title: Muscular response to functional treatment of skeletal open-bite and deep-bite cases: an electromyographic study.
abstract: OBJECTIVE
  To examine the muscular response of masseter and anterior temporal muscles to functional orthodontic treatment in skeletal open-bite and deep-bite subjects using electromyography (EMG).
  
  
  METHODS
  The study sample consisted of 31 subjects (18 males, 13 females) grouped into skeletal open-bite (mean age 12.6 ± 2.5 years) and deep-bite (mean age 11.6 ± 2.1 years) groups and into prepubertal and pubertal growth stages. All subjects received functional orthognathic treatment. EMGs recorded masseter (MMA) and anterior temporal muscle activity (ATMA) bilaterally during swallowing, chewing, and maximum intercuspitation before treatment (T1), 3 months after treatment (T2), and 6 months after treatment (T3). The differences in muscular response of the masseter and anterior temporal muscles to functional treatment in skeletal open-bite and deep-bite subjects were examined using repeated measurement (ANOVA) in factorial sequence and Duncan tests.
  
  
  RESULTS
  The open-bite group showed increased masticatory muscle activity and anterior rotation of the mandible. The deep-bite group showed decreased masticatory muscle activity, posterior rotation of the mandible, and an increase in gonial angle. Muscular response to functional treatment was observed during both growth stages, but it was more pronounced during puberty.
  
  
  CONCLUSIONS
  Skeletal and neuromuscular improvements were observed in both treatment groups. Alterations in muscle activity as a result of functional treatment were observed in both growth stages, but they were more pronounced during puberty. For neuromuscular adaptation to occur, at least 6 months of functional treatment is required.
authors.affiliation: Department of Orthodontics, School of Dentistry, Ankara University, Besevler, Ankara, Turkey. dtozgeuslu@gmail.com
authors.forename: Ozge
authors.initials: O
authors.lastname: Uslu
authors.forename: Zuleyha Mirzen
authors.initials: ZM
authors.lastname: Arat
authors.forename: Mehmet
authors.initials: M
authors.lastname: Beyazoya
authors.forename: Ozden Ozyemisci
authors.initials: OO
authors.lastname: Taskiran
mesh_terms: D000202:Activator Appliances; D000222:Adaptation, Physiological / Q000502:physiology; D002508:Cephalometry; D002648:Child; D003679:Deglutition / Q000502:physiology; D004576:Electromyography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008334:Mandible / Q000473:pathology; D008406:Masseter Muscle / Q000503:physiopathology*; D008409:Mastication / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology; D024343:Open Bite / Q000628:therapy*; D017289:Orthodontic Appliances, Functional; D057887:Overbite / Q000628:therapy*; D011627:Puberty / Q000502:physiology; D012399:Rotation; D013703:Temporal Muscle / Q000503:physiopathology*; D013997:Time Factors