Evolution of Brackets

REVIEW ARTICLE

Evolution of Orthodontic Brackets 1

Dr.. Tamizharasi Dr Tamizharasi , Dr. Dr. Senthil Kumar

1& 2

Professors

Department of Orthodontics KSR Institute of Dental Science & Research, Tiruchengode, Tamil Nadu.

Introduction One of the most important passive components of fixed appliances is brackets. brackets. They are merely handles for attachment of the force producing producing agents. Brackets can affect the directions of the force vectors when torque, angulations, and in/out are built into the brackets. Orthodontic treatment is based upon specific force applications to the dentition, the maxilla and the mandible. In order to obtain these forces, orthodontic brackets are attached to the teeth. teeth. Previously Previously,, brackets were were banded to the teeth. But, after, after, the introductions of bonding resin, brackets are rarely banded to the teeth. History It is difficult to imagine that there was a period in Orthodontics before the invention of brackets. Yet this was the situation when Angle developed and perfected treatment procedures with his “E” arch which provided no axial tooth control. control. During this time he also advocated the pre-treatment extraction of teeth and devised methods to close extraction spaces "sans" brackets. The pin and tube appliance1 overcame the weak point in his “E” arch. Thus the prototype of bracket was conceived. The problems of pin and tube appliance appliance were overcome in ribbon arch appliance by Angle with the introduction of first orthodontic bracket – “the ribbon arch bracket” brack et”1. It had a vertical vertical slot slot facing facing occlusally occlusally and was was made in gold. The next major advancement advancement in bracket design that had withstood the test of time was the first

2

ABSTRACT: Orthodontics distinguishes and differs itself from the other branches of medicine by its widespread use of an array of devices made of almost all the biomaterials known. From metals to plastic and from ceramics to composites, these materials bring beauty and health. Brackets evolutions from the introduction of pin and tube to lingual, magnetic and self ligating brackets are rapid in pace and play a significant role in advancement of Orthodontic field. Though, we all are using recent brackets which are currently available in the markets, it is important to know the past history of brackets which was used earlier.. Thus, this article reviews the history earlier history of various orthodontic bracketss and it's advantages bracket advantages and disadvantages. disadvantages. We suggest that that many more review studies should come aiming at the biocompatibility biocompatibility,, aesthetics and treatment treatment results of each bracket. bracket. Such studies will help the practitioner to decide the bracket selection for his treatment plan.

edgewise bracket with a horizontal slot (0.022” x 0.028”). Ever since many modifications had come in bracket design and in bracket material. Classification Brackets can be classified according to:1. Wi Widt dth h of bra brack cket et a. Mesiod Mesiodistall istallyy narrow narrow ex., ex., Ribbon Ribbon arch arch bracke bracket, t, Begg bracket b. Mesiod Mesiodistall istallyy wide ex., Edgewis Edgewise e bracket, bracket, Straigh Straightt wire bracket 2. Sl Slot ot of bra brack cket et a. Hor Horizo izonta ntall slot ex., ex., Edgewis Edgewise e bracket bracket b. Vert ertica icall slot ex., ex., Begg Begg brack bracket et 3. Ma Mate teri rial alss a. Metal – Stainless Stainless steel, steel, Gold, Gold, Titaniu Titanium, m, Nickel Nickel b. Pla lasstic icss c. Ceramics d. Comb Combination ination – Metal Metal reinforc reinforced ed plastics plastics,, metal metal reinforced ceramics 4. Mo Move veme ment nt of of toot tooth h a. Tip Tippin ping g moveme movement nt – Begg Begg brack bracket et b. Bodily movem movement ent - Strai Straight ght wire brack bracket et c. Tip Tippin ping g & Bodily Bodily movem movement ent – Combi Combinat nation ion bracket, Tip-Edge bracket 5. Lig Ligati ation on of bra bracke ckett a. Conven Conventional tional ligatio ligation n – Edgewis Edgewise e bracket, bracket, Begg bracket b. Self-l Self-ligation igation-- Edgelo Edgelokk brack bracket, et, SPEED brack bracket et

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Evolution of Orthodontic Brackets

