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Arch expansion with fixed appliance technique


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arch expansion

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Arch expansion with fixed appliance technique

  1. 1. Arch expansion with fixed appliance techniques 1 DrRavikanthLakkakula
  2. 2. 2 1. Introduction 2.Classification of expansion appliances 3.Fixed appliances i) Rapid maxillary expansion appliance Tooth born : Hyrax , Isaccson. Tooth and tissue born : Hass , Derichsweiler , Arnold, IPC expander. Contents DrRavikanthLakkakula
  3. 3. 3 ii) Slow maxillary expansion appliances W arch , Quad helix, NiTi expander, Trombone appliance, Transforce appliance, Mobile intraoral arch appliance, Williams expander, Srping jet, 3D modular appliance, Begg technique , Preadjusted edgewise technique, Invisaligners. 4. Retention and stability. 5. Conclusion. 6.References. DrRavikanthLakkakula
  4. 4. 4  Expansion in arch has been one of the oldest means of creating space in the dental arches. 1. It is also one of the conservative method of gaining space. 2.It can also be used to correct the intermaxillary and dental arch relationships primarily in transverse direction. 3.It enables correction of crossbites early in treatment. • In 1860 Emerson C Angell placed a screw between maxillary premolar of a girl aged 14 yrs and wider her arch in two weeks. • In 1877 Walter coffin demonstrated the expansion of the maxillary arch using spring which caused separation of the mid palatal suture in children. INTRODUCTION DrRavikanthLakkakula
  5. 5. 5  Pfaff, in 1929 described improved nasal function after maxillary expansion.  Haas, in 1960 reported increased nasal width, gain in arch and lowering of mandible with bite opening. DrRavikanthLakkakula
  6. 6. 6 Maxilla Mandible Skeletal Expansion is possible by opening the mid palatal suture. Not possible to expand the basal bone . Dento-alveolar Possible . Possible to certain extent. Scope of expansion in jaws DrRavikanthLakkakula
  7. 7. 7 To correct lateral Malrelationships of Dental Arches Failure of the two dental arches to occlude normally in lateral relationship, known as lateral or posterior crossbite, may be due to localized problems of tooth position or alveolar growth, or to gross disharmony between maxilla and mandible. Dentoalveolar crossbite with good apical base width (left) and crossbite with a deficient apical base width (right). Need for expansion DrRavikanthLakkakula
  8. 8. 8 Lack of harmony between the maxillary and mandibular widths usually is due to a bilateral constriction of maxilla. In such cases, the muscles shift the mandible to one side to acquire sufficient occlusal contact for mastication, causing unilateral crossbite though the constriction is bilateral. DrRavikanthLakkakula
  9. 9. 9 Rarely, there may be true unilateral crossbite due to asymmetric lateral growth of maxilla e.g in case of hemifacial microsomia. A more severe condition is that in which the mandibular denture occludes completely within the maxillary arch. DrRavikanthLakkakula
  10. 10. 10 On the basis of the type  Removable  Fixed On the basis of the effect by the forces  Slow / Dentoalveolar / Orthodontic Fixed &Removable.  Passive - Frankel .  Rapid / Orthopedic - Fixed . On the basis of the region to be expanded  In the lateral direction.  In AP direction – unilateral / Bilateral. classification DrRavikanthLakkakula
  11. 11. 11 Orthodontic Expansion: It is well known that expansion of the dental arches can be produced by a variety of orthodontic treatments, including those that employee fixed appliances. Orthopedic Expansion : Rapid maxillary expansion (RME) appliances are the best examples of true orthopedic expansion in that changes are produced primarily in the underlying skeletal structures rather than by the movement of teeth through alveolar bone. DrRavikanthLakkakula
  12. 12. 12 Passive Expansion When the occlusion is shielded from the forces of the buccal and labial musculature, a widening of the dental arches often occurs. This expansion is not produced through the application of extrinsic biomechanical forces, but rather by intrinsic forces such as those produced by the tongue. Example as passive expansion are the dimensional changes in the dental arches produced by such vestibular shield appliances as the FR-2 of Frankel. DrRavikanthLakkakula
  13. 13. 13 1.Rapid Palatal Expansion Appliances e.g. : Haas appliance. 2. Slow Palatal Expansion Appliances e.g. : Quad Helix ,NiTi expander etc. 3. Dentoalveolar expansion Appliances e.g. : Conventional fixed appliances . Fixed Appliances DrRavikanthLakkakula
  14. 14. 14 1. Increased anchorage and retention. 2. Minimal effects on speech 3. Continuous action over a long period of time. 4. Patient’s compliance is not required. Advantages of Fixed Expansion Appliances DrRavikanthLakkakula
  15. 15. 15 Effect of RME on Maxillary and Mandibular Complex Maxillary skeletal effect: When viewed occlusally, there is the opening of the midpalatine suture was nonparallel and triangular with maximum opening at incisor region and gradually diminishing towards the posterior part of palate. When viewed frontally, the maxillary suture separates Superoinferiorly in a nonparallel manner. It is pyramidal in shape with the base of pyramid located at the oral side of the bone. Rapid maxillary expansion appliances DrRavikanthLakkakula
