 Hello friends, so I am back with the part 2 of retention and relapse. We have already covered the basic portions such as theorems of retention, schools of thoughts and keys for lower retention etc. In this session we will be discussing about the retention plan, different types of retention appliances or retainers and some agenda procedures to aid in retention. Moving on, retention plan. So what is retention plan? It is basically planned during the diagnosis and treatment planning phase. Retention plan comprises of the requirements for retention, the types of retentive measures and duration of its use that is how long it has to be used for better stability and is often decided at the time of diagnosis and treatment planning. And also retention depends on what is accomplished during the treatment that is the final outcome or final result what we have got. So retention planning is divided into three categories depending on the type of treatment instituted. First one is no retention required. Second one is limited retention that is in terms of both time and appliance wearing. And third one is the permanent or semi-permanent retention. See each one in detail. First one is cases that require no retention. Basically the best examples are corrected cross bites. So when adequate overbite has been established and reasonable axial inclination has been achieved in case of cross bites you no longer need any particular retentive measures. So for example in this case you can see there is anterior cross bite and after correction we got an adequate overbite and axial inclination. So there is no need of special retention plan to maintain whatever we achieve because the positive overbite is enough to hold the lower incisors in position. Another example is the posterior cross bite and there also you can see after achieving the perfect cusp fossa relationships you no longer need any particular retentive measures. So next example is the serial extraction that is the condition that have been treated by serial extraction. And another one is the conditions that have been achieved by retardation of maxillary dental and skeletal growth and the patient has passed the growth period. So that is another example where you had a maxillary deficiency case where you got the result and in those cases also you no longer need any particular retentive method. Last but not least is the previously blocked out tooth which was moved into the occlusion. So these are the conditions where you do not require special retentive methods. So the second category is the limited retention required. So the cases in this category are class 1 non extraction cases, class 1 or class 2 extraction cases, then ectopic eruption of teeth or the presence of supernumerary teeth corrected deep overbite cases. So in these cases you require retentive methods, retention planning but there is you do not require retention for a longer period of time. So next one is the cases requiring permanent or semi-permanent retention. So these are includes cases treated by expansion, then cases of generalized spacing, severely rotated teeth and midline diastema cases. So in all these cases there is high chance of relapse. So maintaining the achieved result for a longer period of time is highly recommended and for that you have to use a retentive method which is which stays there for a longer period than the normal. Now to maximize the post-treatment stability for that we use retention appliances or retainers. So retainers are passive orthodontic appliances that help in maintaining and stabilizing the position of the teeth long enough to permit reorganization of the supporting structures after the active phase of orthodontic therapy. There are different types of retainers or retention appliances that is a removal, offset and aesthetic types. So that we will be discussing in the coming slides. And what are the ideal requirements of retention appliance? So it should hold the tooth firmly in corrected position. It should allow the retained teeth to respond in a physiologic manner against functional forces and it should be as self-cleansing and sturdy. So retainers can be categorized into removable, fixed and aesthetic. So let's see each one in detail. So the first one is removable retainers. So the main examples are holly retainer, beg wrap-around retainer, spring or barrel retainer, headgear, functional appliances, marked retainer, thermo-micro sensor. So the most commonly used retainer is the holly retainer appliance and it is introduced by Charles Augustus Holly and it is made up of acrylic and wire component. And the acrylic portion covers the palatal or lingual mucosa and contacting the lingual surface of the teeth. A labial bow or round stainless steel wire of 0.7 to 0.8 mm is constructed to contact the labial surface of four or six anterior. And this as you can see on the picture, there is a labial bow and Adam's glass on the first molars and there's an acrylic portion which covers the entire palatal surface. This gives a proper retention. The one advantage of this holly retainer appliance is facilitating posterior or crucial settling in three months and it maintains lateral expansion also. But the main disadvantage is that because of the crossover wire that is the retentive arm of the labial bow which passes through, passes between the canine and the first primola, it causes a wedging effect and it can open the extraction space that is, that was closed. So that is the disadvantage of holly retainer appliance and there are several modifications to avoid this type of wedging effect. So the first modification is the hollies with long labial bow to prevent the wedging effect especially in first primola extraction cases, you can use a long labial bow. The next is the hollies with acrylic labial bow that is acrylic placed on the bridge of the labial bow that is mainly used in case of rotator teeth. The modification is hollies with soldered labial bow to Adam's to prevent the space opening. So the space opening is basically because of the crossover wire and the wedging effect. So to avoid that crossover wire, you can directly solder the labial bow to the Adam's. And another modification is the hollies with an anterior bite plane that is usually used for corrected deep bite cases. And another one is the hollies with a contoured labial bow that is, this is basically to maintain a control over anterior tooth. So the fitted labial bow or the contoured labial bow exactly adapt to the labial surface of the six anteriors. So next one is the Beck wrap around retainer that was