Pendulum appliance

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Pendulum is an orthodontic appliance, developed by James J. Hilgers in 1992, [1] 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. [2]

Orthodontics field of dentistry dealing with irregularities in the teeth

Orthodontics and dentofacial orthopedics, formerly referred to as orthodontia, is a specialty of dentistry that deals with the diagnosis, prevention and correction of malpositioned teeth and jaws. The field was established by such pioneering orthodontists as Edward Angle and Norman William Kingsley.

The Journal of Clinical Orthodontics is a monthly peer-reviewed medical journal covering the practical aspects of orthodontics and practice management. The editor-in-chief is Robert G. Keim. It was established in 1967 as the Journal of Practical Orthodontics, obtaining its current title in 1970.

Contents

Management

The initial design of the appliance used the occlusal rests which were bonded to the premolars for retention. However, premolars can also be banded for the retention purposes. Pre-activation of the appliance mandates bending of the TMA springs 90 degrees or parallel to the midline of the palate. Then once the appliance is in the mouth, the springs are inserted into the lingual sheaths of the molar bands to allow the force distally and medially. The patient then presents every 3 weeks for the re-adjustment of the springs.

As the molar moves distally, forces of the spring cause the molar to move in an arc towards the middle of the palate. Therefore, this can lead to crossbite in the posterior teeth. In order to avoid this side-effect, the adjustment loops are opened to counteract this medial movement of 1st molars.

Treatment effects

A study published by Ghosh et al. [3] in 1996 stated that the mean maxillary first molar distalization was 3.37 mm, with a distal tipping of 8.36° and the mean reciprocal mesial movement of the first premolar was 2.55 mm, with a mesial tipping of 1.29°. They also stated that the eruption of maxillary second molars had minimal effect on distalization of first molars. In addition, the reported increase of Lower Anterior Facial Height for patient's who had pre-existing vertical growth. They concluded that the pendulum appliance was an effective and reliable method for distalizing maxillary molars. Another study done by Bussick et al. [4] looked at effects of pendulum appliance on 101 patients. These authors reported a slight higher distalization of maxillary first molar by 5.7 mm and a distal tipping of 10.6°. The also reported anchorage loss when the anterior teeth moved mesially by the 1.8-mm anterior movement of the upper first premolars, with a mesial tipping of 1.5°. Both the abovementioned studies, observed slight maxillary first molars intruded and slight first premolars extrusion. This study also saw increase of lower anterior facial height by 2.2 mm but they found no significant difference in lower anterior facial height increase between patients of high, neutral, or low mandibular plane angles.

Components

Pendex

Pendex is an appliance, similar to Pendulum, which is known to correct the transverse deficiency of maxillary teeth in addition to distalizing the upper molars. This appliance includes the expansion screw.

Related Research Articles

Palatal expansion

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. Although the use of an expander is most common in children (8%-18%), it can be, and has been, successfully used in adults too, although the effects of expansion are slightly more uncomfortable in the adult patient. The amount of correction and the age of the patient can lengthen time of desired expansion to many months. A patient who would rather not wait several months for the end result 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.

Overjet

Overjet is the extent of horizontal (anterior-posterior) overlap of the maxillary central incisors over the mandibular central incisors. In class II malocclusion the overjet is increased as the maxillary central incisors are protruded.

Crossbite

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.

Lingual arch

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.

Cephalometric analysis is the clinical application of cephalometry. It is analysis of the dental and skeletal relationships of a human skull. It is frequently used by dentists, orthodontists, and oral and maxillofacial surgeons as a treatment planning tool. Two of the more popular methods of analysis used in orthodontology are the Steiner analysis and the Downs analysis. There are other methods as well which are listed below.

Serial extraction is the planned extraction of certain deciduous teeth and specific permanent teeth in an orderly sequence and predetermined pattern to guide the erupting permanent teeth into a more favorable position.

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 sides of the teeth. The main advantage of lingual braces is their near invisibility compared to the standard braces, which are attached on the buccal (cheek) sides of the tooth. Lingual braces were invented by Craven Kurz in 1976.

Dr. William J. Clark is a Scottish orthodontist known for developing Twin Block Appliance in Orthodontics. This appliance was developed by Dr. Clark in 1977 in Scotland and since then this appliance has been used in correction of Class 2 malocclusions with retrognathic mandible. He also developed invisible TransForce Appliance in 2004.

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.

Lip Bumper is an appliance used in Dentistry, especially Orthodontics, for various purposes to correct a dentition by preventing the pressure from the soft tissue. Lip bumper is usually used in an orthodontic treatment where one has a crowded maxillary or mandibular teeth in an arch.

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Activator Appliance is an Orthodontics appliance that was developed by Viggo Andersen 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 Frankel in 1950s. 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.

Molar distalization is a process in the field of Orthodontics which is used to move molar teeth, especially permanent first molars, distally (backwards) in an arch. This procedure is often used in treatment of patients who have Class 2 malocclusion. The cause is often the result of loss of E space in an arch due to early loss of primary molar teeth and mesial (forward) migration of the molar teeth. Sometimes molars are distalized to make space for other impacted teeth, such as premolars or canines, in the mouth.

ACCO or Acrylic Cervical Occipital Anchorage is an appliance in field of orthodontics which is used for distalization of maxillary molars. This appliance is a removable type of appliance which was developed by Herbert I. Margolis. This appliance is intended to be worn 24 hours a day except during meals. It is one of the few removable appliances made for distalization of molars and thus require patient compliance for the treatment to be successful.

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 prevalence varies between different populations, for instance, occurring with 16% in black people and 4% in white people. The term "open bite" was coined by Carevelli in 1842.

References

  1. Hilgers, J. J. (1992-11-01). "The pendulum appliance for Class II non-compliance therapy". Journal of Clinical Orthodontics. 26 (11): 706–714. ISSN   0022-3875. PMID   1298751.
  2. Kinzinger, G.; Fuhrmann, R.; Gross, U.; Diedrich, P. (2000-01-01). "Modified pendulum appliance including distal screw and uprighting activation for non-compliance therapy of Class-II malocclusion in children and adolescents". Journal of Orofacial Orthopedics. 61 (3): 175–190. ISSN   1434-5293. PMID   10863877.
  3. Ghosh, J.; Nanda, R. S. (1996-12-01). "Evaluation of an intraoral maxillary molar distalization technique". American Journal of Orthodontics and Dentofacial Orthopedics. 110 (6): 639–646. ISSN   0889-5406. PMID   8972811.
  4. Bussick, T. J.; McNamara, J. A. (2000-03-01). "Dentoalveolar and skeletal changes associated with the pendulum appliance". American Journal of Orthodontics and Dentofacial Orthopedics. 117 (3): 333–343. ISSN   0889-5406. PMID   10715093.