Molar distalisation in Orthodontics

Introduction
History
Indications and contraindications
Timing of distalization
Second molar extraction
Mandibular molar distalization
Rickett’s criterion
Classification and various distalization appliances
References

1. MOLAR DISTALIZATION Dr. Miliya Parveen

2. CONTENTS: Introduction History Indications and contraindications Timing of distalization Second molar extraction Mandibular molar distalization Rickett’s criterion Classification and various distalization appliances References

3. INTRODUCTION: Distalization is a conservative method that is utilized in orthodontics to gain space by moving posterior teeth distally. May be combined with other space gaining strategies, such as expansion, or can be used alone. Many methods have been used which may differ in their place - extraoral or intraoral, site of action in upper and/or lower arch, and cooperation needed by the patient (removable or fixed).  

4. HISTORY: Kingsley was the first person to try to move the maxillary teeth backwards in 1892 by means of headgear. Oppenheim advocated that position of mandibular teeth as being the most correct for individual and use of occipital anchorage for moving maxillary teeth distally into correct relationship without disturbing mandibular teeth. In 1944, he treated a case with extra-oral anchorage for distalizing maxillary molar.

5. Renfroe (1956) reported that lip bumper primarily devised to hold hypertonic lower lip caused a distal movement of lower molars. Gould (1957) was first person to discuss about unilateral distalization of molars with extra-oral force. Kloehn (1961) described the effects of cervical pull headgear. Graber T.M. (1969) extracted the maxillary II molar and distalized the first molar to correct class II div.I .

6. INDICATIONS FOR MOLAR DISTALIZATION: ( i ) To mesially position the maxillary first molar ( ii ) Preferred in patients with low mandibular plane angle ( brachycephalic type) or normal ( mesocephalic type ) ( iii ) Mild to moderate class II molar relationship, which are not indicated for extraction ( iv ) To correct the second molar position ( v ) To achieve ideal overbite and overjet ( vi ) To early correct class II pattern ( vii ) To regain the lost space (space regainer )

7. CONTRAINDICATIONS FOR MOLAR DISTALIZATION ( i ) Patients with high mandibular plane angle and excessive LAFH ( ii ) Patients with skeletal or dental open bite ( iii ) Severe class II skeletal pattern with an orthognathic maxilla and retrognathic mandible ( iv ) Excessive overjet and proclination of anterior teeth ( v ) Crowding in the posterior segment (vi) Patients with temporomandibular joint problems

8. OTHER CONSIDERATIONS FOR MOLAR DISTALIZATION : Growth Pattern: unfavorable or vertical growth tendency are contraindicated. Degree of Overbite: advantage in deep overbite cases is however a disadvantage in Class III cases and open bite cases. Second Molar: Unerupted second molars rarely create resistance to the distal movement of the maxillary first molars. Indeed even they move distally in response to moving first molar

9. 4. Age of the patient: Dewel (1967) and Hass (1970) observed faster rate of molar distalization in patients in mixed dentition to those in the adult dentition. This is probably as Armstrong observed that the skeletal system of younger patients is apparently more dynamic, possessing a greater capacity to remodel. 5. Presence of other force systems: A force system applied for distalization of first molars may be negated or augmented by the presence of other force systems like intraoral elastics, arch wires, etc. For example, presence of a tip back bend in the arch wire mesial to the molar requires a greater compensational distal root rotation force to cause distalization of first molar by translation.

10. TIMING OF DISTALIZATION: Different views have been expressed by different authors, Joseph M.Sims (1977): suggested that the patient should be treated before the age of 9yrs as the root of the molar to be moved has not completed its growth and the orthodontic distal tipping or distal bodily movement is easier. Ottolenguri (1914): suggested that the first molars should be moved backward against unerupted second molars during orthodontic treatment with caution as such movement could result in root resorption of the first molar.

11. David J.Snodgrass (1996): stated that in the mixed dentition, molar distalization should not be carried out until full development of the maxillary first molar roots. In the permanent dentitions, molar distalization is most effective before the full eruption of the second molar. James J. Hilgers (1992): suggested that the distal movement of the first molars is most efficient before the eruption of upper second molar.

12. MAXILLARY SECOND MOLAR EXTRACTION IN MAXILLARY FIRST MOLAR DISTALIZATION: Hilgers (1992) suggested that when a great deal of distal movement is needed and it is preferable not to extract the upper first bicuspids, it is always beneficial to remove the upper second molars and let the third molars drift into place.

