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Evolution of orthodontic appliances /certified fixed orthodontic courses by Indian dental academy


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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats. …

The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

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  • ‘’
    “MEN will never barter their souls or spill blood for it ; yet this time-tested stainless steel,with the single exception of intrinsic value offers more desirable characteristics to the fine-metal worker yhan do the precious metals themselves. The craftsman asks only that his material be chemically INERT , naturally beautiful, strong yet amenable to his artistrty ; it is the buyer who measures precious metals by price.”
  • Transcript

    • 2. INDIAN DENTAL ACADEMY Leader in continuing dental education
    • 3. INTRODUCTION  The word orthodontics is derived from two greek words , ORTHOS meaning RIGHT OR CORRECT; and ODONTOS meaning TOOTH. AND the term “ DENTOFACIAL ORTHOPAEDICS “ was suggested …….. By NORMAN BENNET. ORTHODONTICS may be described as the study of growth and development of the masticatory apparatus and the prevention and treatment of abnormalaties of this
    • 4. Orthodontics has made tremendous strides as a specialised branch of Dentistry. In fact, it was the FIRST Bonafide dental speciality with the SECOND oldest qualifying Board in ALL of DENTISTRY and MEDICINE. ORTHODONTICS was then considerded a part of the regular prosthetic course, and accorded SECONDARY CONSIDERATION. This academic affliation still exists, in some areas of the world, and indicates a primarily mechanical
    • 5. orientation of orthodontic philosphy and treatment procedures. Fortunately, the development of orthodontics as a speciality has been more successful. Orthodontic therapy depends upon the reaction of the teeth, and more generally the facial structures to a gentle but persistent force. Orthodontic treatment is based on the principle that if prolonged pressure is applied to a tooth, tooth movement will occur and the bone around the tooth remodels.
    • 6. The term EVOLUTION according to dictionary means –’’ any process of FORMATION OR GROWTH; DEVELOPMENT. And an ORTHODONTIC APPLIANCE can be defined as— appliance by means of which mild pressure may be applied to a tooth or a group of teeth in a predetermined direction.
    • 8. “MEN will never barter their souls or spill blood for it ; yet this time-tested stainless steel, with the single exception of intrinsic value offers more desirable characteristics to the fine-metal worker than do the precious metals themselves. The craftsman asks only that his material be chemically INERT , NATURALLY BEAUTIFUL, STRONG yet amenable to his artistry ; it is the buyer who measures precious metals by PRICE.”
    • 9. the starters  Like metallurgy, dentistry has a long history of artistic creativity . Over 4500 years ago when the metal worker was sweating copper from malachite for weapons, making primitive tools from “bia n pet” (meteoric iron), and separating GOLD from crushed quartz stone literally using what became known as the GOLDEN FLEECE, the “TOOTHER” was likely splinting the teeth of the Egyptian court.
    • 10.  Time passed from the Bronze Age to the Iron Age and the industrial Revolution until, in the latter half of the 19th century , Henry Clifton Sorby (1863-1887) and Edward Hartley Angle (1886-1930) professionally ascended to become the pioneers of modern Metallography and modern orthodontics, respectively. Yet from all these artistic developments , the formalized scientific under standing of both fields was limited to about the last 100 years .
    • 11. THE BEGINNINGS  Teeth were regarded by the ancients as very precious to the extent that “ . . . Special penalties [ were exacted ] for knocking out the teeth of an individual, either freeman or slave.” As early as 400 B.C , Hippocrates referenced in his writings the correction of tooth irregularities . And while Greece was in its Golden Age , the Etruscans ( the precursors of the ROMANS) were burying their dead with appliances that were used to maintain space and prevent collapse of the dentition during life. Then in a roman tomb in Egypt
    • 12. Breccia finds a number of teeth bound with a GOLD WIRE , and at the time of CHRIST , Aurelius Cornelius Celsus first records the treatment of teeth by FINGER PRESSURE. Thus , inherent malocclusions and the use of corrective force are recognized, the virtue of maintaining space is appreciated, and the first orthodontic material is documented – a gold ligature wire… IN All these early references , it was clearly evident that the interest in treating irregularities of the teeth was purely esthetic.
    • 13. EARLY CONTRIBUTORS The FRENCH and ENGLISH dominated the earliest contributions to the field of orthodontics , which as yet had not been formally named. Among these contributors is PIERRE FAUCHARD (1723) who Invents the expansion arch and gives the first comprehensive discussion of appliances . The reputed father of dentistry details the use of ligature wires and gold or silver mechanical devices . He corrects teeth using finger pressure and silk thread and intuitively recognizes that the source of a force does not matter in mechanotherapy .
