RETENTION AND RELAPSE IN ORTHODONTICS

A descriptive presentation highlighting the challenges orthodontics face in the management of relapse and effective management strategies to assist retention after orthodontic treatment

1. RETENTION and relapse in orthodontics DR BIMMA NWEZE

2. OUTLINE INTRODUCTION TERMINOLOGIES HISTORY THEORIES OF RETENTION AETIOLOGY OF RELAPSE FACTORS AFFECTING PLANNING FOR RETENTION CONCLUSION REFERENCES

3. INTRODUCTION Within the realm of orthodontics, one of the most intricate phases lies in preserving the corrections accomplished during the course of orthodontic treatment. The achievement of aesthetics and functional occlusion should not mark the end of orthodontic intervention. Stability can only be achieved if the forces derived from the periodontal and gingival tissues,the orofacial soft tissues ,the occlusal forces and post treatment facial growth are in equilibrium. Finalization of treatment should involve active stabilization and passive guidance problems. Meticulous planning and implementation of an effective retention strategy is critical to ensuring success of orthodontic treatment .

4. TERMINOLOGIES RETENTION Moyers defined retention as maintaining newly moved teeth in a position long enough to aid in the stabilizing correction It is describes the method of minimizing or preventing relapse RELAPSE Loss of any correction achieved by orthodontic treatment (Moyers) It simply is the loss of stability of orthodontic results and therefore any change from final tooth position at the end of treatment

5. HISTORY/SCHOOL OF THOUGHT OCCLUSAL SCHOOL : Proper occlusion is a key factor in determining stability of newly moved teeth. APICAL BASE SCHOOL : Apical base is an important factor in the correction of malocclusion and maintenance of stability of already treated cases (Lundstrom) Inter-canine and Intermolar widths should be maintained during orthodontic treatment to minimize retention problems (McCauley) Arch length cannot be permanently increased to a major extent (Nance) MANDIBULAR INCISOR SCHOOL : Grieves and Tweed suggested that post treatment stability increased when mandibular incisors were placed upright or slightly retroclined over the basal bone. MUSCULATURE SCHOOL : Rojers postulated that functional muscle balance is necessary in order to ensure post treatment stability.

6. 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 overcorrected as a safety factor Theorem 4 Proper occlusion is a potent factor in holding teeth in their corrected positions

7. Theorem 5 Bone adjacent to the tissue must be allowed time to reorganize around newly positioned teeth Theorem 6 If the lower incisors are placed upright over the 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

8. Theorem 8 The farther the teeth have been moved the lesser the risk of relapse Theorem 9 Arch form particularly the mandibular arch cannot be permanently altered by appliance therapy Theorem 10 Many malocclusion requires permanent retaining device model

9. LOWER INCISOR RETENTION Raleigh Williams proposed six keys to eliminate lower incisor retention KEY 1 : The incisal edge of the lower incisor should be placed on the A-Pog line or 1mm in front of it KEY 2 : The lower incisor apices should be spread distally to the crown and the lower lateral incisors must be spread more than those of the central incisors KEY 3 : The apex of the lower cuspid should be positioned distal to the crown KEY 4 : All four incisor apices must be in the same labiolingual plane KEY 5 : The cuspid root apex must be positioned slightly buccal to the crown apex KEY 6 : Flattening lower incisor contact points by slenderizing or stripping creates flat contact surfaces which help resist labiolingual crown displacement .

10. KEY 1 The incisal edge should be placed on the A-P line or 1mm in front of it. This is because the position serves as the optimum location to ensure lower incisor stability. It also creates optimum balance of soft tissues in the lower third of the face for all variations in apical bsse differences within the normal range

11. KEY 2 The lower incisor apices should be spread distally and the lower lateral incisors must be spread more than those of the central incisors When the lower incisor roots are left convergent or even parallel the crowns tend to bunch up and a fixed lower retainer is needed to prevent post-treatment relapse The Begg technique has been found to be more effective in achieving the necessary progressive spreading

12. KEY 3 The apex of the lower cuspid should be positioned distal to the crown Angulation of the lower cuspid is important in creating post-treatment incisor stability This is because it reduces the tendency of the cuspid crown to tip forward into the incisor area If this happens the lower incisor crowd up even if the roots are spread and the incisal edges are on the A-P line or in front of it