13. According to Samir E. Bishara , various advantages and disadvantages of second molar extraction are as follows: Advantages: Facilitation of first molar distal movement Reduction in the amount and duration of appliance therapy Disimpaction of third molars Faster eruption of third molars Less likelihood of relapse Good functional occlusion Disadvantages: Too much tooth substance removed. Extraction site located far from the area of concern in moderate to severe anterior crowding.

14. MANDIBULAR MOLAR DISTALIZATION: Orthodontic displacement of the mandibular molar, other than extrusion, is reputed to be extremely difficult, due to the large root area and root anatomy. Indications - To correct mandibular incisor alveolar protrusion, with or without associated crowding To straighten a curve of Spee at the expense of the posterior sectors Preoperative orthodontic preparation of class III compensation Dental class III associated with skeletal class I malocclusion Moderate skeletal class III, to be managed non-operatively by dentoalveolar compensation

15. UPPER MOLAR POSITION: Cephalometrically , according to Rickett’s criterion , Upper molar position is the horizontal distance from Pterygoid Vertical Line or PTV Line to the distal surface of the maxillary first permanent molar. This measurement indicates whether sufficient space is present or not for the second and third molars . The clinical norm is age+3 and clinical deviation is +/-3 mm (in growing patients ) . In non-growing patients, the mean value is 18 mm.

16. CLASSIFICATION:

17. VARIOUS MODALITIES TO DISTALIZE MOLARS: • Appliances traditionally used to distalize molars can be divided into two categories: Extraoral and Intraoral. Extraoral Appliances: A typical extraoral appliance includes face-bows that attach to tubes on the upper first molars and headgears that attach to auxiliaries connected to the arch wires .

18. B . Intraoral appliances: Vast number of intraoral appliances also has been advocated for the purpose of molar distalization. These appliances can be removable or of fixed type and can be categorized into two groups. INTER-ARCH: Tandem Yoke 3 Dimensional Bimetric Distalization Arch Modified Herbst Appliance Saif Springs Klapper Super Springs Eureka Springs Jasper Jumper

19. INTRA-ARCH: A. Maxillary Arch Removable Appliance - • Cetlin appliance • ACCO (acrylic cervical occipital appliance) • Modified ACCO appliance • Removable molar distalization splint • Molar Distalizing Bow • Segmented Removable appliance for Distalization (RMD) • C-space regainer

20. II. Fixed Appliance – • Transpalatal arch • Nance palatal appliance • Modified Nance appliance for molar distalization K loop • Pendulum appliance and modifications • Jones jig • Distal jet and its modifications • Intraoral Bodily Molar Distalizing Appliance (IBDA) • Lokar Molar Distalizer Lingual Distalizer System Fixed piston appliance Greenfield lingual distalizer Lingual distalizer system “New Distalizer ” appliance Crozat treatment Crickett appliance Frog appliance • Super elastic NiTi wire • NiTi Coil Springs • Magnets SAS (Skeletal Anchorage System)

21. Mandibular Arch Franzulum appliance Modification of Distal Jet appliance Unilateral Frozat Appliance SAS (Skeletal Anchorage System)

22. EXTRA-ORAL – BILATERAL DISTALIZATION: A. CERVICAL PULL (Low Pull or Kloehn ) - In patients with decreased vertical skeletal dimension. Restrict forward growth of maxilla and/or to prevent the forward growth of maxillary posteriors. Force is below the occlusal plane producing both extrusive and distalizing force. Used in deep bite, hypodivergent bases. Outer bow is longer than inner and bent upwards so that both point of force application and line of force lie above the centre of resistance of molar.

23. B. OCCIPITAL PULL - Force is above the occlusal plane and is distalizing and intrusive. Skeletal or dento -alveolar open bite and/or steep mandibular plane angle ( hyperdivergent ) as it provides a vertical force. Outer bow is same length as inner and bent upwards so that line of force is through the centre of resistance of molar .

24. EXTRA-ORAL – UNIATERAL DISTALIZATION: Power Arm Outer bow is longer and/or wider than other Longer bow located on the side to receive greater distal force. Disadvantage - also generates lateral forces (tends to move the favoured molar into lingual crossbite and other molar into buccal crossbite ) Soldered – Offset Face Bow Outer bow is attached to inner bow by a fixed soldered joint placed on the side favoured to receive the greater distal force.

