Stability Retention and Relapse in orthodontics

By
Ashok kumar A
Department of orthodontics
STABILITY RETENTION & RELAPSE
IN
ORTHODONTICS
1
Dr.Ashok kumar - Orthodontics

• Introduction
• Definition – Stability, Retention & Relapse
• Normal changes in untreated dentition
• Schools & theorems of retention
• Factors influencing relapse and retention
• Types of retainers
• Retention plan
• Duration of plan
CONTENTS
• Retention protocol & stability
- Extraction & Non extraction cases
- Arch expansion
- Class I , Class II & Class III cases
- Deep bite & Open bite cases
- Orthognathic surgery cases
- Cleft lip & palate cases
• Adjunctive periodontal procedures
• Recent advances – Mechanical & Biomedical agents
• Conclusion
2

“Stability is the condition of maintaining equilibrium.” This refers to the quality or condition of
being stable; the fixity of position in space or the capacity for resistance to displacement.
Physiologic stability is a term defined by rossouw and appears to encompass the acceptable changes a
clinician can expect; it includes normal ageing changes of the dentition, which take place
irrespective of treatment outcome.
Relapse–“Loss of any correction achived by orthodontic treatment”. It involves a return of correction
of skeletal dysplasia, as well as the dental malocclusion, returning towards the pretreatment position.
INTRODUCTION
Terminology: Semantics of Post orthodontic Treatment Changes in the Dentition P. Emile Rossouw Semin Orthod 1999;
3

• Hellmant - 'Retention is not a separate problem in orthodontia but is a continuation of what we are
doing during treatment. A complete result must be accomplished before retention is applied.
• The finalization process should include both active stabilization and passive guidance procedures,
rather than rigid fixation of teeth, which after treatment could be in un physiologic positions.
Retention – “Maintaining newly moved teeth in position , long enough to aid in
stabilizing their correction.”- Moyers
Terminology: Semantics of Post orthodontic Treatment Changes in the Dentition P. Emile Rossouw Semin Orthod 1999;
4
“Retention is one of the most difficult problems in orthodontia; in fact, it is the problem.” - Oppenheim

Normal changes in the
Untreated Dentition
5

• Bolton-Brush Growth Sample shows the following general longitudinal changes (Behrents)
1. Considerable craniofacial alteration beyond 17 years in males and females
2. Craniofacial changes continue into the oldest age spans (83 years) in an apparently adaptive
but decelerating manner .
3. Vertical changes – common in adulthood.
4. Mandibular plane rotations –
Forward direction in males &
Backward or vertical direction in females
Orthodontics, current principles and techniques by Graber & Vanarsdall -6th edition 6

5. Sexual dimorphism – shown
6. Soft tissue changes:
a. Soft tissue changes – greater than skeletal changes
b. Changes include – elongation of the nose,
flattening of the lips and augmentation of the chin
Orthodontics, current principles and techniques
by Graber & Vanarsdall -6th edition
7

Lower Incisor Irregularity
1. Changes in alignment in the untreated lower arch occur at various developmental stages.
On average, crowding decreases between 7 and 12 years (mixed dentition development)
and increases thereafter (loss of Leeway and eventually E-space).
2. Role of erupting third molars in the development of mandibular incisor crowding
3. Crowding of the mandibular incisors was observed in vertical growers as a result of chronic
airway obstruction
4. Mesial migration of teeth caused by physiological
mesial drift, by the anterior component of the force
of occlusion on mesially inclined teeth .
Orthodontics, current principles and techniques by Graber & Vanarsdall -6th edition
8

• Overbite and overjet increase significantly from the mixed to the permanent dentition. During
the maturation of the permanent dentition (13–20 years), these changes were reversed, and
decreases in overbite and overjet were observed by Barrow & White(1952),Bjork(1953) .
• Arch length decreases over time , longitudinal data show that changes in arch dimensions, as
well as lower incisor crowding occur as part of the normal ageing process .
• Late mandibular incisor crowding, thus, may be unrelated to any previous orthodontic
treatment. There is no doubt that normal untreated occlusions provide valuable insight into
longitudinal changes and thus management of tooth alignment.
9

