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  1. CONTENTS • Introduction • Evolution Of Headgear • Classification Of Headgear • Biomechanics Of Headgear Use • Clinical Uses • Effects Of HeadgearTreatment • Clinical Steps
  2. • Types Of Headgear • ComparisonWith Other Functional Appliances • CombinationTherapy • Reverse Pull Headgear • Safety Issues • LongTerm Effects • Conclusion • References
  3. INTRODUCTION • Headgears are the most common among all the orthopedic appliances. • This family of appliance is typically used to restrict the downward and forward growth of the maxilla. • Maxillary growth is restrained and/or redirected so that basal bones become more harmoniously related to one another as the unimpeded mandible “catches up” during normal growth.
  4. EVOLUTION OF THE APPLIANCE • “One surprising feature of the history is the frequency of the rediscovery of identical principles, their materialization differing only in minutiae of manufacture” Dr. Angle(1900)
  5. EVOLUTION OF HEADGEAR The use of extra-oral force is around 100 years old. The “headcap” was described by Kingsley in 1866 and Farrar in 1870’s. It’s objective was limited to retraction of upper teeth. Angle in 1888 described his extra- oral attachment for maxillary dental protrusion .It had a long pin soldered onto E arch at the midline
  6. Kingsley’s Headgear Angle’s Headgear
  7. In 1898, Guilford talked about directional pull by activating rubber bands of skullcap above or below the ear. In 1888, Goddard described the making of a vulcanite casing for moulding black rubber against anterior teeth to which was attached headcap with rubber elastic bands.
  8. In 1921, CalvinCase extended the application of extraoral therapy. Here was the first solid mention to the upper molars being moved distally-the labial bar was extended to the bicuspid area on the dental archwire and forced the molars and entire arch backward.
  9. In 1936, Oppenhiem inVienna was called upon to treat an actress who rejected visible appliances. He placed molar bands and dental bow all the way to the molars and applied the headcap. Silas Kloehn , Buleah Nelson andWilliam B Downs achieved success with this technique. Kloehn went on to combine the dental bow and the facebow in a soldered joint making the center apparatus removable.
  10. In 1938, first cephalometric presentation of treated cases by Brodie. It was determined that the treatment used at this time had little effect on structures other than alveolus and successes could be usually explained by a holding of the maxillary dentition while growth of the mandible occurred. In 1946, Epstein presented his master thesis on extraoral traction. He found positive distal molar movement. No maxillary alteration was noted.
  11. Ricketts and Downs used only neck strap portion of Kloehn headcap. Kloehn in the meantime also used only the neckstrap.
  12. In 1950, Fisher attached smaller dental bow to the edgewise archwire In 1951, Jarabak introduced extraoral traction by attaching hooks on the archwires with anteriors banded with neckstrap or straight pull. In 1960, McCulloch reintroduced highpull to intrude upper incisors. In 1953, Buleah Nelson had shown posterior shift of pt A by 5mm.
  13. Brass wire was wrapped dental and face bow to contact andact as soldering assembly.The ends remained flexible and the force at the apex of the arch moved the molars sideways and contributed to arch expansion. Beads of solder employed as stops against the molar tubes. To prevent distal tipping, outer bow was extended upward till tragus and this helped in molar extrusion which inturn aided in bite opening and tubes shifted gingivally. By 1955, FACEBOWS WERE MADE COMMERCIALLY.Two errors were introduced Dental bow made too rigid Dental arch was bent on a radius too small for a normal dental arch
  14. In 1954, Ricketts introduced expansion and contraction type headgears. Effects of cervical headgear noted.-suture widening- opening of nasal suture-palate tipping downward-took soft tissue nose with it. Schudy recognised undesirable mandibular rotation and anti-Kloehn move took place. Neck strap was replaced by oblique pull.Proved by RM computer data analysis.
  15. In 1963,Weislander treated patients with Kloehn type headgear, which utilized a neck strap and 300-400gm of force. Showed skeletal changes with reorientation of jaw relationships. Jacobson in 1976 explained the mechanics associated with headgear therapy. In 1978Teuscher used headgear with activators. And subsequently in 1980's and 1990's many people employed headgear with their appliances like with Clark’s twin block.
  17. AccordingTo use -To distalize maxillary dentition- Face bow headgear -To protract maxillary dentition- Face mask/ Reverse Pull headgear
  18. Reverse Pull HeadgearFacebow Headgear
  19. AccordingTo Root (1975) suggested simplified classification Attached to teeth Attached to arch wire - J- Hook headgear
  20. J-Hook Headgear
  21. Acc0rding to pull High pull Occipital/parietal Straight pull Low pull Cervical/kloehn
  22. High-pull Headgear Straight-pull Headgear Cervical -pull Headgear
  23. Based on where soldered joint b/w outer & inner bow placed- Asymmetric headgear- Fixed type Swivel type Symmetric- headgear
  24. Parts Of Face-bow Headgear • Face bow • Force element • Head cap or cervical strap
  25. FACE BOW • Metallic component that transmits extra oral forces on posterior teeth. • Consists of- – Outer bow – Inner bow – Junction
  26. Face bows are of two types- Inner and outer bow type J-hook type- Each J-hook consists of a 0.072" wire contoured so as to fit over a small soldered stop on the arch wire, usually mesial to upper lateral incisor.
  27. • Outer bow- Made of 0.072” stiff round wire contoured to fit face. Can be – Short – Medium – Long Distal end curved to form hook- gives attachment to force element.
  28. The outer bow ends anteriorly to the ears. In all cases, the outer bow is positioned in the horizontal plane parallel to and even with the inner bow. When using a high pull retractor, the end of the outer bow should coincide with the location of the maxillary first molars. It is bent 60 degree angle superior to horizontal.The outer bow must be adjusted fit the face of the patient. Should be 5 to 10mm away from cheeks.
