Essentials of Orthodontics Aravind Sivaraj
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IntroductionCHAPTER 1

The term orthodontia was apparently used first by the Frenchman Le Foulon in 1839. The name of the specialty Orthodontics comes from two Greek words “ortho” meaning right or correct “odontos” meaning tooth and “ics” meaning science.
Orthodontics is the branch of dentistry concerned with prevention, interception and correction of malocclusion and other developmental abnormalities of the dentofacial region.
British Society for Study of Orthodontics (1922)
“Orthodontics includes the study of the growth and development of the jaws and face particularly, and the body generally, as influencing the position of the teeth; the study of action and reaction of internal and external influences on the development; and the prevention and correction of arrested and perverted development.”
Proffit (1975)
“Orthodontics is the area of dentistry concerned with the supervision, guidance and correction of the growing and mature dentofacial structures, including those conditions that require movement of teeth or correction of malrelationships and malformations of related structures by the adjustment of relationships between and among teeth and facial bones by the application of forces and/or the stimulation and redirection of the functional forces within the craniofacial complex.”
American Association of Orthodontics (1993)
American Association of Orthodontics (AAO) renamed the specialty from Orthodontics to Orthodontics and Dentofacial orthopedics in 1984. They modified the definition of orthodontics in 1993 as, “The area and specialty of dentistry concerned with the supervision, guidance and correction of the growing or mature dentofacial structures, including those conditions that require movement of teeth or correction of malrelationships and malformations of their related structures and 2the adjustment of relationships between and among teeth and facial bones by the application of forces and/or the stimulation and redirection of functional forces within the craniofacial complex. Major responsibilities of orthodontic practice include the diagnosis, prevention, interception and treatment of all forms of malocclusion of the teeth and associated alterations of their surrounding structures; the design, application and control of functional and corrective appliances; and the guidance of the dentition and its supporting structures to attain and maintain optimal occlusal relations, physiologic function and esthetic harmony of facial structures.”
Orthodontist (Orthodontic Specialist)
A graduate of an accredited dental school who additionally has followed a postgraduate full-time academic program in orthodontics, in accordance with the requirements of his/her national, state, or provincial law. The duration of the postgraduate orthodontic training varies in different countries or areas of the world. For example, in the USA a two-year full-time academic training beyond general dental school is required to obtain the title of orthodontist, whereas in the European Union and India the minimum requirement is three years.
Branches of Orthodontics
Orthodontics can be broadly divided into:
Preventive Orthodontics
It is the action taken to preserve the integrity of what appears to be normal at a specific time.
Interceptive Orthodontics
It is that phase of science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions in the developing dentofacial complex.
Corrective Orthodontics
Corrective orthodontics recognizes the existing malocclusion and the need for employing certain technical procedures to reduce or eliminate the problem and the attendant sequelae.
Surgical Orthodontics
They are the surgical procedures that are undertaken in conjunction with or as an adjunct to orthodontic treatment.
Aims of Orthodontic Treatment
The aims and objectives of orthodontic treatment has been summarized by Jackson as Jackson's triad, they are:
  1. Functional efficiency: The orthodontic treatment should aim at improving the functions of the stomatognathic system, as many malocclusions tend to alter the normal functions.
  2. Structural balance: Orthodontic therapy should maintain a structural balance between hard tissues of teeth and bones to that of soft tissues of muscles and tongue.
  3. Esthetic harmony: Many malocclusions are associated with poor facial appearance and dental esthetics; hence orthodontic treatment should aim at improving the esthetics of face and teeth.
Unfavorable Sequelae of Malocclusion
Malocclusion leads to many problems that can be listed as:3
  1. Unfavorable psychological and social squeal.
    1. Introversion, self-consciousness.
    2. Response to uncomplimentary nick-names like Bugs bunny, Buckteeth or Bucky beaver.
  2. Poor appearance: Interference with normal growth and development and accomplish-ment of normal pattern
    1. Cross bites causing facial asymmetries.
  3. Improper or abnormal muscle function
    1. Compensatory muscle activities such as hyperactive mentalis muscle activity, hypoactive upper lip, increase buccinator pressures and tongue thrust that occurs as a result of spatial relationship of teeth and jaws.
      These activities are unfavorable and serve to increase the departure from normal.
