# **RETENTION** J. Mike Razza, BS, DDS, Cert Orthod Associate Professor - Orthodontics University of Western Australia School of Dentistry Contemporary Orthodontics – Chapter 18 Level IV Advanced Orthodontics Unit B Complex Orthodontics Retention J. Mike Razza, BS, DDS, Cert Orthod Associate Professor - Orthodontics University of Western Australia School of Dentistry Contemporary Orthodontics – Chapter 18 Level IV Advanced Orthodontics Unit B Complex Orthodontics Retention **RETENTION - Historical Perspective** 1. The Occlusion School 2. The Apical Base School 3. The Mandibular Incisor School 4. The Musculature School 1. The Occlusion School 2. The Apical Base School 3. The Mandibular Incisor School 4. The Musculature School **A Review of the Literature** Richard A. Riedel  Theorem 1: Teeth which have been moved in or through bone by orthodontic appliances often have a tendency to return to their former positions  Theorem 2: The elimination of the causes of a malocclusion will prevent recurrence  - **Theorem 1:** Teeth which have been moved in or through bone by orthodontic appliances often have a tendency to return to their former positions - **Theorem 2:** The elimination of the causes of a malocclusion will prevent recurrence This is a clinical photograph showing the anterior view of the upper and lower dental arches, featuring a midline diastema between the maxillary central incisors. The image serves as a visual example for Theorem 1 regarding teeth moved by orthodontic appliances. <a name="Theorem3"></a> A **Review** of the Literature Richard A. Riedel **Theorem 3:** *Overcorrection of a malocclusion is a safety factor in retention* </br><br><br>  <a name="Theorem3"></a> A **Review** of the Literature Richard A. Riedel **Theorem 3:** *Overcorrection of a malocclusion is a safety factor in retention* </br><br><br> Clinical photo of the maxillary arch showing the anterior teeth with green arrows indicating the direction of tooth movement or space closure, illustrating the concept of overcorrection in malocclusion retention. A Review of the Literature Richard A. Riedel * Theorem 4: Occlusion is an important factor in retention; therefore, an orthodontist should attempt to produce the best possible occlusion of the teeth * **Theorem 5**: Bone and adjacent tissues must be allowed to reorganize around the newly positioned teeth for some length of time     A Review of the Literature Richard A. Riedel * Theorem 4: Occlusion is an important factor in retention; therefore, an orthodontist should attempt to produce the best possible occlusion of the teeth * **Theorem 5**: Bone and adjacent tissues must be allowed to reorganize around the newly positioned teeth for some length of time Clinical photo showing the anterior and lateral views of a patient's dentition with teeth in occlusion, illustrating the importance of producing the best possible occlusion as stated in Theorem 4. Clinical photo: This figure shows a close-up view of the upper and lower dental arches in occlusion, highlighting the alignment of teeth and gingival tissues. It illustrates Theorem 4 from the text, which states that occlusion is an important factor in retention. Clinical photo showing a frontal view of the patient's upper and lower teeth in occlusion, illustrating the alignment of the anterior dentition. Clinical photo showing a close-up view of the patient's maxillary and mandibular teeth in occlusion. The image illustrates the alignment of the dental arches, specifically highlighting the relationship between the upper and lower incisors and canines. # A Review of the Literature **Richard A. Riedel** ▼ Theorem 5: Bone and adjacent tissues must be allowed to reorganize around the newly positioned teeth for some length of time   A Review of the Literature **Richard A. Riedel** ▼ Theorem 5: Bone and adjacent tissues must be allowed to reorganize around the newly positioned teeth for some length of time Labelled diagram: A cross-sectional illustration of a tooth embedded in bone, showing the anatomical layers including enamel, dentin, and pulp. The image highlights the periodontal ligament fibers extending from the cementum to the surrounding alveolar bone. A labelled diagram illustrating the principal gingival fibre groups, including free gingival fibres, transseptal fibres, dentogingival and interdental fibres, and their attachment to alveolar bone. # A Review of the Literature # Richard A. Riedel ■ Theorem 6: Placing the lower incisors upright (*plus or minus 5 degrees from perpendicular to the Mandibluar plane*) over basal bone will result in a more stable correction of a malocclusion and they are more likely to remain in good alignment  Richard A. Riedel ■ Theorem 6: Placing the lower incisors upright (*plus or minus 5 degrees from perpendicular to the Mandibluar plane*) over basal bone will result in a more stable correction of a malocclusion and they are more likely to remain in good alignment Labelled diagram: This figure illustrates the angular relationship between the lower incisors and the mandibular plane. It depicts a side view of teeth and jawbone with lines indicating that the tooth axis forms an 110-degree angle relative to the horizontal, while the root aligns at a 90-degree angle to the Mandibular plane. A Review of the Literature Richard A. Riedel • Theorem 7: Corrections carried out during periods when the patients are growing are less likely to relapse     A Review of the Literature Richard A. Riedel • Theorem 7: Corrections carried out during periods when the patients are growing are less likely to relapse Clinical photo of an orthodontic appliance, likely a removable retainer or active aligner with wire clasps and pink acrylic components, fitted over the upper and lower anterior teeth. Clinical photo: A close-up view of an upper dental arch demonstrating a removable orthodontic appliance, specifically a Hawley retainer with a labial bow wire. The image shows the metal framework engaging the anterior teeth and the acrylic plate covering the palate. Clinical photo: A profile view of a young boy wearing an orthodontic headgear appliance. The device consists of a blue neck strap with white circular attachments and a beige headband secured to the back of his head, connected by metal rods to a facebow extending over his nose. Clinical photo of a patient's mouth showing an orthodontic appliance, likely a removable retainer or bite plate with metal clasps, positioned over the upper and lower teeth. **A Review of the Literature** **Richard A. Riedel**  Theorem 8: The farther teeth have been moved, the less the likelihood of relapse similar to over-correction  **A Review of the Literature** **Richard