  29. Outer bow resting passively between lips Outer bow several millimeters from cheek
  30. Length of outer bow is critical to the desired effect
  31. • Inner bow- – Made of 0.045” or 0.051” round stainless steel wire contoured around dental arch & molars. – Inserted into max. 1st molar buccal tubes – Stops placed mesial to molar tubes on it to prevent it sliding too far through tubes.
  32. The methods used to make the inner bow stop mesial to the 1st molar are : Bayonet Bends / Horizontal inset bends : which prevent the anterior portion from impinging on brackets on teeth. Stops : Cylindrical tubes with an internal diameter corresponding to inner bow diameter. U’ loop : have the advantage that it will allow for the adjustment to the antero-posterior length of the inner arch during treatment. This is necessary when the upper molars are being moved distally , in order to clear the bow from incisors
  33. Trevor Johnson friction stops: with internal diameter of 0.045" which can be soldered to inner bow to serve as stops. Preformed inner loops: serve as adjustable stops as well as shock absorbers and are angulated for clearance.They also facilitate necessary unilateral adjustments to keep the facebow comfortably centered, increase facebow length as molars gradually move distally & reduce facebow length as incisors are retracted.
  34. Proper adjustment of the inner bow will allow the wire to slide in and out of the headgear tubes easily when the posterior strap is not attached. Adjustments to the inner bow can be made in six directions: bucco-lingually, superior- inferiorly, anteroposteriorly. First Bucco-lingual force is controlled. If the bow is inserted into one headgear tube, the other bow end should be expanded approximately 5mm buccal to the opposite tube. This expansion bend is made near the anterior portion of the inner bow
  35. As a class II molar relationship is corrected, the relative forward movement of the lower arch will produce a cross bite tendency unless the upper arch width is expanded If maxillary arch expansion is desired and a face bow is used, a greater amount of expansive force must be built into the inner bow. Inner bow is expanded.
  36. Vertical adjustments can be made at molar adjustment loops
  37. When the patient closes his mouth and relaxes his lips, the anterior junction of the inner and outer bows should not be pushing either lip in vertical direction. The bow should be in a passive position between the lips. In order to maintain this position , the posterior ends of the inner bow are adjusted superiorly or inferiorly. Antero-posterior adjustment. Inner-outer bow junction is just anterior to the point where the lips seal. It may be necessary to enlarge or constrict the loops in the inner bow to achieve this position
  38. • Junction – – Rigid joint b/w inner & outer bow. – Can be soldered, wire wrapped soldered or welded joint. – Placed in- • Midline- Symmetric Headgear • Off Centered– Asymmetric Headgear
  39. Force element • Provides force to bring about desired effect. • Comprise of springs, elastics & other stretchable materials. • Connects face bow to head cap or neck strap.
  40. Springs : Calibrated tension springs are available. They have the advantage that the applied force can be varied. Elastics : Serve as force elements and are available in the following forms: • Neck bands with strong/medium pull • Extraoral plastic chins. Safety pads : for elastic bands Neck pads with length 180 mm Flexi pads in roll form for individual size.
  41. Friction Release Systems :These include safety release to reduce "sling- shot' hazards by means of clips which release automatically when pulled with excessive force.They provide case of assembly and include an inner steel coil to provide a consistent traction force.
  42. Head cap or cervical strap • Takes anchorage from rigid skull bones or back of neck. • Selection based on pt. needs.
  43. CLASS II CORRECTION There are 2 primary treatment goals for the stable correction of class II malocclusion: •The first is to flatten the occlusal plane during treatment. •The second goal is to hinge the mandible closed during treatment. Both goals contribute to overtreatment of class II relationships and therefore contribute to the stability of the final treatment result.
  45. • Force - changes or tends to change the position of rest of body or its uniform motion in straight line. • Centre of resistance- point where resultant of constraining forces when acting will tend to cause pure translation of body in direction of force. – Fixed point. Mechanical principles that need to be defined include the following-
  46. According toWorms et al (1973) – CR of max. 1st molar at trifurcation of roots Poulton (1959)- geometric centre of fully banded max. arch- b/w premolar roots- designated as “M”
  47. – Barton (1972)- CR of banded max. arch will vary according to number of teeth banded & size of their roots.
  48. Braun et al, 1999 • Holding amalgam plugger in the maxillary vestibular region while the teeth are in occlusion and soft tissues and lips are relaxed.Then facing buccally amalgam plugger is positioned at one half of the distance from inferior border of the orbit to the functional occlusal plane and corresponding to the distal contact of maxillary first molar. • A mark is made on the skin and checked for asymmetry.
  49. • Centre of rotation- point around which body will rotate or tip. – Changes acc. to external force application – If line of action of force (LOF) is above CR- centre of rotation moves coronally & one gets counterclockwise moment. – Vice versa if LOF passes below CR
  50. • Line of action – direction in which force acts. Line connecting point of origin to point of attachment. • Point of origin of force – anchorage from occipital or cervical region.
  51. • Point of attachment of force – refers to hook present on distal end of outer bow to which force element is attached. – Direction of force can be altered by altering point of attachment Varying length varying angle b/w of outer bow outer & inner bow
  52. Zero moment Line of force (LFO): is a line that connects the center of resistance of the molar to the point of force application on the cervical strap or the headgear strap The different moments and forces produced by the different headgear depend on the situation of the outer bow in relation to the LFO. Contasti GI , Legan HL.Biomechanical guidelines for headgear application. J Clin Orthod 1982;16(5):308-12
  53. • Contasti GI , Legan HL.Biomechanical guidelines for headgear application. J Clin Orthod 1982;16(5):308-12
  54. Cervical Pull Headgear The decision to treat with cervical headgear needs to be based on a complete understanding of the desired tooth movement and the force system that is produced with this headgear style. The different moments and forces produced by the cervical headgear depend on the situation of the outer bow in relation to the LFO.
  55. When the outer bow ends anywhere on this line, the displacement of molar will always be translational. Outer bow is equal length to inner bow. The amount of force would vary depending on how far away the end of outer bow is from the point of application, or how much elastic stretches.
