PURPOSE: to evaluate the ultrasonographic thickness of masseter and anterior portion of the temporalis muscle and facial dimensions in children with normal occlusion and unilateral crossbite, in deciduous and early mixed dentition. METHODS: the sample comprised 49 children of both genders, divided into four groups: deciduous-normal occlusion, deciduous-crossbite, mixed_normal occlusion and mixed_crossbite. Muscle thickness was compared between the right and left sides (normal occlusion) and normal and crossbite-side (crossbite) (Student's "t" test) and related to facial dimensions and body variables (Pearson's and Spearman's correlation test). Facial dimensions were determined by measuring standardized frontal photographs: anterior facial height (AFH), bizygomatic (FWB) and intergonial width (FWI), and AFH/FWB and AFH/FWI ratios. RESULTS: the results showed that the anterior temporalis muscle at rest was significantly thicker in the crossbite side in the mixed-crossbite group (p=0.05). Masseter thickness did not show significant differences between the sides in all groups. Weight and height did not correlate with masticatory muscle thickness; but FWB and FWI showed being positive, and AFH/FWB and AFH/FWI ratios showed having negative correlation with masseter thickness, i.e. children with a long-face pattern showed smaller muscle thickness. CONCLUSION: in the sample studied, the influence of functional characteristics on craniofacial structures was observed in young children by masticatory muscles ultrasonography and facial dimensions exam.
Ultrasonography; Masseter Muscle; Temporal Muscle; Malocclusion; Face
