Lingual braces are one of the many types of the fixed orthodontic treatment appliances available to patients needing orthodontics. They involve attaching the orthodontic brackets on the inner (lingual vs. buccal) sides of the teeth. The main advantage of lingual braces is their near invisibility [1] compared to the standard braces, which are attached on the buccal (cheek) sides of the tooth. [2] Lingual braces were invented by Craven Kurz in 1976. [3]
Craven Kurz with Jim Mulick in 1975 developed the Cruz Lingual Appliances in United States. The first patient to be treated by lingual braces was by Kurz in Beverly Hills in 1976. She was a member of Playboy Bunny Club and after being presented with metal braces option, she wanted to get braces which did not show metal. [4] It was from her demand that Craven developed the lingual braces. Craven consulted with Dr. Jim Mulick at UCLA School of Dentistry after which this appliance was developed. Craven's practice was dominated by adult patients, many of whom were celebrities. Initial problems faced by Craven included irritation caused by appliance to tongue and patient's speech problems. Additionally, there was a higher rate of brackets being broken due to lower teeth touching upper brackets. [4]
Eventually, a dental company named Ormco started developing lingual brackets in conjunction with Dr. Kurz. [5] After working on several prototypes of brackets initially, the company also faced same problems: Irritation caused to the tongue and high bracket failure rate. Then, an inclined plane was added to the lingual brackets and the company saw lower failure rates. This plane allowed the shearing forces to convert into compressive forces. After the development of the inclined plane, Kurz filed for a patent in 1976. The first brackets to be produced were in 1979 by Ormco. Kurz eventually started working with the orthodontic company Ormco to develop his next 7 generations of the lingual bracket. Initial patients were seen at private practice of Kurz where the brackets were directly bonded, as compared to indirect bonding with majority of the lingual braces. Eventually, Dr. Kurz lectured to many orthodontists around US and showed his cases to the other clinicians. [6] In the early 1980s, the interest with lingual braces started to gather steam as other companies such as Unitek, Forestadent started to develop their own groups to study these appliances. [7] [8]
The first organization to form around lingual braces was Société Française d'Orthodontie Linguale or French Orthodontic Society for Lingual Orthodontics in 1986. American Lingual Orthodontic Association was also established in 1987 and they had their first meeting in Washington that year. Dental Lingual Assistant Association was also formed around the same time. Europe saw its first lingual organization formed named The European Society of Lingual Orthodontics (ESLO) in 1992. This was followed by more societies being formed across Europe and Asia. Previously, the lingual braces were introduced to many doctors in Europe. Around the same time, many orthodontists started seeing problems in their cases and popularity of lingual braces declined by 1989. [7]
Below are listed generations of the Ormco brackets that were created between 1976 and late 1980s.
Brackets were initially bonded with a system known as Torque Angulation Referencing Guide (TARG) which allowed a clinician to place brackets on lingual surfaces of teeth by using the natural anatomy. Then another method called Custom Lingual Appliance Set-Up Service which allowed a clinician to set up brackets on a model first and then indirectly bond them on patient's teeth later on with a tray.Evolution of Lingual Self-ligating brackets
In 1999, use of self-ligating brackets in lingual orthodontics was first presented by Neumann and Holtgräve who suggested the use of SPEED (Strite Industries Ltd.) self- ligating labial brackets for application in the lingual technique.
Dr. Lawrence Andrews invented the Straightwire Appliance in 1970s. This allowed values of tip and torque to be incorporated into the brackets. [9] When developing the lingual brackets, Craven used reciprocal tip and torque values of that of Lawrence Andrew's straightwire appliance for each tooth in his lingual brackets. Eventually first order bend at the junction of the canine and premolar, and the premolar and molar were placed in the wires as these values were not incorporated in the brackets. [10]
An advantage of the lingual brackets over the buccal brackets is the less decalcification marks on the buccal side of the teeth which is more visible to the naked eye. Patients with poor oral hygiene can have increased white spot lesions which present themselves buccally and can stay there post-orthodontically if proper oral hygiene is not maintained. [11]
Initial appliances formed in 1980s irritated patient's tongues and had higher breakage rate. However, different companies made the bracket profile smaller and smoother which allowed less irritation to soft tissues around the bracket. However, the same problems still persisted over the years and treatment approach presently is to inform the patient that irritation and speech impairment will improve in 2–3 weeks after the bracket placement. [12] [13]
A systematic review and a meta-analysis published in 2016 stated that lingual braces cause greater amount of pain in tongue, problem maintaining oral hygiene and problems with speech and eating difficulties. [14] [15]
Lingual brackets are located more closely to the center of resistance of a tooth than brackets placed on a buccal surface of a tooth. Thus when a patient bites down, the biting forces are directed through the center of resistance of those anterior teeth. Thus the light continuous forces directed towards the upper lingual brackets may induce slight intrusion of the upper anterior teeth. However, forces that are felt on the anterior teeth seem to be minimal, in milligrams. An optimum force needed to intrude teeth is 30-40g. [16]
