Mandibular movement patterns during speech in subjects with temporomandibular disorders and in asymptomatic individuals

The mandibular movements used during speech modify space to allow different articulation postures proper for each sound. Temporomandibular disorders (TMD) may cause modifications in these movements due to joint and muscular conditions. The aim of this study was to verify the amplitude and the characterization of the mandibular movements during speech, using computerized electrognathography, in individuals with TMD and in asymptomatic individuals, analyzing possible interferences of these dysfunctions. One hundred thirty-five (135) adult subjects were divided into two groups: GI with 90 participants diagnosed with TMD and GII with 45 asymptomatic participants. Their mandibular movements were observed during the sequential naming of pictures containing all of the word sounds, which occur in the Brazilian Portuguese language. The records were obtained with computerized electrognathography (BioEGN - BioPak system, BioResearch Associates, Inc., Milwaukee, WI). Mean values of the amplitude were described for the two groups. The analysis of such results showed statistically sign cant differences between the means of the values, obtained for the two groups in the opening and retrusion ranges. Statistically significant differences were not established for the presence and the range of the deviations in laterality, during speech. Prevalence of bilateral deviations was verified in GII and unilateral deviations in GI. This study describes the 3-dimensional thresholds of mandibular movements in speech for Brazilian Portuguese, for the investigated individuals of both groups. The presence of TMD shows reduction in mandibular opening and retrusion ranges and prevalence of unilateral deviation movements during speech.