A. Riedel**  Theorem 8: The farther teeth have been moved, the less the likelihood of relapse similar to over-correction Clinical photographs of a dental arch displaying multiple carious lesions and decay, particularly affecting the molars. **A Review of the Literature** **Richard A. Riedel** Theorem 9: The arch form particularly in the mandibular arch, cannot be altered permanently by appliance therapy. Treatment should be directed toward maintaining the arch form presented by the original malocclusion **A Review of the Literature** **Richard A. Riedel** Theorem 9: The arch form particularly in the mandibular arch, cannot be altered permanently by appliance therapy. Treatment should be directed toward maintaining the arch form presented by the original malocclusion **Theorem 9: arch form**  **Theorem 9: arch form** Clinical photos showing the mandibular dental arch in two views: a frontal view with the tongue elevated and an occlusal view. The images illustrate the V-shaped form of the lower arch, highlighting the arrangement of teeth within this specific anatomical curve. # A Review of the Literature ## Richard A. Riedel + Riedel considers the following three rules to be the most important: + 1) teeth tend to move back toward their former position; + 2) the arch form of the mandibular arch cannot, in the majority of cases, be permanently altered by appliance therapy; + 3) bone and adjacent tissues should be allowed time to reorganize around newly positioned teeth Richard A. Riedel + Riedel considers the following three rules to be the most important: + 1) teeth tend to move back toward their former position; + 2) the arch form of the mandibular arch cannot, in the majority of cases, be permanently altered by appliance therapy; + 3) bone and adjacent tissues should be allowed time to reorganize around newly positioned teeth # A Review of the Literature **Richard A. Riedel** * Other factors influencing the retention of treated malocclusions include: * Tooth-size Discrepancies * Axial Inclinations * Growth * Root Paralleling in Extraction Cases * Equilibration * Musculature * Duration of Retention Other factors influencing the retention of treated malocclusions include: - Tooth-size Discrepancies - Axial Inclinations - Growth - Root Paralleling in Extraction Cases - Equilibration - Musculature - Duration of Retention A Review of the Literature Richard A. Riedel - Tooth-size discrepancies If the maxillary anterior teeth are too large for the mandibular, the maxillary teeth must be placed in one of several positions: deep overbite, greater overjet, combination of greater overbite and overjet, or the maxillary posterior teeth fitting into a more or less distal relationship to the mandible Review **Bolton Discrepancy** #### Tooth-Size Discrepancies If the maxillary anterior teeth are too large for the mandibular, the maxillary teeth must be placed in one of several positions: deep overbite, greater overjet, combination of greater overbite and overjet, or the maxillary posterior teeth fitting into a more or less distal relationship to the mandible. Review **Bolton Discrepancy**. A Review of the Literature Richard A. Riedel - **Axial inclinations** - Axial inclination of maxillary and mandibular incisors influences the retention of correction of a deep overbite. Tipping incisors into too upright of a relationship usually results in a deep anterior overbite  #### Axial Inclinations Axial inclination of maxillary and mandibular incisors influences the retention of correction of a deep overbite. Tipping incisors into too upright of a relationship usually results in a deep anterior overbite. A lateral cephalometric line drawing of a human skull profile featuring red annotations illustrating the axial inclination of the mandibular incisors. The diagram includes red lines representing the long axis of the teeth and curved arrows indicating the movement or tipping of the lower front teeth. # A Review of the Literature Richard A. Riedel * Growth and sex differences* - Growth is an aid in the correction of many types of orthodontic problems and it may also be of such character as to cause relapse of treated orthodontic cases. There is a marked difference between the maturation of skeletal and dental patterns of male and female #### Growth and Sex Differences Growth is an aid in the correction of many types of orthodontic problems and it may also be of such character as to cause relapse of treated orthodontic cases. There is a marked difference between the maturation of skeletal and dental patterns of male and female. A Review of the Literature Richard A. Riedel * Root Paralleling in Extraction Cases - Unless the roots of teeth on either side of the extraction sites are made parallel, spaces may open or teeth rotate due to load distribution on the teeth   #### Root Paralleling in Extraction Cases Unless the roots of teeth on either side of the extraction sites are made parallel, spaces may open or teeth rotate due to load distribution on the teeth. A labelled diagram showing the progression of orthodontic tooth movement, specifically illustrating how root paralleling and interarch elastics are used to align roots in extraction cases. A line diagram of the maxillary and mandibular dental arches with vertical lines superimposed over specific teeth, illustrating the concept of root paralleling during extraction procedures. A Review of the Literature **Richard A. Riedel** - Equilibration - Riedel is of the opinion that functional interferences as a cause of relapse in treated orthodontic cases has been over-emphasized #### Equilibration Riedel is of the opinion that functional interferences as a cause of relapse in treated orthodontic cases has been over-emphasized. # A Review of the Literature ## Richard A. Riedel - Musculature - We cannot predict accurately a stable position of the teeth with respect to equilibrium of muscle forces  #### Musculature We cannot predict accurately a stable position of the teeth with respect to equilibrium of muscle forces. Clinical photo: A close-up frontal view of the patient's dentition showing a significant anterior open bite and deep overjet, where the upper incisors are positioned far forward relative to the lower teeth. #A Review of the Literature **Richard A. Riedel** - *Duration of Retention* - The debate concerning the length of use of retention devices has simply not been resolved. It is not known whether prolonged retention provides for greater stability or even if prolonged mechanical restraint is biologically desirable #### Duration of Retention The debate concerning the length of use of retention devices has simply not been resolved. It