25. Swivel-Offset face bow Outer bow is attached to inner bow through a swivel joint located in an offset partition on the side favoured to receive the greater force. Spring – Attachment face bow An open coil spring is warped around one of the inner bow terminal and conventional bilateral face bow. On the side favoured to receive greater force.

26. INTRAORAL METHODS – INTERARCH DISTALIZATION: TANDEM YOKE The Bimetric arch modules are designed for ease of insertion and removal. They consist of 0.040 inch end sections (provide rigidity and support), the inter-maxillary hooks and an anterior arch bar of 0.022 inch true chrome for flexibility. The molar buccal tube combines rectangular tube of 0.018 x 0.025 inch or 0.022 x 0.028 inch with the 0.045 inch round tube at the gingival position - key to successful distalization of upper molars with minimal tipping.

27. 3D BIMETRIC DISTALIZING ARCH AND 3D MANDIBULAR LINGUAL ARCH Wilson in 1978 introduced the concept of “modular orthodontics” and the method of rapid molar distalization This treatment approach to distalizing maxillary molars has been designed using a 3D biometric distalizing arch and a 3D mandibular lingual arch with class II elastics. Wilson’s biometric distalizing arch has a 0.022 anterior section and 0.045” posterior section that fit into the headgear tube. A 5 mm long, open coil is inserted between the Omega adjustable stops and buccal tube. The coil springs were compressed to 3 mm to produce a 2 mm activation and movement.

28. INTRA-ARCH DISTALIZATION - MAXILLARY REMOVABLE APPLIANCES: CETLIN APPLIANCE Forward by N.M Cetlin & Ten Hove in 1983. The Cetlin appliance utilizes a removable appliance intraorally to tip the crowns distally and then an extraoral force to upright the roots. Consists of 2 distalizing spring mesial to 1st molars, anterior bite plate to disocclude the posteriors Spring activated to 1-1.5mm

29. ACCO Appliance Originally devised by Dr. Herbert Margolis The ACCO (Acrylic Cervical Occipital anchorage) appliance is a removable acrylic appliance which is used in conjunction with a Headgear to effect distal mass movement of buccal segments. This removable appliance exerts a continuous distalizing force on the molars, with the springs reactive forces dissipated through the acrylic button into the palate and the maxillary teeth mesial to the molars.

30. MODIFIED ACCO APPLIANCE B.Guliano Maino and Paloa Mura et al., in 2006 introduced a modified version of ACCO appliance. The major difference is that the Adams clasp engaging each first premolar terminates in a helix embedded in the acrylic plate. When the distal end of the clasp is cut off, it becomes a finger spring used to distalize the first premolar With the original ACCO appliance, distalization ended when the first molar had been overcorrected into a super Class I relationship and the second premolar had drifted distally. With the modified appliance, treatment continues until both premolars are Class I and some spontaneous canine distalization has occurred.

31. REMOVABLE MOLAR DISTALIZATION SPLINT Ritto A.K. (1995) described use of removable molar distalizer appliance in both maxillary as well as mandibular arch - small , comfortable and more esthetic than conventional removable plates. The appliance consists of a clear splint made form 1.5 mm Biocryl in a Biostar machine. If both upper first molars are to be moved distally at the same time, the spint extends from the area of the upper left first or second premolar. If only one molar is to be moved, the splint extends to the terminal molar on the opposite side.

32. MOLAR DISTALIZING BOW Jeckel and Rakosi (1991) The appliance is easy to handle and wear. The distalizing bow fits into the anterior slot and posteriorly into the conventional molar headgear tubes, which lie in the same plane as the anterior slot or just above it. Consists of 0.8 to 1.5 mm thick thermoplastic splint extending into buccal sulcus. To activate the appliance, central section of bow must be pressed and fitted into anterior slot. This compresses the coils and force is transmitted to molar.