13. KEY 4 All four incisor apices must be in the same labiolingual plane Spreading the apices of the lower incisor roots distally causes a strong reciprocal tendency for the crowns to move mesially Strong mesial pressure on the crowns during the root spreading process causes a tendency for the contact points to displace each other labiolingually This causes a reverse movement of the apices linguolabially

14. KEY 5 The cuspid root apex must be positioned slightly buccal to the crown apex There is a natural tendency for the crown of the cuspid to upright over its root apex Occlusal forces await their chance to exert lingual forces on the lower cuspid crown If at the end of treatment the forces of occlusion can more easily move the crown to the space reserved for the lower incisors because of a functional pressure

15. KEY 6 Flattening lower incisor contact points by slenderizing or stripping creates flat contact surfaces which help resist labiolingual crown displacement. The slightest amount of continuous mesial pressure can cause various degrees of collapse in the lower incisor segment Post-treatment pressure on the lower incisors from the molars can cause displacement of lower incisor contact points

16. AETIOLOGY The etiology of relapse is complex and unclear. Several factors have been found to compromise the stability of orthodontic results. They include ROLE OF SUPPORTING TISSUES SOFT TISSUE FACTORS OCCLUSAL FACTORS FACIAL GROWTH AND OCCLUSAL DEVELOPMENT

17. SUPPORTING TISSUES The supporting periodontal and gingival tissues as well as the alveolar bone are involved during orthodontic tooth movement. Forces applied to these structures cause widening of the periodontal space and disruption of collagen fibers. Time is therefore required to allow for reorganization of these structures following treatment Timelines have been suggested which indicate the duration each structure requires to remodel.Although variation exists within individuals Alveolar bone usually remodels within 3-4 months Gingival collagen and principal collagen fibers usually take as much as 6 months Greater than 232 days are needed for the formation of transseptal and free gingival elastic fibers whose attachment to the dental arch is influenced by tooth position and direction throughout fiber development.

18. SOFT TISSUE FACTORS Normal function and balance of orofacial musculatures are very important in facial balance and occlusal stability after orthodontic treatment. The neutral zone is a zone of equality between centripetal and centrifugal forces Lying in a neutral zone of soft tissue balance between the lips,cheeks and tongue. The maintenance of tooth position is conditional on the response of an intact periodontium to resist lingual than labial forces. Orthodontic treatment should aim for teeth position within a narrow zone. Placing the teeth in a markedly labial or lingual position increases risk of relapse SIGNIFICANCE Muscle aberration may be expected in Class II and Class III muscular malocclusion, Skeletal deep bite, Presence of abnormal habits Use of exercise training program to strengthen muscles of mastication and facial muscles to aid in treatment as well as retention.

19. OCCLUSAL FACTORS TOOTH SIZE DISCREPANCY AXIAL INCLINATION TRANSVERSE DISCREPANCY THIRD MOLARS

20. Need for retention Gingival and periodontal tissues require time post-treatment to reorganize Soft tissue pressures are likely to cause relapse if teeth are placed in an unstable position Growth post-treatment may cause relapse

21. MEASUREMENT OF RELAPSE Clinical assessment Orthodontic indices e.g PAR or Little index Study model Clinical photographs Cephalometric analysis

22. FACTORS AFFECTING PLANNING FOR RETENTION INFORMED CONSENT AGE OF PATIENT ORIGINAL MALOCCLUSION GROWTH PATTERN OF THE PATIENT TYPE OF TREATMENT PERFORMED TYPE OF RETAINER NEED FOR ADJUNCTIVE PROCEDURES TO ENHANCE STABILITY DURATION OF RETENTION

23. INFORMED CONSENT ROLE OF THE ORTHODONTIST ROLE OF THE PATIENT

24. AGE OF THE PATIENT Normal physiological may be confused with relapse in a pt who earlier received orthodontic treatment Increasing age of patient usually presents with slow tissue remodeling and soft tissue age related changes Normal maturation changes include decrease in arch length after adolescence, static or reduced intermolar width after 13 years, small decrease in overbite and overjet This may indicate permanent retention to avoid relapse Also patients who present with minimum to moderate periodontal disease may require permanent retention