  56. If the outer bow is placed above this line, it passes distal to center of resistance the moment produced by the force will be in a counterclockwise direction. Outer bow is long. If the outer bow is adjusted below this line the moment created will be clockwise. However, the direction of the forces are the same - extrusive and posterior.Tends to steepen occlusal plane. In such cases outer bow is short length..
  57. If the outer bow is located below the neckstrap, the resultant force will be a small intrusive one, instead of extrusive. Of course, a distal force and large clockwise moment will also be produced The direction of pull provided by the cervical headgear is especially advantageous in treating short-face Class II maxillary protrusive cases with low mandibular plane angles and deep bites, where it is desirable to extrude the upper posterior teeth.
  58. High Pull Headgear This style headgear always produces an intrusive and posterior direction of pull, due to the position of the headcap.The direction of the moment that is produced is dependent on the position of the outer bow . If the outer bow is placed anterior to the LFO, either above or below the occlusal plane level, the moment produced will be counterclockwise. On the other hand, if the outer bow is placed posterior to this line, the moment produced will be in a clockwise direction.
  59. The magnitude of this moment will be proportional to the distance of the outer bow to the CR. If a distal and intrusive movement with no moment is desired, the outer bow must be placed somewhere along the LFO.
  60. This force system would be beneficial in a long-face Class II patient with a high mandibular plane angle, where intrusion of maxillary molars would decrease facial height and improve the facial profile.
  61. Straight Pull Headgear This style headgear is a combination of the high-pull and cervical headgear, with the advantage of increased versatility. Depending on the force system desired, the orthodontist has the opportunity to change the location of the LFO. The prime advantage of this headgear is its ability to produce an essentially pure posterior translatory force.
  62. This is accomplished by placing the LFO through the center of resistance, parallel to the occlusal plane. Clinically, this means bending the outer bow to the same level as CR, and hooking the elastic to a notch at the same vertical level. The relation of the outer bow to the LFO dictates the direction and magnitude of forces and moments. Placing the outer bow above the LFO will produce a posterior force, counterclockwise rotation, and most often an intrusive force
  63. If the outer bow is below the LFO, the force produced will be posterior and superior, and the moment will be in a clockwise direction.
  64. The straight-pull is the headgear of choice in a Class II malocclusion with no vertical problems. It is also the headgear of preference when the main thrust of headgear wear is to prevent anterior migration of maxillary teeth, or possibly even translate them posteriorly.
  65. Vertical Pull Headgear The main purpose of this headgear is to produce an intrusive direction of force to maxillary teeth, with posteriorly directed forces. If the outer bow is hooked to the headcap so that the line of force is perpendicular to the occlusal plane and through the CR, pure intrusion may take place. The vertical-pull headgear is not as commonly used as are the others. However, it is very useful when pure intrusion of buccal segments is required, as in the Class I open-bite patient.
  66. The head is divided into two components: the anterior component from the LFO forward and the posterior component located behind the LFO. If the outer bow is placed anywhere in the anterior compartment, the moment created will be counterclockwise, and the forces produced will be intrusive and posterior. If the outer bow is placed anywhere in the posterior section, the moment will be clockwise and the vertical force will be intrusive, but the horizontal force will be forward
  67. Asymmetric Headgear Right versus left asymmetries can be corrected using transpalatal or lingual arches to correct asymmetric molar axial inclinations. The same mechanism can be used to correct asymmetric molar rotations. If buccal occlusion is asymmetric e.g. Class I on one side and class II on the other side, without asymmetries either in molar axial inclinations or in rotations, then it is most logical to achieve the correction with asymmetric headgear. Distal forces exist on both sides, but they are three times greater on the long outer bow side than on the short outer bow side
  68. ASYMMETRIC HEADGEAR • Asymmetric headgear is used when different distalization forces are needed on one side of the jaw than the other to correct a Class II molar relationship. It is effective in producing asymmetric distalization of molars; simultaneously undesirable lateral displacing forces are found which may lead to posterior crossbite. • Lateral displacement is directly proportional to the asymmetry of the outer arch.That is, the more asymmetric the outer bow, the greater is the buccopalatal movement of the distalized molars.
  69. Haack &Weinstein AJO 1958: Fundamental principle involved in the distribution of the forces to the right and left molars is the geometry of the direction of the right and left forces emanating from the cervical elastic band.
  70. If these forces are symmetrical with reference to the mid-sagittal line of the head, then the distribution of the reactionary forces at the right and left molars will be equal, irrespective of the design of the rigid portions of the appliance (or the point of attachment of face-bow to arch wire). If the direction of forces from the cervical elastic band is asymmetrical with respect to the mid-sagittal line of the head, then the anterior-posterior components of the reactionary forces on the right and left molars will be unequal, the molar nearest the resultant of the two elastic band forces receiving the greater force. Small lateral forces on the molars are always developed by this eccentric design
  71. ASYMMETRIC HEADGEAR 5 types of unilateral face-bow designs are available- • Power-arm face-bow: In this design, one outer bow is longer and or wider than the other, with the longer or wider bow tip located on the side anticipated to receive the greater distal force. • Tends to generate lateral forces which tend to move favored molar into lingual cross bite and other into buccal cross-bite. • Contradicting views on lateral forces.
  72. • Soldered-offset face-bow: In this outer bow is attached to the inner bow by a fixed soldered joint placed on the side favored to receive the greater distal force. • Soldered offset face-bow is not effective in delivering unilateral distal forces, nor will it deliver a net lateral force to its inner-bow terminals.
  73. • Swivel-offset face-bow: a swivel joint located in an offset position on the side favored to receive the greater distal force.
  74. • Baldini, Nobel and Waters, Hershey et al., have reported that lateral forces are developed unavoidably. • But in contrast, Jacobson has demonstrated experimentally that the swivel offset face-bow provides the most satisfactory asymmetric force delivery without undesired lateral components.
