Influence of the Splint Therapy on Muscle Function and on Mandibular Kinetics in the Treatment of a Patient with Malocclusion and Severe Temporomandibular Disorder

INTRODUCTION: Despite the most recent changes in the treatment of temporomandibular disorders, the relaxation splint is still the most employed therapeutic variety.Some authors, however, have doubts about its actions on neuromuscular function and suspect that its effectiveness is onlydue to psychological factors and placebo effect. AIM: In this study an attempt was made to study the neuromuscular response of the stomatognathic apparatus in a temporomandibular disorder patient during splint therapy in order to evaluate its therapeutic effectiveness. MATERIAL AND METHODS:We performed a clinical examination, occlusal analysis and electromyographic and kinesiographic tests in a patient with bruxism, malocclusion and severe temporomandibular disorder, in order to compare the results with those obtained after two months of splint treatment. For this purpose we used a K6I electromyograph and kinesiograph device, the Helkimo test and a Dentatus ARL articulator. RESULTS AND CONCLUSION: After two months wearing the splint, the patient reports symptomatic improvement. Joint and muscle pain are reduced. The study of the mandibular kinetics shows a wider range of movements and less deviation of the midline in openclose recordings. Electromyography shows an improvement of masseter muscle function in clenching and chewing tests and a decrease of temporalis muscle hypertonicity in the mandibular rest position. Furthermore, the function of all the muscles explored, despite the lateral crossbite malocclusion, is more symmetrical

Overbite as an Etiological Factor of TMJ Disorders. Clinical and Electromyographic Exploration

INTRODUCTION: The intermaxillar relationship in overbite is one of the etiological factors of TMJ disorders (Pulinger, Sellingman and Gorbeirn, 1993). Nevertheless, it does not always cause malfunction. Sometimes the compensating mechanisms of the individual prevent the occurrence of symptoms and it only appears when parafunctional habit overloads the stomatognathic apparatus. OBJECTIVE: The aim of this study was to escamine neuromuscular behaviour in patients with such occlusal alteration. MATERIAL AND METHODS: We present two cases with overbite: one bruxist with malfunction and one nonbruxist without symptoms of malfunction. An occlusal analysis and clinical, kinesiographic and electromyographic exploration was performed in both patients. For the analysis we used a Dentatus A.R.L. articulator, Myotronics electromyograph and K6 kinesiograph. RESULTS AND CONCLUSIONS: The results of the exploration were compared with those of a healthy individual with normal occlusion, used as a reference. Lateral movements were restricted and with a mainly vertical component. In both cases there was an increase in electromyographic activity during normal mastication and swallowing, and in maximum force bite there was the same response between anterior temporalis and masseter muscles. The study demonstrated that the mandibular movements in both patients were very similar, and determined by the occlusal factor, in comparison to normal individuals. Nevertheless, the electromyographic exploration shows a different neuromuscular response by the patient adapted to this occlusal problem and the dysfunctional patient

Study of Asymmetrical Muscle Function in Occlusion by Means of Electromyography in Patients with Temporomandibular Disorders

Some authors defend the idea that orthopedic instability, occlusal interferences, and the presence of muscular and/or articular unilateral pain, that are so common in patients with temporomandibular disorders, should necessarily lead to a marked asymmetry in the functioning of the masticatoy muscles and as this asymmetry is quantified in the electromyographic records it could be of great use in diagnosis. AIM OF THE WORK: The purpose of our study was to determine if muscular function in dysfunctional patients is more asymmetrical than in healthy individuals, in order to use this clinical signal in the diagnosis of craniomandibular disorders. METHOD: We carried out electromyographic tests on a group of 22 patients, who had previously been diagnosed as suffering from a temporomandibular dysfunction. After submitting them to Helkimo test, we compared the results of the electromyographic tests with a control group comprising 19 healthy individuals. MATERIAL: For the electromyographic tests we used a K6-I electromyograph, which allowed us to calculate the average electromyographic activity generated by each one of the muscles monitored, in registers of 15 seconds in length. RESULTS: There are significant differences in the means and medians of both groups. The asymmetry index variable discriminates the individuals that belong to each group. CONCLUSIONS: The results of the comparative study indicated that muscular asymmetry is more pronounced in dysfunctional patients. However, the discrimination capacity of the Asymmetry Index variable should be combined with that of other electromyographic variables in order for it to be used as a diagnostic criteria in Cranio-Mandibular Dysfunctions