Description of Brackets Ribbon Arch Bracket The ribbon arch appliance introduced in 1915, was the next step in the evolution of tooth alignment devices. It was actually the first bracket, as such, to be used in an orthodontic appliance. In the ribbon arch appliance, the tube principle was abandoned for the bracket principle. The mesial and distal walls of the tube were removed. Thus these brackets had a vertical slot facing occlusally in contrast to the Begg bracket which faces gingivally. Universal Bracket The name “universal”2 only connotes that the bracket is effective to move and control tooth movement in all planes. It is truly a light wire bracket, designed to be used with light wires, but for stability purposes, heavy wires are also accepted. This in itself makes the bracket “universal” in its implementation. It has two separate slots to receive single or multiple wires for the various tooth movements. The bracket also has wings that enhance the wire action. Begg Bracket These are modified ribbon arch brackets, which are narrow mesio-distally and carry a vertical slot usually of 0.022” size. The ribbon arch brackets designed by Angle were placed inverted by Begg3 with the slot facing gingivally. The round arch wire is loosely fitted and held in place by a lock pin or ligature tie wires. This is responsible for the free tipping and sliding of teeth during the initial stages of treatment. But, because of the narrow bracket and round wire, apical movements are not possible without the use of auxiliary springs. Modern Begg Bracket Dr. William J. Thompson introduced the Modern 4 Begg Technique in the year 1981. It comprises of the advantages of the Begg light wire technique and Straight Wire technique. The gingival, or ribbon-arch slot is designed to permit maximum crown and root tipping movements and the edgewise slot is designed for precise final detailing. These bracket types provide adequate mesiodistal width for optimal rotations, tipping and torque. The base of the four-stage bracket is bevelled to reduce the possibility of friction or binding with the arch wire. The specifications for torque, tip, and in-out placement vary for each tooth. Tip Edge Bracket Dr. Peter C. Kesling designed the Tip Edge 5 bracket . From his experiences with differential tooth movement for 30 years and a thesis written in 1968, he determined that is necessary for each tooth to tip freely either mesially or distally-not in both directions. The face of

Tamizharasi & Senthil Kumar

the edgewise bracket has been changed to permit free crown tipping followed by controlled root uprighting. Lateral extensions of the bracket behind the arch wire provide maximum rotational control even when the tooth is tipped. The wings are lingual to the archwire and therefore not visible. Each bracket has a vertical slot to accept rotating or uprighting springs, power pins and jigs for accurate direct bonding. The slot is rectangular (0.020” x 0.020”) with both the gingival and incisal ends chamfered to facilitate the insertion of auxiliaries from either direction. Ceramaflex II – 256 Begg Brackets The most exciting addition to the Begg appliance component list, are the ceramic brackets. TP Orthodontics Inc markets it as “Ceramaflex II – 256 Begg” brackets. This bracket is polycrystalline alumina and is manufactured by injection moulding. The bonding surface has a polycarbonate base with a slot to enable easy debonding and to avoid enamel fracture that occurs with ceramic brackets2. Edgewise Bracket Angle's final achievement, the edgewise appliance, was the culmination of many years of effort and many different appliance designs attempting to place the teeth according to his “line of occlusion”. The original edgewise bracket as designed by Angle1 was a soft gold bracket with a 0.022” x 0.028” slot which was readily deformed by the forces of occlusion and by tying ligature wires to the bracket.

Various modification of edgewise brackets are: Single Width Bracket It was designed to overcome the problem of tooth rotation. He devised soldered gold eyelets to be placed in the bands. Twin Bracket The next development was the joining together of two edgewise brackets on a common base. It was named after the originator of the idea Swain1 . The Siamese bracket quickly gained popularity for use on upper central incisors and on molar teeth. Its main advantage was its ability to effect most of the tooth rotation without the use of auxili ary eyelet ties. After many years another evolutionary step was the curving of the base of the twin bracket to confirm to the curvatures of the canines and premolar. Lewis Bracket Lewis developed another approach to the problem of efficient tooth rotation. He soldered auxiliary rotation arms that abutted against the bracket itself and thus offered a lever arm to deflect the archwire and rotate the tooth. It does not interfere with occlusogingival deflections of the JIADS VOL -1 Issue 3 July - September,2010 |26|



archwire. The next development in the Lewis rotation bracket was the curving of the base and wings of the bracket to conform to the canine and premolar teeth. Vertical Slot Lewis Bracket A refinement in the Lewis bracket has been the incorporation of a 0.020” x 0.020” vertical slot, making possible the use of uprighting springs to correct axial inclinations if needed. Steiner Bracket This bracket incorporated flexible rotation arms which afforded a rotational effect. It works satisfactorily as long as the flexible arms do not take on a permanent deformation.

