title: Perioral muscle change with FR II treatment.
authors.forename: E H
authors.initials: EH
authors.lastname: Williamson
mesh_terms: D000202:Activator Appliances; D002648:Child; D005152:Facial Muscles / Q000502:physiology*; D005260:Female; D006801:Humans; D008310:Malocclusion / Q000628:therapy*; D008311:Malocclusion, Angle Class I / Q000628:therapy*; D009055:Mouth / Q000502:physiology*; D009968:Orthodontic Appliances, Removable