Orthodontics – Retention

RETENTION  –  Period after active treatment when passive fixed / removable appliances were worn to stabilize the occlusion that had been created

—> appliance —>

RETAINER  –  Passive orthodontic appliances that help in maintaining and stabilizing the position of a single tooth or group of teeth to permit reorganizing of the supporting structures

 

WHY RETENTION IS NECESSARY?

1. The gingival and periodontal tissues are affected by orthodontic tooth movement and require time for reorganization when the appliances are removed.
2. The teeth be in an inherently unstable position after the treatment, so that soft tissue pressure constantly produce a relapse tendency.
3. Changes produced by growth may alter the orthodontic treatment results.

 

Causes of Relapse

• Failure to remove cause of malocclusion
• Lack of normal cuspal interdigitation
• Incorrect axial inclination
• Tooth size disharmony and improper contacts
• Arch expansion
• Failure to manage rotations

 

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Retention Planning

	Time of usage	Cases
NO RETENTION REQUIRED		a. Cross bite b. Dentition treated with serial extraction
LIMITED RETENTION	6 months = whole days and nights	a. Class I non-extraction cases with spacing and protrusion of maxillary incisor b. Class I and II extraction cases c. Early correction of rotated teeth to their normal position before root completion d. Cases involving ectopic eruption or the presence supernumerary teeth e. Corrected deep bites
PERMANENT RETENTION		a. After arch expansion especially in mandibular arch b. Cases of considerable generalized spacing c. Severe rotation or severe labiolingual malposition d. Spacing between maxillary central incisor with an otherwise normal occlusion

 

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Classification of Retainers

1. Fixed retainers -> cemented or bonded to the teeth

0.0195 twisted wire

 

 

2. Removable retainers -> can be removed and reinserted by the patient

 

Removable Retainers

Hawley’s retainer

• With short labial bow
• With long labial bow
• With contoured labial bow
• Continuous labial bow soldered to clasps

 

Begg’s retainer (wrap-around retainer)

 

Kesling’s tooth positioner

 

Essix (vacuum-formed retainers)

 

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References:
Gill, D.S. 2008. Orthodontics at a Glance. Blackwell Munksgaard.
Proffit, W.R; Field, H.W; Sarver, D.M. 2007. Contemporary of Orthodontics. 4th edition. St. Louis: Mosby Elvevier.
Singh, G. 2008. Textbook of Orthodontics. 2nd edition. New Delhi: Unipress.