Ricketts bioprogressive theerapy seminar

Ten principles of bioprofressive therapt explained

1. BIO PROGRESSIVE THERAPY By : SHIBANGI MAZUMDER

2. Contents 2 Introduction. Umbrella concept Principles of Bioprogressive therapy. Visual treatment objective. Orthopedics in Bioprogressive therapy. Forces used in Bioprogressive therapy. Sectional and utility arches. Synopsis of extraction and non-extraction treatment mechanics. Bioprogressive therapy appliances Conclusion

3. Introduction Bio-Progressive therapy is not strictly an orthodontic technique but, more importantly, it’s a whole philosophy of treatment , developed in 1950s by Dr . Robert Murray Ricketts. It grew out of the edgewise technique, also uses parts of light wire technique. It takes advantage of biological progressions including growth, development and function and directs them in a fashion that normalizes function and enhances aesthetic effect. 3

4. Bioprogressive therapy is not strictly an orthodontic technique but more importantly it encompasses a total orthodontic philosophy. BPT accepts as its mission the treatment of the total face rather than narrower objective of the teeth or the occlusion. Dr.Ricketts orthodontic philosophy and therapy involves a broad concept of total treatment rather than a sequence of technical and mechanical steps.

5. Why the name bioprogressive theraphy ? BPT was so named because it progressively includes particular groups of teeth into the theraphy . First the molars and the incisors followed by canines and premolars. Therapeutic interventions applied in planned sequence .

6. Management umbrella Concept The initiation of this series with a discussion of management at the begining rather than at the end is a purposeful clue to its implicit importance in the concept of Bioprogressive therapy. Dr Ricketts states that management is a unique skill; it is the ability to get other people to work with you and for you, to accomplish common objectives. In an orthodontic practice, getting the subordinates to work with you and for you is to treat the patient to happy ending, and to manage the patient so that he gives full cooperation in his treatment.

7. Management of Umbrella Concept Bioprogressive therapy functions well within an efficient management system and management should not be considered an add on component to a series of technical procedures, which ultimately determines the efficiency and effectiveness of treatment. A management system for orthodontists would include the following three things: 1. Quality — This would be the quality of the result. 2. Quantity— This would be the number of patients that are treated 3. Effectiveness — This would be the effectiveness of the treatment design and office management.

8. 8 The system used is Lewis A Allen management system . Based on simple formula - PLANNING – work performed to predetermine a course of action to be followed. ORGANIZING - work performed to arrange & relate the tasks to be accomplished LEADING - work performed to ensure that people act in such a way as to complete our objectives. CONTROLLING - work performed to assess & regulate results.

9. Principles of Bio-progressive therapy Ten principles have been developed in an attempt to communicate an understanding of the mechanical procedures that Bio-progressive therapy may use in developing a treatment plan, including appliance selection and application specific to each individual patient.

10. Principles of Bio-progressive therapy The use of a systems approach to diagnosis and treatment planning by application of the visual treatment objective in planning treatment, evaluating anchorage and monitoring results It was developed by R icketts & called a VTO by Holdaway . Allows orthodontist to visualize the changes that should occur and to prescribe the necessary treatment to cause it to happen. Helps in understanding the interrelationship of various changing parts and the influence that one area has upon another. It is a management tool to permit evaluation of change that is proposed in each area, and the effect that change will have upon the other areas

11. During the average two year treatment experience, treatment changes will account for 70-80% change, while growth changes are limited to 20-30%. Therefore, in our planning, the major factor is to understand the specific alteration that our mechanical therapy will produce. The inter-relationship of change is unique to the VTO, and is of greatest advantage in prescribing a treatment plan that is the most efficient in producing quality results.

12. Torque control throughout treatment Some treatment techniques have designed brackets for a limited contact between the archwire and the bracket or recommended the use of round wires in an attempt to limit the control and allow more freedom of movement of the tooth. Bioprogressive therapy suggest that movement of teeth can be more efficient and various treatment procedures can be more effectively carried through when control of direction of root movement available. The edgewise slot brackets are used in order to keep the bracket and wire sizes smaller, but still have torque control throughout various stages of treatment.

13. 16 Four situation where torque control of root is necessary: Keep roots in vascular trabecular bone during initial stages of treatment for efficient movement of teeth - Torque control allows us to steer the roots away from the denser, thicker cortical bone and through the less dense channels of the vascular bone. Place roots against dense cortical bone for anchorage so that their movement will be limited Torque to remodel cortical bone for U/L incisor retraction through the dense lingual cortical bone, impacted upper cuspids, upper incisor root torquing . Movements of these nature require longer time to allow the more dense bone to be remodeled. Lack of control may cause excess tipping Torque to position teeth in final occlusion.

14. 17 3. Muscular and cortical bone anchorage Muscular Anchorage - Anchorage here is considered in terms of stabilizing the molars and positioning teeth against movement during various stages of orthodontic treatment. Stabilizing the teeth against the horizontal movements and also against vertical or extruding forces produced by cervical headgear to the upper molar is countered by the posterior muscles of mastication like Masseter and Temporalis. In certain facial patterns these musculature seems stronger and able to overcome most orthodontic forces while in others these musculature seems to be weaker and easily overpowered by orthodontic forces.  