    • 14.  In 1819 Delabarre introduces the wire crib,and this marks the BIRTH of CONTEMPORARY orthodontics. Later, Schange would show that the gold wire crib afforded adequate anchorage and formed a base for attachments. A century later,Lufkin would state that “...Schange made an invaluable contribution” because it really marked the beginning of
    • 15. EDGEWISE. In the second half of 19th century(1865), Kingsley advocates plates as retaining devices. In the early part of 20th century, Angle would tout this device as one of the best tooth maintainers. Fifteen years later Kingsley would write his book, “ORAL DEFORMITIES”, which would become the most comprehensive text on the subject in its day.
    • 16. In 1877, Johnston would recommend placing Zinc in a predrilled hole of a steel jackscrew, which was simultaneously invented by Dwinelle and Gaine (1849), to “… give it the same immunity from oxidation as gold or platinum.”Modern books term this the concept of the ‘ SACRIFICIAL ANODE’.
    • 17. the enlightenment In 1908,Norman William Kingsley already called Angle “…one of the greatest empirics of his day”. Angle identified and lauded many people who sought the truth – Fauchard,Fox,Harris,Kingsley, Magill,Schange and Wescott; .He also criticized and wrote scathing letters to those he thought were poisoning the newly formed practice of “ORTHODONTIA” as it was called in 1917 . He particularly admired Kingsley who , like Farrar
    • 18. (1926),was hailed by his contemporaries as “the father of orthodontia.”Kingsley made particularly substantive contributions to our knowledge of occipital anchorage, which in that period would have been using elastic straps, forged Stubbs’ steel,and a swaged silver plate.
    • 19. On the other hand, a material was the proximate cause of the rift between those who used heavy and bulky NICKEL-SILVER appliances(the german school) and Angle and his contemporaries. In 1906, Angle and most of his graduates resigned from the society, in part because of their difference towards nickel- silver alloys( ie, German silver or“NEUSILBER”), which were first introduced by Angle to the U.S in 1887 but which were actually Copper, Nickel, and Zinc Alloys that contained no Silver.
    • 20. Composition of ALLOYS used during 20th century
    • 21. During this period, Gold, Platinum, Silver, Steel, Gum rubber, Vulcanite and, occasionally, Wood,Ivory, Zinc and Copper were used as was brass in the form of loops, hooks, spurs and ligatures. 14-18 -karat Gold was routinely used for wire bands, clasps, ligatures, and spurs,as were iridiumplatinum bands and archwires and Platinized gold for brackets. The advantage of gold was that you could heat treat it to variable stiffness(30%) , which was comparable to today’s beta-titanium alloy. This was accomplished by heating at 450°C(842°F) for 2
    • 22. REPORTED PROPORTIES of ALLOYS used during 20th century
    • 23. minutes, cooling to 250°C(482°F) over a period of 30 minutes, and finally quenching to room temperature. Gold has excellent corrosion resistance too. In 1920, Dewey presents a paper on clock spring auxiliary as an “Application of spring forces from Gold and Platinum removable Appliances.” This presentation was credited as being the long awaited response to the nickel-silver appliances that caused the rift 14 years earlier.
    • 24. Finally, in the Dental cosmos(1928) we see the design of what was to be known as the edgewise appliance which was never formally named by EDWARD ANGLE in his lifetime.
    • 25. EDGEWISE PARAPHERNALIA OF 1928 WINGLESS BRACKET Without an archwire engaged With an archwire engaged
    • 26. EDGEWISE PARAPHERNALIA OF 1928 PROTOTYPE OF MODERN BRACKET Without an archwire engaged With an archwire engaged
    • 27. Type of STAPLE THREADED WASHER used as spacer LIGATURE WIRE
    • 28. On Aug 11,1930,EDWARD ANGLE passed into history. As a tribute to him, we should recognize that in a 40 year career, he truly did understand patients and their tissues , had knowledge of Biology and engineering, comprehend mechanical requirements, and contributed 4 distinct Biomechanical Appliances– the Angle E arch(1909), the pin and the tube appliance(1911), the ribbon arch(1915), and the edgewise appliance in the year 1925 .
    • 29. No one has yet eclipsed those accomplishments. One could readily argue that Edward Angle was one of the first biomedical engineers. Yet with all these accomplishments, Angle was not the great innovator of novel materials– others would fulfill that role.
