Retention And Relapse 335x70

RETENTION AND RELAPSE

Dr. Ashwin Thejaswi. M

DEFINITON RETENTION: “Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction” –MOYERS

RELAPSE: “The loss of any correction achieved by orthodontic treatment.”

CAUSES OF RELAPSE       

Periodontal ligament traction Relapse due to growth related changes Bone adaptation Muscular factors Failure to eliminate the original cause Role of third molars Role of occlusion

WHY RETENTION IS NECESSARY?  1. The gingival and periodontal tissues are affected by orthodontic tooth movement arc require time for reorganization when the appliances are removed.

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2. The teeth may be in an inherently unstable position after treatment, so that soft tissue pressure constantly produces a relapse tendency.

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3. Changes produced by growth may alter the orthodontic treatment result.

SCHOOLS OF RETENTION 

The Occlusion Base –KINGSLEY

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The Apical Base –ALEX LUNDSTROM, McCAULEY & NANCE

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The Mandibular Incisor School –GRIEVES & TWEED

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The Musculature School ‐ROGERS

THE OCCLUSION BASE – KINGSLEY

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Proposes that proper occlusion is a key factor in determining the stability of the newly moved teeth.

THE APICAL BASE –

ALEX LUNDSTROM, McCAULEY & NANCE 

ALEX LUNDSTROM suggested that the apical base is an important factor in the correction of malocclusion and maintenance of the stability of treated cases.

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McCAULEY added that the intercanine and intermolar widths should be maintained during orthodontic therapy to minimize retention problems.

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NANCE noted that the arch length cannot be permanently increased to a major extent.

THE MANDIBULAR INCISOR SCHOOL – GRIEVES & TWEED 

They suggested that post treatment stability was increased when mandibular incisors were placed upright or slightly retroclined over the basal bone.

THE MUSCULATURE SCHOOL ‐ ROGERS 

According to him functional muscle balance is necessary in order to ensure post treatment stability.

THEORIES OF RETENTION THEOREM 1 : 

Teeth that have been moved tend to return to their former position.

THEOREM 2 

Elimination of the cause of malocclusion will prevent relapse.

THEOREM 3: 

Malocclusion should be over corrected as a safety factor.

THEOREM 4: 

Proper occlusion is a potent factor in holding teeth in their corrected positions.

THEOREM 5: 

Bone and adjacent tissues must be allowed time to reorganize around newly positioned teeth.

THEOREM 6: 

If the lower incisors are placed upright over basal bone they are more likely to remain in good alignment.

THEOREM 7: 

Corrections carried out during periods of growth are less likely to relapse

THEOREM 8: 

The farther the teeth have been moved the lesser is the risk of relapse.

THEOREM 9: 

Arch form, particularly in the mandibular arch cannot be permanently altered by appliance therapy

THEOREM 10: 

Many treated malocclusions require permanent retaining devices.

RAYLEIGH’S 6 KEYS TO ELIMINATE LOWER RETENTION Incisal edges of the lower incisors should be placed on the A‐P line or 1mm in front of it.



The lower incisor apices should be spread distally to the crowns more than is generally considered appropriate and the apices of the lower lateral incisors must be spread more than those of the central incisors.

 Apex of lower cuspid should be positioned distal of the crown

All four lower incisors apices must be in the same labiolingual plane

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The lower cuspid root apex must be positioned slightly buccal to the crown apex.

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The lower incisors should be slenderized as needed after treatment

TYPES OF RETENTION ‐REIDEL

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NATURAL RETENTION OR NO RETENTION

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LIMITED RETENTION OR SHORT TERM RETENTION

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PROLONGED RETENTION OR PERMANENT RETENTION

NATURAL OR NO RETENTION

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Anterior cross bite

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Serial extraction procedures

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Blocked out or highly placed canines in Class I extraction cases

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Posterior cross bite in patients having steep cusps.

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Corrections achieved by retardation of maxillary growth once the patient has completed growth

LIMITED OR S

HORT TERM

RETENTION

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•Class I non extraction with dental arches showing proclination and spacing

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•Deep bites

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•Class I, Class II div 1 and 2 cases treated by extraction.

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•Early corrections of rotated teeth to their normal position before root completion

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•Cases involving ectopic eruption or supernumery teeth

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•Class II div 2 cases for muscle adaptation

PROLONGED OR PERMANENT RETENTION 

Midline diastema

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Severe rotations

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Arch expansion

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Class II div 2 with deep bite cases

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Patients exhibiting abnormal musculature or tongue habits

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Expanded arches in cleft patients

RETAINERS 

ive Orthodontic appliances

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Maintaining and stabilizing the position of teeth long enough to permit reorganization of the ing structures after the active phase of orthodontic therapy.

I

DEAL REQUIREMENTS OF RETENTION APPLIANCE 

It should restrain each tooth in its direction of relapse

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It should permit the forces associated with the functional activity to act freely on the teeth, permitting them to respond in as nearly a physiologic manner as possible

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It should be as self-cleansing as possible and should be reasonable easy to maintain optimal hygiene

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Should be as inconspicuous as possible, esthetically good.

