Reliability between the two-colour chewing gum and the gummy-jelly tests used for the assessment of masticatory performance.

OBJECTIVE: This study aimed to evaluate the reliability of two methods used to assess masticatory performance and attempt to correlate them to achieve interchangeability between the methods. METHODS: Twelve healthy dentate volunteers (men = 6, women = 6; mean age = 28.3 ± 4.1) with no known dental or medical pathologies were requested to participate in this study. Each participant completed three masticatory performance assessments, including two two-colour mixing-ability tests using chewing-gums (CG: gum#1 and gum#2) and the gummy-jelly (GJ) test. For each method, participants created five samples each (total = 15 measurements per participant, gum#1 = 5, gum#2 = 5, GJ = 5). For the gum#1 and gum#2 methods, the predetermined chewing cycles were fixed at 10, 15, 20, 25 and 30 cycles, and for the GJ method, the time duration was fixed at 10, 15, 20, 25 and 30 s. The parameter measures were submitted to Z-score transformation, and Bland-Altman plots were generated to graphically compare the differences between two techniques against their means. Additionally, mountain plot was used to assess the cumulative distribution of measurement error between the methods. RESULTS: A total of 180 measurements were recorded. There were significant correlations between the number of chewing cycles/chewing time and masticatory performance using the gum#1 (r = -.753; p < .001), gum#2 (r = -.838; p < .001) and GJ (r = .730). When all tests were considered together for each method, significant correlations were found (p < .001). A descriptive range of mean values aiming to produce reference value ranges for predictive purposes was achieved considering the interchangeably among the methods [CG = GJ (VoH-mg = dL): 10 cycle = 10 s: 0.329 = 110; 15 cycles = 15 s: 0.177 = 164; 20 cycles = 20 s: 0.130 = 205; 25 cycles = 25 s: 0.086 = 200; 30 cycles = 30 s: 0.077 = 267]. CONCLUSION: The strong correlations and high consistency between the two masticatory performance methods found in this study conclude that the two assessment methods are reliable and interchangeable. Further evaluations are warranted to arrive at a conversion formula for translation of the results between the two methods.

Chewing gum base: A comprehensive review of composition, production, and assessment methods: Advances and approaches in biodegradability.

The gum base mass is a colloidal system and the main component of chewing gum; which is an inert, non-nutritious, indigestible, and insoluble part of chewing gum, therefore this substance does not dissolve in the mouth when chewed. The gum base plays the most crucial role in determining the mechanical properties, flexibility, and overall quality of chewing gum. Moreover, it acts as a delivery system to transport sweeteners, flavorings, and other ingredients in chewing gum. Despite the massive market for chewing gum and the provision of a list of the main ingredients in gum base by the Code of Federal Regulations and some international organizations, there is a lack of information about chewing gum base and its compositions in the literature. Therefore, the purpose of this review is to present an overview of the characteristics, ingredients and applications, production process, assessment, and modification methods of the gum base along with the advances and approaches in biodegradability. Biodegradability concerns play a promoting role in the research and development of chewing gum and its applications in the food industry, medical and dental sectors. Reviewing previous studies can surely help for faster development of this path.

Masticatory performance in oral function assessment: Alternative methods.

