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Activator

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Activator is removable functional appliance treat growing patient in class II div 1 cases

Published in: Health & Medicine
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Activator

  1. 1. Activator Presented by : Ahmed Saeed Baattiah Under supervision of: Prof.Dr.Maher Fouda
  2. 2.  Definition  History And Evolution Of Activator  Indication  Contra indication  Advantage  Disadvantage  Components of the Activator  Mode of Action of Activator  Modifications of Activator  Activator therapy  Case Reports  References Van Beek Activator Harvold-Woodside Activator Teuscher Activator
  3. 3. Definition: *Activator is a loose fitting appliance which was designed by Andreasen and Haupl to correct retrognathic mandible. *The appliance opens the bite, and the mandible is advanced for Class ll correction .
  4. 4. History And Evolution Of Activator  1879 -Norman Kingsley - introduced ( jumping of the bite) to correct sagittal relationship between upper and lower jaws .  1902- Pierre Robin– first practitioner to use functional jaw orthopedics to treat a malocclusion -Monoblock-- in children with glossoptosis Syndrome .
  5. 5.  1908 - Viggo Andresen (Denmark ) - developed a loose fitting appliance on his daughter as a retainer during summer vacations which gave remarkable results . He called it Biomechanical Retainer  Karl Haupl (Germany) – explained how functional appliances work through the activity of the orofacial muscles  Then the activator develop in Norway by Andresen in the 1920 , was the first functional appliance to be widely accepted .
  6. 6. NOW WHAT ARE INDICATIONS OF ACTIVATOR ??
  7. 7. INDICATIONS Various types of activators have been devised for the treatment of various conditions like: • Class II division I malocclusion • Class II division II malocclusion after aligning the incisors • Class III malocclusion – reverse activator is given • Class I open bite malocclusion • Class I deep bite malocclusion • For post-treatment retention • Children with decreased facial height Van Beek activator SKEL activator -Ruhland type II-2
  8. 8. CONTRAINDICATIONS • Cannot be used in correction of Class I problems of crowded teeth where there is disharmony between tooth size and jaw size • Cannot be used in children with excess lower facial height • Cannot be given in cases with lower proclination • In case of nasal stenosis • In non-growing individuals Headgear-activator
  9. 9. ADVANTAGES • Uses existing growth • Minimal oral hygiene problems • Appointments usually short DISADVANTAGES • Requires good patient co-operation • Cannot produce precise detailing and finishing of occlusion. Posterior view of Van Beek activator SKEL activator -Ruhland type II-1
  10. 10. COMPONENTS OF THE ACTIVATOR Basic activator Labial bow : The wire used is spring hardened 0.9 mm stainless steel. It consist of horizontal middle sections, two vertical loops and wire extensions through the canine-deciduous first molar embrasure into the acrylic body. Labial view of the Andresen appliance. Buccal view of the Andresen appliance.
  11. 11. Acrylic portion : This can be fabricated in cold cure acrylic directly on the models or a wax matrix can be made first and then invested in the flask Andresen Appliance - lingual / palatal view. Andresen Appliance with upper model removed. Andresen Appliance with upper model removed.
  12. 12. Mode of Action of Activator When the activator is worn , mandible is held forward and the muscles of mastication are stretched beyond their rest position of postural tonus. It has been suggested that this has two effects : 1. The mastication exert a backward force on the mandible to return to their resting position . This results in a forward force being exerted on the mandibular teeth and a backward force on the maxillary teeth . It is an example for intermaxillary traction . Elastic open activatorRigid open activator
  13. 13. 2. This forward postural position induces growth at the mandibular condyles and temporomandibular joint fossa , which effectively the length of the mandible and basal bone relationship . To summaries :  We get skeletal and Dento alveolar changes as a result of the activator .  Skeletal changes are explained as above and Dento alveolar changes are due to trimming of the activator . Harvold-Woodside activatorLip bumper activator Harvold-Woodside activator - class III
  14. 14. The Herren activator Modifications of activator Elements: Labial bow 0.8 mm spring hard. Function: Modification of the muscular effect through an over dimensional opening of the occlusion. Description: The over dimensional vertical opening of the occlusion, which is intended to alter the muscular activity, is characteristic for this appliance. The elements are bent as in the traditional activator and a wax collar is fixed for the limitation of the acrylic.
  15. 15. The vertical opening for the Herren activator is 8 to 10 mm, determined by the construction bite and then set in the fixator. The design of the appliance of the finished activator does not differ from the classic activator.
  16. 16. The headgear activator according to van Beek Elements: Headgear 1.2 mm spring hard Function: Treatment of malocclusions class II-1 Description: This headgear activator achieves the mandibular position through the lingual wings of its lower base. Headgear-activator according to Herman van Beek. An orthopedic plate, modified into an activator . Effective in Cass II-1 open and deep bite cases.