15. 18 Recent evaluations of morphology of mandible and lower face structures suggest Cephalometric measurements that are describers of facial types and alert us to those types which may require modification of our treatment procedures like to support or lessen the anchorage. Xi point also becomes the apex of an angle describing the lower face height from the corpus axis of the mandible as its lower boundary to the anterior nasal spine of the palate as the upper limit. During normal growth this angle of lower facial height does not change and therefore gives a good indication of the present status as well as future potential of oral form and physiology.

16. 19 Cortical Bone Anchorage - Cortical bone is more dense and laminated with very limited blood supply therefore the physiological process is delayed and tooth movement is slower. Tooth movement can be further delayed where excess forces against the cortical bone can press out the blood supply and limit the physiology and tooth movement. Bioprogressive therapy applies this principle of cortical bone anchorage in stabilizing the teeth in those areas where it desires to limit their movement. Lower molar anchorage is enhanced by expanding the molar roots into dense cortical bone on their buccal surface.

17. 20 4. Movement of any teeth in any direction with proper application of pressure The key factor to the rate at which tooth movement will occur is the blood supply that sustains the physiological action that takes place within the bone itself. Forces that are too heavy cause an ischemia of the blood supply and the tooth movement is delayed. Brain Lee, suggested that the most efficient force for tooth movement is based upon the size of the root surface of the tooth to be moved which he called as Enface root surface or the portion of root that is in the direction of tooth movement.

18. He expressed that force as 200 gms of force/sq.cm of enface root surface area is optimum for efficient tooth movement. Bio progressive therapy suggest that force can be reduced to one half, 100gm/sq.cm of enface root surface.

19. 22 5. Orthopedic alteration Orthopedic forces changes the relationship of the basic supporting jaw structure as contrasted to tooth movement in localized area. It also affects areas associated with supporting structures like condyles of mandible and palatal plates of maxilla Ex ; Headgear , RME. Orthopedic change /alteration of supporting structure is usually associated with treatment of young child where treatment is more effective because of development still associated with these basic structures. Expected mandibular rotation and facial types usually dictate the kind of headgear prescribed.

20. 23 6. Treat the overbite before the overjet correction For stability in function and retention it is vital to correct deep bite relation so as to get proper overjet , and inter incisal relationship of overbite to overjet and interincisal angles. Incisor overbite correction can be done by two methods – Extrusion of posterior teeth- increases LFH by mandibular rotation (unstable in horizontal pattern because of strong muscle force) Intrusion of anterior teeth with little or no mandibular rotation - Bio progressive therapy recommends this as best choice- stability of result optimizing function & prevent interferences.

21. The vertical facial pattern responds more easily to incisors bite opening by molar extrusion and mandibular rotation. The already extreme lower facial height is increased. The short anterior vertical facial height type would best benefit from mandibular rotation, but their strong musculature function resist the molar extrusion. Another complication of overbite interference during treatment is the distal displacement of the condyle in the fossa resulting in TMJ dysfunction and incisor instability due to traumatic interference of the deep bite occlusion Because of these biological and physiological responses, Bio-progressive therapy finds that incisor intrusion is the treatment of choice for the best results.

22. 25 Bite before jet – avoids incisor interferences & posteriors remain in normal stable vertical occlusion established by muscles. Incisor interference- results in proprioceptive input/ neuromuscular interferences that affects patients ability to close posterior teeth, molars allowed to extrude & vertical opening occurs. Utility arches and Sectional arch therapy is used to aid in incisor control so that tooth movement can occur in proper force system

23. 7. Sectional arch therapy It is the basic treatment procedure of BPT. In sectional arch treatment the arches are broken into sections or segments in order to produce efficient tooth movements. Four benefits of sectional arch treatment, It allows light continuous force to be directed for efficient tooth movement. More effective root control in basic tooth movements. It allows us to torque lower incisors away from lingual cortical bone. It reduces binding & friction of brackets as they slide along the archwire . In continuous arch because of the short span between their brackets , very heavy forces of a short duration are usually applied.

24. 27 8. Concept of overtreatment It is necessary for the clinician not only to appreciate the changes to bring the teeth into properly aligned functional occlusion , but to anticipate changes that follow when all the appliances are removed and post treatment adjustments begin to occur. In order to overcome the tendency of relapse , provisions for post treatment rebound as well as post treatment growth changes need to be appreciated & planned for.

25. 28 Bioprogressive therapy suggest four areas where the concept of overtreatment may help : To overcome the muscular forces against the tooth surface in n arrow upper arches, a nterior open bite, u pper anterior protrusion due to lip sucking. Root movements needed for stability: deep bite, paralleling of roots adjacent to extraction sites, severe rotations To overcome orthopedic rebound as heavy forces are eliminated, the basic supportive structures may rebound. To allow settling in retention over treatment of the individual teeth within the arches allows them to settle into a functioning occlusion.

26. 29 9. Unlocking the malocclusion in a progressive sequence of treatment in order to establish or restore more normal function It is necessary during initial examination & evaluation to consider these area of diagnosis: To describe the malocclusion and visualize the position of the teeth in terms of what functional influences have been responsible for their present form. To describe the facial type and skeletal structure. To describe the present abnormal functional influences upon dental arches, or the lack of abnormal development by default. Ex: Upper arch expansion, incisor protrusion correction, TMJ problems

27. 30 10. Efficiency in treatment with quality results, utilizing a concept of prefabrication of appliances Allows the clinician to direct his energies in details of appliance application, diagnosis and treatment planning rather than in their construction.