25. ORIGINAL MALOCCLUSION INCISOR RELATIONSHIP : High risk of relapse in class II division II LOWER INCISOR IRREGULARITY : Prolonged retention of the lower labial segment until the end of facial growth reduces severity of lower incisor crowding GENERALIZED SPACING : Highly prone to relapse and needs permanent retention. ANTERIOR CROSSBITE : Retention is naturally due to increased overbite ANTERIOR OPEN BITE : Extractions improve stability, Incorporation of posterior bite planes in pts with unfavourable growth pattern POSTERIOR CROSS BITE : Highly prone to relapse. Posterior intercuspation,Further stabilization using slight expansion by archwire,at least 3months retainer appliance therapy ROTATIONS : Overcorrection,Early correction to allow formation of new fibers,Pericision

26. GROWTH PATTERN OF THE PATIENT Facial growth continues throughout life generally in the same direction as occurring in adolescence but to a smaller degree Retention of skeletally corrected problems should be carried until cessation of growth The following devices may be used Class II skeletal discrepancy : modified activator appliance, head gear or upper removeable appliance with inclined bite plane Class III skeletal discrepancy : Frankel III, chin cap Deep bite : Anterior bite plane

27. OCCLUSION AT THE END OF TREATMENT Occlusion plays a role in retention and stability Good occlusal relationship aids in providing favourable dentoalveolar compensation Well interdigitated Class I occlusion aids in stability Cases such as Correction an anterior cross bite with a positive overbite requires no retention

28. METHODS OF RETENTION FUNCTIONAL Oral muscle exercise plays a role in maintaining tooth position e.g Lip exercise Activator may also be used as a functional retainer NATURAL Here, proper inter-cuspation and proper incisor relationship will prevent relapse in corrected cross-bite. APPLIANCE THERAPY Use of retainers.

29. RETAINERS Retainers are orthodontic appliances which passively maintain and stabilize tooth position achieved by orthodontic treatment. Factors affecting choice of retainers include but are not limited to Type of malocclusion Esthetic need of patient Cost effectiveness Patient co-operation Duration of retention Oral hygiene of the patient

30. IDEAL REQUIREMENTS OF A RETAINER It should restrain each tooth in its desired position against the direction of relapse movements. It should permit the functional forces to act freely upon the retained teeth permitting them to respond in physiologic manner as possible Easily constructed and tolerated by the patient Strong and durable enough to achieve its objective over a period of time Self cleansing and can provide good oral hygiene Esthetically pleasant .

31. CLASSIFICATION OF RETAINERS ACCORDING TO THEIR FORCE APPLICATION Active retainers : Ni-Ti retainers, Positioners Passive retainers ACCORDING TO THEIR USABILITY BY THE PATIENT Removeable retainers : Hawley’s retainer, Begg’s wraparound retainer, Removeable canine to canine, Removeable molar to molar metal retainers,Positioners,Essix retainers. Fixed retainers : Ling lock retainers, Glass fiber reinforced retainer, V-loop design, Multi stranded stainless steel wire ACCORDING TO THEIR VISIBILITY Visible retainers : these retainers have a labial wire component. They include Hawley’s retainer, Begg’s retainer, Spring retainer, removeable canine to canine, removeable molar to molar metal retainers.

32. Invisible Retainers : These retainers possess a lingual wire placement or are made from transparent thermoplastic sheets. They include : Thermoplastic vacuum-formed retainer,V-loop design, Ling lock retainers, Glass fiber reinforced retainers. ACCORDING TO THEIR GENERATIONS First generation: Plain round 0.032-0.036blue elgiloy wire with terminal loop Second generation: Same as first generation without terminal loop Third generation : Easier to place and conforms more closely ACCORDING TO THEIR METHOD OF FABRICATION Pre-formed Custom made

33. ACCORDING TO ADJUNCTIVE RETENTION PROCEDURES Pericision Frenectomy Interproximal reduction

34. HAWLEY’S RETAINER First designed by Charles Hawley in 1920 It is one of the most commonly used retainer

35. DESIGN Labial bow Adam’s crib Palatal baseplate (which may be full coverage or horse shoe design ADVANTAGES Facilitates proper occlusal settling Armamentarium for fabrication is easily available It can be adjusted according to clinical condition for finished treatments Can be removed for cleaningasily repairable when component parts are broken. Durable Patient compliance is notably better with Hawley retainer because of its reduced bulk

36. DISADVANTAGES Success of the treatment depends on patient compliance Display of labial wire is unaesthetic which affects patient satisfaction Higher evidence of breakage than loss First few weeks,Patients experience interference in speech articulation It may not hold the corrected labial segments in the upper and lower arch for a larger period of time due to insufficient contact surfaces leading to relapse and incisior crowding.

