Soft tissue facial changes among adult females during alignment stage of orthodontic treatment: a 3D geometric morphometric study

Background To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment. Methods 43 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment. Results We observed statistically significant changes in facial shape across the three treatment stages (p = 0.0022). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0045) and from T0 to T2 (p = 0.0072). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.32 mm, 0.21 mm, and 1.34 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.1143). No changes in variance of facial shape were observed across treatment stages (p > 0.05). Conclusion Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

Dento-Skeletal Abnormalities in School-aged Children in Iran: A Cross-Sectional Study

Aim: The aim of this study was to evaluate skeleto-dental abnormalities in 9-11-year-old school children, in Tehran, Iran. Materials and Methods: In this population-based cross-sectional descriptive study, a random cluster sampling was done among 19 school districts. A total of 1,429 socioeconomically and ethnically diverse Iranian schoolchildren, aged 9-11 years were studied. A brief questionnaire including background information such as gender and age was completed by the parents. Clinical examinations included the evaluation of sagittal and vertical skeletal relationship, Facial form (facial index), and the presence of significant asymmetry. Results: There were 758 males and 671 females with the mean age of 10 years±8 months. According to the sagittal skeletal relationship, the most prevalent type was convex (63%) that presenting the skeletal Cl II jaw relation; followed by straight (32.9%); and then concave (4.1%). In the vertical skeletal relationship, 73.9% of the children had an average facial relationship, 18.4 % had a long face pattern; and 7.8% had a short face pattern. Regarding facial form in the frontal view, the most common was the average form (79.3%); followed by narrow (14%); and broad (6.7%). The prevalence of significant facial asymmetry was 15.2%. Conclusion: The prevalence of dento-skeletal abnormalities were high. The majority of the Iranian schoolchildren, aged 9-11 years, had at least one dento-skeletal abnormality, even though it is commonly preventable.

Soft tissue facial changes among adult females during the first six months of orthodontic treatment: a spatially dense 3D geometric morphometric study

Background: To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment.Methods: 18 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment.Results: We observed statistically significant changes in facial shape across the three treatment stages (p = 0.003). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0059) and from T0 to T2 (p = 0.0098). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.31 mm, 0.22 mm, and 1.33 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.103). No changes in variance of facial shape were observed across treatment stages (p > 0.05).Conclusion: Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.