As the mandibular teeth are biting on the upper brackets, it results in an anterior bite plane effect. This eventually leads to the light, continuous intruding force that is being felt on the front incisors. This bite plane effect may also induce slight opening in the posterior molar teeth and these teeth may extrude, leading to correction of deep bite or worsening of an already open bite. This can worsen a Class 2 malocclusion as mandible rotates down and back, leading to more of a Class 2 molar relationship.[ citation needed ]
Due to the small interbracket distance in the lingual braces, compare to the buccal braces, compensatory bends which can be made in finishing phase are tough to create. The distance between brackets anteriorly in lingual braces is about 40% smaller than the buccal braces. Despite the bends, making loops to close spaces also becomes mechanically tough. [17] [18]
Lingual orthodontics is known to have both vertical and horizontal bowing effects during space closure. These effects are related to in terms of closing spaces on an archwire which may not fill the slot completely. Therefore, increased play in the wire to bracket relationship can cause effects which may lead to more of a tipping tooth movement than pure translation, as desired in most cases. These effects can be counteracted by either placing anti-bowing effect curves both vertically and horizontally, by using lighter retraction forces or by steel-ligation of posterior teeth as a unit to prevent the side-effects.[ citation needed ]
Lingual braces and wires are made by many different of companies. Some of them are Incognito (3M), ALIAS (Ormco), Innovation L (Dentsply/GAC International), eBrace (Riton BioMaterials), Stb Light (Ormco) and Harmony (American Orthodontics).
Incognito lingual brackets and wires are made by 3M in Germany. These appliances were initially designed by Dirk Wiechmann. He published his results in 2003 in American Journal of Orthodontics and Dentofacial Orthopedics , where he reported testing these appliances for 18 months on 600 bonded arches on patients in his private practice. [19] The company uses a CAD/CAM technology to combine bracket fabrication and bracket positioning which is done on computer models. The wires and brackets are customized to each patient's anatomy of the lingual tooth surface. The bases of these brackets are bigger than other brackets produced by different companies, however these appliances have thinner bracket base and use less bonding material than other brackets. This may be seen as an advantage by some due to low profile of brackets which may cause less irritation to the tongue of patients, but this does lead to creating 1st order bends in the wires to compensate for the low profile of these brackets. A study done in Germany in 2005 compared the pre-adjusted lingual brackets (Ormco) to customized lingual brackets (Incognito) on a group of 40 German-speaking women. The results stated that customized brackets in the study induced significantly fewer cases of tongue space restriction, pressure sores, reddening or lesions to the tongue in the long term than the pre-fabricated brackets. [20] Even though the results favor the Incognito appliance, it should be kept in mind that this is a subjective opinion of people which may confound the results.[ citation needed ]
Orthodontics is a dentistry specialty that addresses the diagnosis, prevention, management, and correction of mal-positioned teeth and jaws, as well as misaligned bite patterns. It may also address the modification of facial growth, known as dentofacial orthopedics.
Dental braces are devices used in orthodontics that align and straighten teeth and help position them with regard to a person's bite, while also aiming to improve dental health. They are often used to correct underbites, as well as malocclusions, overbites, open bites, gaps, deep bites, cross bites, crooked teeth, and various other flaws of the teeth and jaw. Braces can be either cosmetic or structural. Dental braces are often used in conjunction with other orthodontic appliances to help widen the palate or jaws and to otherwise assist in shaping the teeth and jaws.
In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855–1930), the "father of modern orthodontics", popularised it. The word derives from mal- 'incorrect' and occlusion 'the manner in which opposing teeth meet'.
A palatal expander is a device in the field of orthodontics which is used to widen the upper jaw (maxilla) so that the bottom and upper teeth will fit together better. This is a common orthodontic procedure. The use of an expander is most common in children and adolescents 8–18 years of age. It can also be used in adults, although expansion is more uncomfortable and takes longer in adults. A patient who would rather not wait several months for the end result achieved by a palatal expander may be able to opt for a surgical separation of the maxilla. Use of a palatal expander is most often followed by braces to then straighten the teeth.
Orthodontic technology is a specialty of dental technology that is concerned with the design and fabrication of dental appliances for the treatment of malocclusions, which may be a result of tooth irregularity, disproportionate jaw relationships, or both.
In dentistry, crossbite is a form of malocclusion where a tooth has a more buccal or lingual position than its corresponding antagonist tooth in the upper or lower dental arch. In other words, crossbite is a lateral misalignment of the dental arches.