BACKGROUND: Masticatory function declines with age or disease, implicating a poor chewing efficiency and an often-unconscious change for a less healthy, yet easy to chew diet. Timely screening of masticatory function may foster an early-onset diagnosis and potential treatment. The aim of this study was to compare alternative diagnostic tools for masticatory function to a Jelly-scan test. MATERIALS AND METHODS: Patients aged 70 years and older who were hospitalised for rehabilitation were recruited for this study. A total of four different tests for masticatory function were administered. The Japanese Society of Gerodontology glucose extraction test (Jelly-scan) was used as reference to compare a colour-changing gum test (Gum1-colour) as well as a mixing ability test with a visual (Gum2-visual) and opto-electronical (Gum2-digital) analyses. Receiver operating characteristic (ROC) curves were used to establish the discriminative value, kappa-values were used to estimate individual agreements and correlations were verified using Spearman's tests. RESULTS: Sixty-one patients (Men n = 23, Women n = 38) aged 82.4 ± 6.8 years participated in the experiments. The average number of natural teeth was 16.5 ± 10.5, 34.4% of the participants wore removable dentures. For all tests, the sum of sensitivity and specificity was >150%. All test correlated with Jelly-scan (absolute Rho >0.5). With Jelly-scan 51 participants (83.6%) were diagnosed with "masticatory hypofunction". After reducing the cut-off value of the test from 100 mg/dL to 65 mg/dL, only 33 participants (54%) fulfilled the diagnosis. This post-hoc analysis increased the sensitivity of the Gum2-tests and the agreement to kappa >0.5 for all three tests. CONCLUSION: All three tests can be considered useful screening alternatives. In its original version, Jelly-scan may tend to over-diagnose masticatory hypofunction, hence a novel cut-off with better agreement between tests is suggested.

Subjective and Objective Assessment of Chewing Performance in Older Adults with Different Dental Occlusion.

OBJECTIVES: Satisfactory masticatory function is a significant indicator of improved oral health-related quality of life in older adults, either with or without artificial teeth. The purpose of this study was to examine masticatory performance of older adults with different prosthodontic reconstructions and occlusion, as well as to compare subjective and objective assessment of chewing performance. MATERIAL AND METHODS: This study included 100 participants aged 65 and more. The chewing function questionnaire (CFQ) with answers on the Likert scale 0-4 (0 = no difficulties; 4 = maximum difficulties) was used as an indicator of subjective masticatory assessment. The two-color chewing gum test was used as objective assessment of masticatory function (mixing ability), based on the Z-score values. Dental occlusion was assessed using functional teeth units (FTU). RESULTS: The results obtained using the CFQ and the clinical mixing ability test are in compliance with each other (r = 0.742). A decrease in the number of natural teeth, especially posterior teeth, progressively reduced chewing ability and increased difficulties in mastication. Participants with less FTUs, or with FTUs that are a part of removable denture, had greater reduction in masticatory function compared to those with FTUs composed of natural teeth or fixed partial dentures. CONCLUSION: This study revealed a strong positive correlation between the subjective masticatory assessment in older adults using the validated questionnaire and the objective clinical test of the mixing ability of two chewing gums. Our data on influence of the number and the type of FTU on masticatory performance will be valuable when planning prosthodontic therapy.

Assessment of masticatory efficiency based on glucose concentration in orthodontic patients: A methodological study.

BACKGROUND: Treatment for malocclusion can cause discomfort and pain in the teeth and periodontium, which may impair masticatory efficiency. The glucose concentration method is widely used to assess masticatory efficiency for its convenience in the clinical situation, although its validity has not been shown. OBJECTIVES: The aims were to determine the validity of the glucose concentration method and investigate if this method can be applicable to orthodontic patients with braces. METHOD: Sixteen healthy individuals (7 men, 9 women, and 26 ± 5 years old) and 16 patients with malocclusions needing orthodontic treatment (5 men, 11 women, and 26 ± 4 years old) participated. Glucose concentration was measured after 5-, 10-, and 15-s mastication of gummy jelly and compared to Hue values obtained from the color-changing gum method (reference method). In addition, all participants were asked to fill out the Oral Health Impact Profile questionnaire (OHIP) to assess differences in perception related to the mouth before and after the placement of braces. RESULTS: Glucose concentrations were strongly correlated to measures of the two-color chewing gum methods (R2  = 0.965). Both the glucose extraction and chewing gum hue value were the smallest for 5 s chewing cycles and increased as the number of chewing strokes increased for the 15 s chewing cycles. (Hue: R² = 0.510, p < 0.001; glucose: R² = 0.711, p < 0.001) Masticatory efficiency assessed by both methods was significantly lower in orthodontic patients compared to controls (p < 0.05), even though it was not affected by bonding (p > 0.09). In addition, OHIP scores in physical pain dimension and psychological disability were higher in orthodontic patients than in the control group (p < 0.005). CONCLUSION: Measurement of glucose concentration was confirmed as a reliable and convenient method for assessing masticatory efficiency. Furthermore, it appears that this method is applicable to patients with braces whose perception in the oral cavity could change.