tooth positions prior to appliance removal that would allow the teeth in most instances to settle in nonorthodontic normal's studied by Andrews. He altered the prescription of the Andrews appliance to allow the teeth to be placed in a slightly overcorrected position in all three planes. 3.

Swain altered the prescription of the Andrews appliance to what he thought would allow the teeth to be placed in a slightly overcorrected position in all three planes of space but not so far overcorrected that the 1 teeth would not “settle” into an idealized position . 4. Vari-simplex Brackets The Vari-Simplex Discipline includes a specific bracket system used in case treatment. Dr. Wick Alexander8 described it in the year 1978. The Vari-Simplex system is designed for 0.018” bracket slots and 0.017” wire. Though 0.022” brackets can also be used, he feels patient comfort is improved, treatment time is decreased, and the teeth are more easily moved into their proper positions with the 0.018” slot.

Broussard Bracket 1 It was developed by Garford Broussard . It is a conventional bracket with a closed, rectangular, vertical slot 0.018” by 0.046” which is formed when the bracket is welded onto the band material. Other Modifications: 1 SVED MODIFICATION SINGLE EDGEWISE BRACKET WITH VERTICAL SLOT SINGLE EDGEWISE BRACKET WITH VERTICAL SLOT AND NARROW LIGATURE SLOT SINGLE EDGEWISE BRACKET WITH VERTICAL SLOT AND WIDE LIGATURE SLOT LEE-FISHER EDGEWISE BRACKET MODIFIED LEE-FISHER EDGEWISE BRACKET

5. Bennett & Mclaughlin Technique The authors Richard P. McLaughlin & John C. Bennett9 introduced this technique, in the year 1995. They produced a “Theoretical Bracket Placement Chart” by measuring the distance from the incisal or occlusal edge to the centre of the clinical crown. Values at +0.5mm and +1.0mm were added for larger teeth, and values at -0.5mm and -1.0mm for smaller teeth. 6.

Preadjusted Edgewise Bracket In this bracket system the need for the first, second and third order bends has been reduced by producing a custom bracket for each tooth, in which a combination of varying thickness of bracket base, inclinations of slot and torque of the slot are used to minimize the wire bending for ideal archwire. These characteristics for each tooth are called the “appliance prescription” or “building treatment into the appliance”. 1.

2.

Andrews Prescription Dr. Lawrence F. Andrews6 introduced the Straight Wire Appliance to Orthodontic profession in 1970. His appliance was based on six keys to normal occlusion. He divided the appliance as nonprogrammed, partially programmed and fully programmed appliances. Non programmed brackets are without slot or base inclination. Partly programmed bracket contains 220 slot inclinations. Fully programmed brackets have 220 base inclination. The Roth Set-up The Roth Set-up7 was introduced in the year 1976. The purpose of the Roth setup was to provide idealized

Swain Modification of The Roth Set-up

Segmental Arch Technique Dr. Charles J. Burstone introduced this technique which uses the Medium Diamond Twin brackets of the Orthos prescription. His Vertical Tube Cuspid Bracket10 is very popular featuring an horizontal auxiliary tube.

7.

Bioprogressive Technique Dr. Robert Murray Ricketts 11 introduced the Bioprogressive therapy in the year 1976. There are 3 combinations - standard progressive setup where torque is built into upper incisor and all 4 canines, fulltorque setup where torque built in lower molars and premolars, triple-control setup with rotational control.

8.

Linear Dynamic System The linear dynamic System is a simplified version of the Bioprogressive11 therapy given by Dr. James J. Hilgers in the year 1987. According to him, if double or triple buccal tubes on upper or lower molars are used ideal orthodontic occlusion can be achieved.

9.