  75. • Spring-attachment face-bow: In this, the coil is placed distal to the stop on the side favored to receive the greater distal force. • This design of face-bow were found to be non-effective in delivering clinically significant unilateral distal forces
  76. • Internal Hinge Facebow-It has hinge added mesial to the molar on the side not to be distalized and the external arm is also shortened on the same side. • The internal hinge face-bow has proved to be remarkably effective in achieving asymmetric distalization of the molars
  77. • In contrast to the other designs of facebows, internal hinge face-bow shows lingual displacement of the molar on the light force side. • It may be due to the effect of the internal hinge placed on that side which limits buccal expansion on that side. But on the heavy force side, lingual displacement is more prominent than other facebow designs. • So, the risk of development of posterior cross-bite is more on the heavy force side.
  78. LIMITING LATERAL FORCE: • When the power arm face-bow is reversed, with longer or wider outer bow on the Class I side and shorter outer bow on Class II side, it produces a buccal force on the molar that should be more distalized and thus, preventing crossbite. • Some authors have even suggested using transpalatal bar in association with headgear for avoiding excessive lateral forces. Distal toein bend can be added on the side of the palatal arch where molar distalization is not desired so that mesial force produced by palatal arch can counteract distal force generated by reversed power arm face-bow
  79. • Then equal and opposite distal forces are developed on the other end of the palatal arch with desired buccal force • It can be concluded that the asymmetric headgear are effective in delivering unilateral distalization of molars. • Among various modification of the headgear, power –arm facebow is the most effective design for delivering unilateral distal force. It is very simple in design and easy to fabricate. • Though lateral displacing forces are unavoidable, it can be limited by altering the inner and outer bow configuration and also by using transpalatal bar along with headgear.
  80. Direction of Headgear Force Given by the line of action of force from the point of origin to the point of application of force. Antero-posterior Plane: a) Force directed upwards above the occlusal plane has an intrusive effect on maxilla. b) Force directed downwards below the occlusal plane has an extrusive effect on maxilla. c) Force passing along Center of Resistance produces translation
  81. d) Force away from center of resistance( mesially, distally, apically, occlusally) produces a moment tending to change the occlusal cant. e) Magnitude of moment is determined by moment arm- Greater the moment arm – closer the Center of rotation moves towards center of resistance and greater is the moment. f) Medium length of outer bow is chosen for translation. g) Short / long outer bow chosen when moment is desired
  82. Vertical Plane: a) Direction determined by the sense of the line of action. b) Outer bow along the Center of resistance produces translation. c) Force apical / occlusal to center of resistance produces moment ( Extrusive / intrusive / distal). d) Magnitude dependent on the inclination of line of action.
  83. Timing Of HeadgearTreatment The most optimum treatment time is between maturational stages SMI 4 to 7, a very high velocity period of growth. The next most desirable time to treat is during the accelerating velocity period between stages SMI 1 to 3 The least desirable time is during the decelerating velocity period between maturational stages SMI 8 to 11
  84. Duration of Force Intermittent force for 12 – 14 hrs in preadolescent age from early evening until next morning. Typical duration of treatment of about 12 to 18 months, depending on rapidity of growth and patient cooperation.
  86. • In class II extraction cases- prevent molar moving mesially when anteriors retracted. • Counteracts side effects of Intraoral mechanics by preventing- (occipital headgear used) – Extrusion of molars – Root buccal-crown lingual moment producing lingual crossbite • Also can maintain 1st molar width when used along withTPA
  87. • The reaction force from headgear is dissipated against the bones of the cranial vault, thus adding the resistance of these structures to the anchorage unit. • The only problem with reinforcement outside the dental arch is that springs within an arch provide constant forces, whereas elastics from one arch to the other tend to be intermittent, and extraoral force is likely to be even more intermittent.
  88. Magnitude of Force When line of action is closer to center of resistance greater force of 350 – 450 gms may be applied for orthopedic changes. Forces away from center of resistance that produce a moment should be restricted to 50 – 150 gm as in J – hook headgear to prevent damage to periodontium during dento-alveolar changes that take place during a moment.
  89. TOOTH MOVEMENT • If level of outer bow adjusted such that horizontal forces passes through CR & pt wears headgear 14hrs/day – molar move distal tipping • Intrusion in deep bite cases Headgear can be used in adjunct to upper utility arch. High pull headgear allows more intrusive control permitting maximal incisor movement whilst minimizing possible molar tipping and also used to deliver orthopedic force on developed premaxillary segment. 120 to 150 g force is delivered.
  90. Distalization of molars Headgear is the obvious choice. Full time wear is necessary. If molar extrusion should be avoided so straight pull or high pull is used and not cervical. Force – 300g on each side. Unilateral molar distalization in unilateral class II can be achieved by asymmetric cervical headgear
  91. ORTHOPEDIC CHANGES • If headgear force passes through CR of maxilla- in preadolescent period can prevent forward maxillary growth.
  92. CONTROLLING CANT OF OCCLUSION • J-Hook headgear- – If anteriors extruded- steepen occlusal plane – If anteriors intruded- flatten occlusal plane • Cervical pull headgear- – Extrude molars & flatten occlusal plane. • High pull headgear- – Intrude molars & steepen occlusal plane
  94. TREATMENT EFFECTS • Extraoral traction has been shown to produce a variety of skeletal and dentoalveolar effects in Class II patients. • Even though there is some agreement among investigators as to the effects produced, the clinical management of the appliance, the direction of force applied and the amount of force used may explain some of the differences among investigation.
  95. Magnitude of Force
  96. Duration of Force Many authors have suggested, extraoral appliances should be worn for about minimum 12-14hrs/day
  97. ANTEROPOSTERIOR DIMENSION • Maxillary Skeletal Position A primary treatment effect of extra-oral traction is the restriction of maxillary skeletal growth.There is virtually universal agreement that because of treatment Point A is repositioned posteriorly relative to the remainder of the face, resulting in a reduction in maxillary prognathism.
  98. • Distal movement of the maxillary molars is a typical treatment effect produced by cervical headgear therapy. In contrast, Hubbard and co-workers(1994), who studied a sample of patients treated by Kloehn, reported a mesial movement of the first molar. • Extrusion of the maxillary molars also has been observed, with two to three times as much extrusion reported as would be expected during normal growth. On the other hand, Hubbard and colleagues did not observe molar extrusion.
