Using facial laser scanning for assessing facial symmetry: a prospective study in children affected by crossbite

Facial asymmetry is defined as imbalance between the two sides of the face (hemifaces). Although no human face is perfectly symmetrical, it is difficult to distinguish normal asymmetries from small pathologic asymmetries associated with malocclusions as unilateral posterior crossbite that already are present in the primary dentition. The aim of this longitudinal study was to assess whether correction of unilateral posterior crossbite in the primary dentition results in improvement of facial symmetry. A group of 60 Caucasian children in the primary dentition, aged 5.3 ± 0.7 years, were collected at baseline. The group consisted of 30 children with a unilateral posterior crossbite with midline deviation of at least 2 mm (XB) and 30 without malocclusion (NXB). The XB group was treated using an acrylic plate expander. The children’s faces were scanned using a three-dimensional (3D) laser-scanning device. Non-parametric tests were used for data analysis to assess differences over the 30-month period of follow-up. The XB children had statistically significantly greater facial asymmetry in the lower part of the face (p < 0.05) than the NXB children at baseline. There were no statistically significant differences between the two groups at 6, 12, 18 and 30 months of follow-up. Treatment of unilateral posterior crossbite in the primary dentition period resulted in an improvement of facial symmetry in the lower part of the face (p < 0.05). Treatment of unilateral posterior crossbite in the primary dentition improves facial symmetry, though it creates normal conditions for normal skeletal growth. The use of a 3D laser-scanning device helped us to assess facial asymmetry more objectively.