Abstract
Although daytime clenching is believed to be one of the oral parafunctions leading to dental problems, a treatment strategy has not yet been devised. Electromyogram (EMG) biofeedback (BF) training was performed to ascertain its effect on regulating daytime clenching behavior. However, the long-term effects remain unknown. Therefore, the purpose of this study was to determine the learning effect concerning one month after EMG-BF training.
Twelve subjects (7 males, 5 females: mean age; 31.5 ± 6.3 years) who had mild masticatory muscle pain with daytime clenching behavior were divided into the BF group (n=6) and control (CO) group (n=6) in a random fashion. Subjects were fitted with a hearing-aid-shaped EMG biofeedback apparatus, which was used to record EMG data under natural conditions from the temporal muscle, continuously for five hours on four consecutive days and 1 month after (1 Mo). EMG data on Days 1, 4 and 1 Mo were recorded without biofeedback as the pre-test, post-test, and follow-up test, respectively. On Days 2 and 3, subjects in the BF group were alerted to their clenching behaviors via an alert sound from the EMG biofeedback apparatus. No alert sound was given to the CO group throughout the recording sessions.
No significant difference was observed in the number of clenching events for five hours between the BF group (7.3 ± 5.1) and CO group (7.5 ± 2.1) on Day 1; however, significant decreases were found in the BF group between Day 1 (7.3 ± 5.1) and Day 4 (2.3 ± 1.5; p < 0.05), and Day 1 and 1 Mo (2.0 ± 1.1; p < 0.05; Wilcoxon with Bonferroni's inequality test).
Daytime clenching was reduced in the long term with the help of an EMG biofeedback system under natural circumstances. Daytime EMG-BF training decreased clenching events, and the effect may continue for one month after training.
