Tip-Edge Orthodontics and the Plus Bracket

Richard Parkhouse

• Editore: Mosby Ltd.
• Anno: 2008
• ISBN:
  9780723437581
• Edizione: 2
• Argomento: Medicine
• Categoria: Orthodontics

This comprehensive guide on the innovative Tip-Edge appliance introduces the concept of differential tooth movement into what is essentially a straight-wire bracket system. Prepared by a world-renowned expert, the second edition of this highly illustrated atlas explains the Tip-Edge technique from first principles and now includes important advances in the field, in particular the Plus bracket, an innovation which will greatly enhance the use of this rapidly emerging technique. Clearly written with liberal use of case studies, high quality photographs and line artwork, this atlas is ideal for all orthodontists who are interested in expanding their skills to include the Tip-Edge Plus technique.

• Comprehensive illustrated textbook on the use of Tip-Edge by a world leader in its clinical development
• More than 500 illustrations, many in full colour, present clinical, diagnostic and practical information in an easy-to-follow manner
• Explains the demonstrably superior capabilities of Tip Edge and Plus over conventional bracket systems
• Demonstrates the scope of the technique by numerous case histories which show the successful management of more difficult cases that often cannot be addressed by conventional means
• Ideal for practitioners new to the appliance and those familiar with it who need to keep abreast of advances in the field

• Includes all the new improvements and modifications in this rapidly developing technique, in particular, the Plus bracket
• New clinical cases show the effectiveness of Tip-Edge Plus treatment in both American and British patients
• Contains an expanded section on how to convert to this demonstrably superior technique from traditional straight wire practice

CHAPTER 1 Introduction

Historical perspective 3

Overcoming the limitations of conventional brackets 4

The Tip-Edge® (TP Orthodontics Inc., La Porte, Indiana, USA) bracket was invented by Dr Peter Kesling to introduce differential tooth movement within an edgewise based bracket system.^1-3 As its name suggests, Tip-Edge combines an initial degree of tooth tipping, which greatly facilitates tooth movement, prior to ‘edgewise’ precision finishing.

Based on extensive clinical experience, it is the belief of the author that Tip-Edge is the most significant innovation in fixed appliance orthodontics since the original edgewise bracket.^4,5 While essentially a ‘straight-wire’ appliance itself, in terms of preadjusted bracket specification and elimination of looped archwires and finishing bends, it overcomes the fundamental limitations of today’s popularly accepted straight-wire systems, and opens up new horizons in fixed appliance orthodontics. Now, with the advent of the ‘Plus’ system, the need for auxiliary springs during the root uprighting and torquing phase has been eliminated, so making Tip-Edge significantly more operator friendly.

Although the title of Tip-Edge was originally coined as a nickname, it has since become adopted worldwide, in preference to the official and more formal title of Differential Straight-Arch® (TP Orthodontics Inc., La Porte, Indiana, USA) technique.

Historical perspective

Recognition is rightly given to Dr Edward Angle as the father of fixed appliance orthodontics (Fig. 1.1). The ‘Edgewise’ bracket, which he invented as long ago as 1925, has been the mainstay of fixed appliance practice ever since.⁶ It provides the neatest way of achieving three-dimensional root control and was, in its day, years ahead of its time. Time moves on, however, and many of the intrinsic faults and limitations of edgewise based systems have since been acknowledged, but incompletely addressed.

Fig. 1.1 Dr Edward Angle.

It is little known that Angle himself appreciated that tooth movement was facilitated by allowing a tooth to tip. Previous to his edgewise bracket, he illustrated a crude piston device for retracting a canine into an extraction space, propelled by a threaded screw.⁷ The attachment to the band incorporated a primitive hinge to allow distal crown tipping of the tooth being moved. Unfortunately, he had no means of subsequent root uprighting. Significantly, shortly after he conceived the edgewise bracket, he adopted his well known non-extraction treatment doctrine, to which his edgewise bracket was best suited, although a large number of his results, as history shows, proved to be unstable.