The Damon system of orthodontics is one of many fixed, passive, self-ligating methods of correcting malocclusions. Passive self-ligating systems use brackets that do not require elastic o-rings to hold the wires in place. By not using the elastic o-rings, it is said that the wires freely slide through the slots without friction. However, this may not be correct as it allows more rotation or tipping of teeth before the bracket edges contact the wire, resulting in friction. It is believed that not using o-rings results in better oral hygiene but the research is equivocal, with findings both for and against the theory. To hold the wires in place, the Damon System uses small sliding doors. The addition of 'stops' on the wires helps prevent the wire from becoming displaced from its intended location.
A lingual arch is an orthodontic device which connects two molars in the upper or lower dental arch. The lower lingual arch (LLA) has an archwire adapted to the lingual side of the lower teeth. In the upper arch the archwire is usually connecting the two molars passing through the palatal vault, and is commonly referred as "Transpalatal Arch" (TPA). The TPA was originally described by Robert Goshgarian in 1972. TPAs could possibly be used for maintaining transverse arch widths, anchorage in extraction case, prevent buccal tipping of molars during Burstonian segmented arch mechanics, transverse anchorage and space maintenance.
Self-ligating brackets are defined as "a dental brace, which generally utilizes a permanently installed, moveable component to entrap the archwire". Self-ligating brackets have also been designed which do not require a movable component to hold the wire in place. Self-ligating braces may be classified into two categories: Passive and Active.
Percival Raymond Begg AO was a professor at the University of Adelaide School of Dentistry and a well known orthodontist, famous for developing the "Begg technique". Permanent displays dedicated to the Begg technique can be found in the Smithsonian Institution in Washington DC, the Library of the American Dental Association in Chicago, and the PR Begg Museum at the University of Adelaide.
Craven Kurz was an American orthodontist who is known to be the inventor of the "invisible" or lingual braces in 1975. He was also the founding president of the American Lingual Orthodontic Association.
Anchorage in orthodontics is defined as a way of resisting movement of a tooth or number of teeth by using different techniques. Anchorage is an important consideration in the field of orthodontics as this is a concept that is used frequently when correcting malocclusions. Unplanned or unwanted tooth movement can have dire consequences in a treatment plan, and therefore using anchorage stop a certain tooth movement becomes important. Anchorage can be used from many different sources such as teeth, bone, implants or extra-orally.
Elastics are rubber bands frequently used in the field of orthodontics to correct different types of malocclusions. The elastic wear is prescribed by an orthodontist or a dentist in an orthodontic treatment. The longevity of the elastic wear may vary from two weeks to several months. The elastic wear can be worn from 12 to 23 hours a day, either during the night or throughout the day depending on the requirements for each malocclusion. The many different types of elastics may produce different forces on teeth. Therefore, using elastics with specific forces is critical in achieving a good orthodontic occlusion.
Activator Appliance is an Orthodontics appliance that was developed by Viggo Andresen in 1908. This was one of the first functional appliances that was developed to correct functional jaw in the early 1900s. Activator appliance became the universal appliance that was used widely throughout Europe in the earlier part of the 20th century.
Frankel appliance or Frankel Functional Regulator is an orthodontic functional appliance which was developed by Rolf Fränkel in 1950s for treatment to patients of all ages. This appliance primarily focused on the modulation of neuromuscular activity in order to produce changes in jaw and teeth. The appliance was opposite to the Bionator appliance and Activator appliance.
Pendulum is an orthodontic appliance, developed by James J. Hilgers in 1992, that use forces to distalize the upper 1st molars to create space for eruption of impacted teeth or allowing correction of Class 2 malocclusion. This appliance is a fixed type of distalizing appliance that does not depend on the compliance of each patient to work. Hilgers published an article in Journal of Clinical Orthodontics in 1992 describing the appliance.
Intrusion is a movement in the field of orthodontics where a tooth is moved partially into the bone. Intrusion is done in orthodontics to correct an anterior deep bite or in some cases intrusion of the over-erupted posterior teeth with no opposing tooth. Intrusion can be done in many ways and consists of many different types. Intrusion, in orthodontic history, was initially defined as problematic in early 1900s and was known to cause periodontal effects such as root resorption and recession. However, in mid 1950s successful intrusion with light continuous forces was demonstrated. Charles J. Burstone defined intrusion to be "the apical movement of the geometric center of the root (centroid) in respect to the occlusal plane or plane based on the long axis of tooth".
Open bite is a type of orthodontic malocclusion which has been estimated to occur in 0.6% of the people in the United States. This type of malocclusion has no vertical overlap or contact between the anterior incisors. The term "open bite" was coined by Carevelli in 1842 as a distinct classification of malocclusion. Different authors have described the open bite in a variety of ways. Some authors have suggested that open bite often arises when overbite is less than the usual amount. Additionally, others have contended that open bite is identified by end-on incisal relationships. Lastly, some researchers have stated that a lack of incisal contact must be present to diagnose an open bite.
Orthodontic indices are one of the tools that are available for orthodontists to grade and assess malocclusion. Orthodontic indices can be useful for an epidemiologist to analyse prevalence and severity of malocclusion in any population.