Daily life habits associated with eveningness lead to a higher prevalence of dental caries in children.

BACKGROUND/PURPOSE: Circadian rhythm is an endogenous daily variation observed in most physiological functions including salivary secretion. Irregular lifestyle causes many diseases such as obesity and sleep disorders. The aim of this study is to examine the effects of the timings of sleep and meal on the prevalence of dental caries. MATERIALS AND METHODS: Study was conducted at university hospital in Japan. We asked 230 children (1-16 years old) to record the following life habits for 8 days: waking time, bedtime, mealtimes, snacking frequency, and tooth brushing frequency. We analyzed sleep habits from all data and compared dental caries and life habits using data from subjects with primary (2-7 years old) or permanent (11-16 years old) dentition period. RESULTS: The number of dental caries assessed using the decay or filled teeth (dft) index correlated with bedtime, supper time, regularity of supper time, and snacking frequency in subjects with primary dentition. Multiple regression analysis revealed that bedtime and snacking frequency were mutually independent risk factors for dental caries. No correlations were found between the prevalence of dental caries and other measurement items. The number of caries correlated with the regularity of supper time and age in subjects with permanent dentition. CONCLUSION: Children with daily life habits associated with eveningness have a higher prevalence of dental caries.

A simple test for salivary gland function measuring resting and stimulated submandibular and sublingual secretions.

OBJECTIVE: This study examined the application of a simple screening test for salivary gland function by measuring resting and stimulated submandibular and sublingual secretions. STUDY DESIGN: An assay system was designed to use filter paper incorporating the chromophore of melanoidin or stimuli such as capsaicin and citric acid. We investigated the relationship between resting and stimulated secretions and melanoidin migration at 2 minutes for healthy and dry mouth groups. RESULTS: The healthy group showed a significant increase in the migration of melanoidin in the paper after citric acid or capsaicin stimulation. In contrast, patients with Sjögren syndrome showed no significant migration in spite of the stimulation. However, some participants with Sjögren syndrome or dry mouth showed a significant increase in the migration of melanoidin after stimulation. CONCLUSIONS: These results show that the newly developed method should be useful for evaluation of residual salivary gland function and screening for hyposalivation with dry mouth.