Customized planning of the visible maxillary arch width in harmony with interparopia width and smile width for female facial aesthetics.

BACKGROUND: The visible maxillary arch width (VAW) is an important aesthetic-determining feature. To date, there is no well-established methodology to determine the aesthetically optimal VAW in customized treatment planning. METHODS: In this study, the common traits of the dentofacial configuration were investigated in most attractive Asian and Caucasian female smiles. The smiling photo of a subject was digitally modified based on combined variations of VAW, smile width (SW), transverse facial dimensions (TFD), and vertical facial dimensions. These modified photos were assessed for aesthetics. The aesthetically essential parameters were identified, and their mathematic correlations and reference ranges were determined for different vertical facial patterns. Using the obtained results, a mathematic guidance was constructed for customized smile designing. The applicability of this guidance was tested in Asian females. RESULTS: The most attractive Asian and Caucasian female smiles have intraracial and interracial commonalities in the VAW-to-TFD ratios. The interparopia width (IPD) predominated over facial widths in determining well-matched VAW and SW. For optimal smile aesthetics, the VAW and SW were correlated as simulated by the formula 1.92 IPD ≤ VAW + 2.3 SW ≤ 2.17 IPD, plus the VAW-to-IPD ratio within 0.54 to 0.62 and the SW-to-IPD ratio within 0.61 to 0.71, ranges tailored to vertical facial patterns. This constitutes a mathematic guidance for customized planning of the aesthetically optimal VAW. This guidance was preliminarily validated to be applicable to Asian females. CONCLUSIONS: The VAW-to-TFD ratios were essential for Caucasian and Asian female smile aesthetics. The mathematic guidance could serve as a reference for customized smile designs for Asian females.

Evaluation of the Loading, Unloading, and Permanent Deformation of Newly Available Epoxy Resin Coated Ni-Ti Wires Using Self-Ligating Brackets.

AIM: The purpose of this study was to evaluate the load and unload deflection and permanent deformation of round 0.016'' and rectangular 0.016'' × 0.022'' regular and coated Ni-Ti wires. MATERIALS AND METHODS: Ni-Ti archwires produced by two manufacturers were evaluated. Both regular and coated round and rectangular Ni-Ti wire segments (n = 15) from each group were submitted to a three-point bending test. Both types of wires were evaluated for permanent deformation at the end of a recovery cycle. RESULTS: The coated round 0.016'' Ni-Ti wires produced a significantly lower force in loading (p < 0.01) and unloading (p < 0.01) than regular wires of the same manufacturer and size. There was no significant difference in permanent deformation between coated and regular round Ni-Ti wires from the same company. For rectangular 0.016 × 0.022'' Ni-Ti wires, there was a significant difference in the loading evaluation, but the unloading test presented no significant differences. The permanent deformation of the rectangular wires revealed no significant difference between them. CONCLUSION: The addition of an esthetic coating to these new Ni-Ti wires produced changes in their mechanical properties, manifested as a reduction in the applied force, which should be considered in clinical management.

Treatment and retreatment of a patient with a severe anterior open bite.

An 8-mm anterior and posterior open bite caused by a tongue rest posture habit was closed in a 25-year-old man by means of mandibular soldered tongue spurs and without orthognathic surgery. All maxillary and mandibular first molars were extracted, and the spaces were closed. Inappropriate retention protocol allowed for relapse in a 6-month period. A new 1-year orthodontic retreatment was conducted; after an appropriate retention protocol, the outcomes of treatment were significantly improved.