  16. 16. 16 Maxillary halves : Haas and Wertz found the maxilla to be frequently displaced downward and forward. Palatal vault: Haas reported that the palatine process of maxilla was lowered as a result of outward tilting of maxillary halves. Alveolar process : Because bone is resilient, lateral bending of the alveolar processes occurs early during RME, which rebounds back after a few days. DrRavikanthLakkakula
  17. 17. 17 Maxillary anterior teeth : From the patient’s point of view, one of the most spectacular changes accompanying RME is the opening of a diastema between the maxillary central incisors. It is estimated that during active suture opening, the incisors separate approximately half the distance the expansion screw has been opened, but the amount of separation between the central incisors should not be used as an indication of the amount of suture separation. This diastema is self-corrective due to elastic recoil of the transseptal fibers. DrRavikanthLakkakula
  18. 18. 18 Maxillary posterior teeth : There is buccal tipping and extrusion of the maxillary molars. The posterior maxilla expands less readily because of the resistance produced by the zygomatic buttress and pterygoid plates. Effect of RME on mandible: There is a concomitant tendency for the mandible to swing downward and backward. DrRavikanthLakkakula
  19. 19. 19 RME and nasal airflow: Anatomically, there is an increase in the width of the nasal cavity immediately following expansion thereby improves in breathing. The nasal cavity width gain averages of 1.9 mm, but can be as wide as 8 to 10 mm. It is important for the clinician to remember that the main resistance to midpalatal suture opening is probably not the suture itself, but in the surrounding structures particularly the sphenoid and zygomatic bones. DrRavikanthLakkakula
  20. 20. 20 INDICATIONS/CONTRAINDICATIONS OF RME Rapid maxillary expansion is indicated in cases with a transverse discrepancy equal to or greater than 4 mm and where the maxillary molars are already buccally inclined to compensate for the transverse skeletal discrepancy. Rapid palatal expansion has been used to facilitate maxillary protraction in class III treatment by disrupting the system of sutures, which connect the maxilla to the cranial base, cleft lip and palate patients with collapsed maxillae are also RME candidates. DrRavikanthLakkakula
  21. 21. 21 Finally, some clinicians use the procedure to gain arch length in patients,who have moderate maxillary crowding. It is contraindicated in patients, who have passed the growth spurt, have recession on the buccal aspect of the molars, anterior open bite, steep mandibular plane, convex profiles and who show poor compliance. DrRavikanthLakkakula
  22. 22. 22 CLINICAL MANAGEMENT OF RME The patient/parent should be informed in advance about the upper midline diastema during the expansion phase. This is likely to close spontaneously during the retention period. Patients should be instructed to turn the expansion screw one-quarter turn twice a day (am and pm). It appears that approximately 1 millimeter per week is the maximum rate at which the tissue of the midpalatal suture can adapt, so that tearing and hemorrhaging are minimized compared with rapid expansion protocols. DrRavikanthLakkakula
  23. 23. 23 Regime for screw rotation Timms prescribed it according to the age and expected resistance to separation. Three categories of patients according to age Upto 15 yrs : 180 degree daily divided to two activations of 90 degrees morning and night. Age 15 – 20 yrs : 180 degrees daily divided into four activations of 45 degrees. Age over 20 yrs : 90 degrees daily in two activations morning and night. Over 25 yrs : surgical seperation may be required. DrRavikanthLakkakula
  24. 24. 24 Schedule by Issacson and Zimring In young growing patients, 180 degree daily for 4 -5 days and later 90 degrees daily till desired expansion achieved. In non-growing adult, 180 degree daily for first two days, 90 degrees daily for next 5 -7 days and 90 degrees on alternate days till desired expansion achieved. DrRavikanthLakkakula
  25. 25. 25 Force levels tend to accumulate following multiple turns and can be as high as 10 kg following many turns. Patients should be reviewed weekly and some clinicians recommend that an upper occlusal radiograph be taken one week into treatment to ensure that the midpalatal suture has separated. If there is no evidence of this, it is important to stop appliance activation as there is a risk of alveolar fracture and/or periodontal damage. Active treatment is usually required for a period of 2-3 weeks, after which a retention period of three months is recommended to allow for bony infilling of the separated suture DrRavikanthLakkakula
  26. 26. 26 APPLIANCES FOR RME These are banded and bonded appliances. The banded appliance are attached to teeth with bands on the maxillary first molar and first premolars. The banded appliances are hygienic as there is no palatal coverage. The banded RME are of two types: 1. Tooth and tissue borne . 2. Tooth borne . DrRavikanthLakkakula
