BRACES...ENCYCLOPEDIA!!

History

In 500-300 BC, Ancient Greek scholars Hippocrates and Aristotle both ruminated about ways to straighten teeth and fix various dental conditions.^[1]
Historians believe that two different men deserve the title of being called "the Father of Orthodontics." One man was Norman W. Kingsley, a dentist, writer, artist, and sculptor, who wrote his "Treatise on Oral Deformities" in 1880. Kingsley's writings influenced dental science greatly. Kingsley lived from 1829–1913 and lived in Warren Point, New Jersey. He was a founder of New York State Dental Society in 1868. Also deserving credit is dentist J. N. Farrar, who wrote two volumes entitled "A treatise on the Irregularities of the teeth and their corrections". Farrar was very good at designing brace appliances, and he was the first to suggest the use of mild force at timed intervals to move teeth.
The American dentist Edward Angle is also widely regarded as a father of modern orthodontics. Practising in the late nineteenth and early twentieth centuries, his eponymous classification of dental arch relationships is used worldwide. His textbook, "Treatment of Malocclusion of the Teeth" was first published in 1907. It went into seven much revised editions and laid the foundation of the modern specialty. After tenure as professor of orthodontics in two medical schools, he went on to found the School of Orthodontia in 1910. He designed several fixed orthodontic appliance systems including the ribbon arch and then the edgewise appliance. These have evolved into the sophisticated pre-adjusted and self-ligating systems used by the great majority of orthodontists today.

[edit] How braces work

Teeth move through the use of pressure. The pressure applied by the archwire pushes the tooth in a particular direction and a stress is created within the periodontal ligament. The modification of the periodontal blood supply^[2] determines a biological response which leads to bone remodeling, where bone is created on one side of the tooth by osteoblast cells and resorbed on the other side of the tooth by osteoclasts.
Two different kinds of bone resorption are possible. Direct resorption, starting from the lining cells of the alveolar bone, and indirect or retrograde resorption, where osteoclasts start their activity in the neighbour bone marrow. Indirect resorption takes place when the periodontal ligament has become subjected to an excessive amount and duration of compressive stress. In this case the quantity of bone resorbed is larger than the quantity of newly formed bone (negative balance). Bone resorption only occurs in the compressed periodontal ligament. Another important phenomenon associated with tooth movement is bone deposition. Bone deposition occurs in the distracted periodontal ligament. Without bone deposition, the tooth will loosen and voids will occur distal to the direction of tooth movement.
A tooth will usually move about a millimeter per month during orthodontic movement, but there is high individual variability. Orthodontic mechanics can vary in efficiency, which partly explains the wide range of response to orthodontic treatment.

[edit] Types of braces

Modern orthodontists can offer many types and varieties of braces:

• Traditional braces are stainless steel, sometimes in combination with nickel titanium, and are the most widely used. These include conventional braces, which require ties to hold the archwire in place, and newer self-tying (or self-ligating) brackets. Self-ligating brackets may reduce friction between the wire and the slot of the bracket, which in turn might be of therapeutic benefit.^[3]
• "Clear" braces serve as a cosmetic alternative to traditional metal braces by blending in more with the natural color of the teeth or having a less conspicuous or hidden appearance. Typically, these brackets are made of ceramic or plastic materials and function in a similar manner to traditional metal brackets. Clear elastic ties and white metal ties are available to be used with these clear braces to help keep the appliances less conspicuous. Clear braces have a higher component of friction and tend to be more brittle than metal braces. This can make removing the appliances at the end of treatment more difficult and time consuming.^{[citation needed]}
• Gold-plated stainless steel braces are often employed for patients allergic to nickel (a basic and important component of stainless steel), but may also be chosen because some people simply prefer the look of gold over the traditional silver-colored braces.
• Lingual braces (Incognito Braces) are custom made fixed braces bonded to the back of the teeth making them invisible to other people. In lingual braces the brackets are cemented onto the backside of the teeth making them invisible while in standard braces the brackets are cemented onto the front side of the teeth. Hence, lingual braces are a cosmetic alternative to those who do not wish to have the unaesthetic metal look but wish to improve their smile.
• Progressive, clear removable aligners (examples of which are Invisalign , Originator, ClearCorrect) may be used to gradually move teeth into their final positions. Aligners are generally not used for complex orthodontic cases, such as when extractions, jaw surgery, or palate expansion are necessary.
• For less difficult cases spring aligners are also an option that can cost much less than braces or Invisalign (one example is NightShiftOrtho) and still align primarily the front six top and bottom teeth.
• A new concept under development is the "smart bracket." The smart bracket contains a microchip capable of measuring the forces applied to the bracket/tooth interface. The goal of this successfully demonstrated concept ^[4] is to significantly reduce the duration of orthodontic therapy and to set the applied forces in non-harmful, optimal ranges.

