details about retention,theories of retention,schools of retention,retention appliances and relapse.

1. JOSNA THANKACHAN
FINAL YEAR PART I
AL-AZHAR DENTAL COLLEGE
RETENTION
APPLIANCES

2.  INTRODUCTION
 THEORIESOF RETENTION
 RALEIGHWILLIAMSKEYS TO ELIMINATELOWERRETENTION
 TYPESOF RETENTION
 RETAINERS
 CLASSIFICATION
 REMOVABLERETAINERS
 FIXEDRETAINERS
 ACTIVERETAINERS
 CONCLUSION
 REFERENCES
CONTENTS

3.  What is retention?
 has been defined by Moyers as
“Maintaining newly moved teeth in
position long enough to aid in stabilizing
their correction”.
INTRODUCTION

4.  Why is retention necessary?
 Retention is necessary for 3 main reasons
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 may be in an inherently unstable position
after the treatment,so that soft tissue pressures
constantly produce a relapse tendancy.
3. Changes produced by growth may alter the
orthodontic treatment.

5. If teeth are not in an inherently
unstable position and if there is no
further growth, retention still s vitally
important until gingival and periodontal
organization is complete.
Retention cannot be abandoned until
growth is essentially completed.

6.  What is relapse?

 Relapse implies loss of
any correction
achieved by orthodontic
 treatment.

7. CAUSES OF RELAPSE
L
Text book of orthodontics,SRIDHAR PREMKUMAR

8. SCHOOLS OF THOUGHT PERTAINING TO
RETENTION/HISTORY OF RETENTION
 There are 4 schools of thought pertaining to
retention:-
1. Occlusion school of thought(kingsley)
 A/C to this,proper occlusion of teeth is a potent factor in
maintaining the stability of the teeth.
 At the end of active orthodontic treatment there should
be proper intercuspation and interdigitation.
 There should be cusp to fossa relationship between
maxillary and mandibular teeth.

9. 2. Apical base school of thought(Axel lundstrom)
 A/C to this,apical base is one of the most important
factors in both correction of malocclusion as well as
maintenance of correct occusion.
 Intercanine and intermolar width should be altered to
prevent relapse.
 Nance advised to increase the arch length only to a
minimal extent.

10. 3. Mandibular incisor school of thought(Grieve and
Tweed)
 This theory postulated that the mandibular incisors
should be placed upright and over the basal bone.
4. Musculature school of thought(Roger’s)
 Establishing proper functional muscle balance is a
must to achieve stable occlusion.
 Improper muscle balance leads to relapse.

11. THEOREMS ON RETENTION
 There are 10 theorems of which 9 are put forward
by Riedel and the last one by Moyer.
 THEOREM 1
 “Teeth that have been moved tend to return to their
former positions”
 THEOREM 2
 “elimination of the cause of malocclusion will prevent
recurrence”

12.  THEOREM 3
 “Malocclusion should be overcorrected 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 to
reorganize around newly positioned teeth”.

13.  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 teeth have been moved ,the less likelyhood
of relapse.

14.  THEOREM 9
 “arch form particularly in the mandibular arch,cannot be
altered permanently by appliance therapy”.
 THEOREM 10
 “many treated malocclusions require permanent
retaining devices”.

15. PRINCIPLES OF RETENTION
 Relapse potential may be predicted by evaluation of
initial occlusion; teeth usually want to return to their
original position; this is due to gingival fibers and
unbalanced lip-tongue forces
 Full-time retention is required for 3-4 months to
allow for reorganization of PDL
 Retention should continue for at least 12 months in
non-growing patients or until growth has ceased in
growing patients

16. TYPES OF RETENTION
 natural/no retention
 Limited or short term retention
 Medium term/moderate retention
 prolonged/permanent/semi permanent retention

17. NATURAL RETENTION
--Occlusion is self retentive
--an upper incisor is moved over the bite, no retention is
required
--Conditions that do not require any retention
 anterior crossbite
 Serial extraction procedures
 Blocked out or highly placed canines in class I
extraction cases
 Posterior crossbite in patients having steep cusps

18. SHORT TERM RETENTION
 Limited retention-3-6 months
 Class I non-extraction with dental arches showing
proclination and spacing
 Deep bite
 Class I,Class II div 1 and div 2 cases treated by
extraction

19. MEDIUM TERM/MODERATE RETENTION
 Supporting tissue will take longer time to adapt
 Retention may extend between 1-5 years
 Class I non extraction cases,with protrusion and
spacing of maxillary incisors
 Corrected deep bites in classI or class II
malocclusion
 Corrected class II div 2 malocclusion

20. PROLONGED/PERMANENT/SEMI PERMANENT
RETENTION
 Cases treated by expansion particularly in the
mandibular arch
 Generalized spacing with arch length excess
 Severe rotatation
 Midline diastema
 Cleft palate cases
 Adult patients with periodontal problems
 Severe labiolingual malposition

21. RALEIGH WILLIAMS KEYS TO ELIMINATE
LOWER RETENTION.
6 keys:-
1. Incisal edge of the lower incisor should
be placed on the A-P line or 1mm infront of
it. This position of the lower incisor
ensures stability following treatment. It also
creates optimum balance of soft tissues in
the lower third of the face.