developed, introduced by PR Beck. As you can see on the picture, it also has acrylic part and wire component. Since there is no crossover wire, there will not be any wedging effect. And it also allows vertical settling in posterior segments since no crossover wires and allows interdigitating of buckle segments while maintaining arch relationships. And it also prevents space from reopening. So another one is the wrap around clip on retainer. Basically consists of plastic bar usually wire reinforced along the labial and lingo surface of teeth. As you can see on the picture, it's a canine to canine clip on retainer basically used to prevent re-rotation of maxillary incisors. And another one is the canine to canine clip on retainers has the great advantages that it can be used to realign irregular incisors if mild crowding has developed after treatment. But it is well tolerated as a retainer alone. And upper canine to canine clip on retainer occasionally is useful in adults with long clinical cramps but rarely is indicated and usually would not be tolerated in younger patients because of occlusion interferences. And in this picture you see the canine to canine clip on retainer and instead of canine to canine a full arch wrap around retainer can also be advised in cases where primarily the perirond will break down present and that requires blending of the teeth together. So the next one is the functional appliances. So it is functional appliances are also can be used as a retainers. So basically it uses retainer appliance to maintain results achieved in class 2 and open bite malocclusion cases where growth has still left. So in cases where you got a functional correction that is in a case of mandibular deficiency after functional appliance therapy you got a perfect profile with proper mandibular advancement. In those cases you can still use that functional appliance as a retainer also. So activators, twin blocks and nearby planes can be used as retainers in those cases. So next category is the fixed retainers. As you can see on the picture a portion of wire is bonded to the lingual surface of the teeth to maintain their position. So fixed retainers are generally used in conditions where intraarch instability is anticipated and prolonged retention is needed. So the examples for fixed retainers are banded canine to canine retainer, bonded canine to canine retainer, banded spur retainer, diastema maintenance, anti-rotation band, pontic maintenance. Moving on, there are three types of retainers according to Zachrison. So he classified it into first generation, second generation and third generation. So this is the first generation retainer. They used a round O32 to O36 inch blue algae wire. And the second generation he used a twisted three-stranded O32 inch wire. And in third generation he used an O32 inch stainless steel or O30 inch gold coated wire. Another one is the banded canine to canine retainer. So in this instead of bonding the canines are firstly bonded and then the retainer wire is soldered onto the canine bands. So that is canine to canine banded retainer. The main disadvantage was it was aesthetically not pleasing and there are also enamel decalcifications were seen on the banded canines. So in bonded canine to canine retainer, instead of banding the wire portion is bonded to the lingual surface of the tooth. And in earlier that is the three generations of retainers by Zachrison, he just bonded only the two canines, right and left canines. But here they bonded each tooth with that wire portion. So flexible wire is used here, it's a multi-stranded wire. So it allows physiological moment of teeth. So another one is the rigid mandibular canine to canine retainer. This attachment is only to the canines and it maintained the inter-canine width and they used a thick single-stranded stainless steel wire here because of the rigidity it is less effective in preventing individual tooth rotations and it will not allow normal physiological moments of teeth. Another one is the banded spur retainer. So the band on the rotator tooth just two spurs welded to it lingually and laborally. So the spur rest on the adjacent tooth to prevent relapse. Basically it is used in rotated de-rotation cases. Another important area where prolonged retention is necessary is the diastema maintenance. So corrected diastema, you have to maintain the result and you have to prevent any space opening post treatment. So you have to use a fixed retainer and utilize lighter wires and the wires should be bonded above the singulum that is it should be out of the occlusion there should not be any occlusion interference. And can prevent bite deepening if lower incisors erupt. So that's the advantage of fixed retainer when used in case of diastema. So these are the fixed retainer indications. So the main indications were prolonged retention cases that require prolonged retention, well donely compromised cases and adult cases and diastema generalized spacing all these cases. Fixed retainer is a must and all other points you can note down. And the advantage of fixed retainer it is easy and well tolerated by the patient. It do not compromise on aesthetics and there will not be any interference with speech and no complaints problems, reduced risk of caries under loose bands. There are certain disadvantages also for fixed retainers they are the time consuming and technique sensitive interference with the bite and it can prevent settling of occlusion sometimes and pedontal problem can be created and unwanted moment of the tooth and small spaces between incisors can be seen. Moving on to the third category that is the aesthetic retainers. So they comprises of thermoplastic retainers, tooth positioners, diamond splint retainer, optic herbs retainer, VFR multi layer hybrid retainers all these are examples of aesthetic retainers. So it's basically made up of 1.5 mm polybenyl chloride sheet. Aesthetic retainers are contraindicated in patients with poor oral hygiene. This is because these retainers are retained by the plastic engaging the undercut ginger well to the contact point. If the oral hygiene is poor then hyperplastic ginger can obliterate these areas of undercut. So there are certain other situations in which this type of retainers are not advisable to use they are swollen intraproximal tissue, severe pretreatment, dental rotation and dental arch expansion. Another important retainer category comes under aesthetic retainers as the tooth positioners introduced by HD Kisling in 1945. So he designed these are plans basically to use during the