The Level Anchorage System It consists of a banded or bonded edgewise appliance with built-in tip, torque, and offset and an analysis and treatment-planning chart with a step-by-step treatment JIADS VOL -1 Issue 3 July - September,2010 |27|


procedure for seven different extraction and non extraction choices. 10. The “ORTHOS” System Dr. Craig Andreiko12 , applied computer-aided engineering technology to orthodontic appliance design in developing the Orthos System, truly incited a worldwide movement away from pre-adjusted appliances based on 1960s metrology. 11. The Bios System “Bios” is a light-wire, higher-torque version of the Orthos appliance system. Dr. Jim Hilgers designed the Bios system13 to allow for earlier torque control with lighter wires. It differs from the Orthos prescription by virtue of its increased torque in upper incisors and in the mandibular posterior segment, as well as lingual root torque in upper and lower cuspids. Lingual Brackets Dr. Kinya Fujita14 introduced the Mushroom arch wire appliance in the year 1979. In the lingual bracket, the opening of the slot was set on the occlusal surface of the teeth in order to facilitate the fitting of the wire. The groove for lockpin insertion was set mesiodistally in the slot and an auxiliary groove was set in the occlusogingival direction to facilitate correction of the mesiodistal tipping of the teeth. Self Ligating Brackets Self ligating brackets were introduced in the seventies with the Edgelok bracket. These brackets have the advantage of aesthetics and comfort. The possibility of puncture wounds from ligature ties is nil. The most common used brackets are “Mobil-Lok brackets”, “Insert bracket”, “SPEED brackets15”, “ Activa Brackets”, “Damon SL Brackets” , “Time Bracket” etc., Shortened chair time and slightly less incisor proclination appear to be the significant advantages of self-ligating system16 . Recently, the introduction of active and passive self-ligating brackets has presented a challenge to the speciality because of the novel ligation mode and the potential alterations in load and moment expression during mechanotherapy. Bioefficient Brackets Dr. Anthony D. Viazis designed the Bioefficient brackets17 in the year 1995. These triangular brackets are twin brackets with a single-slot type. It was designed to provide the first differential stiffness bracket to accommodate the new, differential-force superelastic wire. Adhesive Precoated Brackets The orthodontic resources of United and the adhesive expertise of 3M have combined to create the first Adhesive Precoated metal brackets. It does not set until it's light cured.

Bracket Materials gold.

The first orthodontic attachments were made of Since the introduction of Stainless steel it has


remained the most widely used material in the manufacture of orthodontic attachments. Plastics were introduced in the late sixties and ceramics have been introduced in the mid eighties. Titanium bracket have solved the problems of nickel sensitivity, corrosion, and inadequate retention. It's one-piece construction requires no brazing layer, and thus it is solder and nickel-free. TP orthodontics has introduced the Nu-Edge bracket in the year 1997. It uses cobalt chromium alloy that is essentially nickel free. Polycarbonate brackets were described and tested by Newman in 1969. Later,polyurethane, fiber-reinforced, and filler-reinforced brackets became available18 . They have limited popularity because of clinical problems of staining – rendering them unaesthetic, distortion and tearing of the bracket –particularly from torsional forces. More efforts are directed improving the strength of polycarbonate/ polymeric brackets by reinforcing the weak plastic matrix. These types of brackets are reinforced with ceramic, glass or even with metal inserts. Ceramic brackets were first introduced in 1987 and it has found wide acceptance and still holds more promise. The number of problems such as excessive bond strength, enamel fracture on debonding, brittleness of the bracket and surface finish has been largely addressed in the second generation of ceramic brackets. Magnetic brackets were introduced by Kawata et 19 al ., in 1987. The magnetic material that first employed clinically was a cast alloy consisting of 25% to 30% chromium, 15% to 25% cobalt, and 45% to 60% iron. Recently, a new material that contains a rare earth metal –samarium has been included in the magnet. The magnet has at the present time the highest availa ble coercivity and maximum energy product.

Bracket Width The wider the bracket, all other things being equal, the easier it will be to generate the moments needed to bring roots together at extraction sites or to control mesiodistal position of roots in general. The wider bracket reduced both the force needed to generate the moment and the contact angle, and is thus advantageous for space closure by sliding. Despite their advantage, wider brackets also have disadvantage. The wider the bracket on a tooth, the smaller the interbracket span between adjacent teeth, and therefore the shorter the effective length of the archwire segments between supports. The maximum practical width of a wide bracket is about half the width of a tooth, and even narrower brackets have an advantage when teeth are malaligned, because the greater interbracket span gives more springiness.