• A-braces ^[5] are another new concept in dental appliances. In the shape of a capital letter A, A-braces are applied, adjusted, removed and completely controlled by the user. At the ends of the A's arms are angled knobbed bits that the user bites down over. The width between the bits is adjusted by turning the crossbar, housed across the arms. A user never has to experience pain because the pressure is so easy to control. A-braces may serve as self-adjustable retainers and palate expanders.^{[citation needed]}

[edit] Procedure

A patient's teeth are prepared for application of braces.

Orthodontic services may be provided by any licensed dentist trained in orthodontics. In North America most orthodontic treatment is done by orthodontists, dentists in diagnosis and treatment of malocclusions—malalignments of the teeth, jaws, or both. A dentist must complete 2–3 years of additional post-doctoral training to earn a specialty certificate in orthodontics. There are many general practitioners who also provide orthodontic services.
The first step is to determine whether braces are suitable for the patient. The doctor consults with the patient and inspects the teeth visually. If braces are appropriate, a records appointment is set up where X-rays, molds, and impressions are made. These records are analyzed to determine the problems and proper course of action. Typical treatment times vary from six months to two and a half years depending on the complexity and types of problems. Orthognathic surgery may be required in extreme cases. About 2 weeks before the braces are applied brackets are required to spread apart back teeth in order confirm enough space for the bands.
Teeth to be braced will have an adhesive applied to help the cement bond to the surface of the tooth. In most cases the teeth will be banded and then brackets will be added. A bracket will be applied with dental cement, and then cured with light until hardened. This process usually takes a few seconds per tooth. If required, orthodontic spacers may be inserted between the molars to make room for molar bands to be placed at a later date. Molar bands are required to ensure brackets will stick. Bands are also utilized when dental fillings or other dental work make securing a bracket to a tooth infeasible.
An archwire will be threaded between the brackets and affixed with elastic or metal ligatures. Elastics are available in a wide variety of colors. Archwires are bent, shaped, and tightened frequently to achieve the desired results. Brackets with hooks can be placed, or hooks can be created and affixed to the archwire to affix the elastic to. The placement and configuration of the elastics will depend on the course of treatment and the individual patient. Elastics are made in different diameters, colors, sizes, and strengths.
Modern orthodontics makes frequent use of nickel-titanium archwires and temperature-sensitive materials. When cold, the archwire is limp and flexible, easily threaded between brackets of any configuration. Once heated to body temperature, the archwire will stiffen and seek to retain its shape, creating constant light force on the teeth.

Dental braces, with a transparent powerchain, removed after completion of treatment.

In many cases there is insufficient space in the mouth for all the teeth to fit properly. There are two main procedures to make room in these cases. One is extraction: teeth are removed to create more space. The second is expansion: the palate or arch is made larger by using a palatal expander. Expanders can be used with both children and adults. Since the bones of adults are already fused, expanding the palate is not possible without surgery to unfuse them. An expander can be used on an adult without surgery, but to expand the dental arch, and not the palate.
Each month or two, the braces must be adjusted. This helps shift the teeth into the correct position. When they get adjusted the orthodontist takes off the colored rubber bands keeping the wire in place. The wire is then taken out, and may be replaced or modified. When the wire has been placed back into the mouth, the patient may choose a color for the new rubber bands, which are then fixed to the metal brackets. The adjusting process may cause some discomfort, which is normal.

[edit] Post-treatment

In order to avoid the teeth moving back to their original position, retainers may be worn once the treatment with braces is complete.
Patients may need post-orthodontic surgery, such as a fiberotomy or alternatively a gum lift, to prepare their teeth for retainer use and improve the gumline contours after the braces come off.

