The extent of separation between the maxillary and mandibular teeth in the fabrication of interocclusal splints designed to achieve efficiency and muscle relaxation is controversial and undefined in the literature. Based on this premise, the aim of this study was to evaluate the effect of interocclusal splint thicknesses of 3 and 6 millimeters on the electrical activity of the anterior temporal and masseter muscles during rest and dental clenching. Twenty asymptomatic individuals (10 males and 10 females) were selected using the Research Diagnostic Criteria (RDC). Electromyography (EMG) was performed both with and without the 3- and 6-mm splints using the Bio EMG software package, which recorded values given in microvolts (µV). The results, which were assessed using analysis of variance (ANOVA) to a 5% significance level (p < 0.05), showed increased electrical activity of the masticatory muscles during dental clenching compared with at rest, with greater activity in the masseter muscle. The electrical activity did not differ according to the thickness of the splints or between males and females. We can conclude that both splint thicknesses are effective in treating muscle hyperactivity given their similar clinical behavior for asymptomatic individuals.

Fabrication of occlusal splints in centric relation for temporomandibular disorders (TMD) patients is arguable, since this position has been defined for asymptomatic stomatognathic system. Thus, maximum intercuspation might be employed in patients with occlusal stability, eliminating the need for interocclusal records. This study compared occlusal splints fabricated in centric relation and maximum intercuspation in muscle pain reduction of TMD patients. Twenty patients with TMD of myogenous origin and bruxism were divided into 2 groups treated with splints in maximum intercuspation (I) or centric relation (II). Clinical, electrognathographic and electromyographic examinations were performed before and 3 months after therapy. Data were analyzed by the Student's t test. Differences at 5% level of probability were considered statistically significant. There was a remarkable reduction in pain symptomatology, without statistically significant differences (p>0.05) between the groups. There was mandibular repositioning during therapy, as demonstrated by the change in occlusal contacts on the splints. Electrognathographic examination demonstrated a significant increase in maximum left lateral movement for group I and right lateral movement for group II (p<0.05). There were no significant differences (p>0.05) in the electromyographic activities at rest after utilization of both splints. In conclusion, both occlusal splints were effective for pain control and presented similar action. The results suggest that maximum intercuspation may be used for fabrication of occlusal splints in patients with occlusal stability without large discrepancies between centric relation and maximum intercuspation. Moreover, this technique is simpler and less expensive.

Este trabalho teve por finalidade quantificar a protrusão mandibular necessária para diminuir significativamente a energia vibratória da articulação temporomandibular (ATM), verificada por meio da eletrovibratografia, como um meio auxiliar de diagnóstico da recaptura do disco articular deslocado anteriormente. Dezoito pacientes com diagnóstico de deslocamento anterior do disco com redução e estalos na ATM foram submetidos ao exame eletrovibratográfico na consulta inicial e tratados com placa oclusal estabilizadora e placa reposicionadora anterior com protrusão variando de 1 a 5 mm, checando-se a energia vibratória em cada uma destas posições. Os dados obtidos na consulta inicial foram usados como grupo controle. Na consulta inicial, os pacientes apresentaram vibrações com intensidades mais elevadas no meio e final da abertura bucal. Em uma única sessão, a protrusão era realizada a partir de 1 mm por meio de placa reposicionadora anterior e realizado novo exame de imediato, até atingir 5 mm. Após a mandíbula ser protruída 5 mm, apenas 2 pacientes apresentavam alguma vibração, com uma média de 0,6 a 2,8 Hz. A análise estatística foi realizada por análise de variância e teste de Tukey (a=0,05). Os resultados indicaram que 3 mm seria a protrusão mínima necessária para reduzir significantemente a energia vibratória e recapturar o disco articular.

This study quantified by, electrovibratography, the amount of mandible protrusion required to decrease significantly temporomandibular joint (TMJ) vibratory energy as an aid in the diagnosis of the recapture of anteriorly displaced disk. Eighteen patients diagnosed as having anterior disk displacement with reduction and TMJ clicking were submitted to electrovibratographic examination at the first appointment and treated with a stabilizing appliance and anterior positioning appliance with 1 to 5 mm protrusion. Vibratory energy was checked in each of these positions. Baseline data were used as control. At the first appointment, the patients had vibrations with more elevated intensities at the middle and late phases of the mouth opening cycle. At only one clinical step, mandible protrusion was obtained with the anterior repositioning appliance, ranging from 1 to 5 mm protusion. At each new position, a new electrovibratographic exam was made. After the 5-mm mandibular projection, only 2 patients presented vibration, with means between 0.6 and 2.8 Hz. Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.05). The outcomes of this study indicate that 3 mm is the minimum amount of mandible protrusion to significantly decrease the TMJ vibratory energy and to recapture the displaced articular disk.

A efetividade da Estimulação Neural Elétrica por Microcorrente (MENS) foi avaliada e comparada à terapia por Placas Oclusais em pacientes com desordens temporomandibulares (DTM) de origem muscular. Vinte pacientes foram divididos em quatro grupos. Um recebeu a terapia por placas interoclusais e MENS (I); outro, placas e MENS placebo (II), o terceiro, somente MENS (III) e o último grupo, MENS placebo (IV). Os resultados obtidos foram submetidos a uma análise de variância (p<0,05). Houve redução dos níveis de dor em todos os grupos: o grupo I (placas e MENS) obteve uma taxa de redução de 47,7%; o grupo II (placa e MENS placebo), 66,7%; o grupo III (MENS), 49,7% e o grupo IV (MENS placebo), 16,5%. Apesar disso, não se verificaram diferenças estatisticamente significantes entre MENS e utilização de placas interoclusais em relação à diminuição de dor muscular em pacientes com DTMs após 4 semanas.

The effect of Microcurrent Electrical Nerve Stimulation (MENS) was evaluated and compared with occlusal splint therapy in temporomandibular disorders (TMD) patients with muscle pain. Twenty TMD patients were divided into four groups. One received occlusal splint therapy and MENS (I); other received splints and placebo MENS (II); the third, only MENS (III) and the last group, placebo MENS (IV). Sensitivity derived from muscle palpation was evaluated using a visual analogue scale. Results were submitted to analysis of variance (p<0.05). There was reduction of pain level in all groups: group I (occlusal splint and MENS) had a 47.7% reduction rate; group II (occlusal splint and placebo MENS), 66.7%; group III (MENS), 49.7% and group IV (placebo MENS), 16.5%. In spite of that, there was no statistical difference (analysis of variance / p<0.05) between MENS and occlusal splint therapy regarding muscle pain reduction in TMD patients after four weeks.