Influence of sleep bruxism severity on masticatory efficiency: electromyographic analysis.

The objective of the present study was to ascertain masticatory efficiency by evaluating electromyographic activity in the masseter and temporalis muscles in subjects with sleep bruxism of varying severity, as determined by BiteStrip. Thirty-four subjects with sleep bruxism were divided into two groups: a mild sleep bruxism group with a mean (± standard deviation) age of 31.3 ± 6.2 years (n = 15) and a severe sleep bruxism group with a mean age of 29.8 ± 7.1 years (n = 19). Full-night polysomnography (PSG) was performed in eligible subjects. The linear envelope integral was used to determine masticatory efficiency on the basis of the electromyographic signal of the masseter and temporalis muscles during habitual and non-habitual chewing. There was significantly higher (p .05) electromyographic activity in the severe bruxism group than in the mild bruxism group during both peanut chewing in the right (p = .03) and left (p = .03) temporalis muscles and raisin chewing in the right (p = .01) and left (p = .05) temporalis muscles. Furthermore, Parafilm M chewing showed similar results in the right (p = .008) and left (p = .02) temporalis muscles. These results suggested that subjects with severe sleep bruxism had lower masticatory efficiency.

Analysis of the sleep period and the amount of habitual snoring in individuals with sleep bruxism.

BACKGROUND: The literature does not report any association between habitual snoring and sleep bruxism, but these situations can be a reason for frequent complaints of individuals, impairing the quality of life. This study was performed to investigate the sleep period and amount of habitual snoring in individuals with sleep bruxism observing expiratory, inspiratory, and mixed snoring. MATERIAL AND METHODS: A total of 90 individuals were screened and divided into the following groups: with sleep bruxism (n=45) and those without sleep bruxism (n=45). Single night sleep polysomnography was performed to diagnose sleep bruxism, quantify habitual snoring and sleep period. The results were tabulated and submitted to a Multivariate analysis of variance (MANOVA) to compare the means of the two independent groups, considering the affected diagnosis of sleep bruxism, snoring (independent variables) and age as covariate. For the post hoc, was used correcting for multiple comparisons (Bonferroni test, P<.05). RESULTS: There was statistically significant difference among the groups ( p=.001) in the sleep period, in that individuals with sleep bruxism slept for a longer duration (with sleep bruxism group: 460 minutes and without sleep bruxism group: 401 minutes). There were no statistically significant differences among the groups for the number of inspiratory, expiratory and mixed snores, but was observed greater amount of snoring in the with sleep bruxism group. CONCLUSIONS: The main finding of this study is that individuals with sleep bruxism slept longer than the control group. It may also be suggested that individuals with sleep bruxism tended to increase the amount of habitual snoring during sleep.

Cross-cultural adaptation, reliability and construct validity of the Tampa scale for kinesiophobia for temporomandibular disorders (TSK/TMD-Br) into Brazilian Portuguese.

Fear of movement (kinesiophobia) seems to play an important role in the development of chronic pain. However, for temporomandibular disorders (TMD), there is a scarcity of studies about this topic. The Tampa Scale for Kinesiophobia for TMD (TSK/TMD) is the most widely used instrument to measure fear of movement and it is not available in Brazilian Portuguese. The purpose of this study was to culturally adapt the TSK/TMD to Brazilian Portuguese and to assess its psychometric properties regarding internal consistency, reliability, and construct and structural validity. A total of 100 female patients with chronic TMD participated in the validation process of the TSK/TMD-Br. The intraclass correlation coefficient (ICC) was used for statistical analysis of reliability (test-retest), Cronbach's alpha for internal consistency, Spearman's rank correlation for construct validity and confirmatory factor analysis (CFA) for structural validity. CFA endorsed the pre-specified model with two domains and 12-items (Activity Avoidance - AA/Somatic Focus - SF) and all items obtained a loading factor greater than 0·4. Acceptable levels of reliability were found (ICC > 0·75) for all questions and domains of the TSK/TMD-Br. For internal consistency, Cronbach's α of 0·78 for both domains were found. Moderate correlations (0·40 < r < 0.60) were observed for 84% of the analyses conducted between TSK/TMD-Br scores versus catastrophising, depression and jaw functional limitation. TSK/TMD-Br 12 items and two-factor demonstrated sound psychometric properties (transcultural validity, reliability, internal consistency and structural validity). In such a way, the instrument can be used in clinical settings and for research purposes.