28. Visual treatment objective It is like “Blue print for building a house”. Its a visual plan to forecast the normal growth of the patient & anticipated influences of treatment so as to establish the individual objectives for that patient. Helps orthodontist to take advantage of growth. By superimposing a progress tracing between tracing & forecast goal, orthodontics may evaluate progress along a definitely prescribed route. Any deviation from expected progress will become apparent immediately & need for mid course corrections. 31

29. 32 STEPS IN CONSTRUCTION OF VTO Cranial base prediction Mandibular growth prediction Maxillary growth prediction Occlusal plane position Location of dentition Soft tissues of the face

30. 33 VTO-CRANIAL BASE PREDICTION He constructed a point at the intersection of basion-nasion line to the facial axis and named it the cc(center of cranium) point. Place the tracing paper over the original tracing, starting at CC point, follow these to construct the cranial base: Trace the Basion-Nasion plane. Put mark at point CC Grow Nasion 1mm/ yr for 2yrs. Grow Basion 1mm/ yr for 2yrs Slide tracing back so Nasions coincide and trace Nasion area. Slide tracing forward so Basions coincide and trace Basion area.

31. 34 VTO MANDIBULAR GROWTH PREDICTION-ROTATION The mandible rotates open or closed from the effects of the mechanics used and the facial pattern present . Mechanics : Convexity reduction- Facial axis opens 1deg/5mm. Molar correction – facial axis opens 1deg/3mm. Overbite correction – Facial axis opens 1deg/4mm. Cross bite correction – Facial axis opens 1- 1.5 deg. Recovers half the distance. Treatment mechanics may open facial axis as in class II mechanics or close with high pull head gear and extraction

32. 35 Facial pattern – facial axis opens 1deg in dolichofacial and vice versa. Superimpose at Basion along the Basion – Nasion plane . Rotate ‘up’ at Nasion to open the bite and ‘down’ at Nasion to close the bite using point DC as the fulcrum. This rotation depends on anticipated treatment effects . Trace condylar axis , coronoid process, and condyle

33. 36 VTO- MANDIBULAR GROWTH PREDICTION - CONDYLAR AXIS GROWTH On condylar axis make mark 1mm/ year down from point DC. Slide tracing along condylar axis so that new mark on Ba-N plane. Extend condylar axis to Xi point and locate a new Xi point. With old and new Xi points coinciding, trace corpus axis, extending it 2mm/ yr forward of old PM point. CORPUS AXIS GROWTH After new PM point is marked, trace the posterior border of ramus and lower border of mandible

34. 37 VTO- MANDIBLE GROWTH PREDICTION – SYMPHYSIS CONSTRUCTION Slide back along the corpus axis super imposition at new and old PM. Trace the Symphysis and draw in mandibular plane. Construct the facial plane from NA to Pog . Construct facial axis from CC to Gn

35. VTO- MAXILLARY GROWTH PREDICTION- To locate the new maxilla within the face, superimpose at Nasion along the facial plane and divide the distance between “original” and “new” Mentons into thirds by drawing two marks To outline the body of the maxilla, superimpose mark ≠1 on the original menton along the facial plane. Trace the palate (with the exception of point A)

36. 39 VTO- MAXILLARY GROWTH PREDICTION – POINT A CHANGE RELATED TO BA-NA These are the maximum ranges of point A change with various mechanics: Mechanics Maximum range HG -8mm Class ll elastics -3mm Activator -2mm Torque -1 to -2mm Class lll elastics +2 to +3mm Facial mask +2 to +4mm Construct new Apo plane  

37. 40 VTO- OCCLUSAL PLANE POSITION For each mm of distal movement point A will drop ½ mm Superimpose mark 2 on original menton and facial plane, then parallel mandibular planes rotation at menton . Construct occlusal plane (may tip 3 deg either way depending on class II or class III treatment)

38. 41 DENTITION - LOWER INCISOR The lower incisor is placed in relation to Symphysis Occlusal plane APO plane Superimpose on the corpus axis at PM. Place a dot representing the tip of the lower incisor in the ideal position to the new occlusal plane, which is 1mm above the occlusal plane and 1mm ahead of the APO plane. Draw in the lower incisor in the final position as required by the arch length. The angle is 22deg at +1mm to the Apo plane and + 1mm to occlusal plane , but the angle increases 2deg with each mm of forward compromise.

39. 42 LOWER MOLAR Without treatment the lower molar will erupt directly upward to the new occlusal plane. With the treatment - it moves forward 1mm of forward movement equals 2mm of arch length. We move the lower incisor forward 2mm in this case. There was also 4mm of leeway space, therefore it allows us to move the lower molar forward by 4mm on each side. Lower incisor forward2mm = +4mm of arch length Leeway space = +4mm of arch length=+8mm of arch length

40. 43 UPPER MOLAR Trace the upper molar in good class I position to the lower molar. Use the old molar as a template. UPPER INCISOR Place upper incisor in good overjet and overbite(2.5mm)with lower incisor with an interincisal angle of 130º+/- 10º. Openbite patterns at a greater angle, deepbite pattern at a lesser angle.

41. 44 VTO SOFT TISSUE NOSE Superimpose at nasion along the facial plane and palatal plane. Move prediction back 1mm/ yr along the palatal plane . Trace tip of nose fading into bridge.

