Mandibular movement range in children.

Background: identification of the mandibular movement range is an important procedure in the evaluation of the stomatognathic system. However, there are few studies in children that focus on normal parameters or abnormalities.

Aim: to determine the average range of mandibular movements in Brazilian children aged 6 to 12 years; to verify the difference between genders, in each age group, and between the different age groups: 6-8 years; 8.1-10 years; and 10.1-12 years.

Method: participants of the study were 240 healthy children selected among regular students from local schools of São Paulo State. The maximum mandibular opening, lateral excursion and protrusive movements, and deviation of the medium line, if present, were measured using a digital caliper. Student T test, Analysis of variance and Tukey test were considered significant for p < 0.05.

Results: the mean values observed in the studied sample were: 44.51mm for maximum mandibular opening; 7.71mm for lateral excursion to the right; 7.92mm for lateral excursion to the left; 7.45mm for protrusive movements. No statistical difference was observed between genders. There was a gradual increase in the range of mandibular movements, with significant differences mainly between the ages of 6-8 years and 10.1-12 years.

Conclusion: during childhood the range of mandibular movements increases. Age should be considered in this analysis for a greater precision in the diagnosis.