Journal of Dental Research, Vol 68, 1110-1114, Copyright © 1989 by International & American Associations for Dental Research Online Journals
Methodological considerations concerning the use of Bruxcore Plates to evaluate nocturnal bruxism
C. J. Pierce and E. N. Gale
Department of Behavioral Science, University of Pittsburgh School of Dental Medicine, Pennsylvania 15261.
The purpose of this study was to evaluate the Bruxcore Plate (BP) as a
dependent measure of nocturnal bruxing activity. As part of a bruxism
treatment study, we evaluated 100 nocturnal bruxers for bruxing activity
before, during, and immediately after treatment and again at a six-month
recall. The first 40 subjects wore both a BP and an EMG (electromyographic)
unit for every night of each 14-night evaluation period (baseline;
post-treatment; six-month recall). During the treatment period, these
subjects wore the EMG unit but no Bruxcore Plates. Another 40 subjects wore
the EMG unit and never used Bruxcore Plates. We evaluated a 20-subject
no-treatment control group by two methods. Ten control subjects were
evaluated with the EMG unit and the BP and another ten with the EMG unit
alone. We hypothesized that the BP would not measure the same construct as
an accepted EMG measure of bruxing activity, and that the BP would effect
changes in EMG measured nocturnal bruxing activity. The results supported
the conclusions that the BP did not measure the same construct as the EMG
measure, and that the BP did effect changes in nocturnal bruxing activity.
Correlations of BP scores with EMG data for equivalent measurement periods
were low or non-existent. For the control group and the massed practice
(negative practice) treatment group, there were significant interaction
effects for EMG-measured bruxing episodes per hour for BP vs. no-BP Groups,
with respect to measurement periods (time). Interpretation of these results
indicated that BP evaluation of nocturnal bruxing activity was confounded
with measurable treatment effects.