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Strong enough to bear the rigors of day to day usage.

R

EMOVABLE

R

ETAINERS

Hawley’s appliance  With long labial bow  With contoured labial bow  Continuous labial bow soldered to clasps  With elastic replacing labial bow 

Begg’s retainer Single arrowhead partial wraparound retainer

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Clip‐on retainer/spring aligner Wrap around retainer Kesling tooth positioner Invisible retainers

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HAWLEY’S A

PPLIANCE

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The retainer consists of a labial extending from canine to canine with retentive clasps on permanent molars.

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Good retention

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Prevents anterior teeth from rotating or developing gaps.

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Prevents the opening up of extraction spaces.

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Capable of closing minor spacing in the anterior segment.  

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MODIFICATIONS OF HAWLEYS APPLIANCE:

BEGG’S RETAINER 

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Labial wire that extends up to the last erupted molars Wire curves around the molar and get embedded in acrylic that spans the palate.

R

EMOVABLE WRAP AROUND RETAINER This is the second most commonly used removable retainer.

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INDICATIONS: Primarily when periodontal break down requires splinting the teeth together.

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Disadvantages over Hawley’s :

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1. Individual tooth movements are not allowed to stimulate periodontal reorganization.

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2. Less comfortable.

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3. Not effective in maintaining overbite correction.

S

PRING RETAINER APPLIANCE: It is a versatile appliance which can be used as ,

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Anterior retainer in either arch.

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Can be used as active appliance to re align incisors (post relapse)

R

EMOVABLE PLASTIC HERBST RETAINER: It has property of both single arch and dual

arch retainers

Components: 

Upper and lower plastic splints connected on

each side by the telescoping Herbst mechanism.

T

OOTH POSITIONERS AS RETAINERS: Tooth Positioners can be used as removable

retainers. They should be worn at least 4 hrs during daytime and full night time wear.

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Can be effective in maintaining occlusal relationships and intra arch tooth positions.

E SSIX RETAINER These are thermoplastic co polyester vacuum formed retainers.

A

DVANTAGES:

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Esthetic and absolute stability of anterior teeth

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Less expensive, good durability, oral hygiene maintenance.

 

Less bulk and thickness (0.015 inch).

D 

RAWBACKS:

Cannot be used for expanded arches

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Prolonged use can cause anterior open bite

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Less durable when compared to Hawley retainer.

F IXED R

ETAINERS

CLASSIFICATION 



Intracoronal

Fixed Appliance Band and spur retainer Direct splinting

Extracoronal Canine to canine bonded/banded Flexible spiral wire retainer Mesh pad retainer

I

NDICATIONS

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Maintenance of lower incisor position during late mandibular growth.

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Following closure of diastema.

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Maintenance of bridge- pontic space.

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Compromised periodontal conditions with the potential for post orthodontic teeth migration.

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Prevention of rotational relapse.

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Prevention of relapse after the correction of palatally erupted canines

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Prevention of opening up of closed extraction space.

A

DVANTAGES

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Reduced need for patient co-operation.

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Can be used when conventional retainers cannot provide same degree of stability.

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Bonded retainers are more esthetic.

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No tissue irritation.

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Tolerated by patient

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Do not affect speech.

DISADVANTAGES 

More cumbersome to insert.

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Increased chair side time

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More expensive

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Banded variety may interfere with oral hygiene maintenance.

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More prone to breakage.

 

FLEXIBLE SPIRAL WIRE RETAINERS 

ADVANTAGES:

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1. They may allow safe retention of treatment results when proper retention is difficult or even impossible with traditional retainers.

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2. They allow slight movement of all bonded teeth and segment of teeth

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3. They are invisible, neat and clean and can be placed without occlusal interference.

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4. They can be used alone or in combination with removable retainers.

D

ISADVANTAGES:

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1. Good oral hygiene should be maintained.

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2. Daily flossing should be recommended gingival to the wire.

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3. Undesirable movement of bonded teeth may occur if the wire is too thin or not ive while bonding.

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4. Not indicated in deep bite cases where wire cannot be placed out of occlusion

BANDED AND BONDED CANINE TO CANINE RETAINERS 

Banded -0.036/0.04” wire

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Bonded -0.036” mesh on canine.

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Bonded –mesh throughout the length

P

REVENTION OF

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Over rotation.

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Prolonged retention.

R

ELAPSE

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Treatment of rotated tooth should be performed at early age.

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Placement of teeth in oro–facial soft tissue balance.

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Placement of teeth in occlusal equilibrium.

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Pericision – surgical resection of stretched fiber around gingival socket margin (supra-alveolar fibers).

CONCLUSION 

Retention is a part of orthodontic treatment.

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The benefit of orthodontic treatment cannot be appreciated without undergoing retention of the moved teeth for a period of time.

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Though many devices are available for retention of orthodontically adjusted teeth, they must still be tailor-made to suit each individual.

REFERENCES 

Gurkeerat Singh – A Textbook of Orthodontics

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S M. Balaji – Textbook of Orthodontics

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Graber’s – Textbook of Orthodontics