[Mandibular movements in speech: interference of temporomandibular disfunction according to pain indexes].

Background: temporomandibular disorders can cause general alterations of the mandibular movements due to modification in the condition of muscles and articulations. Electrognathography, a computerized exam used to complement the diagnosis of these disorders, allows the objective delineation and record of the mandibular movements, determining their amplitude and speed.

Aim: to verify the characteristics of mandibular movements of individuals with temporomandibular dysfunction and in asymptomatic individuals during speech, through computerized electrognathography, analyzing possible interferences of this dysfunction and severity implications regarding pain indexes.

Method: 135 adults were divided in four groups based on their pain indexes, using a numeric scale: zero for pain absence, one for mild pain, two for moderate pain and three for severe pain. Mandibular movements were observed during the sequential naming of balanced pictures taking in consideration the occurrence of phonemes in the Brazilian Portuguese language. Records were obtained using computerized electrognathography (BioEGN - BioPak system).

Results: the analysis of the results point that differences indicated as significant for mandibular opening amplitude and mandibular closing speed occurred between index zero and all of the other pain indexes. Regarding mandibular opening speed during speech, statistically significant differences were obtained between index zero and index three. It was observed that mandibular movements in speech are discreet, with an anteroposterior component and deviations in laterality.

Conclusion: the presence of temporomandibular dysfunctions causes reduction in the values of maximum mandibular opening and a reduction in both mandibular opening speed and mandibular closing speed during speech The different pain indexes: mild, moderate and severe do not seem to determine larger reduction of these values.