  99. There is virtually no literature that addresses the effect of the cervical-pull facebow on the mandibular dentition other than the treatment effects that are produced in association with fixed appliance treatment. There appears to be no effect.
  100. • The anteroposterior relationship of the chin has been correlated to the amount of vertical opening produced during treatment. A downward and forward rotation of the mandible and a similar movement of Point B and pogonion have been reported, as has an opening of the mandibular plane angle.
  102. • Commonly calledACCO appliance. • AC – Acrylic • CO – Cervical OccipitalAnchorage. • A removable plate is used to distalize maxillary molars bodily. During 2nd phase during which space consolidation occurs, extraoral forces help maintain anchorage posteriorly.
  103. • Lateral springs are added to aid distal movement of molars and occlusal coverage can increase the resistance to dislodgement of extraoral traction • This appliance was later modified by addition of 1mm buccal tubes to labial wire and soldering them vertically at canine-lateral incisor to receive j-hook and addition of inclined plane to avoid retrusion
  104. HEADGEAR WITH ACTIVATOR: – Reported by Stockli +Teuscher (1964) wherein a cervical HG was attached to upper molars. – Pfeiffer attached the HG directly to the activator and applied occipital traction to achieve better vertical and rotational control during Class II treatment. – Bass modified the appliance and used a 'J' hook headgear.
  105. – Primary treatment objective is to restrict developmental contributions that tend to cause a skeletal Class II and at the same time attempt to correct antero- posterior relation of jaws. – Usage mainly limited to mixed dentition with force application of 250 gms/side.
  106. First described by wherein the headgear is fixed to a tube soldered to the molar attachment. High-pull force direction using 1000 gms/side of force and worn for 12-18 hrs/day in mixed dentition period. Produces a synergistic effect on correction of skeletal Class II cases wherein the Herbst Appliance stimulates mandibular growth while this headgear force redirects maxillary growth.
  107. Headgear WithTwin Block A functional orthopedic appliance system ,W. J. Clark, Am. J. Orthod. Dentofac. Orthop. THE CONCORDE FACE-BOW The twin block technique uses a new method of applying inter- maxillary traction. The Concorde facebow combines intermaxillary and extraoral traction by the addition of a recurved labial hook to a conventional face-bow. Intermaxillary traction is applied as a horizontal force from the labial hook to the lower appliance, eliminating the unfavorable upward component of force associated with conventional intermaxillary traction.
  108. MILLSVIG APPLIANCE Consists of an active expansion plate with a jack-screw to eliminate maxillary narrowing and crossbite. Soldered buccal tubes to molars receive face-bow end.
  109. Jacobson splint
  111. Tulloch JF, Proffit WR, Phillips C Outcomes in a 2-phase randomized clinical trial of early Class II treatment. (Am J Orthod Dentofacial Orthop. 2004) • In a 2-phased, parallel, randomized trial of early (preadolescent) versus later (adolescent) treatment for children with severe (>7 mm overjet)Class II malocclusions. • Favorable growth changes were observed in about 75% of those receiving early treatment with either a headgear or a functional appliance. After a second phase of fixed appliance treatment for both the previously treated children and the untreated controls, however, early treatment had little effect on the subsequent treatment outcomes
  112. • This suggests that 2-phase treatment started before adolescence in the mixed dentition might be no more clinically effective than 1-phase treatment started during adolescence in the early permanent dentition. • Early treatment also appears to be less efficient, in that it produced no reduction in the average time a child is in fixed appliances during a second stage of treatment, and it did not decrease the proportion of complex treatments involving extractions or orthognathic surgery. Tulloch JF, Proffit WR, Phillips C Outcomes in a 2-phase randomized clinical trial of early Class II treatment. (Am J Orthod Dentofacial Orthop. 2004)
  113. Stephen D. Keeling Anteroposterior skeletal and dental changes after early Class II treatment with bionators and headgear (Am J Orthod Dentofacial Orthop1998) • Both bionator and head-gear treatments corrected Class II molar relationships, reduced overjet and apical base discrepancies, and caused posterior maxillary tooth movement. • The skeletal changes, largely attributable to enhanced mandibular growth in both headgear and bionator subjects, were stable a year after the end of treatment, but dental movements relapsed.
  114. A prospective randomized clinical trial was conducted to evaluate the early treatment of Class II, Division 1 malocclusion in pre-pubertal children. Facial and occlusal changes after treatment with either a headgear or a Frankel function regulator were reported. The results indicate that both the headgear and function regulator were effective in correcting the malocclusion Headgear versus function regulator in the early treatment of Class II, Division 1 malocclusion: A randomized clinical trial J. Ghafari,F. S. Shofer, U. Jacobsson Hunt, D. L. Markowitz, and L. L. Lasterb
  116. • Headgears are generally used for the purpose of reinforcement of anchorage or for maxillary distalization. However, when an anterior protractory force is required, a protraction head gear is used.
  117. • Hickham claims he was the first to use a reverse head gear. However, this modality was made popular by Delaire around the same time. • A reverse pull head gear basically consists of a rigid extra-oral framework which takes anchorage from the chin or forehead or both for the anterior traction of the maxilla using extra-oral elastics which generate large amounts of force upto 1 Kg or more.
  118. • It can be used in a growing patient having a prognathic mandible and a retrusive maxilla. • It can also be used for selective rearrangement of the palatal shelves in cleft patients. • It can be used in correction of post surgical relapse after osteotomy. • It can be used to treat certain accessory problems associated with nose morphology such as lateral deviations.
  119. • Sites of anchorage- – Anchorage from skull (forehead) – Anchorage from chin – Anchorage from chin & forehead
  120. BIOMECHANICAL CONSIDERATIONS Amount of force: The amount of force to bring about skeletal changes is about 1 pound (500 gms) per side. Direction of force: Most authors recommend 15-20 degree downward pull to the occlusal plane to produce a pure forwardTranslatory motion of the maxilla. Duration of force- Low forces (250 gm/side) take 13 months to produce desired results. However, very high force values like 1600- 3000 gms reduced treatment time to 4 – 21 days. Frequency of use: Most authors recommend 12-14 hrs of wear a day.