Why retention is necessary ?
The proposed basis for holding teeth in their treated position is to
1) Allow for periodontal and gingival reorganization
2) To minimize changes from growth.
3) To permit neuromuscular adaptation to the corrected tooth position and
4) To maintain unstable tooth position if such positioning was required for reasons
of compromise or aesthetics.
Contemporary Orthodontics – WILLIAM R. PROFIT 6 th EDITION
10

SCHOOLS OF RETENTION
11

The Occlusion School
• According to Kingsley, proper occlusion is a key factor in determining the stability of the newly
moved teeth.
The Apical Base School
• Alex Lundstrom suggested that the apical base is an important factor in the correction of
malocclusion and maintenance of the stability of the treated cases.
• Mc Cauley added that the intercanine and intermolar widths should be maintained during
orthodontic treatment to minimize retention problems.
• Nance noted that the arch length cannot be permanently increased to a major extent.
12

The Mandibular Incisor School
• Grieves and Tweed have suggested that post-treatment stability was increased when the
mandibular incisors were placed upright or slightly retroclined over the basal bone.
The Musculature School
• The dentition is encapsulated from outside and inside by muscles. According to Rojers,
functional muscle balance is necessary in order to ensure post-treatment stability.
13

Riedels Nine Rules of
Retention & Relapse
14

• Richard A. Riedel has outlined principles of relapse & retention as 'Rules‘ which were further discussed
by George Fahn, R.H.W. Strang and H.M. Lang.
• Henry Kaplann (1988) published an up-to-date review & scientific rationale of retention & relapse .
Theorem 1
“Teeth that have been moved tend to return to their former position.”
Theorem 2
“Elimination of the causes 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 to reorganize around newly positioned teeth.”
Theorem 6
“If the lower incisors are placed upright over basal bone, they are 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 less likelihood of relapse.”
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.”

FACLORS INFLUENCING
RELAPSE AND RETENTION
17

18

Facial types, craniofacial growth and relapse
• Type A- Both mandible and maxilla grow downward and forward but at the same pace.
• Type B- Both of them grow downward & forward, but maxilla grows > mandible, resulting
mostly in vertical growth.
• Type C- The mandible grows at a greater pace than maxilla, these are horizontal growers.
19

• In short face syndrome - with a low mandibular plane angle, management of deep bite is
difficult due to the presence of a strong chain of elevator muscles which tend to keep the mandible
in an anticlockwise rotation. It require longer retention with an anterior bite plane touching the
lower incisors and no separation of posteriors
• In vertical growth pattern, an over eruption of buccal segment teeth is expected, & the vertical
position of molars has to be retained with high pull headgear or posterior bite blocks to prevent
opening of the bite.
20

Late mandibular growth
• The late mandibular growth continues especially in horizontal growers (Type C) after adulthood
and is thought to be responsible for lower incisor crowding.
• As the mandible continues to grow downward and forward, the bite deepens and lower incisors
confined by the upper incisors are bound to tip lingually in a crowded state.
• The untreated lower incisors in adults show increased crowding with age while intercanine widths
and arch lengths continue to decrease with age .
21

Bolton tooth size discrepancy
• Deviation in the Bolton discrepancy would not allow a good finish of occlusion, that is, overjet and
overbite with good functional contacts.
• Most often, the discrepancy is in the form of mandibular tooth excess , IPR of lower anterior teeth
provides better inter-proximal contacts and therefore stable position - Dr Williams .
• Maxillary tooth material may be deficient as is seen with smaller lateral incisors. Such cases would
require proximal composites or veneers on the teeth with smaller mesiolingual dimensions.
22