42. 45 SOFT TISSUE POINT A & UPPER LIP Divide the horizontal distance b/w original & new upper incisor tips into 3 rds by using 2marks. Superimpose along the facial plane at the occlusal plane. Soft tissue thickness of upper lip will not change. Superimpose new & old bony point A & make a mark at soft tissue point A is traced. Keeping the occlusal plane parallel, superimpose mark # 1 (posterior mark).Trace upper lip connecting with soft tissue point A

43. 46 LOWER LIP, POINT B & SOFT TISSUE CHIN In constructing the lower lip , bisect the overjet & overbite of the original tracing & mark the point. Superimpose inter-incisal points keeping occlusal planes parallel. Trace lower lip & soft tissue B point. Soft tissue thickness of lower lip will remain the same. Eliminate lip strain if any

44. 47 VTO COMPLETED Superimpose on the Symphysis & arrange the soft tissue of chin. It drops down & should be evenly distributed over the Symphysis taking into consideration reduction of strain & bite opening.

45. Role Of Orthopedics Any manipulation that alters the normal growth of the dentofacial complex in either direction or amount. For the sake of simplicity, it is important to closely evaluate only four basic areas of superimposition. The first two areas of superimposition are to define specific orthopedic change( i.e a change in growth direction or amount, or both, of basilar bone. The second two areas of superimposition are used to define specific tooth movements on denture base.

46. Generalized orthopedic response with Cervical Headgear alone- The general orthopedic response in the mandible is highly variable, depending upon facial growth type, the maxillae invariably respond in a highly predictable way to a line of force directed at the level of, or below, the rotational center of the maxillae. At a point which roughly approximates the top of the pterygomaxillary fissure, the maxillary complex rotates in a clockwise direction This rotational effect accounts for the reduction in maxillary protrusion, a downward canting of the palatal plane and concomitant nasal changes, the nasal bone pivots downward and backward at the frontonasal suture

47. 52 Generalized orthodontic response with Cervical Headgear alone- In weak muscular growth patterns, the extrusive effect of cervical headgear, are elicited as negative response in the mandible( i.e orthopedic in nature), and, in strong muscular growth patterns, the extrusive forces of the cervical headgears are seen as the responses in the dentition( i.e orthodontic in nature). Upper molars-extrusion of upper molars Upper incisors-tip lingually Lower molars-upright and move distally Lower incisors-tip labially

48. The Reverse Response In those cases where a cervical headgear is utilized in combination with a lower utility arch, the maxillary orthopedic response is the same however the mandibular orthopedic response differs. The extruding upper molar will, as it is moved distally, again pick up (through incline plane effect) the lower molar and upright that tooth in a distal direction. This effect is enhanced by the tipback in the utility arch. As the lower molar uprights, the distalizing force is translated, through the utility arch, to the lower incisors. These teeth will first intrude and then start to follow the lower molar distally eventually become encased in heavy cortical bone preventing further intrusion. At this point as the action of utility arch continues, its overall response is applied towards retarding the normal vertical eruption of lower molars.

49. The intermittent extrusion of the upper molar, in conjunction with the strong muscular pattern, results in stabilizing (and often distalizing ) the entire lower dentition. This action is referred to as the reverse response of the lower utility arch and can be utilized to set back the lower arch, for anchorage and for arch length.

50. 55 Expansive Response In the Class II , the anterior portion of the maxillae generally is tapered toward the midline and the buccal occlusion would be in lingual crossbite if the maxillae were moved straight back into a Class I position over the present mandibular arch form. From the mechanical standpoint a progressive widening and tipping of the alveolar base is accomplished by a widening of the inner bow of the face bow. This expansive process provides for several distinct considerations: 1. Reciprocal expansion of the lower arch. This can be observed as an anterior movement of the lower incisor and in the horizontal plane increases in arch width occurs. 2. Preventing impacted second molars. When the upper first molar is translated distally without expansion, the incline planes of that tooth start to reciprocally constrict the lower molars, carrying them to the lingual. This tends to either impact the lower second molar or force them buccally .

51. SOFT TISSUE ESTHETIC CHANGES Reduction of the maxillary protrusion, also allows the soft tissue chin, dominated by the upward strain of mentalis muscle, and the constricting influence of the quadratus muscle, to distribute evenly over the symphysis.

52. Factors affecting orthopedic change The direction and duration of force are equally significant as the amount of force applied.  Force Direction Forces applied to the maxillae through the face bow are either a . Restrictive (retard downward and forward growth) b. Rotational a. Restrictive forces occur when the vectoral sum of forces lies above the centre of resistance of the maxillae b. Rotational forces occur when the vectoral sum of forces lie below the centre of the resistance of the maxillae.( i.e tip the maxilla downward and backwad )

53. 58 FEATURES TAKEN INTO ACCOUNT IN DESIGN OF NEW RICKETTS HEADGEAR. Neck strap with force of 500gms will produce orthopedic effects. This led to the introduction of strong bow, unannealed to prevent bending/ breakage & laser welding. Headgear tube is kept gingival to keep the force closer to the center of root so that less extrusion force is produced. Banding the anterior teeth & placing a continuous arch tends to bind the 2 halves of the maxilla together & prevents convenient permanent expansion. If these teeth were banded the continuous arch wire were not to be used as the dental bow can rest under the incisal bracket wing Extra anterior elastic is not employed because of tendency of deep bite.

