title: Preliminary study of electromyographic characteristics for distinguishing centric relation and protrusion in edentulous patients.
abstract: The mean voltages of the masseter and anterior temporal muscles of 30 Chinese edentulous patients were recorded in centric relation and protrusive positions (from 1 mm to 4 mm anterior to centric relation) under two given occlusal force conditions. It was found that the mean ratio of individual voltages of the anterior temporal muscles to the masseter muscles was equal to or greater than 1.2 in centric relation, but the ratio was less than 1.2 in protrusive positions in most of the subjects. The results demonstrated that the ratio of voltages of the anterior temporal muscles to masseter muscles may be a reliable parameter for distinguishing centric relation from protrusion in Chinese edentulous patients.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: S G
authors.initials: SG
authors.lastname: Shi
authors.forename: O Y
authors.initials: OY
authors.lastname: Guan
authors.forename: C F
authors.initials: CF
authors.lastname: Zhang
mesh_terms: D000368:Aged; D001732:Bite Force; D016302:Centric Relation; D003766:Dental Occlusion; D004576:Electromyography; D005260:Female; D006801:Humans; D007574:Jaw Relation Record; D008297:Male; D008334:Mandible / Q000502:physiology*; D008406:Masseter Muscle / Q000502:physiology*; D008875:Middle Aged; D009066:Mouth, Edentulous / Q000503:physiopathology*; D009068:Movement; D013703:Temporal Muscle / Q000502:physiology*; D014716:Vertical Dimension