Third molars and relapse
• The role of erupting third molars in the causation of the relapse has long been debated .
• Recent research has questioned the role of third molars in the causation of the anterior crowding.
• The therapeutic removal of third molars for prevention of relapse of lower anterior crowding is
not justified.
• Between the ages of 18 and 21 years, the lower arch is stable in terms of tooth alignment and
mesial drift, regardless of third molar status or continuing mandibular growth.
Contemporary Orthodontics – WILLIAM R. PROFIT 6 th EDITION 23

Periodontal health
• The presence of periodontal disease causes the forces of occlusion to act adversely and therefore
cause migration of the teeth.
• Occlusal trauma was considered a significant contributor to periodontal migration. However,
research has proven that occlusal trauma alone would be incapable of causing migration in the
absence of disease of the periodontium.
• In patients with previously treated severe periodontal disease, permanent retention is advised. For
those with minimal to moderate disease, a more routine protocol can be used.
24

Sex, Age And Race
• It is a well known fact that females are early maturers than males. The mandibular growth in females
may be completed by 13 years while males continue to grow beyond 16 years
• Skeletal adaptations occur better in younger age and hence the stability in the outcome. The skeletal
changes with functional appliances and with RME are two good examples.
• Racial predilections - For example, class III is more common in Mongoloids and bimaxillary protrusion
with a large tongue and thick lips are more common in Africans and some races in South India.
• Accordingly, the bimaxillary patients treated with extractions of all first premolars encroach upon the
tongue space and therefore have greater possibilities of relapse.
25

Systemic Diseases
• The common diseases that affect the bone turnovers are hyperparathyroidism and disorders of the
pituitary glad like acromegaly.
• While in hyperparathyroidism the lamina dura may not be directly affected, the jaw bones show
area of bone formation and resorption where the bone is replaced with multinucleated giant cells
contained in 'brown nodes'.
• In acromegaly, the mandibular condyle would show excessive growth and lengthening of the
mandible, therefore, causing relapse of the treatment outcome.
Diagnosis and management of malocclusion and dentofacial orthopedics – O P Kharbanda 3rd Ed 26

Lower anterior teeth position
RALEIGH WILLIAMS KEYS TO ELIMINATE
LOWER INCISOR RETENTION
27

Key 1: The incisal edge of the lower incisor -placed on the A-Pog line or 1 mm in front of it.
Key 2: The lower incisor apices should be spread distally to the crowns.
Apices of lateral incisors must be spread more than those of central incisors.
Key 3: The apex of the lower cuspid should be positioned distal to the crown.
The occlusal plane should be used as a positioning guide. This reduces the tendency of the
canine to tip forward into the incisor area.
Key 4:The lower cuspid root apex must be positioned slightly buccal to the crown apex.
Key 5:All the four lower incisor apices must be in the same labiolingual plane.
Key 6:Flattening lower incisor contact points by slenderizing or stripping creates flat
contact surfaces. Flat contacts surfaces help resist labiolingual crown displacement.

TYPES OF RETAINERS
29

CONVENTIONAL
REMOVABLE RETAINERS
• Transparent vacuum formed retainer (VFR),
tooth positioner
• Circumferential retainers (Begg retainer)
• Hawley retainer
• Hawley retainer with bite Plate
FIXED
LINGUAL RETAINERS
• Flexible spiral wire (FSW) retainers in the
maxillary arch
• FSW retainer in the mandibular arch
• Preformed 3-3 bonded retainers
• Lower lingual arch as a retainer
30

RETAINERS AFTER
DENTOFACIAL ORTHOPAEDICS
• Functional appliances (class II & III)
• Anterior and posterior bite plates
• Headgear
• Chin cup
ACTIVE RETAINERS
• Functional appliances (class II & III malocclusion)
• Headgear , Chin cup
• Anterior and posterior bite plates
• Spring aligners
• Transparent vacuum-formed aligner
31

Clear plastic retainers
• The appliance is nearly invisible, and allowance can be made for minor corrections of derotation or
space closure to be incorporated by making necessary changes on the dental plaster model.
• Demerit - This appliance does not allow for vertical settling of occlusion
• A study found that patients receiving VFRs seem to be significantly more likely to be 'very satisfied'
currently (50%) compared to those with Hawley (35%) or permanently bonded (36%) retainers
32

Kesling’s tooth positioner - H.D. Kesling 1945
• It is made up of thermoplastic rubber material and covers the upper and lower clinical crowns
and part of the adjacent gingiva.
• A positioner is essentially used as an aid to finishing, & to obtain ideal occlusion & also to
maintain the correction.
Limits
• This appliance is bulky and patient cooperation can be poor.
• The patient is unable to speak with the appliance in place &
risk of TMJ problem.

