[Association between laryngeal findings and vocal qualities in muscle tension dysphonia with supraglottic contraction].

Muscle tension dysphonia (MTD) is a voice disorder associated with abnormal laryngeal posture or glottic configuration induced by excessive contraction of the laryngeal muscles, and supraglottic contraction is one of the characteristic findings in MTD. In recent study we investigated the changes in laryngeal findings and voice quality and the association between them in the course of voice therapy for MTD with supraglottic contraction. The effects of voice therapy on the laryngeal and the vocal findings were assessed by two rating methods: the MTD score and the conventional GRBAS scores and both scores were gradually improved. Of the two components of supraglottic contraction, false vocal cord compression was more curable than anterior-posterior compression at the aryepiglottic level. Little correlation was found between the scores at the first examination, but significant associations (p < 0.05) were found between the differences of MTD score and G/R/S scores but not B/A scores before and after the series of voice therapy. These results suggest that supraglottic contraction is a crucial factor worsening voice quality and that MTD score is useful to assess the efficacy of voice therapy for MTD.