33. C-SPACE REGAINER Kyu-rhim Chung et al., (2000) This appliance can be used to intrude teeth as well as to move them distally or sagitally . And also can be used to achieve bodily molar movement without significant incisor flaring A 0.010” x 0.040” open coil spring is soldered immediately distal to the helix and 0.028” ball clasps are used between lateral incisor and canine to retain the appliance

34. Pendulum Appliance Introduced by Dr. Hilger in 1992. It is a hybrid appliance that uses a large Nance acrylic button in the palate for anchorage, along with 0.032” TMA spring that deliver a light, continuous force to the upper 1Ms. INTRA-ARCH DISTALIZATION - MAXILLARY FIXED APPLIANCES: Fabrication of Active part: Right and left pendulum springs with 0.032 TMA wire, consist of a recurved molar insertion wire, a small horizontal adjustment loop, a closed helix and a loop for retention in the acrylic button.

35. Activation: A ctivated by using a bird beak plier by keeping the round beak inside and the square beak outside; the springs are opened and made parallel to the midline. E ach pendulum spring is brought forward with finger pressure, the mesial end of the recurved loop is grasped with a Weingart plier, and the spring is seated in the lingual sheath . Reactivation: Checked about every three weeks and reactivation is done by holding helix with a bird beak plier and the spring is reactivated by pushing it distally toward the midline.

36. M- Pendulum In this modification of the pendulum appliance, the horizontal loops are inverted to allow bodily distalization of molars. Once distal molar movement has occurred, the loop can be activated simply by opening it. The activation produces buccal and/or distal uprighting of the molar roots and thus a true bodily movement rather than a simple tipping or rotation. The preactivation bends given prior to intraoral placement is also 40 to 45 degree rather than 60 degree as in conventional or Hilger’s pendulum appliance. MODIFICATIONS OF PENDULUM APPLIANCE:

37. Modified Pendulum with removable arms It has removable TMA arms that can be reactivated outside the mouth. Double over two 7-9mm lengths of .032" TMA wire to form bayonets. Attach each bayonet to an M-Pendulum arm, either by using a laser welder or by wrapping .010" ligature wire around the arm and soldering the unit together with silver wire and a miniflame . Embed each bayonet in the soft acrylic that will be used to form the Nance button, producing sheaths in which to insert the removable arms. The removable arms can be reactivated during treatment without deboning and rebonding the occlusal rests of the Nance button.

38. We modify the M-pendulum by using four removable arms, for both the first and second molars. The pressure exerted by the pendulum will be less, since the distalization force is used to move the second molars and first molars sequentially, rather than simultaneously. Once the second molar has been distalized , their arms are left passively in place for anchorage, and the first molar arms are activated for distalization and intrusion. After the first molars have been distalized , the pendulum is replaced with a Nance button. Modified pendulum appliance for anterior anchorage control

39. Has a distal screw that divides the Nance palatal button in to 2 parts: the anterior part, used for anchorage and posterior part with the pendulum springs and thus the active elements of the appliance. Before placement, the pendulum springs are activated for distalization (targeted force: 180-200 N) and are given additional i ntegrated uprighting activation (30°) Pendulum K Appliance

40. Bone Supported Pendulum (BSP) Appliance • In 2007 Andres Escobar et al., introduced a modified pendulum appliance, the bone supported pendulum appliance (BSP) with 2 endosseus screw for anchorage in the palatal area was used for maxillary molar distalization ( force of approx. 250gm) and prevent the loss of anchorage generally associated with mesial movement of the premolars and labial movement of maxillary incisors.

41. Crickett Appliance Victor C.West (1984) Embraces essential features of quadhelix but replacing palatal and lingual bars of upper and lower appliances with Quad and bi-helix respectively. Upper palatal and lower lingual bars are constructed with 0.032” yellow and 0.038” blue elgiloy respectively. Cribs, clasps and occlusal rests from 0.028” blue elgiloy lingual arm from 0.030” yellow and buccal arm from 0.045” blue elgiloy . Effects a variety of tooth movements, including rotation, torquing , and distalization of molars.

42. Jones Jig In 1992 Richard Jones and Michel White used open coil nickel titanium spring to deliver 70-75 gm of force, over a compression range of 1-5 mm to the molars. Jones Jig assembly consists of bands on the upper second premolars attached to a Nance Palatal arch. The Jig main was attached through the headgear and bracket slot to upper first molar bands. An eyelet tube is then place anterior to the spring; such that when the eyelet tube is pushed distally the Ni-Ti coil spring gets compressed exerting a distalization force on the molars.

