Vitti M, Basmajian J V, Ouellette P L, Mitchell D L, Eastmen W P, Seaborn R D
J Dent Res. 1975 Jul-Aug;54(4):844-9. doi: 10.1177/00220345750540042401.
The electromyographic (EMG) examination of 11 normal individuals in whom bipolar fine-wire indwelling electrodes were placed showed no EMG activity during rest periods and only very slight to slight activity during normal oral functionsmduring aberrant oral activity, such as thumb-sucking, the orbicularis oris and genioglossus muscles gave a marked EMG response and the buccinator muscles were slightly active. These findings may help explain the classical malocclusions seen in tongue-thrusters and thumb-suckers.