Current therapy

An overview of facial aesthetic units

Facial esthetics have always received much attention in orthodontic treatment, especially in young adult female patients. Three-dimensional (3D) soft-tissue changes after orthodontic extraction have not been fully explained. This study evaluated the 3D morphologic changes after orthodontic extraction in young female patients using a structured light scanner.

Forty-five adult female patients aged 20-25 years were enrolled in our study. The treatment group consisted of patients who received orthodontic treatment with 4 premolar extractions, and the control group was composed of young female volunteers who had not undergone any orthodontic treatment. To monitor the soft-tissue changes, 9 morphologic regions and 12 landmarks were identified for the 3D deviation analyses. The spatial deviations of landmarks and regions in the x, y, and z directions were constructed for quantitative analysis. Color map images were constructed to visualize soft-tissue displacement as a qualitative evaluation. The paired sample test was used to compare differences at the beginning of the experiment (T0) and after 24 months (T1) in both groups. An independent t test with Bonferroni correction was performed to compare differences between the treatment and control groups. A linear regression test was performed between incisor retraction and changes in the perioral tissues.

Subtracting the effect of aging from the lip changes in the control group, the treatment group showed a statistically significant difference in the displacement of labrale superius (−1.37 mm), labrale inferius (−1.89 mm), the upper lip region (−0.98 mm), and the lower lip region (−1.36 mm) along the z-axis. No significant differences were found between the treatment and control groups in the temporal, parotideomasseteric, and buccal regions. Pearson correlation tests indicated a positive correlation between incisor tip retraction and changes in soft tissues (two-dimensional cephalometric analysis, 3D landmark measurements, and 3D regional measurements). The correlation coefficient ranged between 0.45 and 0.55.

Three-dimensional soft-tissue changes were mainly concentrated in the upper and lower lip regions in adult female patients after the 4 premolars were extracted. For female patients aged 20-25 years with 4 extracted premolars, soft-tissue changes in the temporal, parotideomasseteric, and buccal regions were not clinically significant.

This study aimed to investigate the overall and regional accuracy (trueness and precision) of digital three-dimensional (3D) facial scans obtained from four tablet-based applications, which were (Bellus) the Bellus Dental Pro® (Bellus3D, Inc. Campbell, CA, USA), (Capture) the Capture®: 3D Scan Anything (Standard Cyborg, Inc. San Francisco, CA, USA), (Heges) the Heges® (by Marek Simonik, Ostrava, North Moravia, Czech Republic), and (Scandy) the Scandy Pro 3D Scanner® (Scandy LLC, New Orleans, LA, USA).

A mannequin's face was marked with 63 landmarks. Subsequently, it was scanned 5 times using each scan application on an iPad Pro® (Apple Inc., Cupertino, CA, USA). The digital measurements were obtained with MeshLab® (CNR-ISTI, Pisa, Tuscany, Italy) and compared to the manual measurements using a digital vernier calliper (Truper Herramientas S.A., Colonia Granada, Mexico City, Mexico). The absolute mean difference and the standard deviation of the dimensional discrepancies were calculated. Moreover, the data were analysed by using one-way ANOVA, Levene's test, and Bonferroni´s correction.

The absolute mean trueness values were Bellus 0.41 ± 0.35 mm, Capture 0.38 ± 0.37 mm, Heges 0.39 ± 0.38 mm, and Scandy 0.47 ± 0.44 mm. Moreover, precision values were Bellus 0.46 mm, Capture 0.46 mm, Heges 0.54 mm, and Scandy 0.64 mm. Comparing the regions, Capture and Scandy showed the highest absolute mean difference, which was 0.81 mm in the Frontal and Zygomaticofacial regions, respectively.

The trueness and precision of all four tablet-based applications were clinically acceptable for diagnosis and treatment planning.

The future of the three-dimensional facial scan is auspicious, and it has the potential to be affordable, accurate, and of great value for clinicians in their daily practice.

The nasal aesthetic subunit principle has been widely accepted as the standard for nasal reconstruction with forehead flaps. However, in our experience, one's impression of a reconstructed face can easily be represented by the nose's entire appearance rather than a single nasal component. Accordingly, we hypothesized that total nasal reconstruction focusing more on the facial aesthetic subunit principle would be superior to focal nasal subunit partial reconstruction. Here, we investigated the indication range of total nasal reconstruction and analyzed its effectiveness.

Between July 2006 and December 2017, 32 patients who underwent total or subtotal nasal reconstruction were recruited. The total nasal reconstruction group (n = 20) was treated according to our modified facial aesthetic unit concept, while the subtotal reconstruction group (n = 16) was treated according to the nasal aesthetic subunit principle. Using retrospective reviews, we compared surgical details and aesthetic, and functional outcomes with visual analog scale scores.

In aesthetic evaluation, nose contour (p = 0.009), nasal symmetry (p = 0.001), and nostril shape (p = 0.041) were superior in the total nasal reconstruction group. Satisfaction regarding the nose (p = 0.036) was significantly higher than that regarding the forehead and labial folds in the total group. Regarding function, there were no significant intergroup differences in nasal airflow, snoring, or olfaction.

We suggest that total nasal reconstruction is not a strategy to avoid because of its aggressive nature. For selected suitable patients, the use of the total nose reconstruction focusing on our one nose concept can be a successful surgical option, and the reconstructed nose can be visualized as a real part of the face.