While several orthodontists of the postwar period reintroduced the concept of extractions in search of greater stability, in crowded or severe discrepancy cases, Dr Raymond Begg (Fig. 1.2) was notable in evolving a different bracket system. The resulting Begg technique marked a radical departure from conventional treatment mechanics.^8,9 In fact, the Begg bracket was itself a modification of Angle’s earlier ‘ribbon arch’ bracket. Its adoption was designed to overcome one of the prime disadvantages inherent in all edgewise systems, which Begg had previously recognized. This is that every tooth is subject to mesio-distal bodily control from the moment of archwire engagement, thus increasing resistance to retraction.¹⁰ By allowing teeth to tip freely during the initial stages of tooth translation, Begg introduced an entirely new sequence of tooth movement, tipping the crowns into their corrected positions before uprighting the roots as a later procedure.

Fig. 1.2 Dr Raymond Begg.

It would be fair to say that Raymond Begg startled the orthodontic world in a big way. The previously unrecognized sheep farmer from Australia, who had nonetheless been a highly favoured pupil at the Angle school of orthodontics, was able to show cases treated with a speed undreamed of with edgewise type appliances, and with a flexibility of tooth movement that enabled ultralight forces to be used. This in turn made fewer demands upon anchorage.

From the time it first appeared in the early 1960s, the Begg appliance aroused keen interest but, perhaps inevitably, was fiercely opposed by established orthodontic thinking. Much of this was no doubt provoked by the safeguarding of vested interests and the professional reputations of many. At the same time, Begg’s appliance, exciting as it was, had inherent problems. Root recovery, sometimes from extreme angles, could be less than reliable, while accurate molar control and buccal segment torque were denied by the inability to use rectangular archwires.

In retrospect, Begg undoubtedly stimulated conventional edgewise thinking towards lighter forces and shorter treatment times. This has since been much aided by advances in metallurgy and reduction of friction between brackets and archwires, a continuing quest which is still much in evidence today. He was also the first to demonstrate the clinical potential of differential tooth movement.

Without question, a most notable innovation in bracket design, which continues to dominate modern orthodontics, came with the advent of the ‘straight-wire’ bracket system, pioneered by Dr Lawrence Andrews in the late 1970s.^11-13 This was a direct development of the edgewise design, and introduced the concept of a preadjusted appliance. By incorporating in–out adjustments and finishing angulations of tip and torque into the bracket itself, individualized finishing prescriptions for each tooth became available, based on Andrews’ own research. The edgewise operator was thus relieved of the necessity of placing finishing torque into the rectangular archwires in all cases, let alone all those second order ‘beautifying bends’ required to achieve correct mesio-distal root angulations. Such new technology, essentially simple as it was, set higher standards for case finishing, as previously defined by Andrews’ six keys to normal occlusion.¹⁴ This was further to hasten the decline of the Begg appliance, which boasted no self-limiting prescription finish and was, like edgewise, a lot more challenging to manage in terms of wire bending (Fig. 1.3).

Fig. 1.3 The Begg appliance was intricate and lacked buccal segment torque. Note the auxiliary uprighting springs and spurs, correcting tip and anterior torque respectively.

Strictly, the term ‘straight-wire appliance’ refers to the Andrews version, originally patented to the former ‘A’ Company, incorporating Andrews’ torque-in-base bracket prescriptions. Subsequent alternative prescriptions appeared, notably the Roth ‘modified edgewise’. Following the expiry of the patent, it was predictable that other manufacturers would follow the principle, if not the detail, giving us the plethora of so-called straight-wire brackets that we have today. The Tip-Edge Plus bracket, at the time of writing, remains patented to TP Orthodontics.

Overcoming the limitations of conventional brackets

The undoubted popularity of straight-wire systems should not blind the free-thinking orthodontist to the many limitations that the very design of such brackets imposes in everyday clinical use. Although simplicity of archform makes the orthodontist’s life easier, and individualized bracket prescription facilitates a better detailed finish, it has long been acknowledged that moving teeth ap...