) on TC, VLDL-C, FPG and FTG. BMI tertiles did not a have significant effect on any of these metabolic variables. There was no significant BMI tertile-central obesity status interaction. It can therefore be concluded that the JNC guidelines of WHR > 0.95 to define central obesity can be used, irrespective of BMI, among this population, to identify individuals who have enhanced metabolic risk factors of coronary heart disease (CHD). Furthermore, it can be routinely used for health promotion purposes among Bengalee men.