Influence of Abusive Vocal Habits, Hydration, Mastication, and Sleep in the Occurrence of Vocal Symptoms in Teachers

Some vocal disorders in teachers are associated with occupational factors, but there are few studies that analyze the influence of vocal habits, fluid intake, mastication, and sleep on these disorders. The objective was to analyze the Occurrence of vocal fatigue, hoarseness, and dry throat in elementary and high school teachers and their association with vocal habits, fluid intake, mastication, and sleep. A sample of 422 elementary and secondary school teachers was Studied using a specific questionnaire. The multiple regression analysis showed that hoarseness was associated with absence of water intake (odds ratio (OR) = 1.7; P = 0.047), yelling/speaking loudly (OR = 1.6; P = 0.058), jaw-opening limitations (OR = 3.8; P = 0.003). average of: 6 hours of sleep/light (OR = 1.7; P = 0.039), and waking-up feeling replenished (OR = 2.0; P = 0.020). The presence of vocal fatigue was significantly associated with yelling/speaking loudly (OR = 2.2: P = 0.013), speaking excessively (OR = 2.4; P = 0.023), difficulty to open the mouth to masticate (OR = 6.6; P = 0.003), less than 6 hours of sleep (OR = 4.0; P = 0.008), and waking-up feeling replenished (sometimes OR = 2.8: P = 0.003; or never OR = 3.3 P = 0.002). The presence of dry throat was associated with being a former smoker (OR = 3.3; P = 0.011) and having jaw-opening limitations (OR = 3.9; P = 0.021). In recent years, speech and hearing interventions with teachers have focused on health-care promotion actions and prevention of vocal disorders, prioritizing issues related with hydration and healthy vocal use habits. However, the findings in the present study show the need to further focus on lifestyle habits related to sleep and eating habits.

Mastication effort study using photorefractive holographic interferometry technique

The purpose of this work was the force-displacement response analysis of the masticatory process in a dried human skull by Double-Exposure Photorefractive Holographic Interferometry Technique (2E-PRHI). The load concentration and dissipation of the forces from dried human skull were analysed at applied loading stands as a Simulation of Isolated Contraction (SIC) of some mastication muscles. The 2EHI and Fringe Analysis Method were used to obtain the quantitative results of this force-displacement response. These results document quantitatively the real biomechanical response from dried human skull under applied loading and it can be used for complementary study by finite element model and others analysis type. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Maxillary complete denture movement during chewing in mandibular removable partial denture wearers

To evaluate the pattern of maxillary complete denture movement during chewing for free-end removable partial dentures (RPD) wearers, compared to maxillary and mandibular complete denture wearers. Eighteen edentulous participants (group I) and 10 volunteers with bilateral posterior edentulous mandibles (group II) comprised the sample. Measures of mean denture movement and its variability were obtained by a kinesiographic instrument K6-I Diagnostic System, during the mastication of bread and a polysulphide block. Data were analysed using two-way anova (alpha = 0.05). Upper movement during chewing was significantly lower for group II, regardless of the test food. The test food did not influence the vertical or lateral position of the denture bases, but more anterior dislocation was found when polysulphide blocks were chewed. Group II presented lower intra-individual variability for the vertical axis. Vertical displacement was also more precise with bread as a test food. It can be concluded that mandibular free-end RPD wearers show smaller and more precise movements than mandibular complete denture wearers.

Light-Emitting Diode Therapy in Chemotherapy-Induced Mucositis

Background and Objective: Mucositis is the most common oral complication of cancer chemotherapy, which causes pain on mastication and swallowing, impairs patients` ability to eat and take oral drugs and may determine interruption of the treatment. The aim of this study was to evaluate the effect of light-emitting diode (LED) therapy on chemotherapy-induced mucositis in hamsters. Study Design/Materials and Methods: Animals of both experimental (Group 1; n = 32) and positive control (Group II; n = 32) groups received intraperitoneal injections of 5-fluorouracil on days 0 and 2. All animals had their right and left cheek pouch irritated by superficial scratching on days 3 and 4. In Group I, LED irradiation (630 nm +/- 10 nm, 160 mW, 12 J/cm(2)) was applied during 37.5 seconds at days 3, 4, 6, 8, 10, 12, and 14. In Group II, mucositis was induced, but LED therapy was not performed. The oral mucosa was photographed from day 4 to 14 at 2-day intervals. Photographs were randomly scored according to the severity of induced mucositis (0 to 5). In the negative control group (Group III; n = 6), no mucositis was induced. Biopsies of the cheek pouches of 8 animals (Group I and Group II) were surgically obtained on days 5, 9, 13 and 15 and processed for histological examination. Results: The statistical analysis showed significant differences between irradiated and non-irradiated groups (P < 0.05). However, muscular degeneration was observed in 18% of the samples of Group I. Conclusion: It may be concluded that the LED therapy protocol established for this in vivo study was effective in reducing the severity of oral mucositis, although the oral lesions were not completely prevented. Lasers Surg. Med. 40:625-633, 2008. (c) 2008Wiley-Liss, Inc.