  27. 27. 27 It is a tooth borne appliance, which was introduced by William Biederman in 1968. This type of appliance makes use of a special screw called HYRAX (Hygenic Rapid Expander). The Hyrax Expander is essentially a nonspring loaded jackscrew with an all wire frame. The screws have heavy gauge wire extensions that are adapted to follow the palatal contours and soldered to bands on Premolar and molar. HYRAX EXPANDER TOOTH BORNE RME They consist of only bands and wires without any acrylic covering. DrRavikanthLakkakula
  28. 28. 28 The main advantage of this expander is that it does not irritate the palatal mucosa and is easy to keep clean. It is capable of providing sutural separation of 11 mm within a very short period of wear and a maximum of 13 mm can also be achieved. Each activation of the screw produces approximately 0.2 mm of lateral expansion and it is activated from front to back. DrRavikanthLakkakula
  29. 29. 29 It is a tooth borne appliance without any palatal covering. This expander makes use of a spring loaded screw called Minne expander (developed by university of Minnesota, dental school), which is soldered directly to the bands on first premolar and molars. Issacson expander DrRavikanthLakkakula
  30. 30. 30 The Minne expander is a heavily calibrated coil spring expanded by turning a nut to compress the coil. Two metal flanges perpendicular to the coil are soldered to the bands on abutment teeth. The Minne expander may continue to exert expansion forces after completion of the expansion phase unless they are partly deactivated. DrRavikanthLakkakula
  31. 31. 31 They consist of an expansion screw with acrylic abutting on alveolar ridges. Haas, in 1970, gave the following advantages of tooth and tissue RME 1. Produces more parallel expansion. 2. Less relapse. 3. Greater nasal cavity and apical base gain. 4. More favorable relationship of the denture bases in width and frequently in the anteroposterior plane as well. 5. Creates more mobility of the maxilla instead of teeth. Disadvantage of Tooth and Tissue Borne RME These tooth and tissue borne RME tend to have higher Soft tissue irritation. TOOTH AND TISSUE BORNE RME DrRavikanthLakkakula
  32. 32. 32 The basis for the rapid expansion procedure is to produce immediate midpalatal suture separation by disruption of the sutural connective tissue . The rapid palatal expander as described by Haas is a rigid appliance designed for maximum dental anchorage that uses a jackscrew to produce expansion in 10 to 14 days. He believed that this will maximize the orthopedic effects and forces produced by this appliance have been reported in the range of 3 to 10 pounds. Haas expander DrRavikanthLakkakula
  33. 33. 33  A length of 0.045” SS wire is soldered along the palatal aspects of the bands.  The free ends are turned back and embedded in the acrylic base short of the bands  A jack screw is incorporated.  Banding difficult on malposed teeth as path of insertion is not parallel.  Banding and cementation difficult on deciduous teeth. DrRavikanthLakkakula
  34. 34. 34 The first premolar and molars are banded. Wire tags are soldered to these bands and then inserted to the split palatal acrylic, which contains the jack screw. Derichsweiler expander DrRavikanthLakkakula
  35. 35. 35 Inman power component (IPC) rapid palatal expander IPC is designed for orthopedic expansion along with labial alignment of incisors . As expansion occurs, the IPC controls the NiTi open coil spring force applied to the lingual surface of the anterior teeth. Wire around the distal end of the lateral incisors limits the midline diastema that often occurs during RPE treatment. DrRavikanthLakkakula
  36. 36. 36 Inman Palatal Component E-Arch (Arnold) Expander Ideal for transverse expansion of maxillary or mandibular arches where patient compliance is a concern. A tube-like framework is located on half of the arch which is connected to the Inman Power Component (IPC) on the opposing side. Activation occurs by sliding the collar anteriorly along the IPC compressing the NiTi open coil springs against the tube. DrRavikanthLakkakula
  37. 37. 37 The Bonded RPE were first described by Cohen and Silverman in 1973 . It is similar to the banded version with the exception of the method of attachment to the teeth. This appliance is constructed with an acrylic cap over the posterior segments, which is then bonded directly to the teeth. The bonded appliance has become popular because of its advantages: 1. It can be easily cemented during the mixed dentition stage, when retention from other appliances can be poor. 2. Number of appointments are reduced. BONDED RAPID PALATAL EXPANDER DrRavikanthLakkakula
  38. 38. 38 3. There is reduced posterior teeth tipping and extrusion. The buccal capping limits molar extrusion during treatment and, therefore improves the vertical control, which is particularly useful in class II conditions, as molar extrusion would cause autorotation of the mandible backward and downward resulting in increase in facial convexity and the vertical dimension of the lower face. 4.It provides Bite block effect to facilitate the correction of anterior crossbite (McNamara). DrRavikanthLakkakula
  39. 39. 39 Bonded RME It is introduced by Raymond Howe in 1982 . It Clears the palate of acrylic, no banding, Can be used on malposed teeth where parallel path of insertion is not possible. There is a less error prone as bands dot have to be placed in impression. It is easy to make on deciduous teeth also. DrRavikanthLakkakula
