Keywords
Electromyography; Facial pattern; Masticatory muscles
Abstract
Objective: To evaluate and compare the electromyographic (EMG) activity of masseter, temporalis, mentalis and orbicularis oris muscles during function in patients with different facial growth patterns.
Materials and methods: 75 subjects (38 males and 37 females) with no history of previous orthodontic treatment, jaw surgeries, facial trauma and temporomandibular joint disorder were taken and divided into three groups based on their mandibular plane angle and gonial angle as hypodivergent, normodivergent and hyperdivergent. Lateral cephalograms were traced manually to determine facial type. Electromyographic recordings were done and muscle activities were evaluated at clenching position.
Results: For temporalis hypodivergent group had the highest activity but the difference was not statistically significant (p=0.904). For orbicularis oris hypodivergent group had the highest activity and this difference was statistically significant (p=0.007). For mentalis hypodivergent group had the highest muscle activity and this difference was not statistically significant (p=0.052). Only orbicularis oris muscle showed statistically significant difference in all the three groups during maximum clenching.
Conclusion: Different facial growth patterns had a significant effect on the EMG activity of facial muscles during function. Orbicularis oris muscle activity showed significant difference among the three groups. Muscle activity was higher for the hypodivergent group as compared to the other groups. This indicates that the musculature in hypodivergent patients is strong and in hyperdivergent group is weak. This must be kept in mind while diagnosing and making the treatment plans for both the facial types.
Citation
Gupta A, Singh K, Tandon R, Chauhan A, Kulshrestha R and Trivedi H. Functional Electromyographic Activities of Facial Muscles in Different Growth Patterns. SM J Dent. 2017; 3(3): 1017s.