  17. 17. The models are set into the fixator by a construction bite with a vertical opening of approximately 10 mm. Between the central and lateral incisors the short and strong outer bows are set into the acrylic of the activator. The lower incisors are grasped labially 2 mm in acrylic in order to avoid their protrusion. The lingual surfaces remain free. The upper incisors are also grasped in acrylic. The position of the mandible is achieved through the long lingual wings of the lower base. The upper base plate is kept small. The palatal area of the upper anterior teeth is blocked out with wax in order to allow a retrusion. The lateral bite plane reaches to the center of the occlusal surfaces. In the premolar region, the lower base is extended as far as possible downwards. In combination with a high pull headgear, this appliance with bite block can be used to intrude the upper teeth.
  18. 18. The Teuscher activator Elements: Headgear tubes, torque springs 0.5 mm spring hard, Coffin spring 1.2 mm spring hard Function: Inhibition of the development of the upper jaw with simultaneous mandibular advancement Description: This headgear activator hinders the development of the upper jaw with simultaneous advancement of the mandible. Base appliance with four torque springs. The torque springs only contact the upper incisors in one point shortly underneath the gingival margin. It is bent away slightly to avoid contact with the rest of the clinical crown. The retention is in the interocclusal area.
  19. 19. The headgear tubes lie between both tooth rows in the area of the deciduous molars. The interocclusal area should be high enough to allow a good anchorage of the retentions of the headgear tubes in the acrylic. It should also be checked from the occlusal point of view if they lie parallel to be able to insert the inner bow without any problems. The acrylic base has to cover one third of the lower incisors, and the upper incisors should be covered on the palatal side up to one half and on the labial side, only to the incisal edge.
  20. 20. Modifications of the Teuscher activator a) Torque springs on the central incisors The Teuscher activator allows the design of torque springs on the central incisors in combination with protrusion springs for labial movement on the lateral incisors. b) Sheet springs and labial bow The same effect can be achieved with sheet springs and a labial bow that should contact the most prominent teeth.
  21. 21. c) Labial pads On the Teuscher activator, lip pads for the development of the lower jaw can be attached as in the function regulator according to Fränkel. Therefore the limit of the vestibule has to be erased before making the appliance. d) Lip bumper Also, a lip bumper can be attached directly to the appliance in order to support a protrusion of the lower incisors. It has to be positioned in height of the gingival margin in front of the lower incisors in a distance of approximately 1 mm.
  22. 22. e) Expansion screw Another variation for the expansion of both jaws: an expansion screw between the upper and lower jaw. f) Combination with fixed appliances If the Teuscher activator is used in combination with a transpalatal arch and upper molar bands, the activator has to be liberated in the area of the molar tubes and the palate.
  23. 23. The Harvold-Woodside activator for class II-1 Elements: Labial bow 0.9 mm spring hard, distalizing springs 0.9 mm spring hard Function: Functional change of the occlusal plane in a malocclusion class II-1 Description: A vertical opening of up to 20 mm is necessary for this activator; the smooth lateral bite plane maintains the upper incisors and the lower are grinded In this class II-1 activator the labial bow is bent contacting up to the canines, from there it is bent similar as the buccinator loop to shield the cheek and is then bent through a U-loop again towards the front; the retention finishes in the area of the interocclusal opening. The distalizing springs consist of a big loop in the molar region and have a distal cantilever mesial of the first molars and its retention in the incisal area.
  24. 24. The coverage with wax should be done carefully. The characterizing feature of this appliance is the large vertical opening in the buccal sections which is determined by a construction bite. In order to guide the anterior movement in the posterior region, a thin wax plane is added in the upper jaw and a high wax plane, higher than half of the vertical opening, is added in the lower jaw; the main purpose is to create plane surfaces for the acrylic platforms. If the fixator is closed the separation between both wax planes in the buccal area should be of approximately one millimeter, so that the lateral bite plane presents enough stability.
  25. 25. On the models the extension of the acrylic shield over the whole incisal area in the upper and lower jaw should be limited with a wax frame. The retention of the labial bow lies in the interocclusal acrylic right behind the upper incisors. The models prepared this way can be covered with acrylic and put into the pressure vessel for its polymerization. In the finished appliance, for their proper activation, only the retention of the distalizing springs is covered with acrylic. The labial bow only contacts the upper incisors. The distal limitation of the appliance is the A-line. The labial shield covers the incisors over one third of their clinical crown. The lateral bite planes have no contact at all with the posterior teeth in order to achieve the desired vertical eruption.