  121. • Parts of a reverse pull head gear – Chin cup – Forehead cap – Intra-oral appliance – Elastics – Metal frame
  122. • FACEMASK OF DELAIRE : This was popularized by Delaire in the 60's and also uses the chin and forehead for support.
  123. • TUBINGER MODEL:  This is a modified type of Delaire face mask.  It consists of a chin cup from which originates two rods that run in the midline and is shaped to avoid the interference of nose.  The superior ends of the two rods house a forehead cap from which elastics encircle the head. In addition, a cross bar extends in front of the mouth which can be used to engage elastics.
  124. PETITTYPE OF FACE MASK :  This is also a modified form of Delaire face mask.  It consists of a chin cup and a forehead cap with a single rod running in the midline from forehead cap to chin cup.  A cross bar at the level of the mouth is used to engage elastics.  The advantage of this model is that the forehead cap, chin cup and the cross bar can be adjusted to suit the patient.
  126. SAFETY ISSUES • Injuries have been reported with the use of headgear.They have been associated with the catapult effect of simple elastic extra oral traction and with the face bow coming out at night. • In some cases, facebow either was knocked, pulled out of molar tubes while still attached to headstrap or neckstrap.This lead facebow to recoil and hit patient in face, head or neck. • This detachment and injuries can compromise success of treatment. R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:101-7
  127. • Injuries have occurred with both removable & fixed appliances. • Ranged in severity from minor lacerations to loss of eye. • All occurred in children aged between 9-14 yrs. • The presence of oral micro-organisms on the ends of inner bow radically alters the outcome of the soft tissue trauma, making the patient highly susceptible to infections. R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:101-7
  128. Samuels RHA, Jones ML. Orthodontic Facebow injuries and safety equipment. Eur J Orthod 1994; 16: 385–394. • The ends of the inner bow are the same distance apart as the eyes, increasing the risk of a bilateral injury .
  129. • Facebow injuries to eye can cause little pain at the outset often delaying the child seeking treatment • This delay allow infection to proceed unchecked for a considerable period of time. • Eyeball is also an excellent culture medium, and when it becomes infected it becomes difficult to control. • When one eye is injured there is a risk to the other undamaged eye from a process called sympathetic opthalmitis. Samuels RHA, Jones ML. Orthodontic Facebow injuries and safety equipment. Eur J Orthod 1994; 16: 385–394.
  130. Group 1: 1. The patient was wearing their extra-oral traction while playing and accidentally their hand knocked the facebow out of the buccal tubes and the elastic traction caused it to recoil back causing a soft tissue injury. 2. The patient removed the facebow from their mouth without first disconnecting the elasticated traction and lifted the facebow up in front of their face to remove it. On one occasion the facebow slipped from their hand and the ends of the inner bow caused a facial injury. 3. The facebow was pulled out of the buccal tubes in the patient’s mouth by another child and then released allowing the facebow to catapult back and cause a soft tissue injury. R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:10
  131. Group 2 The second cause has been due to the facebow coming out of the buccal tubes at night while the child was asleep and inadvertently the child has rolled onto the facebow and been injured by the ends of the inner bow R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:10
  132. • In order to prevent these injuries – several safety devices. • These include self releasing extra oral traction systems, plastic neck straps, shielded facebows and locking facebows. • Patients should be instructed on proper use of appliance.
  133. – • Manufactured in a variety of designs. • Modular systems can be used with Headcap or neckcap. • These modules enable a comfortable range of head movement by patient without their unintentional release.
  134. A short travel with a suitable force should avoid the recoil injuries of accidental disengagement, incorrect handling, or undesirable disengagement by another child. However, it will not counter the problem of unintentional release during sleep. The self-releasing extra-oral traction systems can reduce the catapult effect to approximately 10 mm for the headcap and 25 mm for the neck strap, but cannot be relied upon to keep the facebow in place at night.
  135. • Plastic neckstraps – Retain facebow within buccal tubes.. • As the strap is not flexible it cannot accommodate the changing distance between the back of neck and the facebow, and still provide a continuous resistance to the displacement of face bow from buccal tubes.
  136. • Shielded facebows – Shielding on their inner ends in an attempt to reduce the severity or risk of soft tissue trauma. • Shielding does not improve facebow self retentive capability and it can disengage in night. R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:10
  137. Locking orthodontic facebows – To maintain the facebow reliably within the buccal tubes at night would require an alteration to the standard facebow or the buccal tubes to provide some active self-retentive capability The Nitom facebow was designed to be used with a self-releasing headcap or neckstrap with a short travel. It has bilateral locking catches designed to resist light and medium displacing forces, and can be used with fixed ,functional and removable appliances. It has two omega bends so that it can be easily adjusted to fit different lengths of buccal tubes.
  138. Nitom Locking Face Bow
  139. PATIENTS INSTRUCTIONS – 1. Never wear headgear during playful activity. 2. If it ever comes off at night or there are any other problems patient should stop wearing the appliance and return to see clinician. 3. Excessive force should not be used while removing facebow. 4. Before removing facebow patient first must remove headcap/ neckstrap. 5. If any injury occurs to eye, eye should be examined without delay by a suitably trained medical practitioner. R H A Samuels, N Brezniak. Orthodontic facebows-safety issues and current management. Jr Orthod 2002;29:10
  140. Penetrating eye injury from orthodontic headgear- A case report Sara Booth- Mason and David Birnie, 1988 A case report of a severe penetrating ocular injury, which resulted in the loss of the injured eye, following dislocation of a Kloehn bow from an upper removable appliance is reported. The case is unusual in that the injury occurred while the patient was asleep and was probably not due to a catapult injury; in addition the patient unexpectedly developed sympathetic ophthalmitis in the uninjured eye.
