Mouth breathing has been associated with severe impact on the development of the stomatognathic system.
Aim: This paper aims to analyze the electromyographical findings and patterns of electrical activity of the anterior temporal and masseter muscles in mouth and nasal breathing children.
Material and method: The patients were divided into two groups: mouth breathers (n=17) and nasal breathers (n=12). The children underwent bilateral electromyographic examination of the anterior temporal and masseter muscles at maximal intercuspal position and during usual mastication. A Myosystem Br-1 electromyograph with 12 acquisition channels, amplification with total gain of 5938, rate of acquisition of 4000 Hz, and band-pass filter of 20-1000Hz, was used in the examination. The signal was processed in Root Mean Square(RMS), measured in microV, analyzed and expressed as a normalized percentage. The data set was statistically treated with the T-test (Student).
Results: The observed level of electrical activity in the mouth breathing (MB) group was lower in all analyzed muscles, with statistical significance found only in the left temporal muscle; during mastication, mouth breathers also presented increased electrical activity on the right side and on the temporal muscle.
Conclusion: Mouth breathing impacts the electrical activity of the muscles studied at maximal intercuspal position and during usual mastication.