  4. Associated muscle habits
  5. Improper deglutition
    1. Changed function as a result of adaptive demands
  6. Mouth breathing
  7. Improper mastication
  8. Speech defects
  9. Increased caries incidence
  10. Predilection to periodontal disease
  11. Temporomandibular joint problems: Functional problems
  12. Predilection to accidents
  13. Impacted and unerupted teeth, possible follicular cysts, damage to other teeth
  14. Prosthetic rehabilitation complications: Space problems, teeth tipped and receiving abnormal stress.
Need for Orthodontic Treatment
Orthodontic treatment is required to:
  1. Improvement of esthetics
  2. Restoration of proper function of teeth
  3. Reduction of susceptibility of dental caries
  4. Elimination of pathological conditions of the gingival and periodontal tissues caused due to malocclusion of teeth
  5. Correction of malposed teeth prior to construction of partial denture or bridgework
  6. Elimination of harmful habits
  7. Prevention and correction of tempo-romandibular joint abnormalities
  8. To correct speech defects
  9. Decompensation before taking up the case for surgical correction
  10. Additional treatment after surgical correction of congenital deformities and skeletal malocclusions
  11. As a result of accidental injury, loss of teeth or interference with occlusions may make orthodontic treatment necessary
  12. To improve the personality of an individual.
Scope of Orthodontic Treatment
The scopes of orthodontic treatments are:
Orthodontic tooth movement: Application of forces are responsible for altering the tooth positions, dental malocclusions are treated effectively by altering the tooth positions. Orthodontics is mainly employed to alter permanently the tooth positions. Tooth movement can be undertaken in all three planes, transverse, vertical and sagittal.
Dentofacial orthopedic growth modification: Malocclusions associated with skeletal disharmony can be corrected to normal by application of orthopedic forces which are capable of redirecting, modifying and restraining skeletal growth patterns.
Altering the soft tissue patterns: Favorable changes can be brought about in the soft tissues by orthodontic treatment that are 4responsible for normal development and maintenance of dentition and skeleton.
Orthodontics is considered as the oldest specialty of dentistry. Evidences suggest that attempts were made to treat malocclusion as early as 1000 BC. Primitive appliances to move teeth have been found in Greek and Etruscan excavations.
The Greek physician Hippocrates (460–377 BC) is believed to be the father of medicine. He is the first person to establish medical tradition based on facts rather than religion of rancy. A number of references on teeth and jaws are found in his writings.
Aristotle (384–322 BC) was a Greek philosopher who gave medical science the first system of comparative anatomy; he compared human teeth with other species.
The first recorded suggestion for active treatment of malocclusion was by Aulius Cornelius Celcus (25 BC–50 AD) who advocated the use of finger pressure to move the teeth.
Pierre Fauchard, a French dentist, is considered the founder of modern dentistry and he is known as Father of Dentistry. As early as 1723, he developed what is probably the first orthodontic appliance called a Bandelette that was designed to expand the dental arch.
Norman Kingsley, an American dentist, was the first to use extraoral force to correct protruding teeth. He is considered as one of pioneers in cleft palate treatment.
Emerson C Angell (1823–1903) was the first person to advocate the opening of the mid palatal suture, a procedure that later came to be known as rapid maxillary expansion.
William E Magill (1823–1896) was the first person to band teeth for active tooth movement.
Henry A Baker in 1893, introduced what is called Baker's anchorage or the use of intermaxillary elastics to treat malocclusion.
Edward H Angle (1855–1930) (Fig. 1.1) is considered the Father of Modern Orthodontics for his numerous contributions to this specialty. Through his leadership, orthodontics was separated from other branches of dentistry to establish itself as a specialty. Angle's contributions include a classification of malocclusion and orthodontic appliances such as Pin and tube appliance, E-arch, Ribbon arch and Edgewise appliance. Angle also started a school of Orthodontics in St. Louis, New London, Connecticut in which many of the pioneer orthodontists were trained. Angle believed that the whole compliment of teeth could be retained and yet good occlusion could be achieved. He thus advocated arch expansion for most patients.
Calvin S Case (1847–1923) believed that facial improvement was a guide to orthodontic treatment. Case also claims to be the first orthodontist to use intermaxillary elastics. He was a critic of Angle and opposed Angle's philosophy of arch expansion to treat most cases.
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Figure 1.1: Edward H Angle
He advocated the removal of certain teeth to achieve stable treatment results and to improve facial esthetics.
Martin Dewey (1881–1933) was an ardent champion of nonextraction. Dewey also modified Angle's classification of malocclusion.
In 1931, Holly Broadbent and Hofarth independently developed cephalometric radiography, which standardized the positioning of the head in relation to the film and X-ray source. This can be considered a major advancement in orthodontic diagnosis and treatment planning.
Buonocore in 1955, introduced the acid etch technique; this enabled direct bonding of orthodontic attachments to the enamel which greatly enhanced esthetics.
Raymond P Begg of Australia introduced a light wire fixed appliance that was based on the concept of differential force. He also advocated the need for extraction of some teeth to achieve stable results.
While American orthodontists were showing keen interest in improving fixed orthodontic appliances, their European counterparts continued to develop removable and functional appliances for guidance of growth.