is not known whether prolonged retention provides for greater stability or even if prolonged mechanical restraint is biologically desirable. **A Review of the Literature** Richard A. Riedel * Riedel divided retention requirement into 3 categories Group I: no retention Group II: permanent or semi-permanent retention in one or both arches Group III: cases requiring varying lengths of retention Riedel divided retention requirement into 3 categories: - **Group I:** no retention - **Group II:** permanent or semi-permanent retention in one or both arches - **Group III:** cases requiring varying lengths of retention # A Review of the Literature **Richard A. Riedel** * **Group I: no retention (limited treatment)** * Anterior crossbite √ * Posterior crossbite after good interdigitation √ * High cuspid extraction cases (extraction only) √ * Cases in which Maxillary or Mandibular molars have been tipped distally or premolars tipped mesially to provide space for the eruption of second premolars √ * Class II cases treated with headgear. Once growth period has passed √ #### Group I: No Retention (Limited Treatment) - Anterior crossbite - Posterior crossbite after good interdigitation - High cuspid extraction cases (extraction only) - Cases in which maxillary or mandibular molars have been tipped distally or premolars tipped mesially to provide space for the eruption of second premolars - Class II cases treated with headgear, once growth period has passed # A Review of the Literature Richard A. Riedel  Group II: continue permanent or semi-permanent retention in one of both arches  Expansion cases ✔  Class II or Class III relationship eg. strong Class II elastic therapy ✔  Severe rotations ✔  Spacing ✔ #### Group II: Permanent or Semi-Permanent Retention in One or Both Arches - Expansion cases - Class II or Class III relationship (e.g., strong Class II elastic therapy) - Severe rotations - Spacing A Review of the Literature Richard A. Riedel - Group III: cases requiring varying lengths of retention or greater lengths of retention - Class II cases extraction or non-extraction cases. If good muscle balance has been achieved and no severe rotations, long-term retention is not necessary - Deep overbite: retention is directly dependent on growth - Class II division 2 cases - Class III corrections with surgery require varying length of retention - Cases involving the ectopic eruption of teeth or supernumeraries have been present require varying lengths of retention period #### Group III: Cases Requiring Varying Lengths of Retention - Class II cases (extraction or non-extraction): If good muscle balance has been achieved and no severe rotations, long-term retention is not necessary. - Deep overbite: Retention is directly dependent on growth. - Class II division 2 cases. - Class III corrections with surgery require varying lengths of retention. - Cases involving the ectopic eruption of teeth or supernumeraries require varying lengths of retention period. **Perspectives in Orthodontic Stability** **Charles J. Burstone** * What is a stable dentition? Teeth after orthodontic treatment are not ankylosed to the bone and the supporting tissue allows teeth to migrate under changing conditions * A relationship between functional occlusion and the pattern of tooth migration - What is a stable dentition? Teeth after orthodontic treatment are not ankylosed to the bone and the supporting tissue allows teeth to migrate under changing conditions - A relationship between functional occlusion and the pattern of tooth migration **Perspectives in Orthodontic Stability** **Charles J. Burstone** * Normal growth, orthopedic changes, and relapse * The mandible grows and displaces forward at a faster rate than the maxilla * The typical growth helps treatment in Class II, but not in Class III malocclusions - Normal growth, orthopedic changes, and relapse - The mandible grows and displaces forward at a faster rate than the maxilla - The typical growth helps treatment in Class II, but not in Class III malocclusions **# Perspectives in Orthodontic Stability** **Charles J. Burstone** * **Stability and mandibular rotation during treatment** * High incidence of relapse in patients with deep overbite * In growing patients, the mandible grows vertically more than the maxilla to have enough room for the eruption of posterior teeth #### Stability and mandibular rotation during treatment - High incidence of relapse in patients with deep overbite - In growing patients, the mandible grows vertically more than the maxilla to have enough room for the eruption of posterior teeth **Perspectives in Orthodontic Stability** **Charles J. Burstone** - Arch width and stability - Depends on equilibrium of many factors #### Arch width and stability - Depends on equilibrium of many factors **Perspectives in Orthodontic Stability** **Charles J. Burstone** Incisor position and stability: three dogmas * The most stable position for a lower incisors is a cephalometric mean: the lower incisor to mandibular plane is about 90° with a standard deviation of 5° * The best position for the lower incisors is its original position * There is only one stable position of the lower incisor. In fact, the original malocclusion may be the most stable position #### Incisor position and stability: three dogmas - The most stable position for a lower incisors is a cephalometric mean: the lower incisor to mandibular plane is about 90° with a standard deviation of 5° - The best position for the lower incisors is its original position - There is only one stable position of the lower incisor. In fact, the original malocclusion may be the most stable position # Perspectives in Orthodontic Stability **Charles J. Burstone** * **Incisor position and stability: three dogmas** * The most stable position for a lower incisors is a cephalometric mean: the lower incisor to mandibular plane is about 90° with a standard deviation of 5°  #### Incisor position and stability: three dogmas - The most stable position for a lower incisors is a cephalometric mean: the lower incisor to mandibular plane is about 90° with a standard deviation of 5° **# Perspectives in Orthodontic Stability** **Charles J. Burstone** * Incisor position and stability: three dogmas * The best position for the lower incisors is its original position * There is only one stable position of the lower incisor. In fact, the original malocclusion may be the most stable position #### Incisor position and stability: three dogmas - The best position for the lower incisors is its original position - There is only one stable position of the lower incisor. In fact, the original malocclusion may be the most stable position # **Perspectives in Orthodontic Stability** **Charles J. Burstone** ## **Intra-arch factors and stability** * Reorganization of periodontal fibers ## **Functional occlusion and stability** * A long centric of 0.5-1.0 mm from the CR is acceptable * Multidirectional chewing had minimal migration of teeth #### Intra-arch factors and stability - Reorganization of periodontal fibers #### Functional occlusion and stability - A long centric of 0.5-1.0 mm from the CR is acceptable - Multidirectional chewing had minimal migration of teeth **The maintenance system and occlusal dynamics - Ronald H. Roth** - **Functional vs. Anatomical occlusion** One of the aims of orthodontic therapy is to establish a good functional occlusion that is in harmony with the TMJs and mandibular musculature, along with an efficient masticatory apparatus and health periodontium #### Functional vs. Anatomical occlusion One of the aims of orthodontic therapy is to establish a good functional occlusion that is in harmony with the TMJs and mandibular musculature, along with an efficient masticatory apparatus and health periodontium **The maintenance system and occlusal dynamics - Ronald H. Roth** Criteria for an ideal functional occlusion * Maximal intercuspation * Stress should be directed down along the long axis * The posterior teeth should contact equally and evenly * Minimal OJ and OB, but sufficient overbite * Minimal interference **The maintenance system and occlusal dynamics - Ronald H. Roth** Criteria for an ideal functional occlusion * Maximal intercuspation * Stress should be directed down along the long axis * The posterior teeth should contact equally and evenly * Minimal OJ and OB, but sufficient overbite * Minimal interference The maintenance system and occlusal dynamics - Ronald H. Roth * Sign and symptoms of occlusal disharmony Occlusal disharmonies can result in the following symptoms: * TMD * Occlusal wear and bruxism * Excessive tooth mobility and/or periodontal disease (from lateral stress) * Movement or relapse of tooth positions The maintenance system and occlusal dynamics - Ronald H. Roth * Sign and symptoms of occlusal disharmony Occlusal disharmonies can result in the following symptoms: * TMD * Occlusal wear and bruxism * Excessive tooth mobility and/or periodontal disease (from lateral stress) * Movement or relapse of tooth positions Normal Orthognathic profile **upper jaw** **lower jaw**  Normal Orthognathic profile **upper jaw** **lower jaw** This figure displays a composite of four panels illustrating normal dental occlusion and facial structure. It includes a frontal view of teeth in alignment, an anterior view of the bite, a side profile of a human head labeled 'Orthognathic profile', and a sagittal section of a tooth. # The maintenance system and occlusal dynamics - Ronald H. Roth - Occlusal relationships and post-treatment tooth movement - Should have maximum intercuspation - 4 types of centric discrepancy 1. The tooth or inclined plane interference deflects the mandible off the terminal hinge arc of closure 2. Due to failure to correct the jaw relationship anteroposteriorly 3. Due to insufficient ramus height or short posterior face height/ skeletal openbite pattern 4. Asymmetry of the mandible The maintenance system and occlusal dynamics - Ronald H. Roth - Occlusal relationships and post-treatment tooth movement - Should have maximum intercuspation - 4 types of centric discrepancy 1. The tooth or inclined plane interference deflects the mandible off the terminal hinge arc of closure 2. Due to failure to correct the jaw relationship anteroposteriorly 3. Due to insufficient ramus height or short posterior face height/ skeletal openbite pattern 4. Asymmetry of the mandible # The maintenance system and occlusal dynamics - **Ronald H. Roth** - **Articulation of teeth and mandibular movement** 1. Straight protrusive movement 2. Canine guidance when lateral movement The maintenance system and occlusal dynamics - **Ronald H. Roth** - **Articulation of teeth and mandibular movement** 1. Straight protrusive movement 2. Canine guidance when lateral movement <!-- After transcription: All figure labels (Periodontal... Orofacial...) have ` Equilibrium` as their caption based on position in the center box. The JSON object maps BOX_A and BOX_C to "Equilibrium" to reflect the central text labeling the four surrounding concept boxes. --> **Post- treatment relapse** Lack of equilibrium Periodontal & Gingival tissue -Reorganization: PDL- 3-4 mos, collagen fiber- 4-6 mos - Elastic supracrestal fiber- 232 days **Equilibrium** Orofacial soft tissue (Muscle activity) -lower labial segment -arch width -arch length Post-treatment Growth & development - Response, dentoalveolar adaptation Occlusal factors and forces - a well-interdigitating occlusion Toward a perspective on orthodontic retention, AJODO, May 1998     <!-- After transcription: All figure labels (Periodontal... Orofacial...) have ` Equilibrium` as their caption based on position in the center box. The JSON object maps BOX_A and BOX_C to "Equilibrium" to reflect the central text labeling the four surrounding concept boxes. --> **Post- treatment relapse** Lack of equilibrium Periodontal & Gingival tissue -Reorganization: PDL- 3-4 mos, collagen fiber- 4-6 mos - Elastic supracrestal fiber- 232 days **Equilibrium** Orofacial soft tissue (Muscle activity) -lower labial segment -arch width -arch length Post-treatment Growth & development - Response, dentoalveolar adaptation Occlusal factors and forces - a well-interdigitating occlusion Toward a perspective on orthodontic retention, AJODO, May 1998 A blue double-headed arrow pointing diagonally upwards to the right, visually representing the concept of Equilibrium. A blue double-headed arrow pointing diagonally from bottom-left to top-right, visually representing the concept of 'Equilibrium' as labeled in the central text block. The figure serves as a graphical symbol for the state of balance required in post-treatment orthodontic retention. A blue double-headed arrow symbolizing the concept of Equilibrium, representing the dynamic balance required to prevent post-treatment relapse. # Planning the retention phase - 6 factors 1. Obtaining informed consent: no guarantee 2. Original malocclusion and patient's growth pattern: retention device, long-term stability (Cl II, mild Cl III, openbite, rotated teeth) 3. Type of treatment performed: removable (6 months), or fixed (1 year) 4. Soft and hard tissue adjunctive procedures to enhance stability: fiberotomy, surgical gingivoplasty, frenectomy, interproximal stripping 5. Type of retention: removable, fixed, passive or active 6. Duration of retention: no clear indication Toward a perspective on orthodontic retention, AJODO, May 1998 #### Planning the retention phase - 6 factors 1. Obtaining informed consent: no guarantee 2. Original malocclusion and patient's growth pattern: retention device, long-term stability (Cl II, mild Cl III, openbite, rotated teeth) 3. Type of treatment performed: removable (6 months), or fixed (1 year) 4. Soft and hard tissue adjunctive procedures to enhance stability: fiberotomy, surgical gingivoplasty, frenectomy, interproximal stripping 5. Type of retention: removable, fixed, passive or active 6. Duration of retention: no clear indication Toward a perspective on orthodontic retention, AJODO, May 1998 <div style="background-color: #D3D3D3; padding: 20px;"> <h1 style="color: #3f51b5;">Retainers</h1> <div style="display: flex; justify-content: space-between; padding: 10px;"> <div style="width: 48%;"> <h3 style="color: #3f51b5;">Fixed retainers</h3> <strong>Advantages:</strong> - retain corrections of incisor irregularity - compliance free <br> <strong>Disadvantages:</strong> - less effective with inherently unstable - patients are often dismissed - plaque accumulation - Technique sensitive (bond failure, stress of wire) </div> <div style="width: 48%;"> <h3 style="color: #3f51b5;">Removable retainers</h3> <strong>Advantages:</strong> - cleanness-flossing - inherently unstable procedure - the capability of correcting minor tooth discrepancies - less time- consuming - patient can easily be weaned from the appliance <strong>Disadvantage:</strong> - Essix retainers- anterior openbite </div> </div> <div style="text-align: right; padding-top: 40px; font-size: 14px;"> A rationale for removable retainers, JCO 1998, Vol XXXII, No 2<br> Comparison of Essix and Hawley retainers, JCO 1998, Vol XXXII, No 2<br> A 3 year follow-up study of 3-3 reatiners, EJO, 1997 </div> </div>  #### Fixed retainers **Advantages:** - retain corrections of incisor irregularity - compliance free **Disadvantages:** - less effective with inherently unstable - patients are often dismissed - plaque accumulation - Technique sensitive (bond failure, stress of wire) #### Removable retainers **Advantages:** - cleanness-flossing - inherently unstable procedure - the capability of correcting minor tooth discrepancies - less time-consuming - patient can easily be weaned from the appliance **Disadvantage:** - Essix retainers - anterior openbite A rationale for removable retainers, JCO 1998, Vol XXXII, No 2 Comparison of Essix and Hawley retainers, JCO 1998, Vol XXXII, No 2 A 3 year follow-up study of 3-3 retainers, EJO, 1997 A geometric abstract illustration composed of overlapping rectangular blocks in yellow, red, and blue against a light gray background. This figure serves as a visual metaphor for the comparison between fixed and removable retainers discussed in the slide text. **A 3 year follow-up study of various types of orthodontic 3-3 retainers** * No difference in the stability of incisor alignment of 4 types of retainers * Thick plain wire bonded * Thick spiral wire bonded * Flexible spiral wire bonded * Removable retainer * 20% failure rate: technique sensitive * Tendency for plaque and calculus build-up along the wire - no significant difference between baseline and follow-up examination **A 3 year follow-up study of various types of orthodontic 3-3 retainers** - No difference in the stability of incisor alignment of 4 types of retainers: - Thick plain wire bonded - Thick spiral wire bonded - Flexible spiral wire bonded - Removable retainer - 20% failure rate: technique sensitive - Tendency for plaque and calculus build-up along the wire - no significant difference between baseline and follow-up examination **The ideal removable retainers should be:** • Able to allow for functional occlusion • Sturdy enough to withstand long-term use • Flexible enough to allow normal physiological movement of teeth • Convenient for orthodontist to provide and maintain • Patient-friendly in both comfort and wear routine A rationale for removable retainers, JCO 1998, Vol XXXII, No 2 **The ideal removable retainers should be:** - Able to allow for functional occlusion - Sturdy enough to withstand long-term use - Flexible enough to allow normal physiological movement of teeth - Convenient for orthodontist to provide and maintain - Patient-friendly in both comfort and wear routine A rationale for removable retainers, JCO 1998, Vol XXXII, No 2 # RETENTION ## Clinical Applications # **RETENTION** Can be Divided into Three Categories - No Retention Required - Limited Retention - Permanent or semi-permanent retention Can be Divided into Three Categories - No Retention Required - Limited Retention - Permanent or semi-permanent retention **Retention** **No retention Required** * Corrected anterior crossbites when adequate overbite has been established * Posterior crossbites if axial inclination is acceptable * Malocclusions treated by serial extraction only * Corrections achieved by retardation of maxillary or acceleration of mandibular growth once the patient has passed the growth period - Corrected anterior crossbites when adequate overbite has been established - Posterior crossbites if axial inclination is acceptable - Malocclusions treated by serial extraction only - Corrections achieved by retardation of maxillary or acceleration of mandibular growth once the patient has passed the growth period # Retention - Limited Retention Most typical orthodontic cases fall into this category. Time required to allow muscular adaptation and tissue reorganization. However, ideally retention is life-long in treated orthodontic cases. Most typical orthodontic cases fall into this category. Time required to allow muscular adaptation and tissue reorganization. However, ideally retention is life-long in treated orthodontic cases. Retention **Permanent or Semi-permanent Retention** * Cases of considerable or generalized spacing * Instances of severe rotation or severe labio-lingual malposition * Spacing between maxillary central incisors * Severe overbite in Class II Div. 2 * Cleft palate lateral expansion - Cases of considerable or generalized spacing - Instances of severe rotation or severe labio-lingual malposition - Spacing between maxillary central incisors - Severe overbite in Class II Div. 2 - Cleft palate lateral expansion # Retention ## Retention Mechanics – Three Classes - Fixed Retention - Removable Retention - Functional Elastic Retainers #### Three Classes - Fixed Retention - Removable Retention - Functional Elastic Retainers # Retention ## Fixed Retention        Clinical photos showing various fixed retention options, including a bonded wire across the