Assessment of masticatory function in the differential diagnosis of Stage IV periodontitis: A pilot diagnostic accuracy study.

BACKGROUND: After diagnosis of periodontitis is made, detection of Stage IV cases is critical for appropriate management that may call for interdisciplinary care. This study aims to identify and assess the accuracy of a simple screening approach for practice and surveillance of Stage IV periodontitis. METHODS: Masticatory function assessments by both validated self-reported masticatory dysfunction questionnaire and dual-color chewing gum mixing ability test (index test) were conducted in 214 consecutive patients, followed by a full-mouth periodontal examination. Periodontal diagnosis was based on the 2017 World Workshop classification of periodontal diseases (reference standard). Multivariate logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were performed. RESULTS: Overall, the individual patient-reported masticatory dysfunction questions showed low to moderate accuracy for predicting Stage IV periodontitis. The objective measures of masticatory function by calculating the variance of hue from the chewing gum test performed better with an AUROC of 0.840. A diagnostic approach based on age, self-report of altered food type intake, and chewing gum test results exhibited excellent performance for predicting Stage IV periodontitis (sensitivity: 89.7%; specificity:76.3%; AUROC:0.912). CONCLUSIONS: Once the presence of periodontitis has been established, a simple diagnostic approach that does not require specialized workforce, complex, or lengthy assessment allows identification of patients with Stage IV periodontitis. This is important as these patients require specific case work up and interdisciplinary care pathways. Additional studies are required to validate the findings in multiple populations.

The economic benefits of increased sugar-free chewing gum in China: a budget impact analysis.

BACKGROUND: To analyze the potential cost savings in dental care associated with increased sugar-free gum (SFG) use among Chinese teenagers and adults. METHODS: The amount of SFG chewed per year and decayed, missing and filled teeth (DMFT) was collected from a cross-sectional survey to create a dose-response curve assumption. A cost analysis of dental restoration costs was carried out. A budget impact analysis was performed to model the decrease in DMFT and the subsequent cost savings for dental care. Three different scenarios for the increase in the number of SFG were calculated. RESULTS: The average cost savings per person in the Chinese population due to increasing SFG use ranged from 45.95 RMB (6.94 USD) per year to 67.41 RMB (10.19 USD) per year. It was estimated that 21.51-31.55 billion RMB (3.25-4.77 billion USD) could be saved annually if all SFG chewers among Chinese teenagers and adults chewed SFG regularly. CONCLUSION: This study suggests that dental care costs could be significantly reduced if SFG use increased in the Chinese population.

Reliability and validity of a new colour-changing test food with an acid-base reaction for the clinical assessment of masticatory performance.

The aim of this study was to determine the reliability and validity of a new test food for the clinical assessment of masticatory performance. The test food had two overlapping acidic/basic halves. Ten dentate subjects chewed one unit for 10-100 cycles. One subject chewed ten units for the same number of cycles. Differences in the L*, a* and b* colour axes were determined before and after chewing by ANOVA. Colour guides were created based on the values of these axes and matched with the number of cycles. The reliability of the guides was evaluated using 30 images, where three examiners indicated the number of cycles in which the colour closest to that of a chewed material was found. The data were contrasted with the real values of the guides to determine the validity (Kappa coefficients). The equivalence of the guides with the median particle size (X50) was determined using equidimensional curves. The test food progressively changed from green to pink during chewing. As the number of cycles increased, the a* values increased and the b* values decreased (p < 0.05). Overall, the guides showed a Kappa value >0.8 for the intra-examiner and inter-examiner reliability and the validity comparisons. The a* and X50 values were inversely proportional to each other, and the b* values showed a direct relationship with the X50 values. The L* values did not show correspondence. The new test food showed high reliability and validity for the assessment of masticatory performance through clinical colour guides matched with the number of cycles and X50.

