Analysis of TMJ vibration sounds before and after use of two types of occlusal splints

Temporomandibular joint (TMJ) sounds are important and common physical signs of temporomandibular disorders (TMD). The aim of this study was to evaluate the influence of the effect of the use of occlusal bite splints (stabilizing and repositioning) on the sounds produced in the TMJ, by means of the electrovibratography (EVG). Thirty-one patients with TMD from the Dental School of Ribeirão Preto, University of São Paulo, Brazil were selected for this study. Group 1 (n=23) wore stabilizing bite splints and Group 2 (n=8) used anterior repositioning splints. Before and after treatment with occlusal splints both groups were analyzed using the SonoPAK Q/S recording system (BioResearch System, Inc.). The treatments with stabilizing bite splints were satisfactory, since they reduced the total amount of the sound energies (p<0.05), but the use of anterior repositioning splints for no more than 4 weeks produced significantly better results (p<0.01). The total amount of vibration energy involved in the vibrating movements of the TMJ showed significant improvement using anterior repositioning splints.Os ruídos da articulação temporomandibular (ATM) são sinais físicos importantes e comuns da disfunção temporomandibular (DTM). O objetivo do presente estudo foi avaliar o efeito do uso da placa oclusal (estabilizadora e reposicionadora) nos sons produzidos na ATM, por meio da eletrovibratografia (EVG). Um total de 31 pacientes da Faculdade de Odontologia de Ribeirão Preto - USP foram selecionados para este estudo. O grupo 1 (n=23) foi selecionado para usar a placa estabilizadora e o grupo 2 (n=8) para usar a placa reposicionadora. Antes e depois do uso das placas os grupos foram analisados usando o SonoPAK Q/S (BioResearch System). Os tratamentos com placas estabilizadoras foram satisfatórios quando analisados estatisticamente uma vez que reduziram a quantidade total de energia dos sons (p<0,05). O tratamento com placa reposicionadora, por 4 semanas no máximo, produziu melhores resultados estatísticos (p<0,01). A quantidade total de energia de vibração nos movimentos vibratórios da ATM mostrou significante melhora usando a placa reposicionadora

Measurements of jaw movements and TMJ pain intensity in patients treated with GaAlAs laser

The aim of this study was to evaluate the effectiveness of low-level laser therapy (LLLT) on the improvement of the mandibular movements and painful symptoms in individuals with temporomandibular disorders (TMD). Forty patients were randomly divided into two groups (n=20): Group 1 received the effective dose (GaAlAs laser ? 830 nm, 40 mW, 5J/cm2) and Group 2 received the placebo application (0 J/cm2), in continuous mode on the affected condyle lateral pole: superior, anterior, posterior, and posterior-inferior, twice a week during 4 weeks. Four evaluations were performed: E1 (before laser application), E2 (right after the last application), E3 (one week after the last application) and E4 (30 days after the last application). The Kruskal-Wallis test showed significant more improvements (p<0.01) in painful symptoms in the treated group than in the placebo group. A significant improvement in the range of mandibular movements was observed when the results were compared between the groups at E4. Laser application can be a supportive therapy in the treatment of TMD, since it resulted in the immediate decrease of painful symptoms and increased range of mandibular movements in the treated group. The same results were not observed in the placebo group.O objetivo deste estudo foi avaliar a eficácia da terapia com laser de baixa intensidade na melhora dos movimentos mandibulares e dos sintomas dolorosos em pacientes com disfunção temporomandibular (DTM). Quarenta pacientes foram aleatoriamente divididos em dois grupos (n=20): Grupo 1 recebeu a dose efetiva (laser de AsGaAl 830 nm, 40 mW, 5 J/cm2) e Grupo 2 recebeu a aplicação placebo (0 J/cm2), no modo contínuo no pólo lateral do côndilo afetado: superior, anterior, e posterior-posterior e inferior, 2 vezes por semana, por 2 meses. Quatro avaliações foram feitas: A1 (antes da aplicação), A2 (imediatamente após a última aplicação), A3 (uma semana após a última aplicação) e A4 (um mes após a última aplicação). O teste estatístico de Kruskal-Wallis mostrou melhoras significativas (p<0,01) nos sintomas dolorosos no grupo 1, diferentemente do grupo 2. Uma melhora significativa na extensão dos movimentos mandibulares foi observada quando os resultados foram comparados entre os dois grupos na A4. A aplicação do laser é uma terapia de suporte no tratamento da DTM, uma vez que resultou em imediata redução dos sintomas dolorosos e aumento na extensão dos movimentos mandibulares no grupo experimental. Os mesmos resultados não foram observados no grupo placebo

