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Changes in soft tissue profile and electromyographic activity after activator treatment.
Abdulvahit Erdem1, Nihat Kilic, Barçin Eröz
1Department of Orthodontics, Faculty of Dentistry, Atatürk University, Rize, Turkey. aerdem@atauni.edu.tr
Australian Orthodontic Journal
|January 2, 2010
Summary
Activator therapy for Class II division 1 malocclusions alters lip profile and increases temporalis and masseter muscle activity, particularly during swallowing. These findings link orthodontic treatment to changes in facial muscles and soft tissues.
Area of Science:
- Orthodontics
- Craniofacial Biology
- Biomedical Engineering
Background:
- Limited research correlates muscle activity and soft tissue changes in adolescents with malocclusions.
- Understanding these relationships is crucial for effective orthodontic treatment planning.
Purpose of the Study:
- To investigate associations between soft tissue profile changes and electromyographic (EMG) activity of the temporalis, masseter, and orbicularis oris muscles.
- To evaluate these associations in children with Class II division 1 malocclusions undergoing activator therapy.
Main Methods:
- A prospective study involving 25 children with Class II division 1 malocclusions, randomly assigned to a treatment (N=15) or control (N=10) group.
- Lateral cephalometric radiographs and EMG recordings of key facial muscles were obtained at baseline and 12 months.
- Correlations between changes in soft tissue variables and EMG activities were analyzed.
Main Results:
- Activator therapy resulted in significant decreases in upper lip to E line distance (UL-E) and H angle.
- EMG activity of temporalis and masseter muscles increased significantly in both groups, with notable between-group differences.
- Significant correlations were found between lip profile changes and muscle activity during swallowing in the treatment group.
Conclusions:
- Activator therapy is associated with observable changes in lip posture and the EMG activity of the temporalis and masseter muscles.
- These findings highlight the impact of orthodontic intervention on the interplay between facial soft tissues and muscle function.
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