[edit] Retainers

Main article: Retainer (orthodontic device)

Retainers are required to be worn once treatment with braces is complete. The orthodontist will recommend a retainer based on the patient's needs. If a patient does not wear the retainer as recommended, the teeth will move towards their original position (relapse).
A Hawley retainer is made of metal hooks that surround the teeth and are enclosed by an acrylic plate shaped to fit the patient's palate. An Essix retainer is similar to an Invisalign tray. It is a clear plastic tray form-fitted to the teeth and stays in place by suction. A bonded retainer is a wire permanently bonded to the lingual side of the teeth (usually the lower teeth only).

[edit] Pre-Finisher

If a person's teeth are not ready for a proper retainer, the orthodontist may prescribe the use of a pre-formed finishing appliance such as the Pre-Finisher (registered trademark of TP Orthodontics, Inc). This appliance (similar to a mouth guard) fixes gaps between the teeth, small spaces between the upper and lower jaw, and other minor problems that could worsen. These problems are small matters that dental braces cannot fix.
The Pre-Finisher is molded to the patient's teeth by use of severe pressure to the appliance by the person's jaw. The appliance is then worn for the prescribed time, with the user applying force to the appliance in their mouth for ten to fifteen seconds at a time. The goal is increasing the "exercise" time, time spent applying force to the appliance. Like the retainer, the Pre-Finisher is not a permanent addition to one's mouth, and can be moved in and out of the mouth.

[edit] Surgery

Example of prognathism, where teeth have almost reached their final, straight position by braces. This makes the prognathism more obvious, and it will take a surgery, moving the jaw backwards, to give the ultimate result.

See also: Orthognathic surgery

[edit] Complications and risks

Plaque forms easily when food is retained in and around braces. It is important to maintain proper oral hygiene by brushing and flossing thoroughly when wearing braces to prevent tooth decay, decalcification, or unpleasant color changes to the teeth.
There is a small chance of allergic reaction to the elastics or to the metal used in braces. In even rarer cases, latex allergy may result in anaphylaxis. Latex-free elastics and alternative metals can be used instead. It is important for those who believe that they are allergic to their braces to notify the orthodontist immediately.
Mouth sores may be triggered by irritation from components of the braces. Many products can increase comfort, including oral rinses, dental wax or dental silicone, and products to help heal sores.
Braces can also be damaged if proper care is not taken. It is important to wear a mouth guard to prevent breakage and/or mouth injury when playing sports. Certain sticky or hard foods such as taffy, raw carrots, hard pretzels, and toffee should be avoided because they can damage braces. Frequent damage to braces can prolong treatment. Some orthodontists recommend sugar-free chewing gum in the belief that it may expedite treatment and relieve soreness; other orthodontists object to gum chewing because it is sticky and may therefore damage the braces.
In the course of treatment orthodontic brackets may pop off due to the forces involved, or due to cement weakening over time. The orthodontist should be contacted immediately for advice if this occurs. In most cases the bracket is replaced.
When teeth move, the end of the arch wire may become displaced, causing it to poke the back of the patient's cheek. Dental wax can be applied to cushion the protruding wire. The orthodontist must be called immediately to have it clipped, or a painful mouth ulcer may form. If the wire is causing severe pain, it may be necessary to carefully bend the edge of the wire in with a spoon or other piece of equipment (e.g. tweezers) until the wire can be clipped by an orthodontist.
Patients with periodontal disease usually must obtain periodontal treatment before getting braces. A deep cleaning is performed, and further treatment may be required before beginning orthodontic treatment. Bone loss due to periodontal disease may lead to tooth loss during treatment.
In some cases, teeth may be loose for a prolonged period of time. One may be able to wiggle one's teeth for a year or two after treatment or longer.
The dental displacement obtained with the orthodontic appliance determines in most cases some degree of root resorption. Only in a few cases is this side effect large enough to be considered real clinical damage to the tooth. In rare cases, the teeth may fall out or have to be extracted due to root resorption.^[6][7]
Pain and discomfort are common after adjustment and may cause difficulty eating for a time, often a couple days. During this period, eating soft foods can help avoid additional pressure on teeth.
Removal of the cemented brackets can also be painful. The cement must be chipped and scraped off which can cause severe pain in patients with sensitive teeth. Often molar bands have been installed for an extended period of time and they may be embedded in the gums at the time of removal.
The metallic look may not be desirable to some people, although transparent varieties are available. According to a survey published in the American Journal of Orthodontics and Dentofacial Orthopedics, dental braces with no visible metal were considered the most attractive. Braces that combine clear ceramic brackets with thin metal or clear wires were a less desirable option, and braces with metal brackets and metal wires were rated as the least aesthetic combination.^[8]

