ELECTROMYOGRAPHY FINDINGS OF MASTICATORY MUSCLE ACTIVITY IN ADOLESCENTS OF DIFFERENT SOMATOTYPES

Smahliuk L. V., Sheshukov D. V

DENTISTRY

Scentific article

The objective of this study is to evaluate the functional condition of dento-facial area by measuring electromyographic (EMG) activity of masticatory muscles in adolescents of different somatotypes. Object and methods. The study included 44 adolescents (mean age 25,2±0,45) who were diagnosed to have Angle’s Class I malocclusion (1906). Body type of male and female individuals was assessed by applying L. Rees – H.J. Eisenk index (1945). Depending on the index values obtained all subjects were divided into three somatotypes: 8 individuals were found to have hypersthenic body type; 22 individuals had normosthenic body type; and 14 individuals were of asthenic body type. To evaluate the functional condition of dento-facial area, all adolescents were subjected to EMG of temporalis and masseter muscles in the following tests: maximum teeth clenching on the left and right sides, mandible forwards shift (protrusion), mandible backwards shift (retrusion), maximum teeth clenching. We registered maximum and mean amplitudes, symmetry of masticatory muscle activity for each study participant. The findings obtained were processed by using the methods of mathematical statistics to calculate the sample mean (M), dispersion (σ), and the error of mean (m). The difference probability of the findings obtained was found by Student’s t-test; to assess the correlation between semiquantitative and qualitative characteristics, we applied non-parametrical R. Spearman correlation coefficient. The correlation coefficients were considered statistically significant in the case of a probability error p <0.05. The calculations were preformed by using PC software “Microsoft Excel 2007”, “NCSS 2004” and “SPSS for Windows. Release 13.0”. The analysis of data obtained from the teeth clenching on the left side demonstrated the increased bioelectric activity of the muscles on the active side in all subjects. Maximum, mean amplitude and contractions area of the temporal and masticatory muscles were significantly higher on the side of clenching (on the left) than on the balancing side (opposite right side) in asthenics, normostenics (p<0.05), and hypersthenics (p>0,05) that conforms with normal indices. We revealed the bioelectric activity of the masticatory muscles in the test on teeth clenching on the left side was higher than the indices of EMG activity of the temporal muscles in asthenic individuals (with maximum (p> 0.05) amplitude, mean amplitude and area p<0.05) that is the evidences of the physiological functioning of masticatory muscles in the adolescents of this group in this test. The findings for the normostenic group demonstrated the same difference in the EMG activity (for maximum amplitude and area p>0.05, for mean amplitude p<0.05). The test results in hypersthenic individuals showed an excess of masticatory muscle activity over the temporal muscles at maximum amplitude (p<0.05), mean p>0.05, and contraction area (p<0.05). Conclusion. The study has found out a functional imbalance in masticatory muscle activity in adolescents of different somatotypes.

somatotypes, adolescents, electromyographic (EMG) activity

1. Kornetov HA. Klinicheskaya antropologiya – metodologicheskaya osnova tselostnogo podkhoda v meditsine. V:. Izranova V, redactor. Materiali mezhdunar. nauch. konf. Aktual’niye voprosy i dostizheniya sovremennoy antropologii; 2006 Novosibirsk. Novosibirsk; 2006. s. 52-7. [in Russian].
2. Smaglyuk LV, Sheshukov DV. Stomatologichniy status molodich lyudey riznih somatotipiv. Visnik problem biologiyi i meditsini. 2018;1(2):365- 9. [in Ukrainian].
3. Ferrario VF, Sforza C, Colombo A, Ciusa V. An electromyographic investigation of masticatory muscles symmetry in normo-occlusion subjects. J. Oral Rehabil. 2000;l.27(1):33-40.
4. Raman P. Physiologic neuromuscular dental paradigm for the diagnosis and treatment of temporomandibular disorders. J. Calif. Dent. Assoc. 2014;42(8):563-71.
5. Sforza C, Montagna S, Rosati R, De Mendes M. Immediate effect of en elastomeric oral appliance on the neuro-muccular coordination of masticatory muscles: a pilot study in healthy subjects. J. Oral Rehabill. 2019;37:840-7.
6. Tartaglia GM, Lodetti G, De Felucio CM, Sforza C. Surface electromyography assessment of patients with long lasting temporomandibular joint disorder pain. J. Electromyogr kinesiol. 2011;21:659-64.

«Bulletin of problems biology and medicine» Issue 3 (152), 2019 year, 371-374 pages, index UDK 616.742-053.81

10.29254/2077-4214-2019-3-152-371-374