Comparative Assessment between Ibuprofen, Chewing Gum, and Bite Wafers in Pain Control Following First Archwire Placement in Orthodontic Patients.

PURPOSE: This study aimed to investigate the effectiveness of using bite wafers and chewing gum in relieving pain after the activation of the first archwire among Saudi orthodontic patients and evaluating them in comparison with ibuprofen use. Furthermore, the study investigated the effect of chewing gum and plastic wafers on the frequency of orthodontic appliance breakage. MATERIALS AND METHODS: A total of 105 female patients aged 15-35 years, undergoing maxillary and mandibular fixed appliance treatment were classified randomly into three groups of 35 each. In each group, the patients were given one of the following treatments immediately after the placement of the first archwire, every 8 hours for 1 week as needed: ibuprofen (400 mg), or a viscoelastic bite wafer, or chewing gum. A visual analog scale was given to the patients to record their pain perception following initial archwire placement. In addition, the patients were asked to report any incidence of detached brackets while using the above methods. Data were analyzed using analysis of variance (ANOVA). RESULTS: No statistically significant differences were found in pain perception at any time interval among the three groups. The pain experienced at bedtime and 24 hours after wire placement among different groups in the present study was found to be slightly higher with maximum intensity and the pain perception finding at different time intervals within each pain relief method was statistically significant (p = 0.000, p < 0.05). Furthermore, ANOVA results demonstrate no significant differences in bracket detachment between the groups (p = 0.20, p < 0.05). CONCLUSION: The use of bite wafers and chewing gum was effective and comparable to ibuprofen use for pain relief following the initial activation of fixed orthodontic appliances among Saudi orthodontic patients. In addition, the study found no clinically or statistically significant differences in bracket detachment between the groups. CLINICAL SIGNIFICANCE: The nondrug modalities of controlling pain such as chewing gum and/or bite wafers can be used as an alternative to ibuprofen use following the first activation of fixed orthodontic appliances.

Assessment of masticatory performance by geometric measurement of the mixing ability with 2-color chewing gum.

STATEMENT OF PROBLEM: The 2-color mixing ability test has been recently introduced for objective assessment of masticatory performance. However, the ideal bicolor specimens have not yet been identified, and the color analysis of digital images requires improvement. 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<.001). Pearson correlation coefficient confirmed the significant correlation between GD and the number of mastication cycles (r=0.90, P<.001). The hardness loss and mass loss of RG chewing gum were significantly lower than those of commercial chewing gum (P<.001). CONCLUSIONS: The newly formulated chewing gum provides an appropriate test food material for masticatory performance assessment. The new image-processing method discriminated among the different levels of color mixture and quantified the mixing ability.

Intake of caffeine from all sources and reasons for use by college students.

BACKGROUND & AIMS: Caffeine intake in a convenience sample of U.S. college students (N = 1248) was surveyed at five geographically-dispersed United States (U.S.) universities. METHODS: Intake from coffee, tea, soft drinks, energy drinks, gums, and medications was assessed. Associations between caffeine intake and demographic variables including sex, age, race/ethnicity, family income, general health, exercise, weight variables and tobacco use were examined. Reasons for use of caffeine-containing products were assessed. RESULTS: Caffeine, in any form, was consumed by 92% of students in the past year. Mean daily caffeine consumption for all students, including non-consumers, was 159 mg/d with a mean intake of 173 mg/d among caffeine users. Coffee was the main source of caffeine intake in male (120 mg/d) and female (111 mg/d) consumers. Male and female students consumed 53 vs. 30 mg/d of caffeine in energy drinks, respectively, and 28% consumed energy drinks with alcohol on at least one occasion. Students provided multiple reasons for caffeine use including: to feel awake (79%); enjoy the taste (68%); the social aspects of consumption (39%); improve concentration (31%); increase physical energy (27%); improve mood (18%); and alleviate stress (9%). CONCLUSIONS: As in the general U.S. population, coffee is the primary source of caffeine intake among the college students surveyed. Energy drinks provide less than half of total daily caffeine intake but more than among the general population. Students, especially women, consume somewhat more caffeine than the general population of individuals aged 19-30 y but less than individuals aged 31-50 y.