  26. 26. The Harvold-Woodside activator for class III Elements: Labial bow 0.9 mm spring hard, distalizing spring 0.9 mm spring hard Function: Therapy of a class III malocclusion Description: The class III activator should not hinder the buccal segments in their vertical eruption In this class III activator, the labial bow in the lower jaw is bent as an intermaxillary bow; its task in the upper jaw is to shield off the lips through loops bent as labial pads. The retention lies as in the class II appliance, in the anterior area of the vertical opening. Also, the distalizing spring is bent with a big loop in the molar region. Although in this appliance the distal cantilevers are located behind the first molars, the retention ends in the anterior palatal area.
  27. 27. As before, the wax coverage is very important. The big vertical opening corresponds to the one in type-II. In this case, a wax plane that reaches over the half of the vertical opening is added onto the upper jaw. In the lower jaw, the posterior teeth are slightly covered with wax and in the incisal area, from canine to canine, the wax is concavely shaped; the loop and the distal cantilever of the distalizing spring are also covered with wax. For its proper stability, the acrylic in the interocclusal area should show a thickness of one millimeter. The acrylic shield of this appliance only covers the lower incisal area and is correspondingly framed with a wax limitation. Despite its location, a sufficient anchorage has to be guaranteed for the retention of the labial bow. Before adding the acrylic both models have to be hydrated.
  28. 28. In this class III appliance, the distal limitation is also marked by the A-line. Once again, only the retention of the distalizing springs is grasped in acrylic. In the upper jaw, the labial bow does not contact but shields off the lip. The upper teeth only contact the acrylic shield. The acrylic can be trimmed and shaped individually by the orthodontist. The lateral bite plane allows more vertical eruption for the upper posterior teeth.
  29. 29. The activator according to Pfeiffer and Grobety Elements: Modified labial bow with soldered triangular clasp 0.8 mm spring hard Function: Retraction of the upper jaw with simultaneous distal movement of the upper teeth Description: Retraction of the upper jaw, and under influence of the masticatory muscles, mesial movement of the lower teeth with simultaneous distal movement of the upper teeth; the headgear is only used combined with the fixator. The impressions are filled with the bands in order to be able to adapt the finished appliance better. In the original appliance only a modified labial bow with a soldered triangular clasp is bent.
  30. 30. The canine loops of the labial arch are placed as usual in the canine area. Then the wire is bent distally and between the first and second premolar it is bent into the retention. The screw is fixed in the upper jaw and the base plate is limited with wax stripes. The activator additionally consists of lateral bite blocks and an incisal cap in the lower anterior region. The lower impression has to depict the lingual area very well in order to extend the lower lingual wings as far as possible into the sublingual area.
  31. 31. The lower wings of the activator should be very pronounced on the lingual side favoring the activity of the masticatory muscles. This is a lateral view of the activator with its pronounced lower wings.
  32. 32. The activator with spring bows according to Schwarz Elements: Labial bow 0.8 mm spring hard, spring bow 1.2 mm spring hard Function: Activation through muscle function Description: Through the spring bows, which can be activated horizontally or vertically, the muscle activity is stimulated The base appliance only contains few elements, but can be replenished in any way. A labial bow is bent for each upper and lower jaw and the single plates are finished with plane lateral bite blocks.
  33. 33. The polished and finished plates are set onto the models which were articulated according to the construction bite. Now the unifying spring bows can be bent and be added into the acrylic of the single plates of the activator. These spring bows are supposed to enhance muscle activity. The spring bows reach distally over the base plate for a proper activation. Different directions for their activation are possible (horizontal, vertical).
  34. 34. The open bite activator with tongue crib Elements: Labial bow 0.8 mm spring hard, Coffin spring 1.2 mm spring hard, tongue crib 1.0 mm spring hard, mandibular connection bow 1.0 mm spring hard. Function: Intrusion of the posterior teeth, extrusion of the incisors and simultaneous protection of the tongue. Description: The tongue is kept from the teeth because of the tongue loop which follows the curve of the dental arch. The models are set into the fixator with the construction bite and the vertical opening is determined. The labial bows are bent as usual. The connecting bow in the lower jaw and the Coffin spring in the upper jaw are fixed each 1 mm from the gingival tissue. The divided tongue crib is fixed parallel to the lingual or palatal area of the incisors.
  35. 35. The tongue crib consists of two divided loops. For the first half, the wire is bent back 180° in the middle. The separation of the parallel wires corresponds to half of the area to be closed off. The loop is bent according to the curvature of the anterior segment. Both wire ends are bent over for retention and are anchored in the lateral part of the activator. The second half is bent like a mirror image and is set on the other side. The acrylic body of the open activator is designed quite delicately. The anterior open base and the adapted tongue crib make this a well accepted appliance by patients.