    • 30. STAGNATION ABOUNDS From the 1930s to the1960s the proliferation of materials did not occur. With the death of Angle, a time of stagnation eventuates .AS THUROW said, “…the ‘edge-wise men’ literally rode off in all directions at once” what became more important at that time because of their lack of development were CEPHALOMETRICS AND BIOLOGICAL ASPECTS. And so for a while, those fields of knowledge were emphasized, as profound changes to orthodontics occurred at the expense of novel materials
    • 31. and innovative mechanics .It is during this period that BEGG gives this warning to the orthodontic community: “Orthodontics is ill-served by presentation of new orthodontic techniques that are claimed to be based on adaptations of engineering principles but that have not been proven suitable for successful treatment of patients.” During this materials stagnation, we learn that gold alloys have deficiencies too. At the 1931 meeting of the American Association of Orthodontists (AOO), Norris Taylor and George Paffenbarger discussed
    • 32. wrought alloys and intimated that more springiness and fewer cracks at tension points were possible. And at nominally $30 per ounce,Kelsey said that they were costly. Little did they know that the cost of gold would spike to $900 in early 1980.! By the early 1930s, stainless steels were generally available. Although Dumas, Guillet, and Portevin first made stainless steel in France, its “stainless” qualities were first reported inGermany by Monartz
    • 33. also around 1900-1910. Stainless steel languished until World War 1 spurred the development of 3 different kinds of stainless steels, and ironically those developers received the credit for the discovery. During that war, the Germans, British, and Americans developed an austenitic, a martensitic and a ferritic stainless steel, respectively. On the other world, in the early 1940’s, Begg would partner with Wilcox to make what they envisioned to be the ultimate in resilient orthodontic wires– Australian stainless steels.
    • 34. Yet it was not until about 1960 that stainless steel was generally accepted. Nonetheless, in 1933 we find that stainless steel and a chromium alloy are being used, as Archie Brusse (the founder of rocky mountain metal product) -- and so the struggle between gold and stainless steel formally begins.
    • 35. PRODUCTS made from ALLOYS that orthodontics adopted 1936 FORD SEDAN made from stainless steel
    • 36. MAINSPRING of WATCH fabricated from COBALT CHROMIUM alloy
    • 37. HYDRAULIC shape-MEMORY COUPLING manufactured from NICKEL-TITANIUM intermetallic composition
    • 38. SR-71 BLACKBIRD constructed from TITANIUM-MOLYBDENUM alloy
    • 39. Regarding Acrylics, unaesthetic Vulcanite plates with 1.02mm(0.040inch) resilient gold wires were replaced by translucent acrylic plates soon after acrylic’s discovery in 1937. Although Cellulose, Phenol formaldehyde vinyl polymers and copolymers, styrene, and alkyd resins were explored, by the 1940s, acrylic materials were being poly-merized into plates by reacting, under heat and pressure, doughs made from Methyl methacrylate monomer and acrylic powder the latter of which reduced shrinkage.
    • 40. Ultimately, acrylic was so successful that in 1946, 98 % of all denture bases were constructed of this polymer or of its copolymers. Today acrylic is the most frequently used material for retainers – they be a Hawley or a lingual-wire retaining device.
    • 41. What Kingsley(1908) said almost 100 years ago still rings true today – that “… the success of orthodontia as a science and an art now lies in the retainer”. But again stainless steel which is gaining prominence as the soft ligature wire, which was credited to Angle, is now displaced by an 0.254mm(0.010-inch) soft stainless steel wire. Only 3 years later ,Steiner introduces the 0.457mm×0.711mm (0.018-inch ×0.028 inch) slot for stainless steel wires in lieu of the 0.599mm ×0.711mm(0.022-inch×
    • 42. 0.028-inch) slot for gold alloys. And even Jackson proposes to eliminate the Crozat appliance by fabricating it in stainless steel and a nickelchromium alloy (TOPHET metal) but still gold crozat appliance survives to today.