43. Advantages: The extent of forward movement of the anterior teeth while using the Jones Jig is very minimal. Can be used without the need of a full banded upper arch. The coils of Jig can be changed with minimal time and the use of arch wires and class II elastics can be avoided Modification: Jones Jig is modified by Dr. Hickory to be usable without anterior braces. Usually a Nance is placed from the first premolars for anchorage. To avoid braces on the anterior teeth vacuform aligners are used with bonded buttons to support Class II elastics.

44. Clinical Distalization with the Distalix In 1993, Langlade introduced a new appliance called Distalix , a frictionless automatic system. This appliance was originally designed from the quad helix appliance, from which it borrows the four helices, and from Hilger’s distalization pendulum spring.

45. It is constructed with a 0.032 inch blue Elgiloy round wire and can be welded on premolar and/or molar bands, or it can be completely removable, with a palatal tube on molar bands. This appliance can be individualized and adapted to the clinical situation to obtain only a backward movement, an expansion, a molar rotation, or even a combination of all three movements. It produces very light force ranging from 250 to 350gm this is enough to obtain molar distalization in a growing patient. Occasionally, the molars are too far forward and in rotation, in such cases, the Distalix is well indicated.

46. Distal Jet for upper molar distalization : Dr.Carano and Dr.Testa in the year 1996 It is a fixed palatal appliance that can produce unilateral or bilateral molar distalization typically in 4-9 months without relying on patient cooperation. Bilateral tubes of 0.036” internal diameter are attached to an acrylic Nance button. A coil spring and a screw clamp are to slide over each tube. ( NiTi coil springs of 150gms of children and 250gms for adult, appliance can be made of stainless steel spring)

47. The wire extending from the acrylic through each tube ends in a bayonet bends that is inserted into the lingual sheath of the 1 st Molar band. An anchor wire from the Nance button is soldered to bands on the second premolars. The distal jet is reactivated by sliding the clamp closer to the 1 st molar once a month.

48. Double set screw distal jet In 1998 given by Jay Bowman This modification incorporates use of two sets of screw into the activation collar for a more reliable conversion of Distal Jet to Nance holding arch. Of the two set of screws, the mesial set is used for active distalization and the distal set of screw is used to lock on the bayonet wire to prevent mesial movement of the molar

49. Modified mandibular distal jet : It was designed to upright mesially tipped 1st molars, when the original design is applied to mandibular 2nd molars.

50. Lokar Molar Distalizer In 1996 Lokar , had introduced new molar distalizing appliance called “ Lokar molar distalizer ”. Lokar appliance inserts into the molar attachment with an appropriately sized rectangular wire . A- Inserts into molar attachment with a rectangular wire B- Compression spring C- Sliding sleeve D- Groove E- Flat guiding bar F- Round posterior guiding bar G- Immovable posterior sleeve

51. A compression spring is activated by a sliding sleeve, which is tied to the most distal tooth mesial of the first molar by a ligature wire going around the front of the sliding sleeve and is kept in place by resting in the groove, which is formed by the flat guiding bar and the round posterior guiding rod.

52. K-Loop The appliance based on Burstone's principles was designed by Dr. Varun Kalra (1995) to achieve bodily movement or controlled or uncontrolled tipping of molars as required by the case. By altering the moment to force ratio, the clinician can achieve bodily movement. For additional molar movement the appliance is reactivated 2 mm after 6-8 weeks. In most cases, one reactivation produces 4 mm of distal movement . Made up of 0.017 x 0.025 TMA wire .

53. Each loop should be 8 mm long 1.5 mm wide. The legs of K are bent down 20 degrees and inserted into the molar tube and premolar bracket. Stops are bent 1 mm from mesial of the molar tube and the distal of the premolar bracket. These bends help keep the appliances away from the mucobuccal fold allowing a 2 mm activation of the K loop. The 20 degrees bends in the appliance legs produce moments that counteract the tipping moments created by the force of the appliance and these moments are reinforced by moment of activation, as the loop is squeezed into place.

54. Asymmetric Maxillary Molar Distalization with the Transpalatal Arch In 2001 Massililiano and Laura Balducci introduced the use of Transpalatal arch in maxillary molar distalization . A toe in bend in the Transpalatal arch applies a mesiobuccal rotation to the maxillary molar on the side of the bend and a distally directed force against the molar on the opposite side. Made from the 0.032”TMA The Transpalatal arch is inserted from distal into the tube of the maxillary molar used as anchorage, and from the mesial into that of the maxillary molar to be distalized .

