Original scientific paper
Influence of Occlusal Stabilization Splint on the Asymmetric Activity of Masticatory Muscles in Patients with Temporomandibular Dysfunction
Iva Ž. Alajbeg
Melita Valentić-Peruzović
Ivan Alajbeg
Davor Illeš
Abstract
The aim of present study was to evaluate the symmetry of masticatory muscles' activity
at various clenching levels in the intercuspal position in patients with functional disorders
and in healthy subjects. The purpose was also to determine the effect of full-arch
maxillary stabilization splint on the asymmetry of masticatory muscle activity in patients
with temporomandibular dysfunction. In this study 6 TMD patients and 12 healthy
subjects were investigated. Surface EMG recordings were obtained from left and right
anterior temporal, left and right masseter and from the sub-mandibular group in the region
of the anterior belly of the digastric muscle on the left and right side during clenching
with the maximum 100% voluntary contraction (MVC) as well as during clenching
at 50% and 25% of the maximum activity in the position of maximal intercuspation of
teeth. In order to quantify asymmetrical masticatory muscle activity, the asymmetry index
(AI) was calculated for each subject and for each muscle from the average anterior
temporal, masseter and digastric potentials recorded during each test (100% MVC, 50%
MVC and 25% MVC). In the group of patients EMG recordings were repeated during
and after the splint therapy. The asymmetries of masticatory muscle activity was present
in both groups, but in the group of TMD patients the asymmetry indices for anterior
temporal muscle at 100% MVC (p=0.049) and 50% MVC (p=0.031) were significantly
higher. Results have shown that the use of splint suppressed the asymmetry of all muscles,
as during the splint therapy the asymmetry indices were lowered. After the therapy,
the level of temporal muscle symmetry during submaximal clenching in the intercuspal
position increased significantly (p=0.046). This investigation points out that electromyography
may be a valuable method of documenting that asymmetric activity of masticatory
muscles improves after occlusal splint therapy in patients with TMD.
Keywords
occlusal stabilization; masticatory muscles; temporomandibular dysfunction
Hrčak ID:
28064
URI
Publication date:
16.6.2003.
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