Protease inhibitor and metabolic alteration / Inhibidor de la proteasa y alteraciones metabólicas

Protease inhibitors (PIs), part of HAART (Highly Active Antiretroviral Therap) are selective, competitive inhibitors of protease, a crucial enzyme to viral maturation, infection and replication. A lipodystrophic syndrome has been reported in individuals treated with HAART, and associated to hyperglycemia, hypercholesterolemia, hypertrigliceridemia, hyperlipidemia, hypertension and hypreinsulinemia. The HAART-associated metabolic abnormalities were first associated with protease inhibitors, Ritonavir mostly, but the mechamisns that underlie these metabolic alterations are to date, not completely understood. Since PIs are candidate to be the drug of choice for other diseases treatment, such as the Hepatitis C, malaria and some types of cancer, it seems to be important to clarify the metabolic alterations associated to PIs. Wistar rats were treated twice a week with 30mg/kg Ritonavir for 4 and 8 weeks. Total cholesterol, HDL, LDL, VLDL, triglycerides and glycemic levels were measured by the end of each period of time selected. To avoid confunding effects of food intake, the animals were fasted 16 hours before. Our results showed rapid increase in serum triglycerides, total cholesterol, LDL-C and glycemic levels. No significant differences were observed for HDL-C or VLDL serum levels. Our study addresses the importance to observe the possible family history of dyslipidemia or diabetes, and control any other cardiovascular and diabetes risk factors when using protease inhibitors.

Los inhibidores de la proteasa (IP), que forman parte de la terapia HAART (terapia antirretroviral altamente activa), son inhibidores selectivos y competitivos de la proteasa, enzima crucial para la maduración, infección y replicación viral. Un síndrome lipodistrófico, asociado a hiperglucemia, hipercolesterolemia, hipertrigliceridemia, hiperlipidemia, hipertensión e hiperinsulinemia, ha sido relatado en pacientes tratados con HAART. Las anomalías metabólicas asociadas a la HAART fueron relacionadas, inicialmente, a los inhibidores de la proteasa, principalmente el Ritonavir, pero los mecanismos que relacionados a estas alteraciones metabólicas son poco comprendidos. Dado que los IP son posibles candidatos a fármacos de elección para tratamiento de otras enfermedades, como hepatitis C, malaria y algunos tipos de cáncer, es importante esclarecer las alteraciones metabólicas asociadas a los inhibidores de la proteasa. Ratas Wistar fueron tratadas dos veces por semana con 30 mg/kg de Ritonavir por 4 y 8 semanas. Fueron determinados los niveles de colesterol total, HDL, LDL, VLDL, triglicéridos y glucemia, al final de cada período considerado. Para evitar la interferencia de la ingestión de alimentos en las determinaciones de laboratorio, los animales fueron sometidos a un ayuno previo de 16 horas. Nuestros resultados mostraron un rápido aumento sérico de los niveles de triglicéridos, colesterol total, LDL-C y glucemia. No se observaron diferencias significativas para los niveles séricos de HDL-C o VLDL. Nuestro estudio apunta a la importancia de considerar los posibles antecedentes familiares de dislipidemia o diabetes, y controlar cualquier otro factor de riesgo cardiovascular y de diabetes cuando se utilizan los inhibidores de la proteasa.

Tooth wear: use of overlays with metallic structures.

This work is a clinical case report of a patient presenting with marked tooth wear in all teeth, a reduction in the vertical dimension of occlusion, and fatigue in the muscles of mastication. The treatment proposed and effected used a muscle-relaxing appliance and mandibular and maxillary overlay appliances which were adjusted according to the occlusal contacts, vertical dimension of occlusion, and the mandibular positioning. The results obtained were satisfactory in terms of relaxing the muscles involved, reestablishing the dimensions of the lower third of the face, and the functional activities of deglutition, mastication, and speech.

Tooth wear and loss: symptomatological and rehabilitating treatments.

The authors report a clinical case that presented tooth wear and absence, with painful muscular and articular symptomatology, and also alteration in deglutition, mastication and speech. The clinical procedures used were re-establishment of vertical dimension of occlusion, mandibular centric relations, and occlusal contacts through therapeutic removable partial dentures. The condyle position was analyzed in habitual occlusion and in occlusion with dentures, through transcranial radiographs of the temporomandibular joints. Oral rehabilitation was achieved with dental restoration and removable partial dentures.

Association of a temporomandibular disorder and Eagle's syndrome: case report.

We report a clinical case of Eagle's syndrome which required dental intervention due to the presence of exacerbated symptoms indicating an association with a temporomandibular disorder. The therapeutic dental procedures used were an occlusal splint and temporary removable partial dentures. Surgical removal of the styloid process on the left side was later performed as a medical option.