Facial expressions
For maximum smile the mean magnitude of movement increased significantly from T0 until T1 by 2 mm. At T1, smiling became more asymmetric. No differences in shape change or time was observed. The mean magnitude of lip purse decreased from T0 until T1 by 1 mm. Shape change, symmetry, and time for the facial expression did not differ significantly between T0 and T1 (Table Means and 95% CI of the parameters analysing facial expressions pre- (T0) and post-surgical (T1) in all patients (The post-surgical increase in the magnitude of maximum smile and the decrease in the magnitude of lip purse were observed in all but 5 and 6 patients, respectively.Subgroup analysis showed that these results apply to patients with skeletal classes II and III (Table Means and 95% CI in the changes of the facial expressions (T1–T0) compared between patients with skeletal class II (Skeletal class IIMaximum smileSkeletal class IIIMaximum smileSkeletal class IILip purseSkeletal class IIILip purseThe results of the multivariate linear model with the difference in the magnitude of maximum smile as dependent variable showed that the pre- and postsurgical differences in the magnitude of smile cannot be explained by the surgical movements, the type of surgical intervention, or the skeletal class (Table Results of the multivariate linear model with the difference in the magnitude of maximum smile as dependent variable and the surgical movements, the type of surgical intervention, and the skeletal class as explaining variables. The difference in the magnitude of maximum smile cannot be explained by the explaining variablesResults of the multivariate linear model with the difference in the magnitude of lip purse as dependent variable and the surgical movements, the type of surgical intervention, and the skeletal class as explaining variables. The difference in the magnitude of lip purse cannot be explained by the explaining variables