54. Forces used in Bioprogressive therapy The orthodontic movement of teeth occurs as a result of the biological response and the physiological reaction to the forces applied by our mechanical procedures. Brian Lee, following the work of Storey and Smith, measured the surface of the root being exposed to movement— called the enface surface of the root. He, proposed 200 grams per sq cm of enface root surface exposed to movement as the optimum pressure to be applied in efficient tooth movement. Bioprogressive Therapy's evaluation of the applied forces suggests 100 gms per sq cm of enface or exposed root surface as optimum.

55. 60 Forces Used In Bioprogressive Therapy Rating scale for the intrusion of teeth measures the greatest cross section of the tooth surface in cm2. Required forces are shown at 150 and 100 gms / cm2 Lower incisors show .20cm2 of enface root surface, while upper incisors show .40cm2.

56. 61 Forces Used In Bioprogressive Therapy

57. 62 Bioprogressive therapy suggests consideration of following aspects for efficient teeth movement - Size of the root surface involved Cortical bone support Amount of applied force Muscular support –reflected by facial type

58. 63 Forces Used In Bioprogressive Therapy Control of force: Use of long lever arm. Use of loops to increase the length of the wire.

59. 64 SIMPLE LOOP DESIGNS: Incorporates more wire between the teeth & reduce the amount of force COMPLEX LOOP DESIGNS: It uses the combination of simple loops & adds additional wire to further reduce the amount of force while making it more continuous The root surface theory of tooth movement works well for the individual teeth but when inter-arch mechanics & reciprocal factors are analyzed, it becomes apparent that other factors need to be considered in total evaluation of teeth movement i.e physical characteristics of supporting bone through which teeth are being moved

60. 65 Concept of cortical bone support The concept of cortical bone anchorage implies that, to anchor a tooth, its root are placed in proximity to dense cortical bone under a heavy force that will further squeeze out the already limited blood supply & thus anchor the tooth by restricting the physiological activity in an area of dense laminated bone. For efficient movement our mechanical procedures should steer the roots away from denser cortical bone & through the less dense channels of vascular trabecular bone.

61. 66 Lower incisors, canines and Premolars : These are supported on lingual aspect by cortical bone of planum alveolar. During various tooth movements like incisor intrusion /canine retraction, treatment mechanics must be modified to move the roots labially away from this denser heavier support. If the heavier forces are applied to the incisor /canine retraction , then roots being adjacent to cortical bone become anchored. This anchoring will strain molar anchorage , tip & extrude the incisors around planum alveolar bone fulcrum which creates deep bite problems often associated with extraction mechanics.

62. 67 Lower 2 nd Premolars and Molars : The lower 2 nd PM & molars are supported from the buccal by the cortical bone which runs along their buccal surface into the external oblique ridge. To anchor lower molar , the roots are expanded & torqued into this denser avascular cortical bone. Clinical observation have demonstrated that when the lingual cusps are kept down (roots expanded & torqued buccally ) good molar anchorage is being maintained.

63. 68 Maxillary incisors: These are best intruded along their long axis into broadest area of alveolar process. If the roots tips are forward as in class 2 div 2 crowns must be advanced & the roots retracted before intrusion so that they can avoid the cortical bone around point A in maxilla.

64. 69 Maxillary bicuspids and Molars: The roots of 2 nd PM & Molar are often involved with the cortical bone lining the floor of sinus. When molar distalization desired, molars should be kept narrower in trabecular trough area & the forces lighter & more continuous for orthodontic movement.

65. Where the musculature are strong as characterized by deep bite , low mandibular plane angle, brachycephalic type, teeth demonstrate “natural anchorage”. In open bite, dolicofacial pattern, muscles seems weaker & less able to overcome molar extruding & bite opening effect of treatment mechanics. MUSCULATURE ANCHORAGE

66. Development of the Bioprogressive Brackets Factors in bracket design For 3-D control of arch dimension Dr. Edward. H. Angle designed the rectangular slot and provided winged flanges for wire ligation. Narrow single bracket .022 x.028 size was designed to be replaced in the center of buccal or labial surface of tooth. Eyelets or staples for rotational control came later. The treatment wires recommended by Angle were gold wires of .022x.028 inch.

67. 72 Movements were to be intermittent in order to produce the least permanent damage to root and soft tissue . The staple was difficult to engage & sometimes buried under the gingiva. To overcome this, orthodontists tried placing two separate brackets(one mesial, one distal on the tooth) . But this was cumbersome and not efficient. Eventually, instead of two singles, a new design connected the mesial and distal wings, forming what we recognize today as dual bracket. Dual brackets were refined further by adding welding flanges which became available for band / bracket combination.

68. Consequently, 2 principle bracket designs became available : First – Rotation arm Second- Varying lengths & width of twin brackets ie ; Siamese brackets / Dual brackets Advantages of rotation arms: A light force can be delivered. A push /pull can be utilized. A wide inter-bracket distance is available which helps to keep forces lightened. Wide inter-bracket distance makes loop position less critical in multi-looped arches. Sliding of the tooth on the wire is thought to take place with less friction.

69. 74 Advantages of Siamese type brackets : Bracket yields positive control. A simple bracket is easier to keep clean. Bracket is more efficient with very light wire. One of the brackets can be tied as a counter rotation during enmasse movement.