Elevating the use of sugar-free chewing gum in Germany: cost saving and caries prevention.

OBJECTIVE: To analyse the lifetime monetary and health related effects of the consumption of sugar-free chewing gum. MATERIAL AND METHODS: Using a Markov model we assumed that the German consumption of sugar-free chewing gum (111 gums/year) could be elevated to the level of Finland (202 gums/year). The calculation was based on a model patient representing the development of oral health from the age of 12 to 74 years and clinical data on the effectiveness of chewing sugar-free gum. Lifetime and yearly costs for the 'Finland-scenario' were determined and compared with the actual German expenses of the statutory health insurance companies for dental health. RESULTS: The actual total lifetime expenditures of the statutory health insurance companies are 17,199.96€ per capita and would be 12,188.94€ in the scenario with elevated consumption of sugar-free chewing gum in Germany. Thus, 5011.02€ per capita could be saved in a lifetime and 80.82€ per year. CONCLUSIONS: On a national scale, the elevation of the consumption of sugar-free chewing gum in Germany to the level of Finland would lead to a considerable benefit for cost saving and oral health for the statutory health insurance companies.

Health-related quality of life and cost-effectiveness analysis of gum chewing in patients undergoing colorectal surgery: results of a randomized controlled trial.

BACKGROUND: Postoperative ileus (POI) and anastomotic leakage (AL) following colorectal surgery severely increase healthcare costs and decrease quality of life. This study evaluates the effects of reducing POI and AL via perioperative gum chewing compared to placebo (control) on in-hospital costs, health-related quality of life (HRQoL), and assesses cost-effectiveness. METHODS: In patients undergoing elective, open colorectal surgery, changes in HRQoL were assessed using EORTC-QLQ-C30 questionnaires and costs were estimated from a hospital perspective. Incremental cost-effectiveness ratios were estimated. RESULTS: In 112 patients, mean costs for ward stay were significantly lower in the gum chewing group when compared to control (€3522 (95% CI €3034-€4010) versus €4893 (95% CI €3843-€5942), respectively, p = .020). No differences were observed in mean overall in-hospital costs, or in mean change in any of the HRQoL scores or utilities. Gum chewing was dominant (less costly and more effective) compared to the control in more than 50% of the simulations for both POI and AL. CONCLUSION: Reducing POI and AL via gum chewing reduced costs for ward stay, but did not affect overall in-hospital costs, HRQoL, or mapped utilities. More studies with adequate sample sizes using validated questionnaires at standardized time points are needed.

Halitosis Assessment and Changes in Volatile Sulfur Compounds After Chewing Gum: A Study Performed on Dentistry Students.

OBJECTIVE: The objective of this study is to estimate the prevalence of halitosis (with subjective and objective methods), evaluate the immediate effect of chewing gum on volatile sulfur compounds (VSCs), assess the perception of halitosis by dentistry students, and estimate the distribution of positive and negative frequencies, when comparing objective and subjective methods for the diagnosis of halitosis. METHODS: The study was performed on a sample of dentistry students attending the Faculty of Medicine and Health Sciences at the University of Barcelona. A questionnaire about halitosis perception was provided and a clinical examination, organoleptic test (OT), and gas chromatography were performed to determine the presence of halitosis. The subjects were also given chewing gum to modify their breath, and gas chromatography was carried out to evaluate possible changes in VSCs. RESULTS: The sample comprised 80 individuals. Twenty-seven (33.75%) self-perceived halitosis during the period of evaluation; the OT was positive in 38 subjects (47.5%); and individuals positive for halitosis on gas chromatography were distributed as follows: H2S in 25 (31.25%), CH3SH in 28 (35%), and (CH3)2S in 70 individuals (87.5%). A statistical difference before and after chewing gum (P < .05) was found for each VSC; a difference in frequencies was observed between the variable OT and H2S (P < .05) and between the OT and (CH3)2S (P < .001). There was no significant difference (P > .05) between the positive and negative frequencies retrieved between the variable OT and CH3SH and between the OT and the student's halitosis perception. CONCLUSION: Prevalence of halitosis in the studied sample is high, considering that it comprised healthy individuals. The relationship between the OT and gas chromatography is not completely established. Chewing gum could be considered a therapeutic alternative to decrease or neutralize the amount of VSCs present in oral breath.