  36. 36. The Skel activator according to Ruhland type II-1 Elements: For class II-1 – II-2: Labial arch 0.9 mm spring hard, Coffin spring 0.9 mm spring hard, occlusal molar rests 0.8 mm spring hard, occlusal rests canine 0.7 mm spring hard, protrusion spring 0.7 mm spring hard For class III: Labial arch 0.9 mm spring hard, Coffin spring 1.1 mm spring hard, lingual bow 0.9 mm spring hard, connection spring 0.9 mm spring hard Function: A reduced elastic activator with different tasks for class II-1, II-2 and III Description: A reduced elastic activator Type II-1 In the upper as well as in the lower jaw, the labial bows are set into the acrylic between the 1st and 2nd premolar. The distally closed Coffin spring is located in the molar region. The lower incisors area is shaped with protrusion springs. The canines in the upper jaw are held with C-clasps.
  37. 37. The acrylic base is reduced in its anterior part and has no interocclusal acrylic. The delicate design of the acrylic and the relative thin wire elements make this appliance very flexible. Altogether the acrylic body is kept small.
  38. 38. The Skel activator according to Ruhland type II-2 Elements: For class II-1 – II-2: Labial arch 0.9 mm spring hard, Coffin spring 0.9 mm spring hard, occlusal molar rests 0.8 mm spring hard, occlusal rests canine 0.7 mm spring hard, protrusion spring 0.7 mm spring hard For class III: Labial arch 0.9 mm spring hard, Coffin spring 1.1 mm spring hard, lingual bow 0.9 mm spring hard, connection spring 0.9 mm spring hard Function: A reduced elastic activator with different tasks for class II-1, II-2 and III Description: A reduced elastic activator Type II-2 The upper and lower front region is developed using protrusion springs. The labial arch passes between the 1st and 2nd premolar into the acrylic. The first molars are maintained by thorns. The Coffin spring is positioned in the same way as in type II-1.
  39. 39. The acrylic base is the same as in type II-1. From the mesial part of the canines to the distal end of the molars both acrylic parts of the upper and lower jaw are connected. The making of this appliance corresponds mainly to the one of type II-1, it differs only in the protrusion springs in the upper jaw and the lacking of the occlusal rests for the canines.
  40. 40. The Skel activator according to Ruhland type III-a Elements: For class II-1 – II-2: Labial arch 0.9 mm spring hard, Coffin spring 0.9 mm spring hard, occlusal molar rests 0.8 mm spring hard, occlusal rests canine 0.7 mm spring hard, protrusion spring 0.7 mm spring hard For class III: Labial arch 0.9 mm spring hard, Coffin spring 1.1 mm spring hard, lingual bow 0.9 mm spring hard, connection spring 0.9 mm spring hard Function: A reduced elastic activator with different tasks for class II-1, II-2 and III Description: A reduced elastic activator Type III-a The appliance for class III is horizontally divided. Two distal spring bows connect the upper and lower part.
  41. 41. The elements in the lower jaw are two holding thorns and a connecting bow. The upper jaw consists of protrusion springs, an intermaxillary bow and a Coffin spring. First, both parts, upper and lower, are finished separately. Interocclusal acrylic is not necessary. With a construction bite, the upper and lower parts are connected in the articulator through spring bows in the distal part of the plates. Through activation of the intermaxillary bow and both spring bows the lower jaw is retruded.
  42. 42. The Skel activator according to Ruhland type III-b Elements: For class II-1 – II-2: Labial arch 0.9 mm spring hard, Coffin spring 0.9 mm spring hard, occlusal molar rests 0.8 mm spring hard, occlusal rests canine 0.7 mm spring hard, protrusion spring 0.7 mm spring hard For class III: Labial arch 0.9 mm spring hard, Coffin spring 1.1 mm spring hard, lingual bow 0.9 mm spring hard, connection spring 0.9 mm spring hard Function: A reduced elastic activator with different tasks for class II-1, II-2 and III Description: A reduced elastic activator Type III-b In the lower part, the same type can be replenished with a tongue crib which simultaneously serves as a connecting bow. Support thorns can also be placed before the molars if needed
  43. 43. The appliance is also divided horizontally and is activated through the far distally fixed spring bows. The tongue crib prevents a negative influence of the tongue. The intermaxillary bow makes a distal movement of the mandible possible. View of the finished appliance type III b.
  44. 44. The Skel activator according to Ruhland type III-c Elements: For class II-1 – II-2: Labial arch 0.9 mm spring hard, Coffin spring 0.9 mm spring hard, occlusal molar rests 0.8 mm spring hard, occlusal rests canine 0.7 mm spring hard, protrusion spring 0.7 mm spring hard For class III: Labial arch 0.9 mm spring hard, Coffin spring 1.1 mm spring hard, lingual bow 0.9 mm spring hard, connection spring 0.9 mm spring hard Function: A reduced elastic activator with different tasks for class II-1, II-2 and III Description: A reduced elastic activator Type III-c Instead of the spring bows between the upper and lower jaw, a prognathism screw (LS-Duobloc- Screw) was installed. Through this screw a more uniform distal activation of the lower part is possible.
