The effects of myofunctional appliance treatment on the perioral and masticatory muscles in Class II, Division 1 patients.
OBJECTIVE
To evaluate the effect of a myofunctional appliance--the preorthodontic trainer (POT)--on the perioral and masticatory muscles by electromyography (EMG) in individuals with an Angle Class II, Division 1 malocclusion.


METHODS
Twenty children were treated with a POT appliance, which had to be worn every day for 1 hour and overnight. The EMG recordings were made at the beginning and end of POT therapy during maximal clenching, swallowing, and sucking. For statistical evaluation, the Wilcoxon nonparametric test was used at the P<.05 level.


RESULTS
During POT treatment, the EMG value for clenching of the anterior temporal muscle decreased significantly (P<.001). Also, for the mentalis muscle, the EMG value during clenching decreased significantly; for the orbicularis oris muscle, this was true for sucking (P<.05) and clenching (P<.01). For the masseter muscle, all EMG values were decreased during treatment but significantly only for clenching.


CONCLUSIONS
During the 6 months of POT treatment, the perioral and masticatory muscles of Class II, Division 1 patients improved significantly.
Yagci
Ahmet
A
Department of Orthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Uysal
Tancan
T
Kara
Sadik
S
Okkesim
Sukru
S
D002648:Child; D002680:Chin; D003679:Deglutition / Q000502:physiology; D004576:Electromyography / Q000379:methods; D005152:Facial Muscles / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008406:Masseter Muscle / Q000503:physiopathology; D008410:Masticatory Muscles / Q000503:physiopathology*; D009055:Mouth / Q000503:physiopathology; D009119:Muscle Contraction / Q000502:physiology; D020247:Myofunctional Therapy / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D013391:Sucking Behavior / Q000502:physiology; D013703:Temporal Muscle / Q000503:physiopathology