  40. 40. 40 SLOW MAXILLARY EXPANSION (SME) SME procedures produce less tissue resistance around the Circum maxillary structures and therefore improve bone formation in the intermaxillary suture, which theoretically should eliminate or reduce the limitations of RME. Slow expansion has been found to promote greater postexpansion stability, if given an adequate retention period. It delivers a constant physiologic force until the required expansion is obtained. The appliance is light and comfortable enough to be kept in place for sufficient retention of the expansion. Prefabrication eliminates extra appointments for impressions and the time and expense of laboratory fabrication. DrRavikanthLakkakula
  41. 41. 41 For SME, 10 to 20 newtons of force should be applied to the maxillary region only 450 to 900 gm of force is generated, which may be insufficient to separate a progressively maturing suture. Maxillary archwidth increases ranged from 3.8 to 8.7 mm with slow expansion of as much as 1 mm per week using 900 gm of force. DrRavikanthLakkakula
  42. 42. 42 Difference between rapid and slow palatal expansion DrRavikanthLakkakula
  43. 43. 43 Dr Ravikanth Lakkakula
  44. 44. 44 In 1728, Pierre Fauchard developed the expansion arch which was a flat piece of metal scalloped out for ideal position of teeth. The teeth were ligated towards this position. In 1887, Dr. Angle introduced the “E arch” i.e. the expansion arch in which the labial wire was supported by clamp bands on molar teeth. This arch was expanded and teeth were ligated to it. Later molar bands were added. Conventional fixed appliances DrRavikanthLakkakula
  45. 45. 45 It is a fixed type modification of the Coffin spring. First used by Ricketts in cleft palate cases. It is preferred in maxilla and mandibular arch expansion where mild to moderate expansion needed. Wilson appliance / W - Arch DrRavikanthLakkakula
  46. 46. 46 Fabrication It is made up of 1mm SS wire. The anterior part of wire should contact the teeth in crossbite. Posterior part of wire should not extend more than 1 to 2 mm beyond molar bands. The wire is away form marginal gingiva and palatal tissue by 1 to 1.5 mm. DrRavikanthLakkakula
  47. 47. 47 Activation : It can be opened anteriorly at the curve as well as at the posterior apices. It is opened 3 to 4 mm wider than passive width . Expansion rate is 2 mm per month until 2-3mm overexpansion can be indicated . Retention period is 3-4 months after expansion. DrRavikanthLakkakula
  48. 48. 48 It is a modification of W-spring introduced by Dr. Robert Ricketts in 1975. Indications 1. All crossbites needing upper arch expansion. 2. Crowding cases needing mild expansion. 3. Class II cases needing molar distal rotation. 4. Class III cases with constricted maxillary arch. 5. Tongue thrusting and thumb sucking cases. 6. Cleft lip with cleft palate conditions – early treatment. Quad helix DrRavikanthLakkakula
  49. 49. 49 The incorporation of four helices into the W-spring helped to increase the flexibility and range of activation. The length of the palatal arms of the appliance can be altered depending upon which teeth arch in crossbite. It is made up 1mm SS wire either prefabricated or laboratory constructed. DrRavikanthLakkakula
  50. 50. 50 Anterior bridge at the level of distal surfaces of canines. Anterior helices are towards the palate. Posterior helices are placed 2mm distal to the first molars. These are sloped parallel to the palatal surface. DrRavikanthLakkakula
  51. 51. 51 Intraoral activation A Three prong plier is used. 1st bend: Anterior bridge is bent by keeping single beak anteriorly – intermolar expansion. 2nd and 3rd bends are on the palatal bridges to expand lateral arms and counteract mesial molar rotation. DrRavikanthLakkakula
  52. 52. 52 A three-month retention period, with the quadhelix in place, is recommended once expansion has been achieved. If fixed appliances are being used, the quadhelix can be removed once stainless steel wires are in place. The desirable force level of 400 gm can be delivered by activating the appliance by 8 mm, which equates to approximately one molar width. Patients should be reviewed on a six-weekly basis. Sometimes, the appliance can leave an imprint on the tongue, however this will rapidly disappear following treatment. DrRavikanthLakkakula
  53. 53. 53 The quadhelix appliance works by a combination of buccal tipping and skeletal expansion in a ratio of 6:1 in prepubertal children. Modification: Quad helix with 3-4 mm ss tongue cribs soldered to anterior bridge to correct the tongue thrust and thumb sucking habit correction. DrRavikanthLakkakula
  54. 54. 54 Dr Ravikanth Lakkakula
  55. 55. 55 The nickel titanium expander generates optimal, constant expansion forces. It is introduced by Wendell Arndt in 1993. It is a fixed – removable appliance(semifixed). Its central component is fabricated from a 0.036"thermally activated nickel titanium alloy. The rest of the appliance, including the anterior arms, is made of 0.036"stainless steel. The expander may be used simultaneously with conventional fixed appliances, requiring only the addition of lingual sheaths on the molar bands. Niti expander DrRavikanthLakkakula