  45. 45. The acrylic is added in one process by means of a dividing metal plate. In order to install the prognathism screw parallel, a metal pattern is needed for their installation. The SKEL activator type III-c according to Ruhland works through the bilateral activation of the lower screws which move the base of the lower jaw distally against the base of the upper jaw.
  46. 46. The elastic open activator according to Klammt (EOA) Elements: Function: Description: Open activator with wide space for the tongue Palatal bow 1.2 mm spring hard, labial bow 0.9 mm hard Alignment of the anterior teeth The labial bows lie parallel to each other and are bent buccaly of the first molars into a loop. From there, they are guided back mesially of the canines from where they are bent palatal or lingual into the retention. The palatal bow is bent similar to a Coffin spring and connects the acrylic parts.
  47. 47. For an ergonomic finish and material saving, the models are blocked out with wax. Under the palatal bow, a wax spacer is placed to ensure adequate clearance for tissue comfort. The acrylic shares lay orally from the canines to the last molars forming a small band contacting teeth and gingiva. The occlusal surfaces are not covered with acrylic and a vertical support by the acrylic is left only in the canine area.
  48. 48. The rigid open activator (SOA) Elements: Connecting bow 1.5 mm hard, labial bow 0.9 mm hard, supporting thorns 0.8 mm spring hard, protrusion spring 0.7 mm spring hard. Function: Alignment of the anterior teeth Description: Delicate activator with wide space for the tongue For the SOA the elements are bent according to the planned design and are fixed with wax. The rigid connecting bow is under laid with tin foil before its fixation in the area of the first molars of the upper jaw to guarantee an even distance from the palatal gingival tissue.
  49. 49. The acrylic base is designed as in the EOA, as delicate as possible with interocclusal acrylic. The rigid connecting bow gives the body of the appliance certain stability. Because of the rigid connecting bow, with this appliance expansion of the jaws is not possible.
  50. 50. The spring activator according to Sander Elements: Labial bow 0.8 mm spring hard, protrusion loop 0.8 mm spring hard, triangular clasps 0.7 mm spring hard, Adams clasps 0.7 mm hard, palatal bow 3.0 x 1.5 mm half round steel wire, a special spring system according to Sander: 1.0-1.1 mm spring hard wire with simple or triple loop Function: Treatment of skeletal open bites and rehabilitation after TMJ injuries Description: Special springs of 1.0-1.1 mm spring hard wire are located lateral in this appliance and therefore do not hinder the tongue For the making of the spring activator the models are set in the fixator. As the acrylic base of the upper jaw is reduced, the retentions have to be bent according to this situation being anchored into this acrylic segment. The highest part of the palate is covered with a tin foil which is 1 - 1.5 mm thick to guarantee an even distance of the palatal bow and to avoid pressure areas. The finished elements are fixed onto the model, acrylic is added and the plate is finished.
  51. 51. The base of the upper plate should extend palatally as much as to guarantee sufficient retention and stability for the special spring. The upper plate is finished and polished completely in order to allow an even adjustment of the upper and lower bite blocks. Isolated with a thick wax layer, the upper bite block can be set onto the polymerizing lower plate. Another option is to separate both plates with a metal plate. Special attention should be paid to the fact that the labial bow with its occlusal parts does not lie over the occlusal plane. While occluding firmly with the spring activator there should not be any interfering contacts in the anterior area. The widths of the lateral bite blocks have to be adapted orally so that the spring bow can glide past the acrylic to connect the upper with the lower jaw.
  52. 52. The loops have to be bent in such a way that while closing the wire is pushed into the loop, which means it is activated (safety pin principle). The length of the spring can be calculated reaching from the last molar approximately to the first premolar or canine. After polishing both individually made plates and the bite blocks lay even on each other, the height has to be checked in the fixator according to the construction bite. The retentions of the springs have to be anchored as far as possible into the distal area of the acrylic segments. The springs should be incorporated into the plate without strain. Instead of the palatal bow, the spring activator can also be fitted with a transversal expansion screw or headgear tubes. If the headgear tubes are incorporated in the area of the first premolars the triangular clasps cease to apply.
  53. 53. The divided activator with screw for the upper jaw Elements: Labial bow and retention thorns 0.8 mm spring hard Function: Separate expansion of the maxilla Description: The upper expansion screw is anchored in the lower jaw The elements are bent following the design, in this case, additionally with two protrusion springs. The extension of the acrylic base is limited with wax. In this horizontally divided appliance, after bending the elements, the lower jaw is finished separately and polished.