    • 44. a SPEED self-ligating STAINLESS STEEL bracket
    • 45. The STARFIRE single-crystal SAPPHIRE bracket
    • 46. An ALLURE polycrystalline alumina bracket
    • 47. To close out this age, a glimmer of things to come is seen as Buonocore proposes the use of 30- second,85% phosphoric acid etch to enhance bonding of acrylic materials to enamel surfaces. It is now 1958, and DEWEL unifies the practice and science under one aegis
    • 49. PROLIFERATION ABOUDS By the 1960s, gold was universally abandoned in favor of stainless steel. This is how stainless steel was marketed in lieu of gold1) the force per unit activation of stainless steel was greater than that of gold (ie, high stiffness was an advantage) (2) by being smaller in size, stainless steel appliances were regarded as being more esthetic than gold appliances (ie, the smaller the appliance is, the more it appears to disappear). Stainless steel also had excellent corrosion resistance,
    • 50. work hardening capabilities, and a frictional magnitude that was so low that it became the standard of the profession. A FULLY BANDED PATIENT WITH EXTENSIVE STAINLESS STEEL (SS) LOOP MECHANICS IN THE YEAR 1965
    • 51. In the 1960s, bracket bands are disappearing as the bonded miniature bracket appears – thereby punctuating the beginning of esthetic orthodontics. Polycarbonate Brackets with Teflon coated Stainless Steel wire
    • 52. Again in the 1960s cobalt-chromium alloys are introduced. This alloys not only contain cobalt, chromium, and molybdenum but also substantial amounts of nickel and iron. This alloy have high stiffness, and available in 4 different tempers and are
    • 53. heat treatable and thus it permits variable amounts of Formability which is required to place loops, Vbends and various offsets into the archwire. Once deformation is complete, however, heat treatment increases the resilience of the wire by a recommended precipitation- or age-hardening process at 482°C(900°F) for 7-12 minutes.
    • 54. In 1962 Buehler discovers nitinol at the Naval Ordinance Laboratory, so-called because it was acronym for NickelTitanium Naval Ordinance Laboratory. Nitinol has the lowest modulus for any cross section and has the most extensive deactivation (range) capabilities. Now light forces can be offered over a protracted range as any of four combinations of passive or active behaviour and of martensitic or austenitic phase are possible. In some cases the thermoelastic or the pseudoplastic effects(or) both are also exploited, the latter of which is also termed Superelastic, in part because the
    • 55. material has so much springback after displaying what appears to be pure plasticity. By 1970 Andreason brings the intermetallic composition of 50% nickel and 50% titanium to orthodontics through the university of Iowa. By 1986, two “superelastic” alloys are offered– a japanese NiTi and a chinese NiTi. These are active austenitic alloys that form stress-induced martensite. Most recently, nickel-free, titaniumniobium wires have been introduced as a finishing wire.
    • 56. Returning to other materials of the 1970s elastics of all sorts find their niches in the orthodontic profession. Gum elastics were first employed by Maynard(1843); Tucker (1850) was the first to cut rubber bands from rubber tubing. Plastic coatings on archwire occur too. One such coating, poly(tetrafluoroethylene) or teflon has the lowest friction. When this quite soft material is placed in the hostile mechanicochemical
    • 57. environment of the oral cavity, the coating skins off or disappears in as little as 3 weeks. Self-ligating or ligatureless brackets reappeared in the mid 1970s as strite,Ltd, marketed them; these brackets had a stainless steel body and a positive-locking ,spring-clip mechanism. Their advantage was that unlike conventional ligation, friction is purportedly reduced– but most importantly, friction becomes more reproducible.
    • 58. In 1977 the beta phase of titanium was stabilized at room temperature, and the aerospace titaniummolybdenum alloy (β-ΙΙΙ) was produced. This beta-titanium alloy has a modulus closet to that of traditional gold along with good springback, formability , and weldability. By the end of 1970s, four major groups of wire materials came into existence, 3 of developed different amounts of range for a given constant force or if you kept the same range
    • 59. for a given constant deactivation. As a consequence, the armamentarium has expanded from just gold or stainless steel and two slots have been popularized – the 0.559mm (0.022-inch) slot , which was originally used for gold, and the 0.457mm (0.018-inch)slot, which was advocated for stainless steel. Within the capabilities of the present armamentarium, both slots become viable alternatives.
    • 60. CONSOLIDATION OCCURS In the 1980s we have esthetic brackets made from single-crystal sapphire and from polycrystal-line alumina– both having the same inert chemical composition, Al2O3. We also have brackets made from polycrystalline zirconia material,ZrO2 , which reportedly has the greatest toughness among all ceramics. Unfortunately, both these materials inhibit sliding mechanics and they have debonding problems. The single-crystal brackets also exhibit specular
    • 61. highlights, where as some polycrystalline ZrO2 have intrinsically odd colours. In the early 1990s the first pseudocomposite wire from optical fibers is marketed, which financially is a failure. from these examples, we can see that this was clearly a period of consolidation, as practitioners were balking from products that just did not work very well (as was the case in the1970s for the early Nitinol wires).