70. 75 Other factors pertinent to Rickets bracket design : Deep slots - It permits 2 light arches to be employed at once. It permits a chamfer / bevel at the box entrance to facilitate wire seating. It permits bracket profile to be raised for lever access beneath the wing. It provide more adequate distance for torque grooves to be placed.

71. 76 Wide incisal gingival wing - It provides easy access for tie wires. It permits auxiliary light wire to be placed underneath the wing. Can be used for rubber elastic traction. Provides accessibility for cement removal under wings. Softer bracket material - The softer but not annealed material permits closing of bracket for rotation with later reopening at finishing. It can be pinched close around narrower arches for absolute wire engagement.

72. Factors in head gear design Head cap was described by Kingsley 1866 & Farrar in 1870s Objective was limited to retraction of upper anteriors . Angle in 1888 described his extra oral attachment. A long pin soldered to E arch in midline, which rested on central incisor bands where cleats were attached. He recommended it, to be worn during sleeping hours. Intra-maxillary elastic bands were used for traction during day time. 77

73. 78 Recognizing the need for downward pull at the ends of the outer bow, Ricketts working with Downs applied only the neck straps portion of the Kloehn head cap. This was followed by Downs designing a full elastic neck strap / the cervical anchorage still popular today. Finally full arch was banded & h igh pull headgear was reintroduced to intrude the upper incisors – Mc C ulloch 1960

74. Utility and Sectional Arches Historical prospective - Contemporary, full banded edgewise orthodontic approaches utilized light, continuous, round arches in the initial phases of treatment for rotation corrections and leveling the Curve of Spee . But, this led to extrusion of lower bicuspids, uprighting of lower molars, and forward tipping of lower incisors. In order to avoid forward movement of incisors, wire ends were cinched back

75. 80 But as the Curve of Spee in the round arches expressed itself, the roots of lower incisors were thrown against the dense lingual cortical bone, which acted as an anchor leading to the same forward movement of the incisors, and forward movement of the lower molars. To counteract the forward movement of the lower arc, Class III elastics were used. To counteract the eruptive forces of the Class III elastics, headgears were used. When even the smallest continuous round arches are tied into place for leveling, an expansive movement is placed on the buccal segment teeth which tips them up and out to unfavourable axial inclinations.

76. 81 Development of Utility Arches - In the 1950s Dr. Ricketts attempted to counteract the tipping that occurred in the buccal segments in extraction cases by using the lower incisors as an anchor unit to hold the lower second bicuspids and molars in their upright position during retraction. Round arch segments were laced from the lower molars and bicuspids to the lower incisors as the cuspids were retracted. After trying various modifications, Ricketts advocated 0.018 bracket slot, double molar tube, light forces to prevent the flaring of lower incisors, and 0.016 x 0.016 blue Eligloy (chrome- cobalt wire) wire was designed.

77. Construction specifications of the mandibular utility arch The mandibular utility arch is best fabricated from 0.016” x 0.016” blue elgiloy wire in order to create a force system that delivers a continuous force that is light enough to be in the range of 50-75 gms .  Design Principle The principle of the long lever arm, from the molars to the incisors is applied to deliver a light continuous force. The utility arch is stepped down to avoid interference from the forces of occlusion. The buccal bridge section is flared bucally to prevent tissue irritation, opposite the vertical steps as the arch approaches the tissue and as the incisor teeth are intruded.

78. Fabrication of the Mandibular Utility Arch Vertical Step Height In the lower arch it is 3-5mm The only function of the vertical step is to bring the malleable elgiloy wire out of the occlusion to avoid deformation with functional movements. The posterior vertical step is constructed first and should be stopped against the molar tube in order to prevent bending by the forces of occlusion and to effect better molar and incisor movement. The anterior vertical step should be extended far enough beyond the lateral incisor brackets (2-3 mm to allow unraveling and alignment of the incisors).

79. 2) Placement of Labial Root Torque. When the wire is bent at the anterior vertical step 10° - 15° of labial root torque is incorporated. The anterior arch form is then contoured using a small turret/arch forming plier. 3) Finishing the Opposite Side. The same procedure is continued in reverse order after lacing into anterior brackets. 4) Contouring the Buccal Bridges . The stepped down buccal bridge section has a buccal contour that stands way from the alveolus and acts as a bumper against the buccinator muscle. The buccal bridge section is flared outward approximately 1cm per side. By flaring the buccal bridge section at the anterior vertical step, the posterior vertical step is also flared bucally and establishes the 45° buccal root torque.

80. 5) Activation of the Distal Legs. The molar section that extends into the molar tube has a 45° buccal root torque, 30°-45° distal lingual rotation with a 30°-45° tip back bend.   6) Final Arch Form and Activation Characteristics. The precisely contoured anterior arch form will allow the incisors to intrude without advancing. 5°-10° labial root torque will counteract the forward tipping action and allow the incisor roots to avoid cortical bone.

81. 7. Placement of the mandibular utility arch Upon placement of the activated lower utility arch in the lower molar tubes, the anterior section will rest at the bottom of the labial sulcus When it is raised to the level of the incisor brackets it should measure 50-75 gms of force directed to intrude incisor teeth. In order to allow the molar to upright the wire should extend through the molar and should not be bent down distal to the tube. This prevents the crown from uprighting . The posterior vertical step should not be advanced ahead of the molar tube since it will be distorted by the forces of occlusion.