  56. 56. 56 The nickel titanium component has a transition temperature of 94°F. At room temperature, the expander is too stiff to bend for insertion. The expander may be put in a freezer or cooled with gel freeze packs until ready for placement. Alternatively, a refrigerant spray such as ethyl chloride or tetrafluoroethane can be used immediately prior to insertion to chill the expander, which is then wrapped in gauze and placed in the mouth. The moist gauze insulates the cooled expander from body temperature, thereby increasing the working time. DrRavikanthLakkakula
  57. 57. 57 The expander is available in sizes from 26mm to 44mm. In most cases, the simplest way to determine the appropriate size is to measure the mandibular intermolar width at the central fossae. Since the mesiolingual cusps of the maxillary molars should occlude in these fossae, expansion to the mandibular intermolar width will provide optimal occlusion. DrRavikanthLakkakula
  58. 58. 58 A 3mm increment of expansion exerts only about 350g of force and the nickel titanium alloy provides relatively uniform force levels as the expander deactivates. If the mandibular molars are lingually inclined as a dental compensation for a skeletal posterior crossbite, as often occurs, it is appropriate to add another 1-2mm to the expansion requirement. In any case, 2-3mm should be added for overexpansion . If more than 8mm of expansion is needed, two expanders must be used in succession. DrRavikanthLakkakula
  59. 59. 59 Clinical Technique 1. Select the appropriate size expander, based on measurement of the study casts. 2. Adjust the anterior arms of the expander as needed. 3. Wrap the central component with moist gauze and place the expander in the freezer. 4. Determine the appropriate band sizes, and fit bands (with lingual sheaths) as usual . 5. Cement the bands with a dual or light-cured cement. 6. Remove the expander from the freezer, and with the gauze still in place, slide the inserts into the molar sheaths. 7. Remove the gauze from the expander. DrRavikanthLakkakula
  60. 60. 60 An alternative method involves assembly of the expander and bands extraorally and cementation as one unit. This procedure is preferable where access to the palate is restricted and insertion may be difficult. The drawback of this method is that it requires rapid band placement and cementation as the expander warms to oral temperature. DrRavikanthLakkakula
  61. 61. 61 If the molars are rotated, the anterior arms of the expander may not initially contact the buccal segments. It is usually not necessary to adjust these arms until some derotation has occurred. The rate of expansion will depend on the age of the patient. Patients in the primary or early mixed dentition can be expanded in One to two months, depending on the severity of the case. Expansion in adolescents can take as long as three months, and even longer expansion and retention times should be expected in adults. The retention period should be 50-100% of the expansion time. DrRavikanthLakkakula
  62. 62. 62 Advantage of NiTi Expander 1.Self activated. 2.Light continuous forces. 3.Easily adaptable in inactivated state. 4.Automatically expands to a predetermined shape. 5.Requires little manipulation by clinician. 6.Inbuilt safety system. 7.Patient can mitigate pressure responses. DrRavikanthLakkakula
  63. 63. 63 The Transverse Expander has an expansion module to increase the inter-canine width in upper and lower arch to accommodate crowding in the labial segments, or to correct arch width in contracted arches. The appliance inserts in horizontal lingual sheaths on the molar bands and incorporates a gingival step mesial to the molar, placing the body wire close to gingival level. Transforce appliance DrRavikanthLakkakula
  64. 64. 64 A recurved wire extends mesially from the molar sheath and may be used to align irregular anterior teeth from the lingual aspect. This facility is particularly useful when insufficient space exists to place brackets on lingually displaced teeth. The space is created first by transverse expansion before improving alignment prior to bonding brackets on the anterior teeth. DrRavikanthLakkakula
  65. 65. 65 The expansion unit is positioned lingual to the incisors and is very effective in creating space in a crowded labial segment. However it is equally effective in expanding inter-molar width and widening the arch in the deciduous molar or premolar region. The body wire extends from the expansion module to be inserted in a horizontal lingual sheath on the molar band. Although the force delivered to the molar is reduced by the long lever arm, it is nevertheless an extremely efficient mechanism to increase molar width without tipping the molars, by delivering a low continuous force generated by the enclosed nickel titanium spring. DrRavikanthLakkakula
  66. 66. 66 The Transverse Expander is provided in four sizes and the appropriate size can be selected for use in the upper or lower arch. The inter-canine width and inter-molar width is adjusted accordingly. The range of action of the Transverse appliance is 8 mm. The anterior transverse width of the appliance increases in 2 mm increments throughout the series. The mesio-distal length also increases by 2 mm to allow for variation in tooth width. DrRavikanthLakkakula
