ABSTRACT
Bad breath causes embarrassment and affects interpersonal social communication. Morning breath odor is a commonly encountered oral problem which should be rectified with effective oral hygiene measure. Aim: The aim of this study was to assess and compare the effectiveness of different oral hygiene regimens on the reduction of morning bad breath, plaque formation, and gingivitis in healthy young adults. Settings and Design: A four-step, crossover clinical trial was conducted among 40 young adults aged 18–22 years residing in one of the nongovernmental organizations in New Delhi. Materials and Methods: Study participants were divided into four groups, which underwent intervention for 7 days each. Group 1: tooth brushing; Group 2: tooth brushing and mouthwashing; Group 3: tooth brushing and tongue scraping; and Group 4: combination of all. A washout interval of 14 days was employed in between the groups. Breath scores were measured at three time intervals whereas oral health status was recorded at the beginning and the end of each interventional period. Statistical Analysis Used: Appropriate tests such as paired t-test, ANOVA test, and Pearson correlation tests were used in the study. Results: The highest reduction in mean value of breath scores (2.03 ± 0.69) was found in Group 4 followed by Group 3. Similarly, Group 4 showed the highest reduction in mean value of plaque score (0.79 ± 0.19) and gingival score (0.54 ± 0.23) followed by Group 2. Conclusion: Combination of mechanical and chemical oral hygiene measures is an effective regimen for the reduction of morning bad breath.
ABSTRACT
The structural complexity of crossover studies for bioequivalence test confuses analysts and leaves them a hard choice among various programs. Our study reviews PROC GLM and PROC MIXED in SAS and compares widely used SAS codes for crossover studies. PROC MIXED based on REML is more recommended since it provides best linear unbiased estimator of the random between-subject effects and its variance. Our study also considers the covariance structure within subject over period which most PK/PD studies and crossover studies ignore. The QT interval data after the administration of moxifloxacin for a fixed time point are analyzed for the comparison of representative SAS codes for crossover studies.
Subject(s)
Cross-Over Studies , Therapeutic EquivalencyABSTRACT
OBJECTIVES: I used a case-crossover design to investigate the association between air pollution, and hospital admissions for asthmatic children under the age of 15 years in Seoul, Korea METHODS: I estimated the changes in the levels of hospitalization risk from theinterquartile (IQR) increase in each pollutant concentrations, using conditional logistic regression analyses, with controls for weather information. RESULTS: Using bidirectional control sampling, the results from a conditional logistic regression model, with controls for weather conditions, showed the estimated relative risk of hospitalization for asthma among children to be 1.04 (95% confidence interval (CI), 1.01-1.08) for particulate matter with an aerodynamic diameter less than or equal to 10m (IQR=40.4ug/m3) ; 1.05 (95% CI, 1.00-1.09) for nitrogen dioxide (IQR=14.6ppb) ; 1.02 (95% CI, 0.97-1.06) for sulfur dioxide (IQR=4.4ppb) ; 1.03 (95% CI, 0.99-1.08) for ozone (IQR=21.7ppb) ; and 1.03 (95% CI, 0.99-1.08) for carbon monoxide (IQR=1.0ppm). CONCLUSIONS: This empirical analysis indicates the bidirectional control sampling methods, by design, would successfully control the confounding factors due to the long-term time trends of air pollution. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as asthmatic children.