Abstract:
The purpose of this study was to evaluate the effect of nociceptive trigeminal
inhibition-tension suppression system (NTI-tss) splints in changing anterior temporal and
masseter muscle activity during maximum voluntary clenching using an
electromyographic recording system. Subjects consisted of 20 participants with symptom
free temporomandibular disorders(TMD), 10 males and 10 females. Electromyographic
(EMG) recordings of the right superficial masseter muscle and right anterior temporal
muscle activity were obtained during rest position as well as during maximum voluntary
clenching with and without the splint.
The results showed that the EMG activity of the superficial masseter and
anterior temporal muscles decreased significantly during maximum voluntary clenching
on the splint (p<0.05). During maximum voluntary clenching without the splint, anterior
temporal muscle activity was 76 times greater and masseter muscle activities 135 times
greater than that during rest position, whereas during rest position with the splint the
muscle activity decreased by a factor of 13 for anterior temporal muscle and a factor of 58
for masseter muscle. Comparing the percentage changes of muscle activity of maximum
voluntary clenching on the splint and maximum voluntary clenching without the splint, the
percentage change of anterior temporal muscle was 18.2% and the percentage change of
masseter muscle was 46.7% (p = <0.05). The percentage reduction of muscle activity
during maximum voluntary clenching on the splint in anterior temporal muscle was 81.8%
and in masseter muscle was 53.3%. There were statistically significant differences (p =
<0.05) between the male and female groups in the mean value of both muscle activities
during maximum habitual clenching, the percentage change of muscle activity during
maximum voluntary clenching on the splint compared to maximum voluntary clenching
without the splint, and the percentage reduction in muscle activity during maximum
voluntary clenching on the splint.
This study indicated that the splint can reduce muscle activity of the anterior
temporal and masseter muscles during maximum voluntary clenching. However, this was
not studied in the involuntary condition of sleeping. Also the volunteers participating in
this study were healthy and had no problems with muscles of mastication or
temporomandibular joints, so the results might not apply to bruxism and TMD patients.
The study result is therefore only baseline data for future studies which would include
the evaluation of the EMG in involuntary conditions and side effects such as retention of
the splint, and force on anterior teeth. This will be useful knowledge about this oral
appliance for treatment of patients