Hawley’s retainer -
Charles Hawley -
1920
• A Hawley retainer with an anterior bite plane is advantageous in facilitating posterior occlusal
settling during the first few months of retention.
• Occlusal interferences may results from wires of retentive devices such as Adams clasp.
• In the first premolar extraction cases, the extraction space may reopen from the wedging effect of the
labial bow between the canine and premolar.
34

Circumferential retainers/ Begg’s -retainer:
• Dr P.R. Begg used a circumferential retainer which is made up of a single wrap around Labial bow
extending from the distal of the right molar to the left molar. Retention can be achieved through pin head
between second premolar & first molars.
• The wrap around wire distal to the second molars eliminates potential occlusal interferences inherent
to adams clasp & therefore allow vertical settling of occlusion.
• It has additional advantage of maintenance of canine-second premolar in tight contact at extraction cases.
35

Anterior and Posterior bite plates
• Posterior bite plane or acrylic extending on to the occlusal
surfaces of the buccal teeth.
• These may be used to intrude molars and therefore control
open bite relapse .
• Anterior bite plane can-be incorporated into removable
upper retainers to intrude lower incisors and, therefore
control overbite relapse.
36

Fixed lingual retainers
• SS rigid/flexible multistrand wires (common) & also be prepared by fibre resin composite(FRC) threads.
• FSW- Irregular surface offers increased mechanical retention for the composite without the need for the
placement of retentive loops & flexibility of the wire allows physiologic movement of the teeth .
Generations
• Fixed retainers made of blue Elgiloy of dimensions 0.032-0.036 in. were introduced in 1944.
• During 1970, lower fixed retainers were soldered to either first molar bands or
canine bands. A 0.032 in. steel wire is chosen for it provided sufficient rigidity.
• Since 1994, lingual fixed bondable SS wire retainers (0.030-0.032 in.) ,
Sandblasted with aluminium oxide to improve micro-mechanical retention.
• Current orthodontic- the use of 0.0215 in. multi strand wire or 0.030-0.032 in. sandblasted round SS wire
37

Advantages of fixed lingual retainers
1. Lingual retainers are invisible & permit effective retention with the simultaneous individual
movement of the teeth, which is essential for the biological integrity & survival of teeth.
2. This type of retainer keeps extraction spaces closed in adults, maintains diastema closure and pontic
or implant space.
3. Fixed retention is favourable in preventing relapse at 5 and 10 years post-retention.
Disadvantages
1. Calculus and plaque deposition around retainer.
2. Maintenance of oral hygiene would need extra attention.
Dr.Ashok kumar - Orthodontics 38

Flexible wire retainer indications- Zachrisson 1983
1. Closed median diastemas & Spaced anterior teeth
2. Adult cases with potential post-orthodontic tooth migration
3. Accidental loss of maxillary incisors, requiring closure and retention of large anterior spaces
4. Space reopening after mandibular incisor extractions
5. Severely rotated maxillary incisors & Palatally impacted canines.
Indications for placement of a bonded canine-to-canine retainer- Lee 1981
• Planned alteration in the lower inter canine width & After correction of deep overbite.
• After advancement of the lower incisors during active treatment.
• After non-extraction treatment in mildly crowded cases;

• Bonded fixed retainers are now in common use for long term aesthetic retention.
• The failure rate ranges from 10.3 to 47.0% . The failure rate is approximately twice as great in the
maxilla as the mandible and this is most likely because of occlusal factors.
• Bonded fixed retainer may be waved fixed retainer or plain fixed retainer. A meta-analysis was
done to know the differences in the gingival health and plaque index between wave fixed retainer
and plain fixed retainer (Results –No difference )

