Estimulación nerviosa eléctrica transcutánea como complemento a la terapia convencional en pacientes con trastornos temporomandibulares: un estudio caso-control / Transcutaneous electrical nerve stimulation as a complement to conventional therapy in patients with temporomandibular disorders: a case-control study

INTRODUCCIÓN: Para los trastornos temporomandibulares (TTM) el tratamiento de primera línea es el conservador, éste incluye a la terapia convencional, además se ha descrito el uso de la estimulación nerviosa eléctrica transcutánea (TENS). El objetivo de este estudio fue determinar la respuesta terapéutica del TENS como complemento a la terapia convencional comparado con pacientes que recibieron exclusivamente terapia convencional. MATERIAL Y MÉTODOS: Estudio retrospectivo caso-control en pacientes diagnosticados con TTM, tratados en la Clínica de Especialidades de la Escuela de Odontología de la Universidad de Valparaíso, entre los años 2009 y 2012. De los 231 pacientes, 63 cumplieron con los criterios de inclusión y fueron pareados en un grupo convencional y un grupo TENS. Se evaluó el dolor articular y muscular; aperturas mandibulares activa sin dolor, activa forzada y pasiva; y fuerza masticatoria. Se aplicaron test estadísticos de Kruskal-Wallis, Wilcoxon y Spearman. RESULTADOS: Para el grupo TENS, se encontraron respuestas significativas en dolor articular y muscular derecho e izquierdo, apertura mandibular activa sin dolor y fuerza masticatoria. Para el grupo convencional, se encontraron resultados similares a excepción de dolor articular derecho. También respuestas significativas para todas las variables que midieron dolor inmediatamente posterior a la aplicación de TENS. Finalmente se establecieron correlaciones entre la edad y las aperturas activa sin dolor, activa forzada y pasiva. DISCUSIÓN: La terapia convencional y la complementada con TENS demostraron similar respuesta terapéutica a largo plazo, sin embargo, la aplicación del TENS produce una respuesta inmediata que reduce el dolor en el corto plazo

INTRODUCTION: For temporomandibular disorders (TMD), conservative therapies, including conventional therapy, are the first line of treatment, and the use of transcutaneous electrical nerve stimulation (TENS) has also been reported. The aim of this study was to determine the therapeutic response to TENS as complement to conventional therapy compared with patients receiving conventional therapy exclusively. METHODOLOGY: A retrospective study was carried out with patients diagnosed with TMD, treated at the Clinic of Specialties of the Dental School of Universidad de Valparaíso, between 2009 and 2012. Of 231 patients, 63 met the inclusion criteria and were randomly allocated to a conventional therapy group (controls) and a coadjuvant TENS group (cases). Both were evaluated for pain in the temporomandibular joints (TMJ) and masseters, active opening without pain, forced active opening, passive opening, and occlusal force. Statistical analysis was performed with Kruskal-Wallis, Wilcoxon and Spearman tests. RESULTS: For TENS group, significant differences were found for pain in the right and left TMJ, pain in the right and left masseter, active opening without pain, and occlusal force. For the conventional group, the same results were obtained, except for pain in right TMJ. For the variables measured immediately after applying TENS, significant differences were found in all pain variables. Correlations were established with age, active opening without pain, forced active opening, and passive opening. DISCUSSION: Conventional therapy and TENS-complemented therapy showed good therapeutic response, concluding that TENS is a good complement to conventional therapy

Modeling a SI epidemic with stochastic transmission: hyperbolic incidence rate.

In this paper a stochastic susceptible-infectious (SI) epidemic model is analysed, which is based on the model proposed by Roberts and Saha (Appl Math Lett 12: 37-41, 1999), considering a hyperbolic type nonlinear incidence rate. Assuming the proportion of infected population varies with time, our new model is described by an ordinary differential equation, which is analogous to the equation that describes the double Allee effect. The limit of the solution of this equation (deterministic model) is found when time tends to infinity. Then, the asymptotic behaviour of a stochastic fluctuation due to the environmental variation in the coefficient of disease transmission is studied. Thus a stochastic differential equation (SDE) is obtained and the existence of a unique solution is proved. Moreover, the SDE is analysed through the associated Fokker-Planck equation to obtain the invariant measure when the proportion of the infected population reaches steady state. An explicit expression for invariant measure is found and we study some of its properties. The long time behaviour of deterministic and stochastic models are compared by simulations. According to our knowledge this incidence rate has not been previously used for this type of epidemic models.