  141. An 8-year-old child who was trying to remove the facebow by pulling it out of the buccal tubes and passing it over her head whilst still connected to the elastic traction, inadvertently allowed the facebow to slip and it penetrated the left eye. Despite treatment the eye was lost (De Leo and Bertele, 1992). A 13-year-old girl who was wearing her headgear whilst playing: it accidentally became dislodged from her mouth and struck her in both eyes. Despite treatment she became blind in the right eye and suffered some permanent visual impairment of the left (Holland et al., 1985).
  142. PATIENT COMPLIANCE • An important aspect of using extra oral traction is whether appliance is being worn as instructed. • Patient’s compliance can be improved if both parents & clinician provide motivation.
  143. Conventional measuring instruments to indicate headgear co-operation, such as (1) Molar mobility, (2) Cleanliness of headgear tubes and headgear strap, (3) Ease of placement by patient, (4) Space creation between teeth, (5) Molar positioning comparing pre-treatment models and/or cephalograms, and (6) Anchorage maintenance. Cenk Doruk, Ug˘ur Ag˘ar and Hasan Babacan,The role of the headgear timer in extraoral co- peration, European Journal of Orthodontics 26 (2004) 289–291
  144. Direct Measurement Of Headgear Compliance- Headgear Timing Devices • The first reported use of a headgear timing device was by Northcutt in 1974. • He reported on the first commercially available headgear timer manufactured by the Aledyne Corporation.
  145. Selçuk type headgear-timer (STHT) was introduced by Enis Guray 1997 The Selçuk type headgear timer was reported to be 100% accurate, unaffected by intensity of force variables, reliable, easy to construct, safe, and inexpensive. Clinical tests showed a significant increase in headgear wear. An objective appraisal of extraoral force affects is enhanced by having a validating measurement of actual appliance wear.
  148. • Wieslander and Buck studied the stability of cervical traction 6 years post treatment and found that maxillary downward and forward growth continued equally in both treated and untreated group. A minor tendency towards relapse was noted. • Melsen, however by means of metallic implant found that maxillary growth was greater in treatment group than expected during normal growth. • Glenn and coworkers found class II malocclusion with large ANB values and short mandibular lengths were associated with increased incisor irregularity, shorter arch lengths and deeper overbites at post retention stage.
  149. • Elm and coworkers found that treatment effects were relatively stable at 8 years post treatment, with major long term changes related to those patients who had excessive amount of tooth movement during treatment. • Birte Melsen ( AJO 1978) have reported that influence of headgear on growth pattern of facial skeleton was reversible.
  150. The long-term stability of Class II, Division 1 nonextraction therapy, using cervical face-bows with full fixed orthodontic appliances was evaluated for 42 randomly selected patients. Pre-treatment records were taken at a mean age of 11.5 years; the post-treatment and post-retention records were taken 3.0 and 11.6 years later, respectively. The results showed that the ANB angle decreased 2 ° during treatment, most of which was due to the decrease of the SNA angle. T. N. Elms, P. H. Buschang, and R. G. Alexander, Long-term stability of Class II, Division 1, nonextraction cervical face-bow therapy: Am J Orthod Dentofac Orthop 1996;109:386-92.
  151. The mandibular plane angle was not changed significantly during treatment. Although upper incisor inclination was maintained during treatment, the lower incisor was proclined and the lower molar was tipped back. It is concluded that non-extraction therapy for Class II malocclusion can be largely stable when the orthodontist ensures proper patient selection and compliance and attains treatment objectives. T. N. Elms, P. H. Buschang, and R. G. Alexander, Long-term stability of Class II, Division 1, nonextraction cervical face-bow therapy: Am J Orthod Dentofac Orthop 1996;109:386-92
  152. Retention Following Headgear Treatment • For patients treated with headgear, the headgear itself may be the best form of retention until such time that fixed appliances can be used. • An appliance routinely used to hold the retracted maxillary molars is the Nance holding arch.The Nance appliance is not as effective in holding the molars back in the maxilla as the fixed lingual arch is in maintaining E-space in the mandible. • A modified Nance holding appliance, the vertical holding appliance (VHA), may be more successful in such instances since the force exerted by the tongue is vertical and directed to the posterior.
  153. • The effects of two different extraoral appliances were evaluated over a 1-year period. Of the 37 cases selected for study, twenty were treated with a face-bow neck strap and seventeen were treated with a high-pull molar headgear. • Patients ranged in age from 10.10 to 16.6 years and averaged 13.4 years.The appliances exerted less than 600 Gm. of force per side and were worn for 12 to 16 hours per day. All cases were fully banded, and extraction and non-extraction treatment were included. Brown P 1978 A cephalometric evaluation of high-pull molar headgear and facebow neck strap therapy, American Journal of Orthodontics 74 : 621 – 63
  154. The comparison of the two treatment samples revealed that the functional occlusal plane was tipped down at the back as the maxillary molars were more extruded in the neck strap sample. In the high-pull sample, the functional occlusal plane was unchanged and the mandibular molars were more extruded than they were in the neck strap group. Brown P 1978 A cephalometric evaluation of high-pull molar headgear and facebow neck strap therapy, American Journal of Orthodontics 74 : 621 – 63
  155. Vertical relationships provide the key to planning treatment for the individual patient. When vertical growth is judged to be adequate or excessive ,the high-pull molar headgear is the therapy of choice to inhibit further vertical development. In cases exhibiting a deficiency of vertical growth, face-bow neck strap traction may be employed to encourage vertical development. Brown P 1978 A cephalometric evaluation of high-pull molar headgear and facebow neck strap therapy, American Journal of Orthodontics 74 : 621 – 63
  156. The present study aimed to evaluate the cephalometric changes in Class II patients treated exclusively with cervical headgear (CHG) in the maxillary arch and fixed appliances in the mandibular arch as compared with a control group. The sample comprised 82 lateral cephalograms obtained pre- (T1) and post- (T2) treatment/observation of 41 subjects, divided into two groups: M. R. Freitas , D.V. Lima , K. M. S. Freitas , G. Jansonand J. F. C. Henriques, Cephalometric evaluation of Class II malocclusion treatment with cervical headgear and mandibular fixed appliances, European Journal of Orthodontics 30 (2008), 477–482
  157. Group 1 — 25 Class II division 1 patients (20 females and fi ve males), with a mean pre-treatment age of 10.4 years, treated for a mean period of 2.5 years Group 2 — 16 Class II untreated subjects (12 females and four males), with a mean initial age of 9.9 years, followed for a mean period of 2.2 years. The results showed restriction of maxillary forward displacement and also a restriction in maxillary length growth, improvement in the maxillomandibular relationship, restriction of mandibular incisor vertical development, reduction in overjet and overbite, and improvement in molar relationship.