Pierre Robin in 1902 introduced monoblock, which protruded the mandible in cases of glossoptosis.
Viggo Anderson in 1910, developed the activator, which made use of the facial musculature to guide the growth of the jaws.
Rolf Frankel in 1969, proposed the function regulator to treat variety of skeletal malocclusions.
Lawrance F Andrews introduced the Straight Wire Appliance in 1972; this was a preadjusted appliance in which the brackets were pre-programmed to accomplish the desired tooth movements in all the three planes of space. This is considered a major advancement in improving orthodontic treatment results with minimal possible wire bending.
In India, the first dental college, Calcutta Dental College and Hospital was started in the year 1920 by Dr Rafiuddin Ahmed in his private chamber. Dr Ahmed, the Father of Dentistry in India is also known as “The Grand Old Man of Dentistry”. He is credited with the first edition of “The Indian Dental Journal” in October 1925, foundation of the “All India Dental Association” in the year 1927, drafting and passing of the Bengal Dentist Act in 1939, and the passing of the Indian Dentist Act in 1948.
Dentistry as a subject was introduced as a 2 years diploma course to “Licentiate in Dental Science (LDSc). It was changed to the 3 years course in the year 1926 and further modified to the present 4 years BDS course in 1935.
In his work Le Chirurgien Dentiste, Pierre Fauchard (Vannes 1678-Paris 1761) laid the foundations of orthodontic science. Among other things, he illustrated a number of orthodontic treatises and a rudimental orthodontic expansion device called a bandelette, the invention of which was without attribution because it had been use for some time. This brace consisted of a band of silver stabilized with metal or plant-fiber bindings. He also described the surgical straightening of individual teeth.
Te term orthopedics in reference to the stomatognathic apparatus appe ared for the first time in L' Orthopédie ou l'Art de Prevenir et de Corriger dans les Enfans les Difformités du Corps by Nicolas Andry De Bois Regard (1658–1672).
John Hunter (Long Calder wood 1728-London 1793), an anatomist and surgery teacher, devoted three cha pters of his Natural History of the Human Teeth to malocclusions, even proposing a classif cation of them.
A chin cup for nonorthodontic purposes was first described by Francois Cellier, who used it to prevent postex-traction hemorrhage.
Joseph Fox (1776–1816), a student of Hunter, published ‘Te Natural History of the Human Teeth-Describing the Proper Mode of Treatment to Prevent Irregularities of the Teeth'.
JB Lamarck (1744–1829), a zoologist, wrote of the importance of function in the development of organs and the species, forerunning Wilhelm Roux's theories on functional adaptation.
Michael Faraday prepared the first iron—chromium alloy, a precursor of stainless steel.
LJ Catalan (1776–1830) utilized the principles and method of the inclined plane.
CF Delabarre, (1777–1862), in his Meth-ode Naturelle de Diriger la Seconde Dentition, accurately des cribed tooth transition, emphasizing the importance of primary teeth.
In his Manual of Human Anatomy, JF Meckel (1781–1833) described the cartilage of the first branchial arch.
William Imrie named thumb-sucking as an etiologic role in malocclusions.
F Kneisel (1797–1883) published Der Schiefstand der Zähne, the first work in German on malocclusions.
Te American Journal of Dental Science, the first journal devoted entirely to dentistry.
A French scholar, Jacoues Lefoulon, coined the term orthodontosie in a series of articles on “Orthopedia dentaire”, which appeared in the Gazette des Hopitaux.
C Goodyear (1800–1860) discovered that natural rubber hardens when combined with a small amount of sulfur.
The initiative of Chapin Harris and Horace H Hayden (1769–1844), the first school of dentistry, the College of Dental Surgery in Baltimore.
CS Brewster (1790–1870), an American dentist living in Paris, constructed a rubber orthodontic device (Vulcanite plate or Regulierungs platte, according to Schnizer) equipped with springs, introducing a material different from those used until that time.
JS Guinnell described the first orthopedic chin cap appliance.
Malagan-Antoine Desiderabode (1781–1850) published ‘Nouveaux ele ments com plets de la science et al l'art du dentiste', in which he intro duced the concept of Leeway space and the balance of force between lips and tongue.
WE Dwinelle (1819–1896) made an orthodontic plate with screws to widen dental arches. Te screws used were jackscrews.
Lefoulon published a text entirely dev-o ted to orthodontics.
Englishman CR Coffin first introduced the use of piano wire to expand the maxillary arch.
T Ballard (1836–1878) reaffirmed the etiologic role played by prolonged sucking (fruitless sucking) in maloc-clusions.
1866 1876
Norman Kingsley perfected occipital anchorage and extraoral forces. AH Tompson (1849–1914) recog nized the importance of occlusal forces in den toal veolar development and in orthodontic movement.