55. Nance appliance and its modification The Nance holding arch consists of a palatal arch attached to first molar bands and embedded in an acrylic “button” that lies against the palatal rugae . Modification - The active, class II side also had an arm bent similar to a quadhelix with the most anterior terminus soldered to a first Bicuspid band. A 0.020 inch omega loop is soldered to the anterior end of the framework which allowed the distal end of the loop to slide distally as it is opened for activation.

56. Gienally et al., in 1988 and Takami Itoh in 1991 had used a repelling type of magnetic force for distal tooth movement In 1988 Anthony Gienally used intra arch repelling magnets anchored to a modified Nance appliance cemented on the maxillary first premolars, were activated against the maxillary first molars to move them distally. Magnets in all patients were activated by tightening of the 0.014 inch ligature wire to bring the magnets into contact. The procedure of the magnets recommended reactivation of the magnets once every three weeks. Molar Distalization with Magnets :

57. Disadvantage - Forces exerted by magnets drops significantly as spaces are opened. Discomfort to the patient. Labial movement of the anterior teeth was observed despite the use of a nance holding arch. Initial discomfort to the patient because of the size of magnets. Using repelling force, orthodontic force decreased by 50% to 70% with every 0.5mm - 1.0mm of movement hence frequent reactivation was required every two weeks

58. Molar Distalization with Super Elastic NITI Wire U se of superelastic nickel titanium wire with shape memory - Locatelli and Gianelly et al., in 1992. The method produces 1-2 mm molar distalization if the second molars are unerupted and the appliance is easy to insert. Place a 100gm Neo Sentalloy wire with regular archform over the maxillay arch. Mark wire in three places on each side (at distal wing of the first premolar bracket, 5-7 mm distal to the anterior opening of the molar tube, and between the lateral incisors and canines.) Crimp a stop to the archwire at each of the posterior marks, and add hooks for intermaxillary elastics between the lateral incisors and canines.

59. Advantages This method moves the molars distally by 1-2 mm per month with little loss of anchorage. Neosentalloy is easy to insert even after all the teeth have been bracketed or banded. Disadvantages Once the second molars are erupted, distal movement of first molars usually take more time. If the first molars do not move by atleast 1mm / month, a 200 gm 0.018 X 0.025 Neosent alloy wire can be placed with increase in force, therby increasing the chances of loss of anchorage.

60. Fixed Piston Appliance The Fixed Piston Appliance (Greenfield Molar Distalizer ) was introduced by Greenfield in 1995 It is a fixed appliance with buccal and lingual pistons on each side. Placing the pistons at the gingival level reduces the distance of the applied force from the center of resistance of the molar, minimizing the crown tipping moments that are seen with other distalizer .

61. So, according to him this appliance produce bodily distal movement of maxillary first molars without need of extraoral appliance and with no loss of anterior anchorage. Advantages Produces bodily movement of maximum first molars with no loss of anchorage. Does not require the need of patient compliance but allows the use of head gear if required. Uses a light controlled force of only 1.5-2 Oz/tooth Does not interfere with occlusal plane thus maintaining control of vertical dimension.

62. Frog appliance Mehmet bayram et al in 2010 gave frog appliance for upper molar distalization A frog appliance kit consists of a screw, a preformed spring and a screw driver Frog Appliance was found to be a simple, effective, non- invasive, and compliance-free intraoral distalization appliance for achieving bilateral molar distalization .

63. Franzulum appliance Fridrich Byloff et al., (2000) The Franzulum appliance’s anterior anchorage unit is an acrylic button, positioned lingually and inferiorly to the mandibular anterior teeth, and extending from the mandibular left canine to the mandibular right canine. Tubes between the second premolars and first molars receive the active components. Posterior distalizing unit uses nickel titanium coil springs, about 18 mm in length, which apply an initial force of 100-120gm per side .

64. A J-shaped wire passing through each coil is inserted into the corresponding tube of the anchorage unit. The recurved posterior portion of the wire is engaged in the lingual sheath of the mandibular first molar band. During distalization phase, the mandibular molars moved 4.5-5 mm distally while the incisors moved 1mm anteriorly. The mandibular right molar crown tipped 4° distally, and the mandibular incisor crowns tipped 1° labially. Thus, the movement of the incisor crown resulted in an anchorage loss of 1 mm and 1 °.