A global approach to assess the economic benefits of increased consumption of sugar-free chewing gum.

PURPOSE: To analyze the influence of increasing the average consumption of sugar-free gum (SFG) in 25 industrialized countries on dental expenditures due to caries by the national health care systems. It was assumed that large cost savings were possible, because the regular consumption of SFG significantly reduces the relative risk of caries and therefore, improves dental health, which reduces expenditures on dental treatments. METHODS: A budget impact analysis (BIA) was performed to model the decrease in the relative risk of caries and the subsequent cost savings for dental care. Annual consumption of SFG, dental expenditures due to caries, chewing frequencies by age groups and the relative risk reduction for caries due to the consumption of SFG were identified and used as model parameters. Three different scenarios for the increase in the number of SFG were calculated. Besides overall results for all countries together, analyses were conducted for countries grouped by regions and the Human Development Index (HDI). RESULTS: For the entity of all 25 analyzed countries together, possible annual cost savings range from US$805.77 M in the scenario with the lowest increase of SFG consumption up to US$18,248 billion in the scenario with the biggest increase of SFG consumption. Europe and the USA show potential cost savings of US$1,061 billion and US$2,071 billion per year, respectively, if all chewers increase their consumption of SFG by 1 piece per day. The analysis showed the potential cost savings in dental expenditures due to caries that can be achieved by only slightly increasing the consumption of SFG. The regular consumption of SFG cannot replace good dental hygiene like tooth brushing, but can have a significant impact on dental health, which can lead to increased cost savings for health care systems worldwide. CLINICAL SIGNIFICANCE: Based on the fact that a regular consumption of sugar-free chewing gum has the beneficial effect of reducing caries prevalence, an increased consumption may not only lead to improved dental health but significant cost savings in expenditures for dental treatment worldwide.

Assessment of masticatory performance by means of a color-changeable chewing gum.

PURPOSE: Previous research determined the relevance of masticatory performance with regard to nutritional status, cognitive functions, or stress management. In addition, the measurement of masticatory efficiency contributes to the evaluation of therapeutic successes within the stomatognathic system. However, the question remains unanswered as to what extent modern techniques are able to reproduce the subtle differences in masticatory efficiency within various patient groups. The purpose of this review is to provide an extensive summary of the evaluation of masticatory performance by means of a color-changeable chewing gum with regard to its clinical relevance and applicability. STUDY SELECTION: A general overview describing the various methods available for this task has already been published. This review focuses in depth on the research findings available on the technique of measuring masticatory performance by means of color-changeable chewing gum. Described are the mechanism and the differentiability of the color change and methods to evaluate the color changes. Subsequently, research on masticatory performance is conducted with regard to patient age groups, the impact of general diseases and the effect of prosthetic and surgical treatment. RESULTS: The studies indicate that color-changeable chewing gum is a valid and reliable method for the evaluation of masticatory function. CONCLUSION: Apart from other methods, in clinical practice this technique can enhance dental diagnostics as well as the assessment of therapy outcomes.

Thyroid Patient Salivary Radioiodine Transit and Dysfunction Assessment Using Chewing Gums.