  67. 67. 67 The trombone appliance is designed specifically to assist anterio- posterior and tranverse arch development in mandible. Since the t rombone appliance does not interfere with speech and is integrated with conventional fixed appliances, it has excellent potential for both mixed and adult treatment. The design is based on the slide principle, with an inner tube sliding freely within an outer tube to extend or contract the length of the appliance . Trombone appliances DrRavikanthLakkakula
  68. 68. 68 The molar section of the appliance is retained with double lingual posts and includes a vertical tube attachment for insertion of the trombone section of the appliance. The appliance is preactivated to achieve the initial amount of expansion required. The trombone appliance was activated by 1 mm per side. Subsequent bilateral activation was achieved by replacing the silicon compression tubing with tubing that was 1 mm longer, once every 4 weeks to provide 1 mm activation per month until the desired amount of space was achieved. DrRavikanthLakkakula
  69. 69. 69 The distal portion of wire is recurved and retained in a horizontal sheath on the molar band that extends mesially at the gingival level to engage the anterior segment of the lingual arch. The absence of frictional forces allows rapid tooth movement using gentle, controlled lingual forces. DrRavikanthLakkakula
  70. 70. 70 The MIA Mobile Intraoral Arch is a palatal and lingual appliance, described by Dr. Bartel. The MIA system makes the application less time consuming, offering the advantage of inserting and removing the lingual arches into sheaths pre-welded on bands. Easy removal and reinsertion allow greater flexibility and control during treatment. Mobile intraoral arch system DrRavikanthLakkakula
  71. 71. 71 It is made up of .038 inch elgiloy. It is a prefabricated form with various width are available. A quad helix consists of the force producing transverse body, the force generating arms, and the retention loops between them. The transverse body starts occlusal at the sheath and crosses over the arm lingually to allow proper gingival clearance around the neck of the molars. In addition, the body of the arch maintains its flexibility without significantly restricting the tongue. DrRavikanthLakkakula
  72. 72. 72 It can be used with MIA curved rotation sheaths as well as straight lingual sheaths. It is secured with wire tie or Alastik S1 force module. No soldering needed. DrRavikanthLakkakula
  73. 73. 73 Adapt arch in the mouth or on patient model. Use inactivated for initial treatment phase. Anterior helices: Position at first bicuspids Posterior helices: Position at the middle of the sheaths. MIA transverse body: Should miss the tissue by 1 mm in the Maxilla and 2mm in the mandible. Consider future active tooth movements. Arch arms: Should contact the teeth as needed. Arms should contact the teeth needing to be moved (bicuspids and molars) gingivally at the area of the greatest circumference. MIA arch adaptation DrRavikanthLakkakula
  74. 74. 74 MIAArch Activation 1. Activate with a flat nose plier and finger-pressure. 2. Verify activation amount by inserting one retention loop and observing the relationship of the other retention loop to its sheath. 3. Repeat on opposite side to confirm. DrRavikanthLakkakula
  75. 75. 75 The treatment goal always determines the amount of activation for expansion, contraction, torque, and rotation. Heavy permanent forces require activation in only small steps: To avoid molar torque, place a compensatory bend in the double end of the quad helix prior to sheath insertion. Maximum 8 week activation parameters: - Expansion and contraction is 3mm - Rotation is 20 degrees - Torque is 10 degrees DrRavikanthLakkakula
  76. 76. 76  It is successful Mandibular Expansion Appliance was introduced by Dr. Jeff Williams in 1994.  The Mandibular Williams Expansion Appliance is primarily designed for children who are passing through the age of Mid- Mixed Dentition, whose Mandibular arch is constricted, with crowding evident in the newly erupted Mandibular incisors. Williams expander DrRavikanthLakkakula
  77. 77. 77  This Mandibular appliance utilizes two long stainless tubes soldered to each of the lower primary second molar bands with extensions back to contact the lingual of the 6-year molars. An expansion screw is secured to the molar bands by wire extensions extending to transverse the anterior portion of the mandible. DrRavikanthLakkakula
  78. 78. 78  An arc of .016 NiTi arch wire inserts into the forward ends of the stainless tubes and, as the expansion screw is activated the NiTi wire is moved forward to automatically uncrowded the incisors. The .016 NiTi arch wire is glued, with a small bit of composite, to the most lingually positioned incisor. DrRavikanthLakkakula
  79. 79. 79  This wire may be replaced monthly with a slightly longer length of .016 NiTi to maintain positive pressure against the lingual of the incisors. In cases where the Mandibular 6 year molars are fully erupted, they may be banded instead of the primary second molars. Indications for use of Williams Expansion Appliance:  Mandibular arch needing transverse correction.  Mandibular anterior crowding. DrRavikanthLakkakula
