Mandibular movements in children with deciduous and mixed dentition and in young adults with permanent dentition-the association between movements and occlusal traits

Background: Cross-sectional studies of mandibular movements provide data on developmental trends of dentition and support planning of public health services.

Objective: The aim of this study was to measure mandibular movement capacities in children with deciduous and mixed dentition and in young adults with permanent dentition. The influence of age and gender on mandibular movements and the association between mandibular movements and occlusal traits were analysed.

Method: The sample consisted of 1172 Estonians: group 1: children with deciduous dentition; group 2: children with mixed dentition; and group 3: young adults with permanent dentition. Maximum opening, mandibular laterotrusion, and protrusion were registered.

Results: Age was correlated with mandibular movements. Young adults had statistically significantly larger mandibular movements as compared to children with deciduous and mixed dentition, and children with mixed dentition had larger mandibular movements as compared to children with deciduous dentition. Young adult males had larger mandibular movements than females of the same age. Associations were found between mandibular movement capacities and some occlusal traits. Mandibular movement capacities were smaller in children with crossbite and open bite as compared with children without corresponding occlusal traits. Mandibular movement capacities were larger in children with deep bite and increased overjet as compared with those without corresponding occlusal traits.

Conclusion: Mandibular movement capacities are age and gender dependent. Maximum mouth opening, mandibular laterotrusion, and protrusion are related, and mandibular movement and some occlusal traits are associated.