Walter Harris Cofn (1853–1916), an English dentist and son of CR Cofn, perfected the expansion technique introduced years earlier by his father.
Edward Angle (1855–1930), an American dentist, inaugurated fixed orthodontics, presenting a method based on precise mechanical principles and introducing the use of gold multiband devices, the ‘braces' that would. He was the author of the term malocclusion and surely the most important figure in the history of orthodontics, making contributions that were decisive for the birth of this new science. He fought to transform orthodontics into an independent specialty and to have it officially taught. His classifcation of malocclusion, based on the position of the first molars, remians fundamental even today.
John Nutting Farrar (1839–1913), a New York dentist, published the first volume of a basic work, Treatise on the Irregul arities of the Teeth and Teir Corr ection. In his orthodontic work, he paid great attention to the physiologic and pathologic changes in tissues. His teachings also deeply infuenced Viggo Andresen, whose writings show how the activator fully respects the principles Farrar established for intermittent forces.
Wilhelm Roux (Jena 1850-Halle 1924), an anatomist and follower of the Darwin school, founded the first research institute on development in Germany. He devoted his life to the subject, working out the theory of functional adaptation
Walter H Coffin created a vulcanite orthodontic appliance with a W-shaped spring to expand the maxilla.
The fundamental work by Wilhelm Roux, devoted to the mechanisms that regulate development, was published.
20th Century before and during World War-I
Edward Angle and a group of his students founded the Society of Orthodontics in St Louis.
Pierre Robin (Charolles en Bourgogne 1867-Paris 1950), a French doctor and professor of stomatology, described the construction and properties of the monobloc.
Viggo Andresen (Copenhagen 1870–1950) experimented with a removable retention plate following active multi-band therapy in his daughter and was surprised to obtain further clinical improvements. Tis device was named an activator.
Emil Herbst (1842–1917), a German dentist, designed a fxed appliance for forced mandibular advancement.
In the wake of Sandstedt's research, A. Oppen heim discovered the damage done by excessive force and recom-men ded the use of light and intermittent pressure.
Alfred Paul Rogers, a professor at Harvard Dental School in Boston, published an article in which he defned muscles as “living orthodontic appli ances”.
Pierre Robin published Eumorphia, a collection of his writings.
Edmondo Muzj (1894–1994) introduced the teaching of orthodontics at the University of Bologna.
Studying craniofacial growth and anthropometry, M Hellman came to the conclusion that malocclusions are caused by growth disturbances.
Studying growth and comparing humans with other mammals, W Todd confirmed Heilman's conclusions, stating that growth leads to a modif-cation in the proportions of the various parts.
Te Krupp company marketed the first stainless steel dental crowns, shortly followed by clasps, wires, and other materials.
Gustave Korkhaus invited FM Watry to Cologne, where he expounded on Robin's idea and method. Te text of this conference was published in the journal Fortschritte der Kieferorthopadie.
After more than 10 years of close collaboration, Viggo Andresen and Karl Haupl published a book on functional jawbone orthopedics, Funktions-Kieferorthopädie.
Arthur Martin Schwarz (1887-Vienna 1963) published Gebissreinigung mit Platten, entirely devoted to orthod ontic plates.
HG Gerlach experimented with the first open elastic devices, arousing the strong opposition of K Haupl, who criticized the changes made to the activator.
Hans Peter Bimler modified Andre-sen's activator and created the elastic occlusal modeler (Elastischer gebiss-former).
Edmondo Muzi modified the activator, eliminating the palatal part and introintroducing a metal slide curved on the mandibular par to expand the arch.
Wilhelm Balters (1893–1973) began to modify Andresen's activator together with dental technician Fritz Geuer in order to re-educate orofacial disorders.
Hans Muhilemann created the propulsion device similar to the activator but without metal elements, which would later be perfected by Rudolph Hotz at the University of Zurich.
Hugo Stockfisch created the kinetor, an interesting modification of the acti va tor equipped with elastic mastication planes.
H Van Thiel created an activator devoid of the upper part of the palate, predating Klammt's work.
Georg Klammt, a student of Bimler, altered his teacher's appliance because he felt it to be too fragile and created the elastisch-offene activator.
Melvin Moss, a professor at Columbia University, New York, formulated the “functional matrix” theory together with his wife, Letty Salentijn.
Rolf Frankel published the first clinical results obtained with the function regulator.
Georg Schmuth created the kyber-nator, an appliance deriving from the Bionator with the addition of a classic maxillary vesti bular arch and two mandibular vestibular cushions.
Alexander Petrovic formulated his fun-da mental theories about the diferent types of cartilage involved in osteogen-esis and individuated the peculiarities of mandi bular condyle cartilage, which also res ponds to local external stimuli, such as tensing of the lateral pterygoid muscle.