Mitigation of nitrous oxide emissions in grazing systems through nitrification inhibitors: a meta-analysis

Grasslands are the largest contributor of nitrous oxide (N2O) emissions in the agriculture sector due to livestock excreta and nitrogen fertilizers applied to the soil. Nitrification inhibitors (NIs) added to N input have reduced N2O emissions, but can show a range of efficiencies depending on climate, soil, and management conditions. A meta-analysis study was conducted to investigate the factors that influence the efficiency of NIs added to fertilizer and excreta in reducing N2O emissions, focused on grazing systems. Data from peer-reviewed studies comprising 2164 N2O emission factors (EFs) of N inputs with and without NIs addition were compared. The N2O EFs varied according to N source (0.0001-8.25%). Overall, NIs reduced the N2O EF from N addition by 56.6% (51.1-61.5%), with no difference between NI types (Dicyandiamide-DCD; 3,4-Dimethylpyrazole phosphate-DMPP; and Nitrapyrin) or N source (urine, dung, slurry, and fertilizer). The NIs were more efficient in situations of high N2O emissions compared with low; the reduction was 66.0% when EF > 1.5% of N applied compared with 51.9% when EF 10 kg ha(-1). NIs were less efficient in urine with lower N content (<= 7 g kg(-1)). NI efficiency was negatively correlated with soil bulk density, and positively correlated with soil moisture and temperature. Better understanding and management of NIs can optimize N2O mitigation in grazing systems, e.g., by mapping N2O risk and applying NI at variable rate, contributing to improved livestock sustainability

Low Intensity Laser Therapy in Temporomandibular Disorder: a Phase II Double-Blind Study

The purpose of this study was to evaluate the analgesic effect of Low Intensity Laser Therapy (LILT) and its influence on masticatory efficiency in patients with temporomandibular dysfunction (TMD). This study was performed using a random, placebo-controlled, and double-blind research design. Fourteen patients were selected and divided into two groups (active and placebo). Infrared laser (780 nm, 70 mw, 60s, 105J/cm(2)) was applied precisely and continuously into five points of the temporomandibular joint (TMJ) area: lateral point (LP), superior point (SP), anterior point (AP), posterior point (PP), and posterior-inferior point (PIP) of the condylar position. This was performed twice per week, for a total of eight sessions, To ensure a double-blind study, two identical probes supplied by the manufacturer were used: one for the active laser and one for the inactive placebo laser. They were marked with different letters (A and B) by a clinician who did not perform the applications. A Visual Analogue Scale (VAS) and a colorimetric capsule method were employed. Data were obtained three times: before treatment (Ev1), shortly after the eighth session (Ev2), and 30 days after the first application (Ev3). Statistical tests revealed significant differences at one percent (1%) likelihood, which implies that superiority of the active group offered considerable TMJ pain improvement. Both groups presented similar masticatory behavior, and no statistical differences were found. With regard to the evaluation session, Ev2 presented the lowest symptoms and highest masticatory efficiency throughout therapy. Therefore, low intensity laser application is effective in reducing TMD symptoms, and has influence over masticatory efficiency [Ev2 (0.2423) and Ev3 (0.2043), observed in the interaction Evaluations x Probes for effective dosage].CNPq - Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - Brazi

Relação da DTM dolorosa com a função de fala: Quais as possíveis características de movimentos mandibulares e os principais sintomas relatados?

