title: Muscle function during treatment with the functional regulator.
abstract: Thirty subjects of approximately the same age, sex, and dental and skeletal relations were divided into three groups: a control group and two treatment groups, which were studied electromyographically over periods of six months and twelve months. The dental, skeletal and electromyographic data were analyzed and charted on multibargraphs. The investigation revealed the following: 1. The Class I control subjects could be differentiated from the Class II and III subjects on the basis of differences in muscle behavior. 2. The Class II treated subjects exhibited changes significantly different from those seen in the control group in the upper lip and suprahyoid group. 3. The overall changes in the four muscle groups studied in the Class II treated subjects were characterized by a decrease in muscle activity. 4. The Class III treated subjects had changes in lower lip activity and suprahyoid group significantly different from those seen in the control subjects. 5. The Class III treated subjects, with one exception, showed an increase in muscle activity in the four muscle groups. 6. The Class II treated subjects who exhibited the greatest changes in muscle behavior also had the greatest changes in skeletal and dental relations. The opposite was true for the Class III treated subjects. It cannot be stated whether muscle pattern alterations seen in this study are coincidental with the dental and skeletal changes or vice versa. However, it is quite clear that both orofacial muscle activity and dental and skeletal dimensions are altered with the wearing of the Functional Regulator.
mesh_terms: D000202:Activator Appliances; D002508:Cephalometry; D002648:Child; D003679:Deglutition; D003724:Dental Arch / Q000033:anatomy & histology; D004576:Electromyography; D005152:Facial Muscles / Q000502:physiology*; D006801:Humans; D008310:Malocclusion / Q000503:physiopathology; D008409:Mastication; D008410:Masticatory Muscles / Q000502:physiology*; D009968:Orthodontic Appliances, Removable; D013060:Speech; D013997:Time Factors