  54. 54. In the interocclusal area, the upper and lower bite blocks of the divided activator show a separation of almost one millimeter. That is the reason why this area is covered with wax to this height. In the upper jaw, the screw is centered and fixed with wax so that the retentions of the screw stick out into the lower jaw. Therefore, in the anterior region, two notches have to be grinded into the lower base plate. The fixator should be able to open and close without interference. The area of retention in the lower jaw is blocked out with wax.
  55. 55. Now acrylic is added on the upper jaw. While the acrylic is still malleable the fixator is closed. The wax layer in the retention area of the screw prevents the union of the upper and lower plate. This way the upper plate can be sawed, finished and polished separately. After this, both separately produced plates are unified to one appliance. For this purpose, the division and the interocclusal area close to the screw are covered with wax. The upper part of this activator can be expanded without the lower jaw.
  56. 56. The U-bow activator according to Karwetzky Elements: U-bow 1.2 mm spring hard, labial bow 0.8 mm spring hard Function: Movement of the mandible in different directions, according to the specific type (type I-III) Description: Through the addition of different U-bows into the elastic activator, different directions of mandibular movement are possible For the U-bow activator separate upper and lower plates with even grinded bite blocks and other elements (depending on the planed design) are made. If screws are added into the plates, they only have effect on that specific jaw.
  57. 57. Type I distal activator Through both U-loops, which are anchored into the acrylic in the region of the first molars. The long arm of the U-bow is always fixed into the lower jaw, the short arm into the upper jaw. In this type I distal activator the arms of the U-bow point anteriorly. Type II prognathism activator In type II both anchored arms of the U-bow are directed posteriorly. The long arms are situated in the lower plate as seen here.
  58. 58. Type III-a Pan activator In this type III-a two different bows are built in. On the right side, the upper short arm shows distally, on the left side, the short upper arm shows mesially. When activating the U-loops a panning movement to the right is produced. Type III-b Pan activator In the type III-b the U-bows are incorporated opposite as in type III-a. On the right side, the short upper arm shows mesially, on the left side the short upper arm shows distally. This way, when activating, a panning movement to the left is the result.
  59. 59. Medium Opening Activator Medium Opening Activator with upper and lower model removed. The Medium Opening Activator (MOA), fabricated here in clear heat cure material. Design includes: - * Lower incisal capping 3 / 3 . * Anterior Palatal wire 3 / 3 in 1.0mm S.S wire. * Labial Bow 3 / 3 - 0.9mm S.S wire. * Adams clasps 64 / 46 - 0.7 mm S.S wire. * Occlusal rests 64 / 46 - 0.8 mm S.S wire. * Acrylic connecting 'struts' / vertical supports
  60. 60. Medium Opening Activator with upper model removed Medium Opening Activator with lower removed
  61. 61. Another series of MOA pictures. Medium Opening Activator with upper and lower models in situ.
  62. 62. Medium Opening Activator with upper model removed. Medium Opening Activator with lower removed.
  63. 63. Wunderer activator  Used for CI-III malocclusion  Appliance is split horizontally  Screw is embedded in the acrylic behind the incisors  Occlusal surface is covered with acrylic  Weise screw
  64. 64. Kinetor - stockfisch
  65. 65. Cybernator – Schmuth
  66. 66. Palate – free activator - Metzelder
  67. 67. Bonded activator- Hamilton  Mainly used in non compliant patients  Used for expansion along with forward positioning of jaws
  68. 68. Activator therapy  Diagnostic preparation  Bite registration  trimming of activator  Management of the appliance
  69. 69. Diagnostic preparation History -growth status -instant correction -patient compliance Study models -Molar relationship -Midlines -Asymmetries -curve of spee -Dental discrepancies
  70. 70. Functional analysis  Rest position of the mandible  Path of closure from postural rest to habitual occlusion  Premature contacts  TMJ: a functional abnormal cases may need some modification of activator .  Freeway space or interocclusal clearance  Respiration :with allergies or disturbed nasal respiration (Adenoid problem should be recorded ,patient will not be able to tolerate the activator with adenoid problem).
  71. 71. Cephalometric Analysis ( will help in determining the following): - Direction of growth : average ,horizontal or vertical - Differentiation between Position & size of the jaws - Dimensional variations - Axial inclination and position of the maxillary and mandibular incisors . I. Facial skeleton analysis A .The sadle angle: The sadle angle is formed by joining the NS line and ArS line. Its normal value is 123+5o The large sadle angle usually means that there is a posterior condylar position ,and a mandible that is posteriorly positioned with respect to the cranial base and maxilla
  72. 72. b. Articular angle : lies between the upper and lower parts of the posterior contours of the facial skeleton. Normal value 143+6o Increased Ar angle means retrognathic mandible, Decreased means prognathic mandible. c. The gonial angle: acute or small Go angle means horizontal growth pattern and favorable to activator therapy. In case of large angle (vertical pattern), activator treatment is contraindicated. d. The posterior facial height(S-Go) and anterior facial height(N-M) ratio: posterior facial height X 100/ anterior facial height Less than 62% -Vertical growth More than 65% -Horizontal growth. Anterior facial height (nasion and menton) and Posterior facial height (distance between S and Go)
  73. 73. II. Analysis of the jaw bases a. SNA angle expresses the sagittal (antero-posteror) relationship of the anterior limit of the maxillary apical base. SNA angle is large in a prognathic maxilla and decreased in retrognathic Maxilla. b. SNB angle is large in prognathic mandible and small in retrognathic mandible. SNA angle (joining points S, N and A), SNB angle (joining points S, N and B), and Basal angle Joining palatal plane and base of the mandible .