    • 62. and manufactures were being compelled either to improve them or remove them from their inventories. Such was the case for early singlecrystal sapphire brackets because during torquing, the tie-wings tended to break off or, worse yet, removed facial enamel from the teeth. Moreover, when placed on mandibular incisors or canines, for ex; ceramic brackets abraded or chipped the opposing maxillary teeth. As if this was not enough, ceramic brackets in combination with any archwire, except nickel-titanium, always produced the highest frictional forces, whether in the dry
    • 63. or in the wet state. Furthermore, optical fibers, whether coated with nylon or hot-melt adhesives, had such low stiffness properties that they qualified as a “placebo” wire that would only acclimate a patient to the general architecture of his or her appliances. Such a poor performer would later handicap fiber-reinforced composites in the corporate mind of orthodontic manufacturers.
    • 64. EXTRA-ORAL APPLIANCES Extra oral forces in the form of hedagears and chincups, very similar of those of today was used by orthodontists of the late 1800s. Both Kingsley and Angle described and used astonishingly modern appearing appliances of this sort with reasonable success. As orthodontic progressed in the early 20th century, extra oral appliances and mixed dentition treatment were abandoned because they were considered an unnecessary
    • 65. complication. A paper in 1936 by OPPENHEIM revived the idea that headgear would serve as a valuable adjunct to treatment. Rapid development in headgear treatment followed in 1950s and 1960s. with the demonstration in the 1960s of skeletal changes from headgear force to the maxilla, interest in chin cups revive.
    • 66. Until the 1970s, face mask to bring the maxilla forward were dismissed as ineffectual . The French surgeon DELAIRE, working on cleft palate children, demonstrated that the maxilla can be moved forward if the protracting forces on the maxilla are used at early ages. Facemask therapy is an area of continuing innovations in treatment in present and it may yet offer a more satisfactory way of treating maxillary deficiency problems than in the PAST.
    • 67. FUNCTIONAL APPLIANCES The MONOBLOC developed by ROBIN in the early 1900s is generally considered as the forerunner of all functional appliances, but the ACTIVATOR developed in norway in 1920 by VIGGO ANDERSON was the first functional appliance to be widely accepted. Andersons activator became the basis of “norwegian system” of treatment .Both the appliances system and its theoritic underpinnings were improved and extended elsewhere in
    • 68. Europe, particularly by the German school led by HAUPL. HERBST APLIANCE This appliance was first developed in the 1920s and re-introduced recently by PANCHERZ and this is the only FIXED FUNCTIONAL APPLIANCE. The appliance requires little patient compliance and produces a highly variable mixture of skeletal and dental changes.
    • 69. FIXED APPLIANCE According to angle, the first importance in the evolution of fixed orthodontic appliance was the “BOW OF FAUCHARD” of france. This bow ,affixed to the external surface of the teeth, was the forerunner of the modern archwire. MAGILL was the first to use a plain band cemented to the tooth by oxychloride of zinc cement. It was on the foundation of the circumferential archwire and the plain cemented tooth band that modern
    • 70. THE COMING OF A NEW AGE AS we enter the1990s we look back on that century in terms of various type of overall innovations. We had the auto, aviation, polymer, nuclear, space, and computer ages. Indeed, it has been said that more knowledge was amassed in the 20th century than in all previous centuries of mankind. And what we learn about orthodontic materials comes from many of those burgeoning fields. From the viewpoint of true esthetics– in other words
    • 71. from the viewpoint of not making things smaller but of making them TOOTHcoloured. Practitioners assert that esthetics are desirable but that function is paramount. And so we close this century we begin to see attempts to market a continuous fiber composite, success to manufacture CP-titanium and its products and modifications to improve sliding mechanics through ceramic-bracket inserts and self-ligating brackets.
    • 72. CONCLUSION ORTHODONTICS has achieved the status of a recognized specialty of dentistry because of a long period of craftsmanship and professional expertise. While it appears that a certain stagnation has set in the other specialties of dentistry at this time , that is not to be perceived in orthodontics, where a great deal of development is still going on.
    • 73. Orthodontics, and indeed all of dentistry if it is to survive as a profession must continually re-examine its history and find relevant and significant ideals to meet the crisis of today.
    • 74. Thank you Leader in continuing dental education