RESUMO Objetivo Analisar os movimentos mandibulares de pacientes com DTM dolorosa durante a função de fala, a fim de compreender possíveis alterações e quais subgrupos de pacientes podem apresentá-las. Além de identificar quais sinais e sintomas relacionados com a DTM dolorosa são percebidos no desempenho desta função. Método Trinta e dois sujeitos com idade entre 18 e 60 anos (35,1 ± 8,9), 23 com DTM ( DC/TMD; oito homens e 15 mulheres) e nove controles foram avaliados quanto à: autopercepção de sinais e sintomas de DTM durante a fala (ProDTMMulti); amplitude de movimentos mandibulares durante a leitura de lista de palavras (eletrognatografia, Jaw Motion Analyses). Foi calculada a porcentagem de utilização de movimento durante o desempenho da fala em função da amplitude máxima individual, e foram subdivididos grupos de pacientes com DTM dolorosa (DTM-D) e dolorosa/articular (DTM-D/A). Resultados O grupo DTM-D/A apresentou maior porcentagem de utilização de movimento na lateralidade durante a fala que os demais grupos. A dor, os ruídos articulares e a dificuldade para falar foram os sinais/sintomas mais relatados no desempenho da fala. A percepção de ruídos articulares e a presença de desvios laterais foram significativamente superiores no grupo DTM-D/A (p<0,05). Conclusão Os desvios laterais são a principal alteração de movimento mandibular durante o desempenho da fala na DTM dolorosa. Tais desvios são mais esperados nos quadros de DTM articular (deslocamentos de disco e doenças degenerativas). A percepção de dor e de ruídos articulares são as principais queixas relacionadas à função orofacial de fala em indivíduos com DTM dolorosa

Characteristics of TMD noise analyzed by electrovibratography

Studying joint noise is an important parameter for diagnosing temporomandibular dysfunction. In this study, eight groups (n=9) were formed according to joint dysfunction classification, provided by employing vibration analysis equipment. Parameters for analyzing joint noise were: total vibration energy, peak amplitude, and peak frequency. Mouth opening range was also analyzed. Statistical analysis results for each parameter were significant at 1 %. Each analyzed group presented different noise characteristics. This allowed for inclusion of the groups within a determined value category. The patient group with normal condyle/disk relationship always presented the lowest values. The type of joint noise was characterized by analyzing total integral noise, peak amplitude, peak frequency, and mouth opening. Analyzing joint noise using electrovibratography suggests the type of joint dysfunction and may help to establish a diagnosis, as well as a treatment plan

Low Level Laser Effects On Pain to Palpation and Electromyographic Activity in TMD Patients: A Double-Blind, Randomized, Placebo-Controlled Study

The purpose of this study was to evaluate the effect of diode laser (GaAlAs - 780 nm) on pain to palpation and electromyographic (EMG) activity of the masseter and anterior temporalis muscles. The laser was applied on the temporalis and masseter muscles twice a week (four weeks). Forty-eight (48) patients with myofascial pain were randomly assigned between actual and placebo treatments and between the energetic doses of 25 J/cm(2) and 60 J/cm(2), and were evaluated using VAS before, immediately after the final application, and 30 days after the laser treatment. Surface electromyography was performed with maximum dental clenching before and after laser therapy. The results show there were no significant statistical differences in the EMG activity between the groups before and after laser treatment. With regard to the pain at palpation, although both groups presented a significant difference in the symptoms before and after the treatment, only the active doses showed statistically significant reductions in pain level in all the regions of the palpated muscles. However, there was no significant statistical difference between groups (experimental and placebo). In conclusion, low level laser did not promote any changes in EMG activity. The treatment did, however, lessen the pain symptoms in the experimental groups