[edit] Treatment time and cost

Typical treatment time is from six months to six years, depending on the severity of the case, location, age, etc., although research has shown that the average duration is 1 year and 4 months).^{[citation needed]} Treatment can be accelerated using novel planning, unorthodox treatment goals^{[citation needed]} and positioning techniques.
The typical cost of braces ranges widely in various regions. The cost depends on whether both arches are being treated and the length of treatment. Typical orthodontic treatment comprises metal braces on both arches for 12 to 24 months. The 2007 orthodontic practice study done by the Journal of Clinical Orthodontics showed the United States national average cost of braces for comprehensive orthodontic treatment to be $2,000 for children and $5,354 for adults.^{[citation needed]} Some cases in the United Kingdom cost £3,500, although they can much of the time be provided free on the NHS, providing the patient is under 18, a student up to 19, a pregnant woman, a nursing mother or living on a low income.^[9]
In some European countries (e.g. Norway, Finland, Sweden, Slovenia, Slovakia, Germany, Croatia or Denmark) orthodontic treatment is available without charge to patients under 18 (or for treatment to start at 16, such as Republic of Ireland and the UK) as benefits for orthodontic treatment are provided under government-run health care systems. However, in the UK, the National Health Service will not pay for braces if the teeth do not a have protrusion of over 5mm; if there is not a protrusion, it is classed as cosmetic. In some countries (e.g. Ireland), adults can also get treatment at a discounted rate, or claim tax relief after paying a full cost with a private practitioner.
In India this treatment can cost anywhere between INR 10000 to INR 80000. The cost also depends on the type of braces, the type of city the patient is in and on the orthodontist's skill and experience.

References

1. ^ History of Dentistry Ancient Origins
2. ^ Ren Y, Maltha JC, Stokroos I, Liem RS, Kuijpers-Jagtman AM (May 2008). "Effect of duration of force application on blood vessels in young and adult rats". Am J Orthod Dentofacial Orthop 133 (5): 752–7. doi:10.1016/j.ajodo.2007.10.030. PMID 18456151. 
3. ^ Henao SP, Kusy RP (Apr 2004). "Evaluation of the frictional resistance of conventional and self-ligating bracket designs using standardized archwires and dental typodonts". Angle Orthod 74 (2): 202–11. PMID 15132446. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-3219&volume=74&page=202. 
4. ^ Bartholomeyczik J, Haefner J, Joos J, Schubert F, Ruther P, Paul O, Lapatki B (Oct-Nov 2005). "Novel concept for the multidimensional measurement of forces and torques in orthodontic smart brackets". Sensors, 2005 IEEE (Piscataway, NJ: IEEE): 4. doi:10.1109/ICSENS.2005.1597873. ISBN 0-7803-9056-3. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1597873. 
5. ^ World Intellectual Property Organization. WO/2008/092260. http://www.wipo.int/pctdb/en/wo.jsp?WO=2008092260&IA=CA2008000196&DISPLAY=DOCS. 
6. ^ Artun J, Smale I, Behbehani F, Doppel D, Van't Hof M, Kuijpers-Jagtman AM (Nov 2005). "Apical root resorption six and 12 months after initiation of fixed orthodontic appliance therapy". Angle Orthod 75 (6): 919–26. PMID 16448232. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-3219&volume=75&page=919. 
7. ^ Mavragani M, Vergari A, Selliseth NJ, Bøe OE, Wisth PL (Dec 2000). "A radiographic comparison of apical root resorption after orthodontic treatment with a standard edgewise and a straight-wire edgewise technique". Eur J Orthod 22 (6): 665–74. doi:10.1093/ejo/22.6.665. PMID 11212602. http://ejo.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=11212602. 
8. ^ Survey: Most Effective Dental Braces Are Least Attractive Newswise, Retrieved on July 9, 2008.
9. ^ Orthodontic treatment (braces)