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Background: The facial pattern is broadly classified into three major types -average, horizontal and vertical growth patterns. There are three schools of thought for the factors responsible for these different facial patterns among which multifactorial is the most accepted one. Literature also shows relationship between the orofacial muscles and the facial pattern.

Aim: To explore whether the suprahyoid muscles have any influence on the growth pattern of mandible.

Materials and Methods: Electromyographic activities of suprahyoid muscles were evaluated in 30 adults between the age of 18 and 28 years (mean age 23.6 years). Kruskal-Wallis test (p-value<0.05) was applied to compare the mean amplitudes and mean frequencies among three groups during three different activities. The Mann-Whitney ‘U’ (p-value<0.05) test was performed for multiple comparisons of mean amplitudes and frequencies between the groups for the three activities.

Result: The results of the study shows that the suprahyoid muscles group activities are highest in vertical growers and lowest in horizontal growers, the average growers lying somewhere between the two groups during opening and closing, swallowing and protrusion. The difference in the mean amplitude and the frequency among the three groups are statistically significant.

Conclusion: This study indicates that the suprahyoid muscles group activities may have role in modifying the mandibular growth pattern however further study to explore the cause and effect relationship is suggested.

Electromyography, Vertical, Horizontal