PURPOSE: The purpose of this clinical study was to formulate a custom-made, 2-color chewing gum for the mixing ability test and to develop an image-processing method for color mixing analysis.
MATERIAL AND METHODS: Specimens of red-green (RG) chewing gum were prepared as a test food. Twenty dentate participants (10 men, 10 women; mean age 21 years) took part in this study. Each participant masticated 1 piece of RG gum for 3, 6, 9, 15, and 25 cycles, and this task was repeated 3 times consecutively (total n=15 for each participant). The boluses were retrieved and flattened to 1-mm-thick wafers and scanned with a flatbed scanner. The digital images were analyzed using ImageJ software equipped with a custom-built plug-in to measure the geometric dispersion (GD) of baseline red segment. The predictive criterion validity of this method was determined by correlating GD to the number of mastication cycles. The hardness and mass of RG chewing gum were measured before and after mastication. Hardness loss (%) and mass loss (%) were then calculated and compared with those of a commercially available chewing gum.
RESULTS: The 2-way repeated-measures ANOVA with post hoc Bonferroni test showed that GD was able to discriminate among the groups of different numbers of mastication cycles (P
METHODS: Questions about tobacco smoking, smokeless tobacco use, and betel quid chewing were used to create outcome variables such as tobacco smoking, smokeless tobacco use, and 'dual use' (tobacco use and betel quid chewing). Sex-stratified weighted prevalence rates, distribution by socio-demographic factors were presented. Association of demographic factors with tobacco and/or betel quid chewing was assessed by multinomial logistic regression.
RESULTS: Among men, prevalence (%) of tobacco use and betel quid chewing was 40.9 (95% CI 38.1, 42.1) and 58.9 (95% CI 56.3, 61.6) respectively. Among women tobacco use was 3.7 (95% CI 2.0, 4.3) and betel quid chewing 18.2 (95% CI 16.4, 20.0). Among men prevalence of either tobacco or betel quid and 'dual use' was 50.4 (95% CI 48.5, 52.3) and 25.0 (95% CI 23.1, 26.8) respectively, whereas among women the corresponding rates were 17.9 (95% CI 16.2, 19.6) and 2.0 (95% CI 1.6, 2.9). Smokeless tobacco use was low (
SUBJECTS AND METHODS: Clinical outcomes were assessed in 47 patients with 88 LD crowns using modified United States Public Health Service (USPHS) evaluation criteria and survival rates. The questionnaire for predictors included 3 aspects: (a) sociodemographic characteristics, (b) oral health habits (tooth brushing frequency, flossing frequency, and dental visits), and (c) satisfaction of the restorations (aesthetics, function, fit, cleansability, and chewing ability of the crowns, and overall satisfaction). Frequency distributions were computed using univariate and multivariate analysis. The Student t test and analysis of variance (ANOVA) were used to compare means across variables. Correlation analysis was done to assess the association between continuous variables.
RESULTS: The age of crowns was 34.7 ± 9.7 months. The survival rate was 96.6% at 35.9 ± 9.2 months. There was a significant association between successful crown function and oral hygiene measures: tooth brushing (p˂ 0.001), dental visits (p = 0.006), and flossing (p = 0.009). A strong negative correlation was observed between aesthetic satisfaction (r = -0.717, p˂ 0.001) and chewing ability (r = -0.639, p˂ 0.001) with crown age. The linear regression model was significant for all predictors (p < 0.05) except overall satisfaction (p > 0.05).
CONCLUSION: The LD crowns had long survival rates of 96.6% up to 35.9 ± 9.2 months and provided satisfactory clinical performance (low risk of failure). Oral hygiene habits such as brushing, flossing, and regular dental visits influenced patient satisfaction with LD crowns.
Methods: A total of eighteen (18) malocclusion patients were identified. Malocclusion patients were subdivided into 3 groups based on the bracket selection (conventional, self-ligating, and ceramic bracket) with 6 patients for each group. sEMG of muscles were done using a two-channel electromyography device, where pregelled and self-adhesive electrodes (bilateral) were applied. Chewing and clenching of masseter and temporalis muscle activity were recorded for 20 s pre and 6 months of orthodontic treatment using sEMG (frequency 60 Hz). The data were analysed by using repeated measures ANOVA in IBM SPSS Statistics Version 24.0.
Results: Chewing and clenching for masseter muscle showed no significant difference (P > 0.05) in sEMG activity of three types of the brackets. However, for temporalis muscle, there was a significant difference found in sEMG activity during chewing (P < 0.05) and clenching (P < 0.05) between these three brackets.
Conclusion: The activity of temporalis muscle showed significant changes in chewing and clenching, where the conventional group demonstrated better muscle activity pre and at six months of fixed appliances.