22. 2. The lower incisor apices should
bespread 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 central
incisors. In otherwords the lower
incisor roots should be diverging.

23. 3. The apex of the lower cuspid
should be positioned distal to the
crown
4. All 4 lower incisors apices must
be in the same labolingual plane
5. The lower cuspid root apex must
be positioned slightly buccal to the
crown apex.
6. The lower incisors should be
slenderised as needed after
treatment

24. RETAINERS
 Retainers are passive orthodontic appliances that
help in maintaining and stabilizing the position of
the teeth long enough to permit reorganization of
the supporting structures after the active phase of
orthodontic therapy

25. IDEAL REQUIREMENTS FOR
RETAINERS(GRABER)
 It should restrain each tooth that has been moved
in to the desired position
 It should be easily cleanable
 It should allow functional forces to be transmitted to
the retained teeth if worn
 It should be self cleansable
 It should be inconspicuous
It should be strong enough to achieve the objectives
of retention

26. CLASSIFICATION
 Hawley retainer and
modifictions
 Wrap around retainers
 Canine to canine clip
on
 Tooth positioners
 Essix/invisible retainers
 Functional appliances
 Banded canine to
canine retainers
 Bonded canine to
canine retainers
 Diastema maintenance
 Antirotation band
 Band and spur
 Pontic maintenance
REMOVABLE FIXED

27. REMOVABLE RETAINERS
 Effective for retention against intra arch stability
 Effective in growth problems

28. HAWLEY RETAINER
 Most common removable retainer
 Developed in 1920s
 Clasps on molars, palatal coverage, and labial bow with
adjustment loops
 Can incorporate biteplate for deep bite patients

29.  MODIFICATIONS
 Labial bow can be made to extend from 1st premolar
to the opposite 1st premolar. The design helps in
closing spaces distal to canine.
 Solder the bow to the bridge of the Adam’s clasp.This
design avoids the risk of space opening upbetween
the canine and premolar due to the crossover wires.

30.  Fitted labial bow offers excellent retention
 Anterior bite planes can be incorporated to retain
correct deep bite cases.
 Advantages
 Ease of fabrication
 Minimal patient discomfort
 Acceptable to most patients.

31.  Popularized by P.R.Begg
 Consists of labial wire that extend till the last erupted
molar and curves around it to get embedded in
acrylic that spans the palate
 Advantages:there is no cross over wire between the
canine and premolar thereby eliminating the risk of
space opening up.
BEGG’S RETAINER

32. CLIP-ON RETAINER/SPRING ALIGNER
 Made of a wire framework that runs labially over the
incisors and then passes between the canine and
premolar and is recurved to lie over the lingual
surface. Both the labial as well as the lingual wire
segments are embedded in a strip of clear acrylic.
 Used for correction of rotations commonly seen in
the lower anterior region.

33. WRAP AROUND RETAINER
 Extended version of the spring aligner that covers
all the teeth.
 It consists of a wire that passes along the labial as
well as lingual surfaces of all erupted teeth which is
embedded in a strip of acrylic.
 APPLICATION
 Stabilizing a periodontally week dentition.

34. WRAPAROUND MODIFICATION:
“3-3 CLIP-ON”
Used mainly for lower
anterior area
Can realign incisors
and/or maintain lower
incisor space closure
Used if posterior teeth
were well aligned pre-
treatment

35. KESLING TOOTH POSITIONER
 Described by H.D.Kesling in 1945
 It is made of a thermoplastic rubber like material
that spans the inter-occlusal space and covers the
clinical crowns of the upper and lower teeth and a
small portion of the gingiva.
 Needs no activation at regular intervals and is
durable.
 Drawbacks include difficulty in speech and risk of
TMJ problems.

