Evolution of treatment mechanics and contemporary appliance design in orthodontics: A 40-year perspective.

Until the early 1970s, successful treatment with the Begg technique and the Tweed edgewise technique required tedious wire bending. The introduction of Andrews' straight wire appliance changed that, and it was one of the most significant contributions in the history of orthodontics. The straight wire appliance significantly reduced the amount of wire bending and also brought along other options in treatment mechanics. Retraction of the canines with elastic chains and ligature wires became more common. Sliding mechanics in place of closing loops became the method of space closure for a significant number of clinicians. Edgewise force levels were initially used to close spaces; however, it was soon observed that lighter forces were more effective with sliding mechanics. Along with these changes, it became apparent that compensation in the appliance was needed, depending on the type of malocclusion and particularly with varying extraction sequences. Various appliance designs were developed to accommodate changes in mechanics and force levels. These modifications improved tooth positions at the end of treatment as long as the brackets were properly placed. These major changes in appliances, force levels, and treatment mechanics can be traced back to the work of Dr Lawrence Andrews and the straight wire appliances.

Fios ortodônticos: conhecer para otimizar a aplicação clínica / Orthodontic wires: knowledge to optimize clinical application

A grande variedade de fios ortodônticos presente no mercado pode gerar dúvidas quanto à melhor escolha para situações clínicas. Assim, o conhecimento das propriedades mecânicas dos mesmos facilita a escolha para aplicação do movimento ortodôntico na dependência da fase em que o tratamento se encontra. A evolução da tecnologia de manufatura dos fios e a elaboração de novas técnicas ortodônticas geraram a busca por uma melhor qualidade das ligas, a fim de torná-los biologicamente mais efetivos no que diz respeito aos dentes e tecidos de suporte. O presente artigo resume as principais características dos fios utilizados em Ortodontia, em relação ao histórico, propriedades mecânicas e aplicação clínica, de acordo com fases específicas de tratamento.

The huge variety of orthodontic wires brands available in market might generate confusion as regard to the best choice for clinical application. Therefore mechanical properties knowledge about wires would help the professional to apply the best orthodontic technique depending on the treatment phase. The wires manufacturing evolution and the new orthodontic techniques proposed guided the market into the search for better quality alloys, in order to make them biologically more effective to teeth and support tissues. This paper aims to summarize some main characteristics of orthodontic wires related to their history, mechanical properties and clinical application as regard to individual phase of treatment.

Técnicas de combinación en ortodoncia: reseña histórica, últimos avances / Combination techniques in orthodontics: historical review, last advances

Desde la introducción de la técnica de Edgewise por el Dr. Edward Angle, pasando por la técnica de alambres ligeros de Begg hasta la actualidad, la ortodoncia ha experimentado diversas combinaciones y evoluciones dentro de las técnicas hasta llegar al diseño de los brackets de combinación tendencia actual en la fabricación de los mismos, en este trabajo se hace un recuento de la evolución de los brackets de combinación hasta los diseños más actuales.

Lingual orthodontics: a review of its history.

When lingual orthodontics was first introduced about twenty years ago some called it the 'ultimate aesthetic appliance'. Patients and practitioners embraced this new treatment alternative with high expectations. Reports of disappointing results and high costs dampened much of the initial excitement and enthusiasm gradually waned. By the late 1980s, the number of practitioners using the technique had fallen sharply, leaving only a handful who still believed in its potential. Relatively little has been written on lingual orthodontics, almost nothing in recent years. This article takes an objective view of its present status.

Orthodontic wire: a continuing evolution.

Wires have substantial structural presence in active and retentive orthodontic therapy. Wires, and auxiliaries fabricated from wire, may deliver force to produce dental displacements, they may attempt to prevent unwanted displacements, or they may simply carry force from one location to another within the dentofacial complex. Wires may have relatively simple or rather convoluted geometries. The most prominent wire in clinical orthodontic treatment is the "arch wire." Marketed in just two, symmetrical, cross-sectional shapes, its sizes are numerous, and arch wires are manufactured of a variety of metallic alloys and compositions. The primary objective of this article is to trace the history of arch wires over the past century, considering the evolution from the stiff arch bow to the wire exhibiting Hookean material behavior, from the precious metal to the stainless steel to the titanium alloys, and into the era of the "superelastic" wire and a thermomechanical behavior decidedly more complex than its predecessors. Timely, relevant questions that are addressed herein pertain to the current "state-of-the-art" of orthodontic wires, the extent to which the mechanics of the "old" and new wires are understood, and the anticipated arch wire advancements in the near future as a new millennium approaches.