Jaw muscle coordination continues to be studied in normal speakers during simple movements in three dimensions and during complex movements for speech and chewing. Our aim is to understand the role of the lateral pterygoid muscle in jaw opening and in coordination with other muscles of the jaw for different movements in the human. Patients with oromandibular dystonia are being compared with normal to better understand the abnormalities of these patients and to improve our methods of treatment. Preliminary analyses of normal speakers in the study of speech planning suggests that speech is planned in advance and not on a syllable by syllable basis. Comparisons are now ongoing between normal controls and patient groups with Parkinson's disease and cerebellar disease. A breathy voicing onset technique is frequently taught during stuttering therapy. We examined whether this type of voicing onset or its opposing behavior, an abrupt increase in airflow for voice onset, are related to speech fluency in stuttering. Normal speakers used breathy onsets more frequently than stutterers on baseline testing. However, no relationship was found between fluency changes in stutterers with choral reading and change in the proportion of breathy voicing onsets. Subject testing was completed on three treatment trials in stuttering this year: an open trial of botulinum toxin injection comparing unilateral and bilateral injections; a double blind crossover trial of unilateral thyroarytenoid injections of botulinum toxin into one thyroarytenoid muscle; and a double blind cross-over trial comparing the effects of clomipramaine, desipramine and placebo on stuttering in collaboration with the Child Psychiatry branch, NIMH.