  74. 74. c. Basal plane angle (maxillo-mandibular plane angle) normal value is 25. It is smaller in horizontal growth pattern and larger in vertical growth pattern. d. Inclination angle is formed by the Pn line (a perpendicular from soft tissue N) and the Palatal plane. Normal value 85 degree. Anterior cranial base length (1), Maxillary base length(2), Mandibular Base length (3), Ascending Ramus (4) and Inclination angle (5)
  75. 75. III. Dentoalveolar analysis : • Axial inclination of the incisors: i. The upper incisors: SN angle is formed by joining the long axis of the maxillary incisors and SN plane. The posterior angle is measured. Normal value 102o Large angle indicates labial crown tipping. ii. The lower incisors: MP angle is formed by joining the long axis of the lower incisors and mandibular plane. The posterior angle is measured. Normal value is 90+3o Large angle indicates labial crown tipping. Upper incisor inclination (1) Lower incisor Inclination (2)
  76. 76. iii. Position of the Incisors: the most common method is to measure the distance of the incisal edges to the N-Pg line (facial plane). The average position of the upper incisors is 2mm to 4 mm anterior to the Facial plane and lower incisors from 2 mm posterior to 2 mm anterior to the facial plane. Upper incisor position (1), Lower incisor position (2)
  77. 77. Rules for construction bite • In a forward positioning of the mandible of 7-8mm,the vertical opening should be slight to moderate (2-4mm) • If the forward positioning is not more than3-5mm,the vertical opening can be 4-6mm • If the overjet is too large , forward positioning is done in 2-3 stages Bite Registration
  78. 78. Bite Registration Boxing wax Wooden spatula Hot water
  79. 79. Patient bites with incisors edge to edge. ~ 6mm separation of molars
  80. 80. Fold wax lengthwise twice to 1/3 size Do not flatten
  81. 81. Turn folded wax lengthwise and fold once with spatula in between
  82. 82. Crimp lower edge against spatula Do not flatten
  83. 83. Patient bites with incisor edge to edge
  84. 84. Bite of the patient
  85. 85. Trimming of the Activator 1. Sagittal Control a. Class II correction: Trimming is done so as to encourage the mesial movement of the lower molar and distal movement of the upper molar. Trimming of the activator for Class II correction. Note the lower posterior segment is free to erupt vertically and mesially.
  86. 86. Mesial movement of molars Distal movement of molars
  87. 87. b. Protrusion of incisors • In this case lingual surfaces of teeth are loaded with acrylic and a passive labial bow is given Activator design for protrusion of incisors. Note the loading of the entire lingual surface and labial bow away from the incisors to encourage labial movement of the incisors
  88. 88. c. Retrusion of incisors • Here the lingual surface is made totally free of acrylic and an active labial bow is given Activator design for retrusion of incisors. The labial bow here is active and the lingual surfaces of the incisors are relieved for lingual movement of the teeth
  89. 89. 2. Vertical Control a. Intrusion of teeth • Activator design for intrusion of teeth (for anterior intrusion the labial bow is placed below the greatest convexity in the upper and above the greatest convexity in the lower) • In case of intrusion of posteriors load the surfaces of the teeth with acrylic
  90. 90. b. Extrusion of teeth • Here the lingual surface is loaded above the area of greatest convexity in the maxilla and below the area of greatest convexity in the mandible • Also the labial bow can be placed at the gingival 1/3 i.e. below the greatest convexity • In case of posterior extrusion the lingual surfaces below the greatest convexity are loaded. Activator design for extrusion of teeth. (i)Anteriors.(ii)Posteriors
  91. 91. 3. For Transverse Control Jack screw is incorporated into the activator for expansion (trasnverse control) as and when required. Activator with jack screw, for transverse control
  92. 92. • The patient is demonstrated to place and remove the appliance in mouth. • The appliance is to be worn 2 to 3 hours during the day for the first week. • During the second week the patient sleeps with the appliance in mouth and wears it for 1-3 hours each day. • The appliance is checked during the third week to evaluate the trimming. • If the patient is wearing the appliance without any difficulty and following the instructions, checkup appointments are scheduled every 6 weeks. MANAGEMENT OF THE APPLIANCE
  93. 93. Case Reports Case 1 A 10-year-old male patient reported in good health with chief complaint of protrusion of upper front teeth and unpleasant looks. The dental and medical history was unremarkable. Extraoral examination showed convex facial profile with posterior divergence of the face due to retrognathic mandible. Lips were potentially competent and protrusive with 6 mm of interlabial gap, everted lower lip, and hypotonic upper lip.