Radiation-induced salivary gland dysfunction is the most frequent side-effect of I-131 thyroid therapy. Here, a novel saliva sampling method with ordinary chewing gums administered to the patients at appropriate time intervals post-treatment (TIPT) was used to relate this effect to chewing gum saliva activity (CGSA) content. Saliva samples were acquired after the oral administration of prescribed I-131 activity (radioactivity administered [RA]) to 19 differentiated thyroid cancer (DTC) and 16 hyperthyroidism patients of the radioisotope unit (RIU) during 2014 and 2015. The error of this saliva collecting process was found to be 1.2%-2.05%, and so, the method was considered satisfactory. For each patient, the CGSA was plotted against the TIPT producing a curve, R(t). On this, two functions were fitted: a linear on the first few rising data points and a gamma variate over the peak of the R(t). From these, several parameters related to the radioactivity oral transit were calculated and the total radioactivity administered (TRA) during all past treatments of each patient was obtained from RIU records. The patients were asked to report any swelling, dry mouth, taste-smell change, or pain and were graded as a morbidity score (MS) describing the quality of life of each. The peak radioactivity in the saliva samples, Rmax, was found to be proportional to RA and was plotted against the CGSA extrapolated at 24 and 36 hours. The linear fits produced were used to estimate the salivary glands' activity average effective half-life (16.3 hours). The MS of DTC patients was found to depend linearly both on Rmax and TRA (MS = 0.0032 × Rmax - 0.7107 and MS = 0.1862 × TRA +0.66, respectively). Both lines were used to extrapolate symptom thresholds. The measurement of Rmax in DTC patients proved very useful for individualized radiation protection, and the dependence of MS on TRA should be used when additional treatments are considered for repeat DTC patients.

Comparative assessment of chewing gum and ibuprofen in the management of orthodontic pain with fixed appliances: A pragmatic multicenter randomized controlled trial.

INTRODUCTION: The aim of this randomized trial was to investigate the effect of the use of a sugar-free chewing gum vs ibuprofen on reported pain in orthodontic patients. METHODS: This was a 2-arm parallel design randomized controlled trial in 9 sites in the southwest of England. Patients about to undergo orthodontic treatment with maxillary and mandibular fixed appliances were recruited and randomly allocated to an experimental chewing gum group or a control ibuprofen group. Eligibility criteria included patients undergoing fixed maxillary and mandibular appliance therapy, aged 11 to 17 years, and able to use ibuprofen and chewing gum. The primary outcome measure was pain experienced after appliance placement using a mean of 3 recordings on a scale of 0 to 10. Secondary outcome measures were pain experienced in the subsequent 3 days, pain after the first archwire change, ibuprofen use, and appliance breakages. Pain scores were recorded with a questionnaire and posted to a collection center by each patient. Randomization was by means of a central telephone service and comprised computer-generated random numbers used to generate a sequential allocation list, with permuted blocks of variable size (2 and 4) and stratified by center. Neither the clinicians nor the patients were blinded to the intervention. Patients in the control group were permitted to use ibuprofen only, and patients in the experimental group were allowed to use ibuprofen if they did not get sufficient analgesia from the chewing gum. Data were analyzed using the principle of intention to treat with multilevel modeling to reflect the structured nature of the data (scores within patient within site). RESULTS: One thousand patients were recruited and randomized in a ratio of 1:1 to the chewing gum and ibuprofen (control) groups. The male-to-female ratios were similar in the groups. The pain questionnaire response rates were good at approximately 84% and 83% after appliance placement (chewing gum group, 419; ibuprofen group, 407) and 70% and 71% after the first archwire change (chewing gum group, 343; ibuprofen group, 341). The primary outcomes were similar for the 2 groups: mean pain scores, 4.31 in the chewing gum group and 4.17 in the ibuprofen group; difference, 0.14 (95% CI, -0.13 to 0.41). There was a suggestion that the relative pain scores for the 2 groups changed over time, with the chewing gum group experiencing slightly more pain on the day of bond-up and less on the subsequent 3 days; however, the differences had no clinical importance. There were no significant differences for the period after archwire change. The reported use of ibuprofen was less in the chewing gum group than in the ibuprofen group; after appliance placement, the mean numbers of occasions that ibuprofen was used were 2.1 in the chewing gum group and 3.0 in the ibuprofen group (adjusted difference, -0.96 [95% CI, -0.75 to -1.17; P <0.001]); after archwire change, the figures were 0.8 and 1.5 occasions (difference, -0.65 [-0.44 to -0.86; P <0.001]). After appliance placement and the first archwire change, there was no clinically or statistically significant difference in appliance breakages between the chewing gum and ibuprofen groups after either bond-up (7% and 8.8%, respectively) or the first archwire change (4.2% and 5.5%, respectively). No adverse events were reported. CONCLUSIONS: The use of a sugar-free chewing gum may reduce the level of ibuprofen usage but has no clinically or statistically significant effect on bond failures. REGISTRATION: International Standard Randomised Controlled Trial Number (79884739) and National Institute of Health Research (6631) portfolios. FUNDING: This research was supported by an award by the British Orthodontic Society Foundation.

