Molar distalization

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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. [1] 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. [2]

Contents

Distalization in the maxillary arch is easier than the mandibular arch because maxillary bone has more trabecular bone than the mandible, which has higher percentage of cortical bone. One of the most popular devices that is used to distalize molars is known as Pendulum appliance and Pendex Appliance. These were developed by Hilgers in 1990.

Eruption of second molar

It has been reported in the literature [3] [4] that eruption stage of second molar has an impact on the distalization of the first permanent molar. Tipping movement occurs where the first molars are angled backwards when the second molar has not erupted yet. In addition, the treatment duration for distalization of first molars increases if the second molar has already erupted. Therefore, distalization of first molars is recommended prior to eruption of the second molars. [5] Although, there are some studies that do report that there is no connection between eruption stages of second molar and duration of treatment to the distalization of the 1st molars. [6] [7]

Finally in 2013, a systematic review was published by Flores-Mir et al. [8] which looked at efficiency of molar distalization associated with second and third molar eruption stage. The authors concluded that the effect of maxillary second and third molar eruption stage on molar distalization in both the horizontal and angular distalization appeared to be minimal. This systematic review looked at four studies where one study [9] stated that amount of distal movement of maxillary first molar was greater (3mm vs 2mm) and that treatment time was shorter (5.2months vs 6 months) in patients with unerupted second molar vs patients with erupted second molar. However, out of the 4 studies reviewed, this was the only study which favored more distalization with unerupted molars, as others [7] [10] did not agree. The study did have some limitations such as different type of appliances used in different papers and different landmarks used in the evaluation of cephalometric radiograph.

Indications

A careful approach must be undertaken in patients with severe space discrepancy and hyperdivergent growth pattern for the procedure of molar distalization. Ideally, the patients should have well developed nose and chin.

Distalization with headgears

Norman William Kingsley was the first person to try to move the maxillary teeth backwards in 1892 by means of headgear. Albin Oppenheim later advocated for the use of occipital anchorage to move the maxillary teeth backwards. Earlier into the field of orthodontics, molar teeth would be distalized with the use of headgears. Straight Pull (Combination) Headgear for translation of molar distally, Cervical Pull Headgear for extrusive and distalization of teeth in deep bite Class 2 patients and High Pull Headgear for intrusive and distalization of teeth in an open bite patient.

See also

Related Research Articles

Orthodontics Correctional branch of dentistry

Orthodontics is a dentistry specialty that addresses the diagnosis, prevention, management, and correction of mal-positioned teeth and jaws, and misaligned bite patterns. It may also address the modification of facial growth, known as dentofacial orthopedics.

Malocclusion Medical condition

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 "malocclusion" derives from occlusion, and refers to the manner in which opposing teeth meet.

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.

Crossbite Medical condition

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.

Pre-eruption guidance is an orthodontic treatment method that allows for expansion of existing erupting teeth long before they appear in the mouth. The use off pre-eruption guidance appliances and the timing of extractions of certain deciduous teeth aligns the teeth naturally as opposed to orthodontic mechanical movement of permanent teeth into alignment after they have erupted. Research shows that pre-eruption guidance produces far more stable tooth alignment than alternative treatments.

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Anchorage (orthodontics) Way of resisting tooth movement in orthodontics

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.

A lip bumper is a dental appliance used in orthodontics, for various purposes to correct a dentition by preventing the pressure from the soft tissue. Lip bumpers are usually used in orthodontic treatment where the patient has a crowded maxillary or mandibular teeth in an arch.

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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.

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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.

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References

  1. ↑ Sfondrini, M. F.; Cacciafesta, V.; Sfondrini, G. (2002-05-01). "Upper molar distalization: a critical analysis". Orthodontics & Craniofacial Research. 5 (2): 114–126. doi:10.1034/j.1600-0544.2002.01155.x. ISSN   1601-6335. PMID   12086326.
  2. ↑ William R. Proffit; Henry W. Fields Jr; David M. Sarver (2012-04-16). Contemporary Orthodontics, 5e (5 ed.). Mosby. ISBN   9780323083171.
  3. ↑ Graber, T. M. (1955-07-01). "Extraoral force—Facts and fallacies". American Journal of Orthodontics. 41 (7): 490–505. doi:10.1016/0002-9416(55)90143-3.
  4. ↑ Jeckel, Norbert; Rakosi, Thomas (1991-02-01). "Molar distalization by intra-oral force application". The European Journal of Orthodontics. 13 (1): 43–46. doi:10.1093/ejo/13.1.43. ISSN   0141-5387. PMID   2032566.
  5. ↑ Lim, Seung-Min; Hong, Ryoon-Ki (2009-06-29). "Distal Movement of Maxillary Molars Using a Lever-arm and Mini-implant System". The Angle Orthodontist. 78 (1): 167–175. doi: 10.2319/102506-438 . PMID   18193963.
  6. ↑ Muse, Dween S.; Fillman, Michael J.; William J., Emmerson; Mitchell, Robert D. (1993-12-01). "Molar and incisor changes with Wilson rapid molar distalization". American Journal of Orthodontics and Dentofacial Orthopedics. 104 (6): 556–565. doi:10.1016/S0889-5406(05)80439-1. PMID   8249931.
  7. 1 2 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. doi:10.1016/S0889-5406(96)80041-2. ISSN   0889-5406. PMID   8972811.
  8. ↑ Flores-Mir, Carlos; McGrath, Lisa; Heo, Giseon; Major, Paul W. (2013-07-01). "Efficiency of molar distalization associated with second and third molar eruption stage". The Angle Orthodontist. 83 (4): 735–742. doi: 10.2319/081612-658.1 . ISSN   1945-7103. PMC   8754030 . PMID   23167519.
  9. ↑ Karlsson, Ingela; Bondemark, Lars (2006-11-01). "Intraoral maxillary molar distalization". The Angle Orthodontist. 76 (6): 923–929. doi: 10.2319/110805-390 . ISSN   0003-3219. PMID   17090171.
  10. ↑ 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. doi:10.1016/S0889-5406(00)70238-1. ISSN   0889-5406. PMID   10715093.
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