  158. CONCLUSION • Extraoral traction has proved to be a dependable method of class II correction for over 100 years, and this treatment adjunct is used with varying frequency worldwide. • When the correct type of extraoral traction appliance is prescribed for a patient who is cooperative, effective and efficient treatment is the result. In non-cooperative patients, however ,alternative methods of class II correction are indicated
  159. THANK YOU…

Editor's Notes

  1. In order to conduct orthodontic treatment, force and the various modes in which force can be applied for treatment effects is of great significance. Most of forces can be generated from intra oral sources, when the intraoral sources are found to be insufficient, extraoral forces are resorted to. Among the most commonly used extraoral force generating source are the headgears
  2. Upthrough the turn of century, e/o force was main source of anterior retraction… -worn at nt -anchorage cud b gained -no enlightenment was offered for molar correction Angle in 1888 recommended that it be worn during the sleeping hours. Intramaxillary elastic rubber bands were used for traction by day. The use of this appliance was limited to maxillary dental protrusion in patients following upper first bicuspid extraction
  3. its objective was limited to retraction of upper anterior teeth as an outer brace was attached to labial arch bow engaged in crude bands or other forms of attachment to the anterior. The ‘caps” were formed from leather strips or cloth
  4. First, was the usual directional pulls up the long axis of the maxillary anterior following maxillary extraction. Second, was an attachment to the lower anterior, to be used in open bites or protrusive conditions, also after lower extraction. Third and here is the first solid mention of upper molars to be moved distally the labial bar was extended, to the bicuspid area on the dental arch wire and forced the molars and entire arch backward
  5. the full arch was banded and “high pull” was reintroduced to intrude the upper incisors.
  6. outer bow and its types short outer bow is lesser in length than inner bow medium outer bow length is equal to inner bow long outer bow is longer than inner bow
  7. Cervical pull obli downward to horizontal Combi pull to obli upward To verticalz
  8. The vertical-pull headgear is used primarily when a large magnitude of pure intrusion is needed. The outer bow must be located on the LFO to obtain pure intrusion (A). An OB located anterior to the LFO will produce an intrusive force and a smaller posterior force and a counterclockwise moment (B and C). Locating the OB posterior to LFO will cause intrusion a small anterior force and a clockwise moment (D and E)
  9. uggestions to be noted with regard to the use of the asymmetric cervical gear: 1. The differential in length of arms of face-bow need not be great, only sufficient to alter the geometry so that the resultant bisector crosses the molar line closer to the more anteriorly positioned molar than to the other. Excessive difference in arm lengths could increase the lateral forces. 2. The diameter of wires can be increased for greater rigidity; it is suggested that the arch wire be 0.055 inch and the face-bow 0.075 inch (the 0.075 inch face-bow is approximately five times as stiff as the 0.50 inch one). 3. The arms of the face-bow should clear the cheeks so 
  10. SMI 1: third finger, proximal phalanx; width of epiphysis as wide as or wider than diaphysis. SMI 2: third finger, middle phalanx; width of epiphysis as wide as or wider than diaphysis. SMI 3: fifth (little) finger; width of epiphysis as wide as or wider than diaphysis. SMI 4: ossification of adductor sesamoid of thumb SMI 5: third finger, distal phalanx; capping of both sides of epiphysis SMI 6: third finger, middle phalanx; capping of both sides of epiphysis SMI 7: fifth finger, middle phalanx; capping of both sides of epiphysis SMI 8: third finger, distal phalanx; complete fusion SMI 9: third finger, proximal phalanx; complete fusion. SMI 10: third finger, middle phalanx; complete fusion. SMI 11: radius; complete fusion (skeletal growth completed)
  11. Group A Anchorage[edit] This type is considered critical anchorage, which involves 75% movement of anterior teeth and 25% posterior teeth into the space created by extraction. Thus the expectation in this type of anchorage is to bring front teeth back. Group B Anchorage[edit] This type of anchorage is considered moderate, which involves 50% movement of both anterior and posterior teeth into the extraction space. The expectation in this type of anchorage is to see posterior teeth moving forward equally as compared to anterior teeth moving backwards. Group C Anchorage[edit] This type of anchorage is considered non-critical, which involves posterior teeth moving forward 75% of the time and front teeth moving backwards 25% of the time into the extraction space. Greater movement of back teeth is seen in this case. Absolute Anchorage[edit] This type of anchorage is needed in a treatment when there is 0% movement of posterior teeth forward and 100% movement of anterior teeth backwards. This type of anchorage is usually produced by using mini-implants or temporary anchorage device
  12. cervical (Kloehn type) headgear is used, the maxillary molars are driven distally into the “wedge” as the molars are extruded or tipped down and back. The mandible is rotated down and back, increasing the apparent mandibular retrusion and allowing compensatory alveolodental growth to stabilize this undesirable saggital change. The maxillary incisors are usually tipped down and back at the same time, restricting forward mandibular growth. This result is now known as kloehn effec
  13. Recurved labial hook Receive intermaxilary traction
  14. The philosophy behind the use of this max orthop splint is to deliver force to all upper teeth and hard palate
  15. It was concluded that this treatment protocol corrected the Class II malocclusion characteristics primarily through maxillary forward growth restriction