The aim of this study was to evaluate the influence of centric occlusal interference on masseter muscle activity. The subjects consisted of 5 women and 5 men with a mean age of 28.1 ± 2.4 years. Subjects were all in good general health and had no symptoms or signs in the temporomandibular joint. A piece of composte resin of 0.5 mm in height was placed unilaterally on the central fossa of the lower first molar for 1 week to produce centric occlusal interference. A portable EMG system was used 10 measure masseter muscle activity. The recorded EMG data were obtained before and during days 1, 2, 7, and 14 after insertion of the interference. There was a significant decrease in masseter muscle activity immediately after insertion of the interference on day 1. The altered masseter muscle activity gradually recovered from day 2. After removal of the interference on day 7, masseter muscle activity was measured again and was found to have significantly decreased. One week after removal of the interference (day 14), the muscle activity had recovered to the pre-experimental stage with no long-term symptoms. A centric occlusal interference may cause changes in the myoelectric contraction pattern of the masseter muscle. It is apparent that occlusal interferences are associated with short-term clinical symptoms and signs, but they should not have specific long-term detrimental effects.
|Translated title of the contribution||Influence of Centric Occlusal Interference on Nocturnal Masseter Muscle Activity|
|Original language||Chinese (Traditional)|
|Number of pages||8|
|Publication status||Published - 2005|
- centric occlusal interference
- portable EMG
- masseter muscle activity