Bracket Slot Good torque is possible with steel wires and 18mil edgewise brackets. The original 22-slot would have some JIADS VOL -1 Issue 3 July - September,2010 |28|


advantage during space closure but would be a definite disadvantage when torque was later added. If only steel wires are to be used, the 18-mil slot system has advantage over the larger bracket size. NiTi alloys with springback and resistance to permanent deformation have overcome some of the alignment limitations of steel wires in 22 mil slo t brackets, while rectangular NiTi and Beta-Ti wires offer advantages over steel for the finishing phases of treatment and torque control17.

Bracket Bases One of the most important factors in retention of an Orthodontic bracket is type of bracket base. The most common bracket bases are perforated bases, foil mesh bases, photoetched bases and integrated cast type bases. The use of small, less noticeable, metal bases helps avoid gingival irritation. The wire size of the mesh as well as the size and topography of spot welds are also considered in bond strength. Today's favourite bases are die cut from laminates made of a fine mesh, pressed under heat to a foil that can have various thickness. A still promising forward step is the micromechanical retention, achieved by coating the bases with porous metal powder. Coating of bonding agents on bracket bases also increases retention. The coating process increases mechanical retention by creating undercuts on the top and sides of the wire mesh. The brackets are also silanated as a final step which creates higher additional bond strength due to chemical bonding of the bracket with the adhesive. Recycling Though there are still concerns about the possible increased risk of cross infection, yet recycled brackets are still used to reduce the cost per case. Brackets can be recycled either by application of heat to burn off the adhesive or by using chemical solvents to strip off the adhesive. Discusssion Although Orthodontia started to function without the use of brackets, yet today it has become an integral part of it. With the advent of aesthetic brackets and aesthetic archwires the field is becoming more refined day by day. But, still metal brackets have more advantages than aesthetic brackets in reducing the friction during retraction and also facilitates easy debonding procedures. The invention of self ligating brackets has shortened the treatment duration, reduces the patient visits and enhances better patient co-operation. The recent introduction of zirconia-based ceramics as a restorative dental material has generated considerable interest in the dental community. According to Koutayas SO et al20 ., zirconia based orthodontic brackets can be technologically feasible. Heravi F21 states that in future, the reduction in the


curing time and change in light direction may i ncrease the bond strength and reduce enamel fracture during debonding. The bracketless invisible aligner technique has been considered as a new developed orthodontic technique since its appearance during the period of late 1990s. According to Bai YX22 there have been many opportunities for further development and clinical application for this technique with the developments of material sciences, computer software and hardware technology, rapid prototyping techniques, et al. Regarding bracket materials, Eliades T23 states that manufacturing techniques might be modified to include laserwelding methods and metal injection molding. Esthetic bracket research will involve the synthesis of high-crystallinity biomedical polymers with increased hardness and stiffness, decreased water sorption, and improved resistance to degradation. Further, he describes that new plastic brackets might incorportate ceramic wings23. Sims MR24 has viewed the future of brackets from a technical point. According to him, in the next millennium, the genome revolution and knowledge of protein production and control could lead to the genetic correction of dentofacial anomalies and pain-free, biomolecular methods of malocclusion correction and long-term stability. A fundamental change would be in the abolition of bracket systems and their replacement with preprogrammed microchips driven by computers, and the control of PDL blood vessels and cells by pharmacological targeting. Future survival of this profession will depend on a radically different specialist who will be educated with a postgraduate curriculum based on molecular biology and 24 computer engineering . Summary And Conclusion Orthodontia has attained unmeasurable goals in the past century. Today, we are surprised to know that there was a period when Orthodontia was functioning without brackets. The advancement of the size, shape, material and technology of brackets of today is amazing. Hence, it is necessary for the Orthodontist to keep in pace with rapid changing technology of Orthodontic brackets and materials to be a successful clinician. Though various authors have predicted the future of brackets in their own ways yet at present tooth movements produced by bracket-archwire combination will be the ultimate method for years to come. Periodic reviews are necessary for the orthodontist to update his knowledge as well as to decide a better treatment plan and provide better comfort zone to the patient. This article has only reviewed the evolution of brackets. We suggest that many more review studies should come aiming at the biocompatibility, aesthetics and treatment results of each bracket. Such studies will help the practitioner to decide the bracket selection for his treatment plan. JIADS VOL -1 Issue 3 July - September,2010 |29|


Referrences: 1. 2. 3. 4. 5.