Active retainer
Tooth positioner
• They are potentially active retainers as they cause finer tooth movement to the pre-destined position.
• They are fabricated after the teeth have been debonded, an impression taken and the teeth reset in an
ideal position on study models with 0.25 mm of tooth movement possible.
• They are used for realignment of irregular incisors or as functional appliances to manage class II or
class III relapse tendencies
41

Anterior retention of skeletal correction
• For retaining class II correction, an anterior locking plate during day time and a night time
wear of bionator are recommended.
• In children with a tendency for an excessive vertical growth of the maxilla, a high pull
headgear with Kloehn face bow can be used.
• Frankel III or reverse twin block are used for the maintenance of class III treatment.
Diagnosis and management of malocclusion and dentofacial orthopedics – O P Kharbanda 3rd Ed
42

Spring Hawley retainer
• It is used in correcting minor rotations of the anterior teeth. Before fabrication of the spring retainer,
it is essential that space is available to accommodate the teeth needing an alignment.
• In fabricating this appliance, the rotated teeth are set-up on the model in the corrected alignment.
• When worn in the mouth the spring action of the labial and lingual wire and acrylic components
gently aligns the teeth.
43

RELAPSE &
RETENTION PROTOCOL
IN MALOCCLUSIONS
44

Relapse tendency of Extraction and Non-Extraction cases
• Comparisons shows no significant difference between the two at the post retention phase with regard to
the incisor irregularity. Rossouw 1999, Nanda RS 2006, Quaglio CL 2010
• Therefore, the extraction decision must be based on the individual’s treatment needs. It was shown that
early treatment of crowding with extractions might potentially decrease the amount of relapse. Woodside
1999 ,DG Haruki T 1998
• Extraction spaces are closed and the teeth are moved together orthodontically , the adjacent teeth do not
move through the gingival tissue but appear to push the gingivae in front of them into a fold of epithelial
and connective tissue , ( Edward 1971 ) remove this tissue surgically so that relapse could be alleviated.
45

Relapse tendency of Arch Expansion
• Mandibular intercanine width is regarded as a fixed entity, and the early literature recommends that it
should not be expanded, if stability is an objective of treatment.
• Expansion of the maxillary arch - RPEs (relapse approx 20 %) and to a
lesser extent with archwires Gardner D 1976.
46
• Expansion of the mandibular arch - expansion appliances, such as the
lip bumper, and again, to a lesser extent with archwires.
• Postretention arch dimensional changes appear to occur regardless of
the treatment modality, although more arch width is lost after
expansion with archwires alone Taner T 2004.

Class I non-extraction case
• In cases with anterior cross-bite of one or two teeth, no retention is required . In cases with severe
crowding & multiple rotations,either retain with well-fitting Hawley or Begg's wrap around retainer.
• Each case of expansion needs to be reviewed for its original shape of the arch, the amount of
expansion achieved, mode of expansion, post-orthodontic occlusion and muscular pattern. In general,
the better the cusp-to-fossa relationship less is the likelihood of the relapse.
• The teeth should be placed in the neutral zone of the muscular forces where the lingual and
buccal muscular forces are in balance and in harmony.
47

Class I extraction case
• Maintenance of proximal contacts at extraction site is critical .
• Tight contacts are the outcome of a well-finished occlusion which is influenced by the arch form, torque,
marginal ridge relations and mesio distal inclinations of the teeth.
• Use a wrap around Begg's retainer, which would help maintain tight contacts of the arch.
• Placement of flexible spiral wire (FSW) bonded retainer on the lingual of the lower arch is now a
convention & it needs to be extended to the mesial occlusal pits of the second premolars that help to
maintain proximal contacts at the extraction sites.
48

Retention When a Class II Growth Pattern Exists
• Recurrence of a Class II relationship must result from some
combination of tooth movement (caused by local PDL & gingival
factors can be an short-term problem) & differential growth of the
maxilla relative to the mandible (important long-term problem ).
• Overcorrection of the occlusal relationships as a finishing
procedure is important
• Even with good retention, 1 to 2 mm of anteroposterior change
caused by adjustments in tooth position is likely to occur after
treatment .