36. ESSIX/INVISIBLE RETAINERS
 Developed in 1993
 Plastic removable appliance
 Advantages:
 Esthetic
 Patient is more likely to wear
 Inexpensive
 Quick fabrication
 Minimal bulk
 High strength
 No adjustments
 Usually does not interfere with speech or function
 Studies have determined that Essix retainers are as efficient
as Hawley-type or bonded wire retainers

37. POSITIONER
 Can be made as retainer or used for finishing and
then maintained as retainer
 Disadvantages as a retainer:
1. Bulky and difficult to wear full-time
2. Do not retain incisor position as well as a
conventional retainer because patients usually
wont wear full-time
3. Overbite increases due to limited patient wear

38. Advantages as a retainer:
1. Reestablishes normal tissue when gingival
hyperplasia is present
2. Maintains occlusal relationship and intra-arch
position
3. Unlikely to break
4. Can be made with jaws rotated down and
back to prevent Class III relapse
5. Can be constructed to prevent relapse in
skeletal Class II and open bite cases
 Growth control is less effective than part-
time functional appliance or headgear

39. DAMON SPLINT
 Basically, upper and lower Essix retainers
connected
 Retentive splint for Class II, Class III, and bilateral
crossbite treatment
 Assists in tongue training
 Holds teeth and arches in corrected position

40. Designed By Dr. Dwight Damon
 Can be used by adults or patients in mixed
dentition
 Minimal vertical opening to allow for air slot
 Esthetic
 Can be made using:hard pressure formed, dual
hardness/soft liner and elastic silicone

41. FIXED RETAINERS
 Utilized in cases where stability is
questionable and prolonged retention is
planned
 Four main indications:
1. Maintaining lower incisor position
2. Holding diastema closed
3. Implant or pontic space maintenance
4. Retaining closed extraction spaces

42. BONDED CANINE TO CANINE RETAINER
 Commonly used in lower anterior region.
 Canines are banded and a thick wire is contoured
over the lingual aspects and soldered to the canine
bands.
 The bands predispose to poor oral hygiene and are
unesthetic.in addition when these retainers are
removed band spaces are seen around these
bands.
 These drawbacks of the banded retainers have
made them less popular than the bonded retainers.

43. BONDED LINGUAL RETAINERS
 They are retainers that are bonded on the lingual
aspect.
 Stainless steel/elgiloy wire is adapted lingually to
follow the anterior curvature. The ends are curved
over the canine where it is bonded.
 Disadvantage : anterior teeth can sometimes rotate
 This is overcome by using bonded retainers that
are bonded to each of the anterior teeth from
canine to canine.

44.  In case extractions have been done as part of the
orthodontic treatment it may be advisable to extend
the retainer to include the 1st premolar of both the
sides.
 Alternatives
 Use of etched or perforated metal cast bars that can be
bonded on the lingual side of the teeth.
 Braided or multistranded wire that can be bonded
individually to each tooth in a segment.

45.  Advantage
 All individual teeth are retained with no possibility of
rotation of the incisors.
 Use of lighter braided wires permit physiological
movement of the teeth within the periodontal ligament.
 Disadvantage
 The bonding of the lingual retainers on the lingual
surface of the teeth can be accomplished by direct or
indirect bonding.

46. BAND AND SPUR RETAINER
 Used in cases where a single tooth has been orthodontically
treated for rotation,correction or labiolingual displacement. The
tooth that has been moved is banded and spurs are soldered
on to the bands so as to overlap the adjacent teeth.
In case it is used to retain a tooth that has been blocked
partially,the spurs are made on the labial aspect so that tooth
doesnot onceagain get displaced palataly.In derotation cases
,one spur is placed labially and the other lingually to avoid
relapse.

47. ACTIVE RETAINERS
 Spring retainer: realign malpositioned incisors
 Modified functional appliance: manage relapse
potential in Class II or Class III cases

48. ACTIVE RETAINERS
 Spring retainer: realign malpositioned incisors
 Will usually need to perform IPR prior to
appliance placement to prevent proclining
incisors into unstable position
 IPR flattens contacts increasing stability
 Can reduce incisors 0.5 mm/side
 If teeth are severely crowded, retreatment with
bonded brackets is recommended; followed by
fixed retention

49. Modified functional appliance: manage
relapse potential in Class II or Class III
cases
Activator or Bionator:
 Upper and lower retainers joined by inter-occlusal bite
blocks
 Maintain teeth within arch while slightly altering occlusal
relationship
 Example: If adolescent slips back 2-3 mm into Class II
after early correction, this appliance can be used to
recover proper occlusion

50.  No value if used in adults (as no
vertical growth remains)
 Moves teeth (no skeletal change)
 Can only be used if no more than 3mm
correction is needed
 Goal: Hold maxillary posterior segment and
allow for eruption of mandibular posterior
segment anteriorly (Class II)

51. CONCLUSION
 Goals of occlusion are predefined prior to start of
orthodontic treatment.Procedures should be
conducted with extreme care to minimize iatrogenic
effects on dental hard tissues and periodontium.

52. REFERENCES
 CONTEMPORARY OF ORTHODONTICS
BY WILLIAM PROFITT,HENRY W
FIELD,DAVID M SARVER
 ORTHODONTICS ART AND SCIENCE BY
S.I BHALAJHI