title: Comparison of muscle activity and occlusal contacts during maximal and habitual clenching in varied chair positions.
abstract: The activity of anterior temporal muscle, the number of tooth contacts, and total duration of closure during maximal and habitual clenching were studied in varied chair positions. Fifteen subjects were evaluated. The means for the muscle activity of anterior temporal muscle during habitual clenching were 63.5-73.5% of maximum muscle activity. The number of tooth contacts and total duration of closure were significantly increased as biting pressure was increased from habitual to maximal clenching. No significant differences were detected in all variables among varied chair positions. The above results also suggested that occlusal instability was very common. Further research is required to explain the relationship, if any, of these variables to craniomandibular disorders.
authors.affiliation: Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University, Korea.
authors.forename: Y K
authors.initials: YK
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Lee
authors.forename: S C
authors.initials: SC
authors.lastname: Chung
authors.forename: H S
authors.initials: HS
authors.lastname: Kho
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001732:Bite Force; D017271:Craniomandibular Disorders / Q000503:physiopathology; D003766:Dental Occlusion; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011312:Pressure; D016683:Supine Position / Q000502:physiology; D013703:Temporal Muscle / Q000502:physiology*; D013997:Time Factors; D014070:Tooth / Q000033:anatomy & histology*