82. 87 Roles and functions of the lower utility arch Position of the lower molar to allow for Cortical Anchorage Manipulation and alignment of the lower incisors segment Lower utility arch can intrude or extrude or hold lower incisors in the initial phase of therapy.

83. 88 Roles and functions of the lower utility arch 4.Physiologic roles of the lower utility arch. Buccal arm acts as a cheek bumper causing expansion of the buccal occlusion. Activator effect by eliminating the proprioceptive interferences to the lower incisors. Allow better buccal teeth eruption by removing functional interferences. Corrects overbite before overjet thus avoiding incisor interference Maintains the physiologic arch form and/ or molar width.

84. 89 5 .Overtreatment Edge to edge bite. Freeing the buccal segments for unimpeded correction of Class II 6.Role in mixed dentition Resolve arch length problems. Incisor and molar control during transitional stage of buccal dentition. Allows distal eruption of the lower second bicuspid when deciduous molars are uprighted . Rotational correction of the bicuspids and cuspids during eruption interference

85. 90 7. Arch length control 1. Uprighting the lower molars: using the tip back bend of the utility arch uprighting of the molar results in a 2mm gain of the arch length on each side along with leveling of the curve of Spee . 2. Advancement of the lower incisors when lingually placed: Steiner’s rule would dictate that for each 1mm that the lower incisors are brought forward 2mm of arch length is gained. 3. Expansion in the buccal segment: Ricketts rule dictates that for each 1mm of expansion across the bicuspids or deciduous molars, ½ mm of arch length is gained and for each 1 mm of expansion across the molars 1/3 mm of arch length is gained. 4. Saving E space: Space gained when the lower deciduous molars are lost.

86. Types of Utility arches Passive arch Intrusion arch Retraction arch Protraction arch

87. Passive arch Uses Mixed dentition Maintains arch length during transition by preventing mesial migration of molars Influences the eruption of posterior teeth by holding cheek musculature away from erupting teeth Spontaneous arch widening Permanent dentition Maintenance of anchorage – incorporates anteriors Non extraction cases – anchorage after distalization of molars. Extraction cases –placed for anchorage control prior to canine retraction

88. Passive utility arch PASSIVE ARCH USED TO REINFORCE ANCHORAGE

89. Intrusion arch Posterior vertical segment 5 mm anterior to auxiliary tube – intrusion with retraction – prevents labial tipping during intrusion Intrusion produced in two ways Occlusally directed gable bend in posterior portion of vestibular segment Tip-back bend in molar segment – sometimes tips molar back – avoided in maxilla with TPA

90. Simultaneous intrusion and retraction

91. Retraction arch Fabrication similar to IUA(Intrusion Utility Arch) Incorporation of loop allows for longer range of activation Uses – most commonly during final stages of comprehensive edgewise treatment for space closure via retraction of incisors Provides necessary intrusion that must often precede retraction Cases with spacing and proclination With bonded orthopedic appliances ( Herbst , bonded RME)

92. Retraction utility arch

93. Protraction arch Uses Mixed dentition Prior to functional jaw orthopedic appliance therapy in class II patients with retruded upper incisors. Only upper arch strapped with TPA and utility arch Permanent dentition Proclining and intruding incisors in cl II div II cases Presurgical orthopedic phase of treatment for mandibular advancement, to decompensate position of upper incisors

94. Fabrication Vertical segment flush with tube Loop distal to anterior segment and occlusal to vestibular segment Anterior leg lies 2-3 mm anterior to ultimate position when passive Activation tying into anterior brackets gable bend for intrusion Re-activation Bending posterior vertical segment from 90 to 45

95. BASIC BPT APPLIANCES 100 Evolution from standard BPT which originally contained torque & tip in the upper incisors & all canines through full torque for PM & Molars now to the offset in the triple control has been a natural progression consistent with our basic principles Standard BP appliance Full torque BP appliance Triple control BP appliance

96. 101 Standard BPT appliance Used since 1962, torque was included in the upper incisors & all 4 canines. Torque was to be placed in lower buccal segments with all step bends. Torque incorporation & arch form made by the operator.

97. 102 Full torque BPT appliance It included additional torque to the standard setup ,by placing torque in the lower 2 nd bicuspid and lower 1 st and 2 nd molars. The additional torque were adopted for the technique to eliminate excessive torqueing in the wire needed for finishing stages but they were augmented for anchorage.

98. 103 Triple control BPT appliances for non extraction cases It includes features of over treatment of certain torque , overtreatment of rotations & provisions for overtreatment of upper buccal segments. The raised bracket was designed for all canines & 2 nd pm so that a non stepped wire could be used as the ideal final arch wire.

99. Mechanics sequence for extraction cases Treatment plan and sequence of mechanical procedures are planned in progressive stages that will unlock the malocclusion and establish a more normal function. Draw V.T.O that includes changes that are expected with - Normal growth Orthopedic alteration Alignment of teeth Functional and soft tissue changes

100. 105 EXTRACTION MECHANICS Sequence can be best ordered into four g eneral procedure s, Stabilization of upper and lower molar anchorage. Retraction and uprighting of cuspids with sectional arch mechanics. Retraction and consolidation of upper and lower incisors. Continuous arches for details of ideal and finishing occlusion.