6. 7. 8. 9. 10. 11. 12. 13.

Tamizharasi P. Update of Orthodontic brackets.[Thesis]. India: Annamalai University; 1999. 3p. Tamizharasi P. Update of Orthodontic brackets.[Thesis]. India: Annamalai University; 1999. 184p. Begg & Kesling. Begg Orthodontic Theory and Technique. 100-1002 p. Flowers. Variations of Begg Technique. Am J Orthod Dentofacial Orthop. 1961;47(3):288-291 Peter C. Kesling. Expanding the horizons of the edgewise-arch wire slot. Am J Orthod Dentofacial Orthop. 1988;94(1):26-37.Andrews LF. The straight-wire appliance. Br J Orthod. 1979;6(3):125-43. Ronald H. Roth. The Straight-Wire Appliance. J Clin Orthod. 1987; 9:632642. R.G. Alexander. The Vari-Simplex Discipline: Part I – Concept and Appliance Design. J Clin Orthod. 1983; 6: 380-392. Richard P. McLaughlin & John C. Bennett. Bracket placement with the Preadjusted system. J Clin Orthod. 1995; 5: 302-311. Burstone. Horizontal tube cuspid bracket. Clinical Impressions 1996; 5: 3,11. Robert Murray Ricketts. Bio-Progressive therapy as an answer to orthodontic needs- Part I. Am J Orthod Dentofacial Orthop. 1976; 241-268. Dr. Craig Andreiko. Orthos. A New Technology that frees you to focus on the art of Orthodontics. Clinical Impressions. 1995; 3-7, 5-8. Hilgers. Bioprogressive Simplified. Part 2-The Linear Dynamic System. J Clin Orthod. 1987; 10: 716-34. Kinya Fujita. New Orthodontic treatment with lingual bracket mushroom arch wire appliance. Am J Orthod Dentofacial Orthop. 1979; 76(6): 656-675.


14. G. Herbert Hanson. The SPEED System: A report on the development of a new edgewise appliance. Am J Orthod Dentofacial Orthop. 1980; 78(3) 243-65. 15. Stephanie Shih-Hsuan Chen et al. Systematic review of self-ligating brackets. Am J Orthod Dentofacial Orthop. 2010; 137(3): 362-7. 16. R. G. Alexander. The Vari-Simplex Discipline: Part I – Concept and Appliance Design. J Clin Orthod.1983;6:380-392. 17. Julia Krauss, Andreas Faltermerier. Evaluation of alternative polymer bracket materials. Am J Orthod Dentofacial Orthop. 2010; 137(3); 362-7. 18. Kawata, Hirota, Sumitani et al. Clinician's corner – Property of Magnetic brackets. Am J Orthod Dentofacial Orthop. 1987; 9:241-248. 19. Koutayas SO, Vagkopoulu T, Pelekanos S, Koidis P, Strub JR. Zirconia in dentistry: part 2. Evidence – based clinical breakthrough. Eur J Esthet Dent. 2009 Winter; 4(4):348-80. 20. Heravi F. Bayani S. Changes in shear bond strength of ceramic and stainless steel brackets with different visible light curing times and directions. Aust Orthod J. 2009 ;25(2):153-7. 21. Bai YX, Wang BK. Opportunities and challenges during the development of the orthodontic invisible aligner technique(in Chinese). Hua Xi Kou Qiag Yi Xue Za Zhi 2007; 25(6): 521-4. 22. Eliades T. Orthodontic materials research and applications: part 2. Current status and projected future developments in materials and biocompatibility. Am J Orthod Dentofacial Orthop. 2007; 131(2): 253-62. 23. Sims MR. Brackets, epitopes and flash memory cards: A futuristic view of clinical orthodontics. Aust Orthod J. 1999; 15(5): 260-8.

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Evolution of Brackets

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