Class II non-extraction case
• The tendency for differential jaw growth resulting in sagittal relapse can be overcome by using headgear
in maxillary retainer or functional appliance (night time bionator or a modified activator) as retainer.
• The maxillary Hawley or Begg's wrap around retainer may be modified to have an anterior bite plane to
help maintain the anterior bite and a forward slide of the mandible.
Class II extraction case
Class II extraction cases would need almost similar retention devices as non-extraction but with care not to
allow the extraction space to open.
50

Class III cases
• Class III children treated with facemask therapy would need to continue night time chin
cup for a considerable period of time, till the mandibular growth is complete.
• FR III and reverse twin block appliance as a retaining device used for young children
immediately following protraction facemask therapy.
• In mild Class III problems, a positioner may be enough to maintain the occlusal
relationships during post treatment growth.
51

Deep bite cases
AGE – Simultaneous intrusion of incisor & extrusion of posterior teeth during active vertical growth is effective .
FACIAL TYPE – Hyperdivergent more favorable .
MOLAR EXTRUSION – Eruptive movement beyond inter occlusal space is not stable due to strong posterior
occlusion & muscle stretching.
INCISOR INTRUSION – Relapse may be due to continued lower incisor eruption ,canting of the occlusal plane ,
incomplete leveling of curve of spee & forward rotation of mandible .
INTER-INCISALANGLE – Large angle – More relapse (Avg .125 – 135 ” )
The lower incisors contact the palatal acrylic of the upper Hawley
retainer & it does not separate the posterior teeth. This prevents
incisor eruption that would lead to return of excessive overbite
52

Open bite cases
• Relapse frequency of AOB in non surgical orthodontic cases - 23% and 38%. In surgical cases, the
success rate is a little higher and is predicted to be around 20% .
• Palate-covering removable appliance (modified Hawley retainer) with bite blocks between the posterior
teeth to create several millimeters of jaw separation & also High-pull headgear to the upper molars, in
conjunction with a standard removable retainer .
• Recently vacuum-formed retainers (clear aligners) with thickened
plastic over the posterior occlusal surfaces may be useful for retention.

Relapse in orthognathic surgery
• The outcome of orthognathic surgery would be stable only when skeletal movements are within the
confines of neuromuscular adaptation.
Orthodontic factors
1) Removal of dental compensations
• In class II cases, this would involve carefully chosen extractions of second premolars in the upper arch
and first premolars in the lower arch.
• The idea is to offset orthodontic relapse in AP direction rather than compound surgical relapse.
2) Corrections of tooth mass discrepancies
• No Bolton discrepanry is present - These have to be managed by routine procedures like interproximal
reduction or cosmetic recontouring or prosthetic rehabilitation.
54

Surgical factors
• Relapse Factors - Surgical stretch of the soft tissues, periosteum, muscles and the submucosal tissue.
• The distraction osteogenesis which allows simultaneous growth of the attached tissues along with the
lengthening of the mandible is considered an option with less relapse.
• One of the methods to minimise relapse is to slightly rotate the mandible clockwise to minimally alter
the position of po-gonion and also to have a rigid fixation.
• Avoid the distraction of condyle from the fossa in which case relapse is inevitable.
• Suprahyoid muscle pull plays a significant role in relapse when the mandible is advanced. In such
cases, suprahyoid myotomy is recommended.
55

Relapse in cleft lip and Palate
• The maxillary expansion in such CL/P is potentially unstable for the lack of the bony structures in the
midpalate and scarring of the palatal tissue.
• The dentoalveolar expansion is often carried out as pre bone graft orthodontics. The SABG integrates,
the split maxilla/alveolus to one segment and therefore reduces the tendency for transverse collapse.
• Orthodontic alignment should achieve good intercuspation for the maintenance of occlusion.
• Restoration of missing teeth with a removable prosthesis followed by fixed prosthesis maintains the
integrity of the arch and expansion.
56
• A rigid fixed retainer with a rigid wire components extending
to the lingual of all teeth is recommended to combat the relapse
which is more so in transverse dimensions.

