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Electromyographic activity and thickness of masticatory muscles in children with unilateral posterior crossbite
A S Andrade1, Maria B D Gavião, M Derossi
1Department of Pediatric Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
Insights
Children with unilateral posterior crossbite (PCB) show asymmetric masseter muscle activity during clenching, but this is not linked to muscle thickness. This finding is crucial for understanding masticatory muscle function in PCB patients.
Area of Science:
- Dentistry
- Biomedical Engineering
- Orthodontics
Background:
- Unilateral posterior crossbite (PCB) is a common dental anomaly affecting masticatory muscle function.
- Electromyographic (EMG) activity and muscle thickness are key indicators of muscle function and morphology.
Purpose of the Study:
- To evaluate electromyographic (EMG) activity and masseter and anterior temporalis muscle thickness in children with unilateral posterior crossbite (PCB).
- To investigate the relationship between muscle activity and thickness in these children.
Main Methods:
- EMG activity and muscle thickness (ultrasound) were measured in 20 children with PCB and 16 controls.
- Data were analyzed comparing crossbite and non-crossbite sides, and between groups.
Main Results:
- The masseter muscle on the crossbite side showed increased EMG activity during maximal clenching in the PCB group.
- No significant differences in muscle thickness were found between PCB and control groups or between sides.
- A correlation between EMG activity and thickness was only observed in the left masseter of the normal occlusion group.
Conclusions:
- Asymmetric muscle activity in children with PCB is not associated with changes in masseter or anterior temporalis muscle thickness.
- Further research is needed to understand the functional adaptations in masticatory muscles in PCB patients.
Abstract:
The aim of this study was to assess the electromyographic (EMG) activity and thickness of the masseter and anterior temporalis muscles in children with unilateral posterior crossbite (PCB). Thirty-six children (22 boys, 14 girls, and mean age of 8.8 +/- 1.1 years) were divided into the following groups: The case group with 20 PCB patients (10 on the left side, 10 on the right side); the control group with 16 normal occlusion (NOccl) subjects. EMG activity was recorded with bipolar surface electrodes at rest and during maximal clenching. The muscle thickness was measured with real-time ultrasound. Data were compared between groups and between sides. The correlation between EMG activity and muscle thickness was also evaluated. The data were analyzed using the Shapiro-Wilks test, Pearson's correlation and Spearman as appropriate, paired and unpaired t- test, and Mann-Whitney test. The results revealed that the masseter of the crossbite side was more active than that of the non-crossbite side in PCB group during maximal clenching. The comparisons of EMG activity between PCB and NOccl groups revealed some variability in the results, depending on the crossbite side. The ultrasonographic evaluation did not show statistically significant differences between groups, nor between sides in the PCB and NOccl groups. Significant correlation between EMG activity and thickness was observed only in the left masseter in the NOccl group. In conclusion, these findings showed that asymmetric muscle activity of the masticatory muscles was not related to the thickness of these muscles in children with PCB.