37. MODIFICATIONS Hawley’s retainer can be modified according to the clinical requirement for retention. It is therefore important to select the appropriate clasp design as clasp crossing the occlusal table can disrupt tooth relationship HAWLEY’S RETAINER WITH ANTERIOR BITE PLANE : This addition controls bite depth such as cases of reduction of a corrected deep over bite.

38. HAWLEY’S WITH LONG LABIAL BOW Incorporation of labial bow from premolar to premolar rather than from canine to canine USE: Space closure distal to the canine

39. HAWLEY’S WITH C-CLASP ON SECOND MOLARS DISTALLY It avoids risk of space opening due to decreased interference with cross over wire

40. HAWLEY'S RETAINER WITH REVERSE U LOOPS This provides better control of the canines

41. HAWLEY’S WITH FITTED LABIAL BOW Fitted labial bow anteriorly and base plate posteriorly USE : Better control of the incisors

42. HAWLEY’S WITH FINGER/Z-SPRING Incorporation of finger/Z-springs makes it an active appliance used to achieve minor tipping movement

43. THERMOPLASTIC VACUUM FORMED RETAINER It is also called Essix retainer Fabricated from a variety of thickness of polyvinylchloride sheets by heating to 475 degrees and vacuum pressure of 1.5 b for 50 seconds DESIGN: Full coverage of all the teeth generally extending across the terminal tooth. The most posterior tooth must be at least half covered to prevent supraeruption

44. ADVANTAGES An aesthetic appliance Easy to construct Cheap Improved patient compliance Better incisor alignment control than the Hawley retainer It permits modifications such as temporary addition of a pontic or wire placement in the palatal side in expansion cases DISADVANTAGES Less settling of occlusion Risk of de calcification in the presence of retainer acting as a resolver Ineffective in retaining intrusion or extrusion movement Partial VFR may cause open bite due to over eruption of teeth

45. POSITIONER’S ‘ACTIVE’ RETAINER Developed by HD Kesling in 1945 It is an elastomeric or rubber removeable retainer It may be pre-formed or custom made DESIGN Thermoplastic rubber material with no wire components Covering of the clinical crown of the maxillary and mandibular teeth although it spares the inter-occlusal space and small portion of the gingiva

46. ADVANTAGES It may provide further minor correction and thus guide in the settling of occlusion Useful when desired finish is not achieved because the case had to be discontinued early Durable as it is unlikely to break Needs no activation at regular intervals DISADVANTAGES Expensive Used for finishing stages of treatment Does not make a good retainer because of the pattern of wear differs from retainers Need for replacement by other forms of retainers after achieving final teeth alignment Lack of patient compliance and acceptance Associated risk of TMJ problems

47. BEGG’S RETAINER Introduced by P.R BEGG Circumferential retainer DESIGN : A labial wire that extends till the last erupted molar and curves around it to get embedded in acrylic that spans the palate MODIFICATION : Begg’s retainer with incorporated delta clasp.

48. ADVANTAGE : It has no clasps and therefore no cross over wire between the canine and premolar thereby eliminating the risk of space opening Incorporation of bite plane to maintain overbite reduction Temporary addition of an acrylic tooth to replace a missing tooth Maintain lateral expansion DISADVANTAGE Less aesthetic due to labial bow Speech interference may occur due to palatal coverage Less retentive than Hawley

49. CLIP-ON/SPRING RETAINER It is a major type of removeable retainer It consists of an acrylic bow seen both along the lingual and labial surfaces of the teeth. Both the lingual and labial wires are embedded in acrylic ADVANTAGES Aesthetic Useful in cases of anterior segment spacing – it can be used to realign minor lower incisor relapse

50. MODIFICATION Modified Barrer retainer which includes cribs on the first molars. It reduces the risk of inhalation.

51. WRAP-AROUND RETAINER It is a modification of clip on retainer but it covers all the teeth DESIGN : It consists of a wire that passes along the labial as well as lingual surfaces of all erupted teeth It is embedded on acrylic INDICATION : Cases of weak periodontal condition