Objective assessment of mastication predominance in healthy dentate subjects and patients with unilateral posterior missing teeth.

We aimed to investigate mastication predominance in healthy dentate individuals and patients with unilateral posterior missing teeth using objective and subjective methods. The sample comprised 50 healthy dentate individuals (healthy dentate group) and 30 patients with unilateral posterior missing teeth (partially edentulous group). Subjects were asked to freely chew three kinds of test foods (peanuts, beef jerky and chewing gum). Electromyographic activity of the bilateral masseter muscles was recorded. The chewing side (right side or left side) was judged by the level of root mean square electromyographic amplitude. Mastication predominance was then objectively assessed using the mastication predominant score and the mastication predominant index. Self-awareness of mastication predominance was evaluated using a modified visual analogue scale. Mastication predominance scores of the healthy dentate and partially edentulous groups for each test food were analysed. There was a significant difference in the distribution of the mastication predominant index between the two groups (P < 0·05). The mastication predominant score was weakly correlated with self-awareness of mastication predominance in the healthy dentate group, whereas strong correlation was observed in the partially edentulous group (P < 0·05). The results suggest that the individuals with missing unilateral posterior teeth exhibited greater mastication predominance and were more aware of mastication predominance than healthy dentate individuals. Our findings suggest that an objective evaluation of mastication predominance is more precise than a subjective method.

Choosing the best image processing method for masticatory performance assessment when using two-coloured specimens.

Objective masticatory performance assessment using two-coloured specimens relies on image processing techniques; however, just a few approaches have been tested and no comparative studies are reported. The aim of this study was to present a selection procedure of the optimal image analysis method for masticatory performance assessment with a given two-coloured chewing gum. Dentate participants (n = 250; 25 ± 6·3 years) chewed red-white chewing gums for 3, 6, 9, 12, 15, 18, 21 and 25 cycles (2000 samples). Digitalised images of retrieved specimens were analysed using 122 image processing methods (IPMs) based on feature extraction algorithms (pixel values and histogram analysis). All IPMs were tested following the criteria of: normality of measurements (Kolmogorov-Smirnov), ability to detect differences among mixing states (anova corrected with post hoc Bonferroni) and moderate-to-high correlation with the number of cycles (Spearman's Rho). The optimal IPM was chosen using multiple criteria decision analysis (MCDA). Measurements provided by all IPMs proved to be normally distributed (P < 0·05), 116 proved sensible to mixing states (P < 0·05), and 35 showed moderate-to-high correlation with the number of cycles (|ρ| > 0·5; P < 0·05). The variance of the histogram of the Hue showed the highest correlation with the number of cycles (ρ = 0·792; P < 0·0001) and the highest MCDA score (optimal). The proposed procedure proved to be reliable and able to select the optimal approach among multiple IPMs. This experiment may be reproduced to identify the optimal approach for each case of locally available test foods.