  80. 80. 80 Activation  The Mandibular Williams Expander is adjusted by turning the screw one turn(= 0.25mm ) weekly twice. The expansion is continued until the proper transverse cuspid position is achieved.  At times, it may be necessary to replace the .016NiTi wire with a stronger wire. Simply remove the original wire from the appliance, measure the new wire, replace the shorter wire with the longer.  Then finish by gluing the new wire to the lingual surface of the most lingually displaced tooth. If needed, the appliance can be left in place until the Mandibular Fixed-Removable Lingual Arch (FRLA) is fitted to the mandibular 6-year molars for retention. DrRavikanthLakkakula
  81. 81. 81  It is prefabricated appliance consist of active component madeup of Niti spring , extended components are madeup of stainless steel wire.  The spring jet offers a lighter consistent force transferred through the use of NiTi springs.  Activation period is every two weeks 90 degrees turn, done by using an allenwrench to tighten the screw in the lock mechanism to hold the compression.  Niti coil spring delivers the 400 grams of force slow, controlled arch expansion for patients with collapsed arches or crossbites. Spring jet DrRavikanthLakkakula
  82. 82. 82 Appliance installation procedure : 1. Bend the wire segment vertically into molar lingual sheath. 2. Cut to the tube to length allowing 1 mm for the bayonet wire entry. 3. From the double back , seat in sheath and check passive fit and parallel relationship. 4. Finish the anterior wire segment for desired corrections keeping as close to the gingival margin as possible. DrRavikanthLakkakula
  83. 83. 83 Forming a bayonet bend 1.Layfree end on the director tube, mark and bend vertically to the sheath entry. 2.From the double back insert free end in director tube and double back in sheath. 3. Check passive fit and finish the anterior segment. DrRavikanthLakkakula
  84. 84. 84 Dr. William Wilson and Robert Wilson introduced a new ‘convertible’ appliance system in which many appliances can be fitted through a single attachment.  3D Modular lingual tube is the key element. It is a dual vertical tube which provides good control over molar tip, torque and rotation. There are 5 different modules of designs that can be fitted precisely into these tubes   3D Quad Helix  3D Palatal Arch  3D Adapter  3D Sectional  3D Lingual Arch 3D Modular appliance DrRavikanthLakkakula
  85. 85. 85 The 3D Quad helix has 2 twin posts which produce friction lock security with the plugs of a 3D adapter tubes. It is made of .038 blue elgiloy wire either prefabricated (6 different sizes) or laboratorary constructed. 3D quad helix DrRavikanthLakkakula
  86. 86. 86 The 3D Quad-Helix very precisely allow the orthodontists control the amount of forces employed and control molars on the three planes of the space, strongly increasing movements control. Dr .Wilson recommends installing the appliance, at first patient visit, absolute passive to malocclusion and starting to activate the 3D quadHelix on a second visit. New activations should be posted on 40 to 40 days period, on majority of cases the activation can not exceed 1 to 2mm in order to keep case under control. DrRavikanthLakkakula
  87. 87. ADAPTATION OF 3D QUAD HELIX Molar rotation Tightening the posts 87 DrRavikanthLakkakula
  88. 88. ACTIVATION Molar control 88 DrRavikanthLakkakula
  89. 89. DrRavikanthLakkakula After use 3D Quad Helix can be cut between the helices and posts to give 3D ADAPTOR This can be used as BUCCAL EXPANDER for Cuspid amd Bicuspid expansion Resiliency of the wire reduces countermoment reaction of molars. 3D adaptor 89
  90. 90. 3D PALATAL ARCH  It is an advanced design with more functions.  As an expansion appliance it is used for both bilateral and unilateral expansion. 90 DrRavikanthLakkakula
  91. 91. 3D LINGUAL ARCH Unilateral molar expansion Buccal root torque on non movement side along with buccal crown tip on expansion side .018” Truchrome wire soldered to lingual arch for buccal / anterior segment expansion 91 DrRavikanthLakkakula
  92. 92. 92 Since there is a tendency for the anchor molars to contract and tip lingually during the first stage of treatment, hence the archwire should be made greater than the dental arch width this is called “expansion for prevention”. In considering the initial .016 premium archwire for a bicuspid extraction case 1. If the dental arch width is satisfactory, the wire should be made 2-3mm wider at each cuspid and 8-10 mm at the molar region. Begg technique DrRavikanthLakkakula
  93. 93. 93 2. If the dental arch requires expansion, the arch wire should be made 4-6mmwider at the cuspid and 15-25mm at the anchor molar. 3. If a bilateral cross bite is present the archwire is made 25-40 mm wider at the side where cross bite is present. Arch expansion is a mass buccal movement in which the arch wire moves both buccal segments buccally and at the same time change the anterior curvature. DrRavikanthLakkakula
  94. 94. 94 Expansion with Archwires Significant expansion may be produced by using overexpanded stainless steel archwires, particularly those with a large dimension for example, 0.021" x 0.025". The archwire should be overexpanded by approximately 10 mm. One advantage of this technique may be that less buccal tipping of the molars occurs during expansion as the rectangular archwire maintains torque control. Pre adjusted edgewise Technique. DrRavikanthLakkakula