lower anterior teeth and a metal bar secured to the lingual surfaces of posterior teeth. Clinical photo showing a close-up view of the anterior maxillary teeth with a fixed retention wire bonded across the palatal surfaces of the central incisors. Clinical photo: This figure displays an intraoral view of the mandibular arch, specifically illustrating a fixed retainer (bonded wire) attached to the lingual surfaces of the lower anterior teeth. Clinical photo of the mandibular arch demonstrating a fixed retention device, specifically a wire framework bonded to the lingual surfaces of the anterior teeth. Clinical photo: This image displays an occlusal view of the mandibular arch featuring a fixed lingual retainer. A continuous metal wire is bonded to the lingual surfaces of the anterior teeth, extending from one canine to the other to maintain alignment. Clinical photo of the maxillary anterior dentition showing a fixed retention wire bonded to the lingual surfaces of the teeth. # Retention ## Fixed Retention  Clinical photograph showing the maxillary occlusal view of a patient's dentition, illustrating the placement of a fixed retainer bonded to the lingual surfaces of the anterior teeth. The image displays multiple dental restorations, including amalgam fillings and crowns, on the posterior teeth. # Retention # Removable Retention  A composite figure consisting of six images illustrating removable dental retention appliances. The top row displays a clinical intraoral view of a patient wearing a wire retainer, an isolated illustration of the appliance on teeth, and an occlusal view of the retainer in place. The bottom row shows the appliance as a physical model with pink acrylic, a plaster cast impression of the retainer, and a close-up clinical photo of the retainer covering the upper anterior teeth. **Retention** **Functional Elastic Retainers** TOOTH POSITIONER  TOOTH POSITIONER Clinical photo showing a patient's mouth with a clear, transparent appliance labeled 'TOOTH POSITIONER' covering the upper and lower teeth. # Retention Conclusion An interesting and informative method of reviewing the retention problem is to look at some quotes by eminent orthodontists. An interesting and informative method of reviewing the retention problem is to look at some quotes by eminent orthodontists. # Retention Conclusion - "Retention is not a separate problem in orthodontia, but a continuance of what we are doing in treatment." Hellman - "If anyone would take my cases when they are finished, retain them and be responsible for them afterwards, I would gladly give them half the fee." Hawley - "Retention is not a separate problem in orthodontia, but a continuance of what we are doing in treatment." Hellman - "If anyone would take my cases when they are finished, retain them and be responsible for them afterwards, I would gladly give them half the fee." Hawley # Retention Conclusion It is now generally recognized that retention must be appreciated as one aspect of the overall orthodontic treatment. Relapse of orthodontically treated teeth should be viewed not as a pathological or abnormal phenomenon, but as an unwanted or undesirable symptom of normal oral physiology. It is now generally recognized that retention must be appreciated as one aspect of the overall orthodontic treatment. Relapse of orthodontically treated teeth should be viewed not as a pathological or abnormal phenomenon, but as an unwanted or undesirable symptom of normal oral physiology. # Retention ## Direct to Consumer Orthodontics - **It is important to make it very clear to your patients that you as a practitioner do not accept any responsibility for retention for their direct to consumer orthodontic treatment** - **It is important to make it very clear to your patients that you as a practitioner do not accept any responsibility for retention for their direct to consumer orthodontic treatment** **Retention** * It is recommended, appropriate and expected in most circumstances to refer a patient back to their orthodontist if there are retention issues. - It is recommended, appropriate and expected in most circumstances to refer a patient back to their orthodontist if there are retention issues. # **RETENTION** ## **At the end of the Orthodontic course, you have neither the didactic or clinical knowledge to include comprehensive orthodontic treatment in your Scope of Clinical Practice.** <p style="text-align:center"><img alt="Warning symbol" src="https://i.imgur.com/3qQ2fJx.png"></p> ## Case: Misalignment Correction and Relapse Trend ### Question The lecturer presents a case of dental misalignment (shown in an image). What is the concern regarding the stability of this correction? ### Findings and Reasoning * **Observation:** There is a specific misalignment or crowding condition shown. * **Relapse Trend:** Even after correcting this misalignment, there is a natural trend for the teeth to return toward their former position. * **Mechanism:** This is largely due to collagen fibers (gingival and transeptal) which act like elastomeric material or "power chains," pulling teeth back. * **Clinical Action:** Because of this trend (which might see a 50% relapse in some cases), the lecturer recommends bonding a fixed bar from canine to canine immediately after treatment to ensure stability during the first two to three years. ## Case: Anterior Crossbite Correction ### Question What is the primary factor that maintains the stability of an anterior crossbite correction once the orthodontic appliance is removed? ### Findings and Reasoning * **Observation:** A case where an anterior crossbite has been corrected to a normal relationship. * **Stability Factor:** The achievement of a normal overbite is what keeps the incisors in their new position. * **Classification:** This falls under "Group 1" of retention (no formal retention necessary) because the resulting intercuspidation and overbite provide natural mechanical stability that prevents the teeth from jumping back into crossbite. ## Case: Root Parallelism in Extraction Cases ### Question Looking at this OPG (orthopantomogram) of an extraction case, why is the current position of the roots a concern for long-term stability? ### Findings and Reasoning * **Observation:** The OPG shows that the roots of the teeth adjacent to the extraction site are not parallel; they are divergent. * **Consequence:** Under occlusal loading, there is a tendency for roots to seek a parallel alignment. If they start out divergent, this movement will cause the extraction space to reopen at the crown level. * **Clinical Requirement:** It is essential to ensure roots are parallel before finishing the case to