65. Unilateral Frozat Appliance In 2004 Gero Kinzinger et al., described an alternative treatment, using an asymmetrically activated lingual arch that allows an intersegmental correction of the malocclusion A rigid and passive buccal wire segments provides sufficient anchorage. On the anchorage side, the lingual arch is bent into an occlusal U loop distal to the soldered point on the molar band, and then curved around to form the lingual arm of the appliance

66. Activation is done by using a three prong plier to make a 1 st order bend on the anchor side of the lingual arch, near the molar band An anti-rotation bend must then be placed in the lingual arch in the region of the molar to be distalized . This activation eliminates the risk of any contact between the molar root and the lingual cortical bone, so that the desired distalization takes place in the cancellous bone

67. The New Distalizer The new appliance for molar distalization originates form a former idea by Dr. Nicola Veltri in 1999 with subsequent personal modifications. Appliance consists of a palatal sagittal screw for bilateral molar distalization according to Veltri , which is connected to bands on maxillary first molars and on maxillary second premolars. Auxiliary device for anchorage is represented by a Nance button which is soldered to the body of the screw.

68. Intraoral bodily molar distalizer In 2000 Ahmet Keles and Sayinsu has introduced a new appliance for bodily movement of molars and eliminated dependence on patient cooperation and did not require headgear wear for molar root uprighting . Maxillary first molars and premolars were banded. On the palatal side hinge cap palatal attachments were welded, and a maxillary impression was taken. On the model, a wide acrylic Nance button was constructed and attached to the first premolar bands with 0.045 inch in diameter stainless steel retaining wires.

69. Appliance is composed of two components, the distalizing unit and anchorage unit. The active part of the appliance is made of 0.032 x 0.032 inch TMA spring. The springs have two components - the distalizer section of the spring applies a crown tipping force, whereas the uprighting section applies a root uprighting forced to the molars. The spring are activated by pulling from mesial to distal and then seating into the palatal hinge cap attachments welded to the first molar bands

70. In 2002, K eles and Sayinsu developed an appliance that eliminated patient cooperation, distal tipping of the molars and anchorage loss - used for both unilateral and bilateral molar distalization Maxillary first molars and first premolars were banded. First premolar bands were attached to a wide acrylic Nance button with 1.1 mm diameter stainless steel retaining wires. The acrylic button also consisted of an anterior bite plane to disocclude the posterior teeth, enhance the molar distalization and correct the anterior deep bite. Keles Slider

71. In the palatal side, 0.9 mm diameter SS wires were embedded into the acrylic at about 5mm apical to the gingival margin of the first molars. These wires passed through the tube and were oriented parallel to the occlusal plane. For molar distalization, a heavy Ni-Ti coil spring ( 2cm long, 0.9 mm diameter, and 0.016 inch thick) was placed between the screw on the wire and the tube, in full compression. The amount of force generated with the full compression of the 2 cm open coil spring was about 200gm - allows consistent application of force at the level of the centre of resistance of the first molars

72. Luis Carriere in 2004 developed a new distalizer with advanced computer technology Carriere Distalizer The Carriere Distalizer is designed to create a Class I molar and canine relationship. The biomechanical objectives of the appliance are as follows: Produce a distal rotational movement of the maxillary first molars. Produce a uniform force for distal molar movement. Independently move each posterior segment, from canine to molar, as a unit. The Distalizer is made of moldinjected , nickel-free stainless steel. It is bonded to the canine and first molar

73. The canine pad , which allows distal movement of the canine along the alveolar ridge without tipping, provides a hook for the attachment of Class II elastics. This pad is the mesial end of an arm that runs posteriorly over the two upper premolars in a slight curve. The posterior end of the arm is a permanently attached ball that articulates in a socket on the molar pad. The ball and socket joint provides 3D control of both the canine and molar.

74. Skeletal Anchorage System for Distalization Sugawara et al., in 2006 developed the Skeletal Anchorage System (SAS), which is a noncompliance appliance The SAS consists of titanium anchor plates and monocortical screws that are temporarily placed in either the maxilla or the mandible or in both, as absolute anchorage units

75. The SAS is a viable modality for distalizing maxillary molars because it uses stable and strong anchorage units . It enables not only single molar distalization but also en masse movement of the maxillary buccal segments with only minor surgery for placing the titanium anchor plates at the zygomatic buttresses.