  95. 95. Auxiliary Arches Expansion arches, also known as jockey arches, are auxiliary wires that can be easily and cheaply constructed at the chair side and incorporated into a fixed appliance during treatment. The expansion arch, which can be made from 0.019" x 0.025" rectangular stainless steel or a larger round steel wire with a diameter of 1–1.13 mm, runs over the main archwire and is inserted into the extra-oral traction tubes of the first molar bands posteriorly and secured anteriorly with a ligature. 95 DrRavikanthLakkakula
  96. 96. Some operators prefer to bend the wire into the buccal sulcus in order to reduce its visibility. 96 DrRavikanthLakkakula
  97. 97. The advantages of using expansion arches are that their construction is cheap and can be carried out easily at the chairside without having to change the molar bands. Expansion is likely to be produced by a degree of molar tipping and this may be reduced by incorporating molar buccal root torque into the main rectangular archwire. 97 DrRavikanthLakkakula
  98. 98. Cross Elastics To produce maxillary expansion, cross elastics run from the palatal aspect of one or more of the maxillary teeth to the buccal aspect of one or more of the mandibular teeth. Recommended force 150-210 grams. 98 DrRavikanthLakkakula
  99. 99. In addition to producing lateral forces, a vertical force vector is also produced which tends to cause molar extrusion. This can be detrimental in patients with a reduced overbite or increased face height. To limit the degree of molar tipping, cross elastics should only be used in conjunction with rectangular stainless steel archwires. Success with this technique is dependent on good patient compliance. 99 DrRavikanthLakkakula
  100. 100. 100 NiTi arch wires are available in preformed arch forms. An over expanded arch form is selected. Because of its Shape Memory and Superelasticity features, a slow continuous force is applied which causes expansion to the original shape of wire. Niti archwires DrRavikanthLakkakula
  101. 101. 101 The invisalign System is proprietary to Align Technology. The clinician sends a rubber base impression (polyvinyl siloxane) to Align Technology laboratories with copies of radiographic films, photographs, and a detailed treatment plan. Invisaligners DrRavikanthLakkakula
  102. 102. 102 In this system, the clinician forms a diagnosis, plans the treatment, and communicates this desired plan through the internet to laboratory technicians who refine these communications via the Computerized “ ClinCheck “, until the clinician is satisfied with the treatment plan. Aligners are then fabricated and shipped to the treating clinician. DrRavikanthLakkakula
  103. 103. 103 After final approval, the treatment sequence is divided into a series of algorithmic stages. Each stage has a maximum tooth movement potential of 0.25 mm per appliance. Stage models are created using computer aided process called “stereolithography”. Individual appliances (aligners) are made from the computer- generated models of each stage and 25 to 30 appliances may be needed for the resolution of a case. DrRavikanthLakkakula
  104. 104. 104 Buccal expansion, in the range of 2 to 4 mm, can be achieved with this appliance to provide space for crowded anterior teeth or to change archform. It is likely that this expansion is largely of a tipping nature, however, if bodily expansion is required, this may be specified (usually as an overcorrection) as the goal for treatment into the computer plan initially. DrRavikanthLakkakula
  105. 105. 105 This appliance, as is true of most removable appliances, is relatively efficient at tipping movements. Patients who usually progress most rapidly are those that have required primarily tipping of their crowns. Anterior tooth alignment achieved by proclining of anterior teeth is predictably accomplished, provided appropriate overcorrection is done for accompanying rotations or overbite corrections DrRavikanthLakkakula
  106. 106. STABILITY OF CROSSBITE CORRECTION The factors which may be important in enhancing the stability of maxillary expansion include:  Achievement of good intercuspation;  Alteration in tongue position.  Expanding the maxilla in some cases may allow the tongue to adopt a higher resting position which may help to maintain increases in transverse arch dimensions; 106 DrRavikanthLakkakula
  107. 107. 107  Mode of respiration : Expansion may be less stable in mouth breathers because of the lower natural tongue position.  Retention: Retainers should be constructed from acrylic and the Hawley type is recommended. The more flexible Essix type of retainer may not have adequate rigidity to counteract relapse forces. DrRavikanthLakkakula
  108. 108. 108 Most of the borderline cases which once were considered for extraction are now being attempted through non extraction approach with required space being provided by arch expansion. Expansion can be done along with fixed mechanotherapy but it can questionable how much expansion can be takes place. In any fixed mechnotherapy only 2 to 3 mm expansion can be carried out. It is indicated only in mild expansion required cases. More than 3mm expansion required then we go to rapid expansion methods. Before treatment is commenced, it is essential that the prognosis for stability of correction is assessed. The main factors influencing stability have been stated. owing to the high relapse potential of transverse expansion, it is important to achieve a degree of over correction and provide adequate retention. Conclusion DrRavikanthLakkakula