Sarcomas primarios de hueso: estudio por citometría estática mediante análisis digital de imagen

Se presenta un estudio morfométrico y densitométrico mediante análisis digital de imagen de una serie de 50 tumores óseos malignos (32 osteosarcomas, 12 condrosarcomas y 6 histiocitomas fibrosos malignos de hueso), con el fin de evaluar la utilidad de la técnica para establecer el grado y el pronóstico de estas neoplasias. Las variables morfométricas y la disposición de la cromatina guardan una estrecha relación con el grado histológico (Spearman; p < 0,05) y muestran diferencias estadísticamente significativas entre los tumores considerados de alto y bajo grado en base a su presentación y evolución clínica. La ploidía estimada por densitometría óptica se comporta como un factor pronóstico independiente en el análisis multivariante de la serie de tumores de alto grado (COX; p < 0,001). La citometría estática, aunque más lenta e imprecisa que la citometría de flujo en la determinación de los picos de ploidía, permite analizar el modelo de cromatina y contribuye objetivamente al establecimiento del grado biológico de los tumores óseos.A densitometry and morphometric assessment by static image cytometry of 50 malignant bone tumors (32 osteosarcomas, 12 chondrosarcomas, and 6 malignant fibrous histiocytomas of bone) was performed in order to assess the validity of the technic in the pathobiological and prognostic evaluation of these neoplasms. A strong correlation between the morphometric features, cromatine distribution and histologic grade was found (Spearman; p < 0.05). These parameters are also statistically different for hight and low grade tumors in clinical staging. The stimation of DNA ploidy by optic densitometry is a significant prognostic factor in the multivariant analysis for the high grade tumors (COX; p < 0.001). Although Flow cytometry is a better procedure to evaluate DNA ploidy peaks, our study reveals static image cytometry as a useful technic for determine the cromatine model and objective assessment of the biological grade of bone neoplasms

Electromiograph Parameters in Thedysfunctional Patient with Open Bite

INTRODUCTION: Open bite is an occlusal problem that appears in 0.5% of the population, and is more frequent in women. There is correlation between open bite and dysfunctional syndrome with TMJ disorders. AIM OF THE STUDY: We attempted to analyze muscular parameters in patients with open bite treated with an occlusal splint by EMG recordings. MATERIAL AND METHODS: Myotronics K6 electromiograph can provide information in the following situations: maximum force bite, lateral and protrusion movements, with and without an occlusal splint. RESULTS: In maximum force bite with the occlusal splint more activity was found in the elevator muscles with a lack of dygastric activity. There was less EMG activity in protrusive and lateral movements with occlusal splint. CONCLUSION: With better support between the dental arches (occlusal splint) more activity was obtained in the elevators when biting, and when interferences were eliminated activity in the contralateral muscles was reduced

Poly[ADP-Ribose] Polymerase-1 Expression Is Related To Cold Ischemia, Acute Tubular Necrosis, and Delayed Renal Function In Kidney Transplantation

Cold ischemia time especially impacts on outcomes of expanded-criteria donor (ECD) transplantation. Ischemia-reperfusion (IR) injury produces excessive poly[ADP-Ribose] Polymerase-1 (PARP-1) activation. The present study explored the hypothesis that increased tubular expression of PARP-1 contributes to delayed renal function in suboptimal ECD kidney allografts and in non-ECD allografts that develop posttransplant acute tubular necrosis (ATN)