finishing and detailing stage of fixed tongue plants therapy where minor adjustments of occlusion can be achieved using these are plans. He also advocated that it can be used as a retainer later and the basic advantages are it maintains intra arch, tooth position and occlusion relationships in the major disadvantage where the bulkiness and it was less effective in retaining rotation corrections and the lower durability. There are several other retainers aesthetic retainers are available in the market nowadays and they are moving on to the advantages and disadvantages of the aesthetic retainers. So the main advantages where provide good is it provides good aesthetics and better control and easy fabrication and adjustment its cost effective used as night guard appliance in cases of bruxism and you can use a minimum thickness sheets for the fabrication and cap it has a cap it is capable of correcting minor tooth defects and the major disadvantage is where it may interfere with vertical settling of occlusion and it may ineffective in cases where expansion is achieved and there is a chance of developing anterior open bite and also increased risk of decalcification in certain areas prone to wear and needs replacement annually. So those are the disadvantages. So the next is the retention period that is how long the retention appliances should be used. Various literatures suggest from no retention to permanent retention however retention should be maintained until completion of growth and concentration should be given to the use of retainers on an as needed basis indefinitely to ensure maintenance of tooth position and relation. So generally removal retainers are born day and night for 3 months followed by 3 months only of night time and gradually reducing the wear and tear. However clinical science of labs should be judged to decide whether to continue or discontinue the retainer that is if any unwanted torque moment you noticed then accordingly you can continue the retainer wear. Another common regime as the usage of the removal retainers is the initially it is advised to want full time for 3 to 6 months then they advise for 12 hours per day for a further 6 to 8 months and retaining appliance can be gradually withdrawn the next 2 months can advise patient to wear it during night time only and another 2 months alternate night time wear is advised to assist the stability of the result. So another case that is where the patient who have experienced significant orthopedic changes during treatment they require more elaborate retention appliances to maintain internal relationships during continued growth. So for the frequency of retention checkups you can do the first retention checkup within 3 months after insertion and schedule 2 to 4 retention checkups in a period of 1 to 2 years and you can also communicate with the dentist regarding effective retention after care. Moving on other than using the retainers there are certain other modalities in which you can improve the post treatment stability so let's see what are the procedures that aid in retention. First one is the periscation or circumferential supracrystall fibrotomy. So this periscation is a minor surgical procedure where surgical transaction of the supracrystall fibros done and this is because these supracrystall fibros are responsible for the relapse tendencies especially in rotation cases. So this CSF reduces relapse of rotation and CSF followed by a removal retainer provided clinically significant reduction in relapse and in poor oral hygiene cases and in medically compromised cases it is contraindicated. Another important procedure is the frenectomy. Frenem is a mucous membrane fold that attaches the lip and cheek to the alveolar mucosa the gingiva and underlying periosteum. When the frenem is attached to attached too close to the gingival margin then it can cause a midline diastema due to the muscle pull. So even after the correction of diastema the aberrant frenem can cause the relapse. So to avoid this you can do a frenectomy along with the sectioning of transeptal fibros. This is the intraproximal stripping. It is usually done to increase the stability especially in case of lower anterior. So better stability of lower incisors will be achieved after intraproximal stripping due to their square shape compared to the triangular original one. Another important topic to be discussed under retention relapse is the active retainers. So active retainers used in cases where orthodontic relapse happened and we required some amount of tooth movement during the retention period. In those cases we use active retainers. Examples are removal orthodontic appliances that continues as a retainer after it has repositioned the teeth and hauled the plants with partial acrylic portion trying to facilitate certain tooth movement. Wrap around retainers used to close residual band spaces. That is you can activate the U-loop of the retainer so that you can close the residual spaces. An activator and bionator in patients who show relapse after growth modulation treatments that is in mandibular advancement, mandibular deficiency cases after getting a good result. If relapse happens you can use the same appliance to get back to the advanced position of mandibles. So these are called active retainers. So that's the end of the session and end of the topic retention and relapse as well. So in the topic retention and relapse you need to remember the important headings. Headings, those are definition of retention and relapse, causes of relapse, schools of thoughts of retention, theorems of retention, six keys for mandibular anterior retention, different types of retention appliances or retainers, and retention, different types of retention protocols, retention period and some agenti-procedure agent retention. So all these things you should be knowing. So to conclude with maintaining teeth in the corrected positions following orthodontic treatment can be extremely challenging. Relapse after orthodontic treatment is the result of teeth moving back towards the original malocclusion but changes in tooth position may also occur as a normal part of the growth and aging process. It's the clinician's responsibility to ensure that patients are appropriately instructed regarding the care of their retainers and provided advice about the timing of retainer review and by whom. So thank you for watching and hope you got a rough idea about the topic and I advise all the students to go back to the basic textbooks and do only three things. Read, read and read again. Have a good day.