  94. 94. Intraoral examination revealed late mixed dentition stage with erupting upper canine and nearly exfoliating second deciduous molar on the left side. Dental arches were "U" shaped and maxillary anteriors were proclined with spacing. The mandibular incisors were impinging on palatal tissue on closure. In occlusion, there was a class II division 1 relationship with increased overjet of 11 mm and overbite of 8 mm. The molar relationship was class II bilaterally.
  95. 95. The lateral cephalogram showed a severe skeletal ANB difference of 7°. The maxilla was normal relative to the cranial base with an SNA at 80°. The mandible was retrognathic with an SNB value of 73°. The maxillary incisors were proclined.
  96. 96. Diagnosis: Skeletal class II jaw relationship with Angle′s class II division 1 malocclusion with average growth pattern. Hand wrist radiograph was taken to confirm the growing status of patient. Treatment plan: Growth modification with myofunctional appliance therapy (activator) followed by final detailing of occlusion with fixed pre-adjusted edgewise appliance. The objectives of growth modification procedure (myofunctional appliance) were to reduce the skeletal class II pattern, achieve a class I skeletal and dental relation, establish normal overjet and overbite, reduce the convex profile, and improve the lip incompetency. Myofunctional appliance (Activator) was planned for growth modification therapy. Patient was instructed to wear the activator for 14 hours/day.
  97. 97. Results achieved: Patient′s soft tissue facial profile was improved, along with lip incompetency, reduction of the severe overjet and deep impinging overbite, and achievement of class I skeletal and dental relationships
  98. 98. The cephalometric analysis after myofunctional therapy demonstrates favorable forward growth of the mandible. There was a reduction of the skeletal class II with a 5° decrease in the ANB angle through forward growth of the mandible. The post-treatment value of SNB at 79° indicates the advancement of mandible.
  99. 99. At the end of treatment, the patient had pleasing and well-settled dentition
  100. 100. Comparison of pre-treatment and post-treatment cephalometric values . Total treatment time was 22 months.
  101. 101. Case 2 An 11½-year-old boy patient reported with the chief complaints of forwardly placed upper front teeth and unpleasant looks. Extraoral examination revealed a convex profile mainly due to retrognathic mandible, incompetent protrusive lips with 7 mm of interlabial gap, upturned prominent nose, deep mentolabial sulcus, and lower lip trap habit.
  102. 102. Intraoral examination of dentition revealed mixed dentition stage. Maxillary and mandibular arch were ovoid in shape with proclined upper incisors and generalized spacing. In occlusion, there was Angle′s class II division 1 relationship with overjet of 13 mm. The overbite was 6 mm. The molar relationship was class II bilaterally. Canine relationship was class II on the right side and was not established on the left side. Upper and lower dental midlines were coinciding with each other and with facial midline.
  103. 103. The lateral cephalometric values showed a convex hard tissue profile with a severe skeletal ANB difference of 7°. The maxilla was slightly prognathic relative to the cranial base with an SNB at 83°. The mandible was retrognathic relative to the cranial base with an SNB at 76°. There was proclination of upper and lower incisors with average growth pattern.
  104. 104. Diagnosis Angle′s class II division 1 dentoalveolar malocclusion on class II skeletal base due to retrognathic mandible. Treatment plan Growth modification with myofunctional appliance therapy (activator) immediately followed by final detailing of occlusion with fixed pre-adjusted edgewise appliance was planned.
  105. 105. Results Saggital correction (skeletal class I) was achieved through growth modification with improvement in the facial profile and lip incompetency and reduction of the severe overjet and deep overbite. At the end of the treatment, the patient had very good facial profile , class I molar and canine relationship, normal overjet and overbite , root parallelism, and normal tooth position.
  106. 106. Evaluation of the cephalometric tracings demonstrates reduction of the skeletal class II with a 4° decrease in the ANB angle through forward growth of the mandible. The post-treatment value of SNA was 82° and of SNB was 79°. Proclination of upper as well lower incisors was also corrected. Comparison of pretreatment, mid treatment and post treatment Cephalometric values
  107. 107. REFERENCES  Gurkeerat Singh ( second edition )  Synopsis of orthodontics  Indian dental academy
  108. 108. THANKS FOR LISTENING

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