Muscular activity disorders in relation to intentional occlusal interferences.

The electromyographic activity (EMG) of the anterior temporal (AT), masseter (M), trapezius (T) muscles and anterior aspect of the digastric (D) was measured in 50 subjects, during six seconds of maximum contraction, bilaterally with and without unilateral premature contacts and individually for each tooth. Special occlusal interferences were designed to assess muscular activity. Muscular activity was measured simultaneously by placing premature contacts on each tooth, under T-Scan monitoring. Premature contacts reduced EMG activity during maximum contraction of the AT, D and M muscles, the highest disruption is in the AT muscle, at the level of upper right 2nd molar, with a 56% reduction in activity. Conversely, there was an increase of activity of the T muscle in all teeth when placing artificial occlusal premature contacts, with the highest difference in the upper right 1st bicuspid. Therefore, occlusal interferences can cause neuromuscular disruptions, thus inducing important muscular discrepancy. Both the EMG and T-Scan monitoring can be considered suitable methods to use in daily dental practice to identify premature contacts and to measure EMG activity.

The identification of temporomandibular joint disease through the masticatory cycle.

The purpose of this study was to determine, by analyzing the masticatory cycle, the presence of TMJ disease prior to initiating any orthodontic treatment. Masticatory data from 80 pre-orthodontic patients were recorded in the frontal and sagittal planes and then analyzed and compared with the pre-established healthy masticatory data of Maruyama et al. 40% of the sample group presented with signs and/or symptoms of masticatory dysfunction and/or temporomandibular joint abnormalities (TMJA). Using Student's t test we found significant differences in the means for all seven parameters measured. Patients with TMJA exhibited significantly slower closing, occlusal and total cycle times, but faster opening. It was usually possible to determine which joint was compromised by the disease from the data.

Identificación de patologías articulares por medio del estudio del ciclo masticatorio, en pacientes preortodóncicos. Parte I: descripción del ciclo masticatorio / Identification of articular pathologies by means of the study of mastication cycle in preorthodontic patients. Part I: description of the mastication cycle

Objetivos: el fin perseguido por esta investigación es actualizar y reconceptualizar el ciclo masticatorio con un estudio preorotóncico. Se prevee dar con nuevos conocimientos acerca del funcionamiento de la masticación y su influencia en la aparición y desarrollo de los trastornos temporomandibulares. Teniendo en cuenta estas premisas se pretende evaluar: a) objetivos generales: desarrollar protocolos de diagnóstico para lograr enfoques destinados a fomentar el control del paciente, manteniendo o incrementando su funcionamiento masticatorio sano. b) Objetivos específicos: determinar la existencia de patologías temporomandibulares a partir de los ciclos masticatorios. Poder desarrollar métodos diagnóstico preventivos para poder detectar tempranamente las afecciones temporomandibulares, patología que ha llevado en estos últimos tiempos a investigaciones que buscan solucionar estos problemas en la población. Implementar como herramienta de diagnóstico y verificación postratamiento, la evaluación de la eficacia masticatoria, movimientos y actividad muscular