52. DAMON’S SPLINT It was introduced by Dr. Damon Dwight DESIGN: Hard pressure formed, dual hardness/soft liner and elastic silicone upper and lower splints joined together with acrylic It is basically a connected upper and lower essix retainers It may be used in adults or patients in mixed dentition ADVANTAGES Holds teeth and arches in corrected position Retentive splint used in Class II, Class III , Bilateral crossbite and orthognatic cases Assists in tongue training

53. FIXED RETAINERS These are fixed to the teeth and cannot be removed by the patient They are invisible retainers which are either banded or bonded to the lingual surface of the teeth. Indicated in cases where prolonged retention is required TYPES Band and spur retainer Banded canine to canine retainer Bonded lingual retainers Passive corrective fixed retainer

54. ADVANTAGES Reduced need for patient co-operation Provides permanent or semi-permanent retention No or minimal tissue irritation Bonded retainers are esthetic in nature Provides degree of stability which conventional removeable retainers may not provide Unlikely to interfere with speech DISADVANTAGES Increased chairside time Technique sensitive and cumbersome to insert Expensive Tend to disco lor

55. BONDED RETAINERS It may be flexible – bonded on the lingual/palatal surface of each individual tooth, Design is a 0.0175” multi-stranded wire, Rigid- where it is bonded only on the canines although it touches the lower incisors. Design is a 0.030 stainless steel wire. ADVANTAGES Invisible and well tolerated by the patient Compliance DISADVANTAGES Time consuming Technique sensitive Difficult to mainatain encouraging plaque and calculus retention

56. INDICATIONS OF A BONDED LINGUAL RETAINER Closed midline diastema Severe pre-treatment lower incisor crowding or rotation Planned alteration in the lower inter-canine width Non-extraction treatment in mild crowding cases After proclination of the anteriors during active treatment After correction of deep overbite

57. BANDED CANINE TO CANINE RETAINERS Usually used in the lower anterior segment Fitting of the canines with preformed bands and adaptation of a thick wire over the lingual contour of the anterior teeth which is then soldered at the end of the canine band

58. BAND AND SPUR RETAINERS: DESIGN : The tooth that has been moved is banded and spurs are soldered to overlap the adjacent teeth. Indicated in cases of single tooth rotation correction or labio-lingual displacement

59. ACTIVE RETAINERS These retainers first bring about some slight tooth movement and then act as passive retainers. INDICATION Irregular incisors alignment Management of class II or class III relapse with functional appliance TYPES OF ACTIVE RETAINERS Barrer Spring retainer Head gear Activator or Bionator

60. MONITORING AND FOLLOW UP There are currently no guidelines or universally accepted retention regimen. Patients should be encouraged to wear retainers at least on a part time basis for as long as they want the teeth to remain well aligned Retainer wear is the patient’s responsibility and must be fully emphasized Long term maintenance and repair of the retainers should be sought by the patient Fixed retainers should be reviewed annually to ensure no excessive calculus build up around the retainer and that the composite and wire are still intact. Patient must realize the commitment prior to starting treatment

61. Wear regimen No universal removeable retainer wear regimen FULL OR PART TIME proponents exist Full time is advised for the first 3-4 months even while eating Although full time wear usually reduce to part time Full time wear for three months gradually reducing to one or two nights a week Full time wear for six months Full time wear for three months reduced to night only for three months Full time wear gradually reducing to one or two nights a week Part time must be continued until growing is complete such as night only for six months Reducing from 10 hours daily in the first six months to one or two nights weekly

62. ADJUNCTIVE RETENTION PROCEDURES CIRCUMFERENTIAL SUPRACRESTAL FIBEROTOMY Also known as Pericision There is a tendency of the elastic fibers within the interdental and dento-gingival fibers to pull the teeth back to its original position PRINCIPLE : Incision to the interdental and dento-gingival fibers ABOVE the level of the aveolar bone. Papilla dividing procedure is used when attached gingiva is thin to prevent relapse INDICATION : Rotated teeth CONTRAINDICATION : Poor gingival health, medical contraindications

63. ENAMEL INTERPROXIMAL STRIPPING Also known as reproximation. This involves the removal of small amounts of enamel mesio-distally. It is suggested that by flattening interdental contacts stability will increase between adjacent teeth INDICATION: Relieve minor crowding of the lower incisors with favourable contact points, To avoid possible proclination and increase inter canine width DISADVANTAGES : Tooth sensitivity, may lead to periodontal disease. It is necessary to repolish enamel surfaces after reduction with diamond abrasion to create smooth enamel surface