Duration of Retention
• Retention is not required where the established occlusion will maintain the treatment outcome, e.g.
corrected crossbite with adequate bite.
• Short-term retention spans 3–6 months with removable appliance and involves full-time wear for
next 3 months except during meal times, followed by night-time wear for next 3 months.
• Medium-term retention spans over 1–5 years with a fixed retainer though a modified functional
appliance or headgear included to the removable maxillary appliance can be used .
• Permanent retention is performed with cleft lip or palate where the prosthesis can be used as a
retainer or in relation with the periodontal problems.
57

Retention plan - Kaplan
58

Cases requiring minimal or no retaining appliances
1. Blocked out canines in class I extraction cases without incisor crowding.
2. Class I anterior cross-bite with sufficient degree of overbite.
3. Posterior crossbites with very steep cusps and no anterior crowding.
4. Class II cases slightly over treated with Kloehn headgear to restrict maxillary growth with sufficient
arch length indicated by mandibular anterior spacing and absolutely no mandibular incisor rotations.
• These patients should follow scheduled checks during the posttreatment adolescent period for
any possible spacing or unfavourable growth changes or TMJ symptoms.
59

Cases requiring indefinite retention
1. Class II division 2 deep bite cases,
2. Severe rotations with poor periodontal health.
3. Undue arch expansion treatment for aesthetic demands.
4. Patients with tongue thrust or uncontrolled muscular habits.
5. Adult Patients.
Diagnosis and management of malocclusion and dentofacial orthopedics – O P Kharbanda 3rd Ed 60

Cases that require operative procedures with indefinite retention
1.Tooth size discrepancies such as larger maxillary teeth may result in an increased overbite.
2. Conversely, larger mandibular teeth will result in end-to-end incisor relationships, maxillary
spacing or buccal end-on occlusion.
3. Proximal recontouring of the mandibular incisor may resolve the Bolton discrepancy if mandibular
anterior tooth material is in excess or vice versa for the maxillary teeth.
4. The microdontic tooth may require aesthetic build-ups with tooth coloured restorative or laminates.
5. Severe rotatrons would need CSF procedure & Frenectomy may be needed for midline diastema.

Adjunctive periodontal procedures
for successful orthodontic results
62

Circumferential fibrotomy
• Supracrestal fibres are main cause & if these fibres can be severed ,the relapse can be minimised.
• The efficacy of this procedure has been found effective in alleviating pure rotational relapse in a 12-14
years of post-treatment follow-up study Edward JG 1988.
Autogenous gingival grafts - Newman GV 1994
• The free gingival graft procedure involves preparation of a recipient site,
done by supra-periosteal dissection to remove epithelium, connective tissue and muscle fibres.
• A graft is harvested, traditionally from the palate, and secured at the recipient site. It creates adequate
zones of attached gingiva, reduces the possibility of a future recession & enhances the health .
• This procedure is recommended prior to the commencement of orthodontic treatment.
63

Maxillary frenectomy
• Abnormal maxillary fibrous frenum has been considered responsible for the recurrent relapse
following the closure of midline diastema.
• Abnormal frenum should be excised after the space closure , removing frenum prior to space closure
produces scar tissue formation, which can slow down subsequent attempts at space closure.
Edwards 1977 - recommends a three-stage procedure when performing a frenectomy.
• The frenum is repositioned apically with denudation of the alveolar bone.
• The trans-septal fibres are severed between the approximated central incisors.
• The labial and/or palatal gingival papillae are recontoured in cases of excessive tissue accumulation.
64