101. 106 STABILIZATION OF UPPER AND LOWER MOLAR ANCHORAGE Upper molar anchorage A. Maximum upper molar anchorage : Nance arch with modifications. Headgear . 1. Expansion places the molar roots out under the zygomatic process where cortical bone support resists change and thus anchors and limits their movement. 2. The molars, placed in distal rotation, tend to resist the forward mesial pull as the cuspids are being retracted on sectional arch springs. .

102. 107 B. Moderate upper molar anchorage: B. Moderate upper molar anchorage : F orward advancement up to half of the extraction space during the treatment procedure A palatal bar without the plastic button support Upper utility arch during cuspid retraction with or without lingual arch Quad helix

103. C. Minimum upper molar anchorage Where the upper molar needs to be advanced the whole distance of the extraction space( 2nd pm extraction). Class III elastics Double delta loop Vertical closing loop

104. 109 Lower molar anchorage More moderate anchorage concepts in the strong muscle patterns and more maximum anchorage concepts in the vertical pattern where the musculature gives weak support. Maximum lower molar anchorage Lower utility arch-four mechanical adjustments- ximum lower molar anchorage Buccal root torque that places the roots against the cortical support to limit their movement. Up to 45° of buccal root torque is placed in a .016 ´x.016 Elgiloy wire. 2. Buccal expansion of the molar section of 10mm on each side is necessary to support the buccal torque. 3. Tipback of 30°-40° keeps the molar upright and resists the forward pull in response to the cuspid retraction springs. The tipback is the reciprocal action that acts to intrude the lower incisors. 4. Distal molar rotation of 30°-45° is also placed in the molar section of the utility arch in extraction cases.

105. 110 B. Moderate lower molar anchorage Contraction utility arch with stepped ahead of the molar tube C. Minimum lower molar anchorage Four anchoring factors Torque , Tip back , Expansion and Rotation are reduced. Round wire in the molar tube may be used to eliminate the binding and torquing to the molar and thereby reduce the anchorage.

106. 111 RETRACTION AND UPRIGHTING OF CUSPIDS WITH SECTIONAL ARCH MECHANICS Canine is located in the corner of the arch so need to be kept in the narrow trough of trabecular bone, and avoid the severe tipping or displacement, which is difficult with continuous wire. Care must be exercised in sectional arch treatment to compensate for the tipping and rotational control in sectional arches. Extreme 90° gable and 90° offset antirotation bends are placed before the springs are placed and activated for the cuspid retraction. The activation of the cuspid retraction springs should produce 100 to 150 grams of force . Only 2-3mm of activation is required to produce the desired force.

107. 112 RETRACTION AND CONSOLIDATION OF UPPER AND LOWER INCISORS: Lower Incisor Very light continuous force of 150gm need to be applied so that cortical bone can be remodelled . Heavy force- produce tipping & extrusion of incisors. Contraction utility arch –incisor retraction with light force-limited extrusion Upper Incisor Remove the Nance lingual arch to allow the alveolar process to remodel. Torque has to be maintained, upper incisors are torqued till the long axis parallel to facial axis.

108. 113 CONTINUOUS ARCHES FOR DETAILS OF IDEAL AND FINISHING OCCLUSION: Continuous and multistranded wires. Finishing arches are placed in final 2 weeks of active treatment. The bands have been removed from buccal occlusion in order that band space closure can allow finer details in occlusion

109. Finishing procedures and Retention The finishing & retention procedures of the BPT are considered, from the beginning stages of treatment as a part of total scheme of treatment. “ Begin with the end in mind”. Every orthodontist has a visual picture in his mind of the ideal occlusion into which the teeth should fit and mesh in the final finished occlusion.

110. 115 Occlusal checklist in finishing An occlusal check list including 8 areas in each arch is used in establishing ideal finishing arch configuration. The patient at this stage is seen at 2 week appointments. During the final 2week adjustment the c uspid & PM bands may be removed to allow closing of the band space. Only the lower arch is activated & light class 2 elastics maintained the overtreatment.

111. 116 Occlusal checklist in mandibular arch Arch width across 2nd molars. Distal of l molar rotated lingually until the disto -buccal cusp approximates mesial on 2 nd molar. Large buccal offset at mesial of l molar. Check inter-bicuspid width for necessary expansion. Proper buccal arch form & contour. PM offset to bring it in contact with distal lingual incline of upper canine . Mesial of canine tucked slightly behind lateral incisors, distal of the cuspid buccal . Over rotation of incisors “smooth arc”

112. 117 Occlusal check list in maxillary arch Width across 1 & 2 nd molars. Distal rotation of 1 molar so that line drawn through disto -buccal & mesio -lingual cusps points to the distal 3 rd of the opposite side cuspid . Mesial offset on molar. Mesial rotation of lingual cusp of l pm to seat in distal fossa of lower l pm. PM offset 2-3mm to avoid lst area of prematurity. Cuspids brought into contact with lower cuspid & pm to establish cuspid raise. Lateral is left labial to allow overtreatment of buccal segment then tucked in. Smooth arc across incisors

113. 118 Retention Retention in Bioprogressive Therapy is the process that sustains and guides the settling from the overtreated or orthodontic occlusion into the final functioning occlusion Two phases of retention: Guiding changes during initial adjustments. Supporting bony and muscular accommodations to changing environment and considering long range influences.