Comparison of frictional resistance between passive self-ligating brackets and slide-type low-friction ligature brackets during the alignment and leveling stage

Clear Aligner Therapy: Up to date review article

The advantages of Clear Aligners Therapy (CAT) include the braces being virtually invisible, comfortable to wear, and removable for eating and brushing; that way, CAT can be used to treat a wide range of orthodontic issues. In 1999, the company Align Technology introduced the frst commercial clear aligner system called Invisalign. The Invisalign system was initially only available to orthodontists, but later became available to general dentists as well. The system quickly gained popularity among patients who were looking for a more discreet and comfortable alternative to traditional braces. In 2000, Align Technology received FDA clearance for the Invisalign system, which further increased its popularity. The biomechanics of clear aligners involve the use of custom-made tooth aligners that are specifcally shaped to guide teeth into desired positions. These aligners are typically made from flexible materials such as polyurethane or ethylene vinyl acetate and are adjusted to apply the necessary forces for tooth movement. Attachment devices, such as power ridges or buttons, are often used to enhance or assist in specifc tooth movements and for retention of the aligner. The use of attachments allows for the exertion of desired force on the teeth, which is crucial for the success of Clear Aligner Therapy. CAT should be used if patients are concerned about the esthetic appearances of their teeth-for example, actors and other individuals that rely on their appearances in public in a professional context-and if the misalignment is not severe, so that clear aligners can still work. One should not use CAT in cases of severe crowding or spacing issues that require extractions. If the patient has complex jaw discrepancies or skeletal issues or if teeth need to be moved extensively in multiple directions, CAT is likely not going to be strong enough. In conclusion, Clear Aligner Therapy is a safe, effective, and convenient orthodontic treatment option that offers patients a virtually invisible way to achieve a straighter, more beautiful smile. With continued advancements in technology and a growing body of research supporting its effectiveness, the future of Clear Aligner Therapy looks bright.

Finishing Analysis of Dental Outcome (FADO) as a New Guide in Orthodontic Treatment

OBJECTIVES

Orthodontic treatment has both functional and esthetic goals. The finishing phase is one of the most important and seeks to solve occlusal, dental, functional, and esthetic problems, offering the possibility of obtaining the best possible outcome. This paper aims to describe the Finishing Analysis of Dental Outcome (FADO) guide as a tool to improve orthodontic treatment results.

METHODS

A literature review of finishing procedures and orthodontic treatment outcomes was made. Moreover, current parameters of the esthetics of the smile were considered. The information was systematized to produce a protocol applicable to practice. This guide includes the assessment of mini-esthetic, micro-esthetic, and occlusal results using the Cast Radiographic Evaluation of the American Board of Orthodontics. Treatment options for each item were also suggested. Clinical cases were used to illustrate the application of the guide.

RESULTS

The FADO Guide is presented and explained to give the clinician a systematic and orderly guide to achieve the best possible results in orthodontic treatment. To fulfill the FADO Guide, cast models, a panoramic radiograph, smile photographs (frontal and lateral), and an intraoral frontal photo are needed. The FADO Guide includes four sections: mini-esthetic evaluation (the evaluation of the smile), micro-esthetic evaluation, occlusal analysis, and radiographic analysis.

CONCLUSION

The FADO guide presents a systematic approach to the application of a finishing protocol in orthodontics. Furthermore, this guideline can improve clinical practice and be used as a checklist to optimize clinical outcomes.

Friction behavior of the wire material Gummetal®

OBJECTIVES

Gummetal® (Maruemu Works, Osaka, Japan), a new orthodontic wire material successfully used in clinical applications since 2006, is biocompatible and exhibits exceptionally high elasticity, nonlinear elastic behavior, plasticity and strength. Systematic comparisons of friction behavior are lacking; thus, the friction of Gummetal® in the binding modus was compared to commonly used low friction wires.

MATERIALS AND METHODS

In vivo tests were run with Gummetal®, CoCr (cobalt-chromium Elgiloy®, Rocky Mountain Orthodontics, Denver, CO, USA), β‑Ti (β-Titanium TMA®, Ormco, Orange, CA, USA), NiTi (nickel-titanium, NiTi-SE, Dentalline, Birkenfeld, Germany), and stainless steel (SS; Ref. 251-925, 3M Unitek, Monrovia, CA, USA) [dimensions: 0.014 inch (0.35 mm), 0.016 inch (0.40 mm), 0.016 × 0.022 inch (0.40 × 0.56 mm), and 0.019 × 0.025 inch (0.48 × 0.64 mm)-β-Ti not available in the dimension 0.014 inch]. These were combined with Discovery® (Dentaurum, Ispringen, Germany), Micro Sprint® (Forestadent, Pforzheim, Germany), Clarity™ (3M Unitek), and Inspire Ice™ (Ormco) and slots in the dimension 0.022 inch (0.56 mm) and, except for the 0.019 × 0.025 inch wires, in the dimension 0.018 inch (0.46 mm). They were ligated with a 0.010 inch (0.25 mm) steel ligature (Smile Dental, Ratingen, Germany). Brackets were angulated by applying a moment of force of 10 Nmm against the wire, which was pulled through the slot at 0.2 mm/s.

RESULTS

In 660 tests using 132 bracket-wire combinations, friction loss for Gummetal® was comparable to and, in a few combinations with Micro Sprint®, significantly lower (p < 0.05) than SS and CoCr. The friction for Gummetal® was significantly lower (p < 0.05) than NiTi, and β‑Ti. In some bracket-wire combinations, lower friction was found with round wires compared to rectangular wires, except for the combination with Inspire Ice™, which was higher but not significant. Slot size did not have a significant effect on friction in most combinations.

CONCLUSION

The low friction associated with Gummetal® wires during arch-guided tooth movement will be a valuable addition to the armamentarium of orthodontists.

Influence of Hyrax screw position on dental movement and cortical bone: A study of finite elements

BACKGROUND

Rapid maxillary expansion (RME) has effects on the dental and periodontal structures of the parts involved, which vary according to the design and position of the expansion screw. The purpose of the study was to determine the optimal three-dimensional position of the Hyrax screw to obtain precise control of the dental movement and effect on the bone cortex using the finite element method (FEM).

MATERIAL AND METHODS

RME was performed from the patient whom two Cone-Beam computerized tomography scans (CBCT) were obtained: T1 before expansion, and T2 three months after stabilization of RME. The FEM model was designed with T1 and of Hyrax photographs. FEM was obtained by comparing the simulation, T2, and clinical results. Three sagittal screw positions (anterior-middle-posterior) and vertical (upper-medium-low) were evaluated.

RESULTS

A coronal- buccal displacement of premolars and first molars was found which decreased in the occlusal-apical direction, presenting different types of dental movement in the screw positions; besides, a tendency of translational movement in the posterior-high location was observed. In the posterior-high position a higher concentration of efforts and homogeneous deformations in the periodontal ligament and vestibular cortex of the cervical area of first molars, first and second premolars were observed, with variations according to the screw position and the distribution of stresses.

CONCLUSIONS

The ideal location of the expansion screw for controlling dental movement and periodontal side effects was the high-posterior position. Key words:Maxillary expansion, dental movement, finite element analysis, orthodontic appliances.