76. Miniscrew Implant Supported Distalization System (MISDS) Papadopoulos  introduced the Miniscrew Implant Supported Distalization System (MISDS) in 2008 . The anchorage unit of this appliance comprised two miniscrew implants in the paramedian region of the palate. The distalization force was applied by the palatally positioned open nickel-titanium coil springs, which pass through the center of resistance of the maxillary molars. Squeezing the coil springs and screwing the anteriorly positioned stop screws following cementation activate the appliance.

77. The main disadvantages of intra-oral distalizing appliances are that they produce undesirable tipping of the maxillary molars and loss of anterior anchorage during distalization. To overcome these disadvantages , Gupta et al, in 2015 developed a new appliance – “MK” versatile spring MK VERSATILE SPRING “MK” spring is made from 0.017˝ × 0.025˝ TMA wire in a “M” configuration. It consists of two helices, one at the central arm, and the other at the arm close to the tooth being mesialized or distalized

78. Spring is activated by opening both the helices by 1 mm every 4-6 weeks till the desired teeth movement is achieved. Distalizing force exerted by spring was 60 g/spring upon 1 mm of activation. Total distal force on molar was 120 gms . Bodily movement of teeth is achieved by opening both the helices placed opposite to each other. The counter clockwise tipping moment created by helix on the first arm is cancelled out by the clockwise moment created by the helix of the central arm, preventing the tipping movement.

79. Maxillary molar distalization with MGBM-system MGBM-System (G.B Maino , A. Giannelly , R. Bernard, P. Mura), is a new intraoral device to treat Class II malocclusions - upper first and second molar distalization. The first phase of Class II treatment by MGBM-System involves the distalization of the maxillary molars to an overcorrected Class I relationship. Anchorage is provided by a transpalatal bar, bonded on the occlusal surfaces, of the maxillary first premolars and connected to two palatal miniscrews inserted directly between the first molar and the second premolar

80. To distalize the first molar before the eruption of the second molar, we use a sectional SS wire extended from the first premolar to the first molar and a compressed 200 g Sentalloy coil spring activated by 10 mm The second distalizing component is a shape memory 018 × 025” SS Nickel Titanium wire with 160 g of force, featuring an excess of length and crimped mesial and distal stops, extending from the second molar, looped vertically for 6 mm in the buccal fold and inserted into the upper tube of the double tube on the sectional wire.

81. CONCLUSION: Every few years, newer and better methods of molar distalization are being developed, especially since the advents of mini-screws into clinical Orthodontics. However, it is in the hands of the clinician to thoroughly analyze the clinical picture and select the appropriate molar distalizing appliance. I t’s not just the superiority of the mechanics but the superior thinking and application of the clinician that can produce a good and stable result.

82. REFERENCES: Charles T Pavlick, Jr. Cervical Headgear Usage and the Bioprogressive Orthodontic Philosophy. Seminar Orthod 1998; 4:219-230. Graber TM. Maxillary second molar extraction in class II malocclusion. Am J Orthod 1969:56(4):331-353. Klohen S J. Evaluation of cervical anchorage force in treatment. Angle Orthod 1961:31:91-104. Subtelny , Sakuda M. Muscle function, oral malformation, and growth changes. Am J Orthod 1966:52:495-517. Elbel H. Advance Nance Holding appliance. J Clin Orthod 1982:16:604-605. Kaprelian G. An effective unilateral face bow. J Clin Orthod 1982:26:60-61. Cetlin N and Tenhove A. Non Extraction Treatment. J Clin Orthod 1983:17:396-413. Tabash et al., Force measurement and design of a torquing high pull headgear. Am J Orthod 1984:86:74-78 West VC. The cricket appliance. J Clin Orthod 1984:28:806-810. Bondmark L, Kurol J. Distalization of maxillary first and second molar simultaneously with repelling magnets. Eur J Orthod 1992:14:264-272. Locatelli R et al., Molar distalization with super elastic NiTi wire. J Clin Orthod 1992:26:277:279. Reiner TJ. Modified Nance appliance for unilateral molar distalization.J Clin Orthod ; 1992:26:402-404. Jones RD and White MJ. Rapid class II molar correction with open-coil jig. J Clin Orthod.1992:26:661-664.

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