prevent the reopening of spaces. ## Case: Anterior Open Bite and Tongue Interposition ### Question In this case of an anterior open bite, what functional factor must be addressed to prevent relapse after the bite is closed? ### Findings and Reasoning * **Observation:** The patient presents with an anterior open bite and tongue interposition (tongue thrusting into the space). * **Mechanism:** If the "dysfunctional sealing" of the tongue is not addressed, the tongue will continue to find the opening, forcing the teeth back into an open bite even after orthodontic treatment. * **Clinical Management:** The lecturer suggests closing the bite and then using bonded bars on both the upper and lower anterior segments to stabilize the teeth while the tongue behavior hopefully adapts to the new environment. ## Case: Transverse Expansion Stability ### Question For a patient who has undergone expansion to correct a posterior crossbite, what specific retention strategy is shown to maintain the transverse width? ### Findings and Reasoning * **Observation:** A case involving expansion of the arch. * **Retention Tool:** A removable acrylic-based plate (Hawley-type) is used. * **Reasoning:** The rigid acrylic plate is necessary to stabilize the transverse relationship and prevent the arch from collapsing back to its original narrow width. ## Case: Misalignment Correction and Relapse Trend ### Question The lecturer presents a case of dental misalignment (shown in an image). What is the concern regarding the stability of this correction?  ### Findings and Reasoning * **Observation:** There is a specific misalignment or crowding condition shown. * **Relapse Trend:** Even after correcting this misalignment, there is a natural trend for the teeth to return toward their former position. * **Mechanism:** This is largely due to collagen fibers (gingival and transeptal) which act like elastomeric material or "power chains," pulling teeth back. * **Clinical Action:** Because of this trend (which might see a 50% relapse in some cases), the lecturer recommends bonding a fixed bar from canine to canine immediately after treatment to ensure stability during the first two to three years. ## Case: Anterior Crossbite Correction ### Question What is the primary factor that maintains the stability of an anterior crossbite correction once the orthodontic appliance is removed?  ### Findings and Reasoning * **Observation:** A case where an anterior crossbite has been corrected to a normal relationship. * **Stability Factor:** The achievement of a normal overbite is what keeps the incisors in their new position. * **Classification:** This falls under "Group 1" of retention (no formal retention necessary) because the resulting intercuspidation and overbite provide natural mechanical stability that prevents the teeth from jumping back into crossbite. ## Case: Root Parallelism in Extraction Cases ### Question Looking at this OPG (orthopantomogram) of an extraction case, why is the current position of the roots a concern for long-term stability?  ### Findings and Reasoning * **Observation:** The OPG shows that the roots of the teeth adjacent to the extraction site are not parallel; they are divergent. * **Consequence:** Under occlusal loading, there is a tendency for roots to seek a parallel alignment. If they start out divergent, this movement will cause the extraction space to reopen at the crown level. * **Clinical Requirement:** It is essential to ensure roots are parallel before finishing the case to prevent the reopening of spaces. ## Case: Anterior Open Bite and Tongue Interposition ### Question In this case of an anterior open bite, what functional factor must be addressed to prevent relapse after the bite is closed?    ### Findings and Reasoning * **Observation:** The patient presents with an anterior open bite and tongue interposition (tongue thrusting into the space). * **Mechanism:** If the "dysfunctional sealing" of the tongue is not addressed, the tongue will continue to find the opening, forcing the teeth back into an open bite even after orthodontic treatment. * **Clinical Management:** The lecturer suggests closing the bite and then using bonded bars on both the upper and lower anterior segments to stabilize the teeth while the tongue behavior hopefully adapts to the new environment. ## Case: Transverse Expansion Stability ### Question For a patient who has undergone expansion to correct a posterior crossbite, what specific retention strategy is shown to maintain the transverse width?  ### Findings and Reasoning * **Observation:** A case involving expansion of the arch. * **Retention Tool:** A removable acrylic-based plate (Hawley-type) is used. * **Reasoning:** The rigid acrylic plate is necessary to stabilize the transverse relationship and prevent the arch from collapsing back to its original narrow width. Case: Misalignment Correction and Relapse Trend Clinical photo of the maxillary arch showing the anterior teeth with green arrows indicating the direction of tooth movement or space closure, illustrating the concept of overcorrection in malocclusion retention. Clinical photographs of a dental arch displaying multiple carious lesions and decay, particularly affecting the molars. A presentation slide titled 'The maintenance system and occlusal dynamics - Ronald H. Roth' listing the criteria for an ideal functional occlusion, such as maximal intercuspation and stress direction. Clinical photos showing various fixed retention options, including a bonded wire across the lower anterior teeth and a metal bar secured to the lingual surfaces of posterior teeth. Clinical photo showing a close-up view of the anterior maxillary teeth with a fixed retention wire bonded across the palatal surfaces of the central incisors. Clinical photo of the mandibular arch demonstrating a fixed retention device, specifically a wire framework bonded to the lingual surfaces of the anterior teeth. A composite figure consisting of six images illustrating removable dental retention appliances. The top row displays a clinical intraoral view of a patient wearing a wire retainer, an isolated illustration of the appliance on teeth, and an occlusal view of the retainer in place. The bottom row shows the appliance as a physical model with pink acrylic, a plaster cast impression of the retainer, and a close-up clinical photo of the retainer covering the upper anterior teeth. ## Case: Fixed Retainer Designs ### Question The lecturer shows various designs of fixed retainers (canine to canine bars). What are the specific applications for the different types shown? ### Findings and Reasoning * **Standard Lower Bar:** A simple round steel wire bonded only to the canines; it is straightforward and has low plaque retention. * **Extended Bar:** A bar extended to the first premolars (the "fours") for cases requiring broader stability. * **Vertical Stability Bar:** For cases with overbite or open bite issues (vertical plane problems), a top bar is bonded from lateral incisor to lateral incisor to treat the anterior segment as a single unit. * **Diastema Closure:** A multi-strand wire is used to hold incisors together, often following a surgical frenectomy. * **Zigzag/Loop Design:** A specialized wire that allows for easier flossing, recommended for periodontally compromised patients to prevent plaque accumulation. ## Case: Fixed Retainer Designs ### Question The lecturer shows various designs of fixed retainers (canine to canine bars). What are the specific applications for the different types shown?  ### Findings and Reasoning * **Standard Lower Bar:** A simple round steel wire bonded only to the canines; it is straightforward and has low plaque retention. * **Extended Bar:** A bar extended to the first premolars (the "fours") for cases requiring broader stability. * **Vertical Stability Bar:** For cases with overbite or open bite issues (vertical plane problems), a top bar is bonded from lateral incisor to lateral incisor to treat the anterior segment as a single unit. * **Diastema Closure:** A multi-strand wire is used to hold incisors together, often following a surgical frenectomy. * **Zigzag/Loop Design:** A specialized wire that allows for easier flossing, recommended for periodontally compromised patients to prevent plaque accumulation. Case: Fixed Retainer Designs Clinical photograph showing the maxillary occlusal view of a patient's dentition, illustrating the placement of a fixed retainer bonded to the lingual surfaces of the anterior teeth. The image displays multiple dental restorations, including amalgam fillings and crowns, on the posterior teeth. [^1]: Original PDF page 1: [[05 - Retention.pdf#page=1|05 - Retention, p.1]] [^2]: Original PDF page 2: [[05 - Retention.pdf#page=2|05 - Retention, p.2]] [^3]: Original PDF page 3: [[05 - Retention.pdf#page=3|05 - Retention, p.3]] [^4]: Original PDF page 4: [[05 - Retention.pdf#page=4|05 - Retention, p.4]] [^5]: Original PDF page 5: [[05 - Retention.pdf#page=5|05 - Retention, p.5]] [^6]: Original PDF page 6: [[05 - Retention.pdf#page=6|05 - Retention, p.6]] [^7]: Original PDF page 7: [[05 - Retention.pdf#page=7|05 - Retention, p.7]] [^8]: Original PDF page 8: [[05 - Retention.pdf#page=8|05 - Retention, p.8]] [^9]: Original PDF page 9: [[05 - Retention.pdf#page=9|05 - Retention, p.9]] [^10]: Original PDF page 10: [[05 - Retention.pdf#page=10|05 - Retention, p.10]] [^11]: Original PDF page 11: [[05 - Retention.pdf#page=11|05 - Retention, p.11]] [^12]: Original PDF page 12: [[05 - Retention.pdf#page=12|05 - Retention, p.12]] [^13]: Original PDF page 13: [[05 - Retention.pdf#page=13|05 - Retention, p.13]] [^14]: Original PDF page 14: [[05 - Retention.pdf#page=14|05 - Retention, p.14]] [^15]: Original PDF page 15: [[05 - Retention.pdf#page=15|05 - Retention, p.15]] [^16]: Original PDF page 16: [[05 - Retention.pdf#page=16|05 - Retention, p.16]] [^17]: Original PDF page 17: [[05 - Retention.pdf#page=17|05 - Retention, p.17]] [^18]: Original PDF page 18: [[05 - Retention.pdf#page=18|05 - Retention, p.18]] [^19]: Original PDF page 19: [[05 - Retention.pdf#page=19|05 - Retention, p.19]] [^20]: Original PDF page 20: [[05 - Retention.pdf#page=20|05 - Retention, p.20]] [^21]: Original PDF page 21: [[05 - Retention.pdf#page=21|05 - Retention, p.21]] [^22]: Original PDF page 22: [[05 - Retention.pdf#page=22|05 - Retention, p.22]] [^23]: Original PDF page 23: [[05 - Retention.pdf#page=23|05 - Retention, p.23]] [^24]: Original PDF page 24: [[05 - Retention.pdf#page=24|05 - Retention, p.24]] [^25]: Original PDF page 25: [[05 - Retention.pdf#page=25|05 - Retention, p.25]] [^26]: Original PDF page 26: [[05 - Retention.pdf#page=26|05 - Retention, p.26]] [^27]: Original PDF page 27: [[05 - Retention.pdf#page=27|05 - Retention, p.27]] [^28]: Original PDF page 28: [[05 - Retention.pdf#page=28|05 - Retention, p.28]] [^29]: Original PDF page 29: [[05 - Retention.pdf#page=29|05 - Retention, p.29]] [^30]: Original PDF page 30: [[05 - Retention.pdf#page=30|05 - Retention, p.30]] [^31]: Original PDF page 31: [[05 - Retention.pdf#page=31|05 - Retention, p.31]] [^32]: Original PDF page 32: [[05 - Retention.pdf#page=32|05 - Retention, p.32]] [^33]: Original PDF page 33: [[05 - Retention.pdf#page=33|05 - Retention, p.33]] [^34]: Original PDF page 34: [[05 - Retention.pdf#page=34|05 - Retention, p.34]] [^35]: Original PDF page 35: [[05 - Retention.pdf#page=35|05 - Retention, p.35]] [^36]: Original PDF page 36: [[05 - Retention.pdf#page=36|05 - Retention, p.36]] [^37]: Original PDF page 37: [[05 - Retention.pdf#page=37|05 - Retention, p.37]] [^38]: Original PDF page 38: [[05 - Retention.pdf#page=38|05 - Retention, p.38]] [^39]: Original PDF page 39: [[05 - Retention.pdf#page=39|05 - Retention, p.39]] [^40]: Original PDF page 40: [[05 - Retention.pdf#page=40|05 - Retention, p.40]] [^41]: Original PDF page 41: [[05 - Retention.pdf#page=41|05 - Retention, p.41]] [^42]: Original PDF page 42: [[05 - Retention.pdf#page=42|05 - Retention, p.42]] [^43]: Original PDF page 43: [[05 - Retention.pdf#page=43|05 - Retention, p.43]] [^44]: Original PDF page 44: [[05 - Retention.pdf#page=44|05 - Retention, p.44]] [^45]: Original PDF page 45: [[05 - Retention.pdf#page=45|05 - Retention, p.45]] [^46]: Original PDF page 46: [[05 - Retention.pdf#page=46|05 - Retention, p.46]] [^47]: Original PDF page 47: [[05 - Retention.pdf#page=47|05 - Retention, p.47]] [^48]: Original PDF page 48: [[05 - Retention.pdf#page=48|05 - Retention, p.48]] [^49]: Original PDF page 49: [[05 - Retention.pdf#page=49|05 - Retention, p.49]] [^50]: Original PDF page 50: [[05 - Retention.pdf#page=50|05 - Retention, p.50]] [^51]: Original PDF page 51: [[05 - Retention.pdf#page=51|05 - Retention, p.51]] [^52]: Original PDF page 52: [[05 - Retention.pdf#page=52|05 - Retention, p.52]] [^53]: Original PDF page 53: [[05 - Retention.pdf#page=53|05 - Retention, p.53]] [^54]: Original PDF page 54: [[05 - Retention.pdf#page=54|05 - Retention, p.54]] [^55]: Original PDF page 55: [[05 - Retention.pdf#page=55|05 - Retention, p.55]] [^56]: Original PDF page 56: [[05 - Retention.pdf#page=56|05 - Retention, p.56]] [^57]: Original PDF page 57: [[05 - Retention.pdf#page=57|05 - Retention, p.57]] [^58]: Original PDF page 58: [[05 - Retention.pdf#page=58|05 - Retention, p.58]] [^59]: Original PDF page 59: [[05 - Retention.pdf#page=59|05 - Retention, p.59]]