64. FRENECTOMY Repositioning of the frenum and sectioning the transeptal fiber with gingivectomy Thick fibrous maxillary frenum is usually the cause of reopening of maxillary diastema after closure. Frenectomy is planned after and not before space closure to prevent scar tissue interfering. This procedure provides long term stability in orthodontically closed midline diastema

65. RECENT ADVANCES MEMOTAIN Ni-Ti Lingual memory retainer fabricated through CAD/CAM Very flexible and precise alternative to available multi stranded lingual retainers Resistant to corrosion and microbial colonization Effective in minor corrections because of shape memory Highly successful in the maxilla as it does not cause occlusal interference or tongue irritation

66. BIOMEDICAL AGENTS Use of biopharmacological agents such as osteoprotegrin, RANKL inhibitor agent denosumab, bisphosphonates like pamidronate and zoledronate, bone morphogenic proteins,relaxin, simvastatin, strontium ranelate,olive oil. They have an inhibitory effect on tooth movement and thus a positive effect on post-treatment stability. LIMITATIONS : Long term safety concerns with agents such as Denosumab

67. DURATION OF RETENTION NATURAL RETENTION MEDIUM TERM RETENTION PERMANENT RETENTION

68. NATURAL RETENTION- Here no retention is indicated. It is only applicable in cases where the occlusion will hold the correction or where no active treatment is taken. Anterior Crossbite with adequate open bite, retroclined or upright teeth and favourable growth pattern Posterior crossbite with adequate cuspal interdigitation, inclination of buccal teeth and favourable growth Serial extractions Correction achieved by retardation of maxillary growth once patient has passed through growth period

69. MEDIUM TERM RETENTION Class 1 Non Extraction cases with proclination of the incisors Class 1 or Class II extraction cases esp until lip and tongue pressure becomes normal Corrected deep bite Early corrections of rotated teeth before root completion Cases involving ectopic eruption or supernumerary teeth

70. PERMANENT RETENTION These cases have higher chances of relapse. Hence permanent retainers are indicated. These include : Spacing and Midline diastema Rotations Anterior open bite Expansion of mandibular arch Peridontal ligament compromised cases Hypodontia cases Cleft lip and palate with scar Correction of overjet with lip incompetence at the end of treatment

71. CONCLUSION Retaining the results for orthodontic treatment is crucial to long term success. Understanding the factors which affect retention and addressing these through personalized treatment plans can help improve stability and minimize relapse. Proper treatment mechanics,good occlusion and excellent retention protocols are important. Close co-operation between the orthodontist and the patients is crucial to ensuring retention is achieved

72. REFERENCES N Dogra, A Jaglan, J Nindra. "Demystifying Retention in Orthodontics - A Review." Bulletin of Environmental, Pharmacology and Life Sciences. Special Issue [2]. 2022:484-489. Shrish Charan Srivastava, Ragini Tandon, Ashish Kakadia. "Modified Begg's Retainer with Incorporated Delta Clasp." Asian Journal of Oral Health & Allied Sciences. 2014;4(1) Littlewood SJ, Kandasamy S, Huang G. Retention and relapse in clinical practice. Aust Dent J. 2017 Mar;62 Suppl 1:51-57. doi: 10.1111/adj.12475. PMID: 28297088. Hussam E. Najjar, Renad Mohammed Alasmari, Asrar Mohammed Al Manie, Khalid Nassir Balbaid, Kuthar Hassan Alzaher, Ashwaq Talal Assiri, Sundus Saad Alqarni, Abdullah Abdul Aziz Turkistani, Sarah Khalid Al Anzi, Bassam Abdullah Alkhudhayr, Shatha Ahmed Alfaifi. "Factors affecting retention and relapse in orthodontics." International Journal of Community Medicine and Public Health. 2023 Aug;10(8):2946-2950. Ahmed M Alassiry. "Orthodontic Retainers: A Contemporary Overview." The Journal of Contemporary Dental Practice. 2019;10.5005/jp-journals-10024-2611. Anand RK, Tikku T, Khanna R, Maurya RP, Verma S, Shrivastava K. "Retainer in orthodontics." J Orthod Dentofacial Res. 2019;5(1):11-15.

73. “ANY FOOL CAN MOVE TEETH BUT IT TAKES A WISE MAN TO MAKE THEM STAY’' - CHARLES HAWLEY