What is new?
• Memotain (new CAD/CAM fabricated) is a wire made of custom-cut nickel-titanium (0.014x0.014 in)
as an alternative to multi stranded lingual retainers.
• Advantage - No need for wire measuring or bending, individually optimised placement, greater accuracy
of fit, tighter IP adaptation, less tongue irritation, better durability & resistance to microbial colonization
• It is beneficial in common break point areas, such as the embrasure between the lateral incisor and the
canine, or the step between the canine and the premolar Kravitz ND 2016 .
Diagnosis and management of malocclusion and dentofacial orthopedics – O P Kharbanda 3rd Ed
Memotain - 'memory' + 'retainer'
65

Current status of research and evidence affecting orthodontic practice
Fixed lingual retainers
• A 5 years follow-up has shown that fixed lingual retainers do not seem to increase the development
of mandibular gingival recession. However, the presence of FSW for longer duration enhances
increase calculus accumulation.(Juloski et al -2017)
• A large group of 20 studies evaluating multi-stranded retainers reported failures ranging from 12 to
50% .The glass fibre bond failures were from 11 to 71 %. (Kloukas et al 2015)
• The selection of the best treatment protocol remains a subjective issue.
66

CYTOTOXIC IMPLICATIONS
• The bisphenol A is released in the mouth from the removable oral appliance.
• The significant release of BA is highest in the vacuum-formed retainer group, followed by
Hawley retainers fabricated by chemical cure; the lowest levels were found with Hawley
retainers fabricated by heat cure.
• Therefore it is concluded that a Hawley retainer fabricated by heat cure is a favourable
choice. (kailasam et al 2017 AJODO )
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Which retainer is a better choice?
• Some relapse is unavoidable after fixed appliance therapy irrespective of retainer choice, and this
is minimal in most patients at 6 months after debonding.
• Bonded retainers have a better ability to hold the mandibular incisor alignment in the first 6
months after treatment than do VFR. Sharma et al 2016 AJODO
• According to Littlewood (2016), there is currently insufficient high-quality evidence regarding
the best type of retention or retention regimen, and so each clinician's approach will be affected
by their personal, clinical experience and expertise, and guided by their patients‘ expectations
and circumstances.
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Can we enhance the bone quality to prevent relapse?
• A group of female albino rabbits supplemented with 15.4 mL/ kg b.w. Per day olive
oil during an orthodontic retention period clinically reduced orthodontic relapse on
rabbit model.
• Histologically, olive oil increased osteoblasts and osteocytes counts and the relative
amount of bone mineralisation of connective tissue layer forming alveolar bone (AB)
at the end of four weeks after the orthodontic retention period. (Al-sadi et al 2017)
69

Recent Advances in Orthodontic Retention -Biomedical agents
70

CONCLUSION
• Retention plan is part of orthodontic diagnosis and planning, and perhaps the most difficult part of the
active orthodontic treatment.
• Choice of retention appliance and retention protocol varies in each patient, according to malocclusion,
treatment mechanics used, extraction pattern, craniofacial morphology, functional anatomy of
stomatognathic system and periodontal health besides systemic health.
• Prevention of relapse is no less challenge than doing orthodontic treatment. While a definite protocol of
retention is still elusive based on the evidence, the choice of appliance seems to be subjective and a
matter of preference by the orthodontist.
71

REFERENCE
 Contemporary Orthodontics —William.R.Proffit – 6th edition.
 Handbook of orthodontics --Robert.E.Moyers —4th edition
 Textbook of orthodontics-- Amir.E. Bishara —1st edition
 Biomechanics in clinical Orthodontics Ravindra Nanda 1st edition
 Orthodontics- Current Principles & Techniques Graber, Vanarsdall, Vig- 4th edition
 Dentofacial orthopedics with functional appliances- Thomas.M.Graber, Thomas Rakosi,
Alexandre.G. Pertovic -2nd edition.
 Diagnosis and management of malocclusion and dentofacial orthopedics – O P Kharbanda
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Stability Retention and Relapse in orthodontics

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