Evolution of straight wire appliance INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
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Contents 1. Introduction 2. History 3. Works of Andrew's 4. The new torqued appliance 5. Vari simplex discipline 6. Bioprogressive system 7. Roth prescription 8. MBT system 9. Combination anchorage technique 10.Level anchorage technique 11.Tip edge bracket system www.indiandentalacademy.com
12. Bioefficent bracket system 13.Butterfly bracket system 14.Élan –Ortho's system 15. Conclusion
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Introduction -Orthodontics is a dynamically growing science. It is constantly undergoing development and is evolving through the discovery of newer techniques and improvements over the older ones. -One of the most important events in evolution of orthodontic appliances was the introduction of fully programmed appliance to fulfill the drawbacks of earlier techniques. -This was the direct result of the pioneering work by Andrew's in the 1970’s and since there has been many developments in the technique. www.indiandentalacademy.com
What is straight wire appliance ? The term straight wire in the present context refers to an archwire that is given the arch form and often the curvature to open the bite –but which is free from the first, second or third order bends. It is a formed but ‘ unbent’ archwire. Meyers and Nelson – 1978 – P A E Briefly about straight wire appliance:Andrew's endeavor to develop an appliance that would permit the use of such an archwire by transferring most of the tooth guidance functions from the archwires to the brackets was based on following reasoning: www.indiandentalacademy.com
1. Eliminating primary bends 2. Secondary bends 3. Variability in archwire bends from operator to operator 4. Some of the bends influence the actions of other bends E.g.:- wagon wheel effect. However, it should be noted that in only few cases, the entire treatment could be completed using straight archwires. Andrews stated that straight wires in progressively larger dimensions take the treatment close to the treatment objectives, but in many cases would require some wire bending in the final archwires to fine tune the results. www.indiandentalacademy.com
HISTORY There were hundreds of different ways to treat patients, which began nowhere and ended nowhere. Pierre Fauchard’s Orthodontic appliance-1728
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Dwinelles Jackscrew-1849
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According To Angle - in 1887 A standard appliance must have five important propertiesSimple Stable Efficiency Delicate Inconspicuous
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The E Arch appliance - 1907
The basic E – arch appliance
the ribbed E -arch
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E Arch Without Treaded Ends
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E Arch With Hooks
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Drawback Once the retention appliance was discarded various degree of malocclusion resulted This appliance failed since it could not correct the axial Relationships of teeth.
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Pin and tube-1910 First appliance that employed a bracket and used bands on most of teeth. Each band of the tooth had a vertical tube that paralleled long axis of the crown of a tooth. Adv:- good axial control Disadv :- limited mesiodistal control www.indiandentalacademy.com
The Ribbon Arch-1915 Brackets were introduced with appliance. Tube of the pin was modified to provide vertically positioned rectangular slot. A ribbon arch of 10x20 gold wire was placed in this slot .
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Edgewise Appliance Angle oriented the slot from vertical to horizontal and inserted rectangular wire into it. This was one of the angle final achievements.
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Single width bracket Original angle bracket was made up of a soft gold with .022 x .028 slot. It was .050 wide and was soldered to gold band material . Angle soldered gold eyelets in appropriate positions on the band. www.indiandentalacademy.com
Twin Bracket Joining together of two edgewise brackets “SIAMESE TWIN BRACKET” The space between two brackets was approx 0.050 Initially for upper central incisors and molars.
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They are available in four sizesExtra wide Standard Intermediate Junior
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Curved Base Twin Bracket It has the advantage of twin bracket offering rotational and greater axial control
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Lewis bracket This was the next development for bringing about efficient tooth rotation. He soldered auxiliary rotation arm that abutted against the bracket itself and thus offered a lever arm to deflect archwire and rotate the teeth. Present day Lewis bracket is a one piece bracket with rotational wings which is equivalent to original edgewise bracket with single width feature. www.indiandentalacademy.com
Lewis bracket
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Advantage – 100% desired tooth rotation . Disadvantage – less control of axial inclination. Curved Lewis bracket advantageIncrease contact with band .
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Steiner bracket Introduced by CECIL STEINER This bracket incorporated flexible rotation arms and therefore did not rely entirely on the resiliency of archwire for tooth rotation. It uses a single width edgewise bracket and has the inherent advantage and disadvantage of the same . www.indiandentalacademy.com
BROUSSARD BRACKET Was designed by “Grayford broussard” Modified edgewise bracket in which there is addition of 0.0185 x 0.046 slot –to accept 0.018 auxiliary wire
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BURSTONE CANINE BRACKET Burstone added a vertical tube to canine bracket for the insertion of retraction spring.
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Universal appliance Spencer Atkinson - 1928 Design-vertical hallow shaft with two lateral welding tabs -central shaft has two slot openings Horizontal – opening labially at gingival third Vertical –opens incisally near the base and extends one third of the bracket height www.indiandentalacademy.com
The incisal slot can hold-.008-.016 round or .008 x.020 up to .015 x .028 wire . - corrections of rotations ,leveling or torque. Gingival slot can only hold round wire ranging from .008 - .016 -mesiodistal axial inclinations ,act as a guide when teeth are moved bodily in mesial or distal direction
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Five Archwire Combinations Available
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The 3-D Universal Bracket(1974) - Jorge Fastlicht 3-D universal bracket is wider mesiodistally and slightly deeper buccolingually
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-1927 Angle had suggested angulating the entire bracket -Holdaway – 1952 suggested bracket overangulation for teeth on either side of the extraction site -Jaraback – 1957 incorporated slot inclination to reduce 3rd order archwire bends -John. j. Stifter - 1958 -By early 1960s, there were individualized bands for each tooth type. www.indiandentalacademy.com
Works of Andrews After his graduation in 1959, Laurence Andrews was looking for a topic to write a thesis that was required for certification by the American Board of Orthodontics. The theme that he chose was the prevalent quality of American Orthodontic practice with respect to static occlusion. He started an assessment of post treatment study models exhibited at the meetings of American Board of Orthodontics, Angle Society and Tweed Foundation.
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He collected study models of 120 non-treated individuals whose occlusion was considered to be ideal by him and his peers. With a keen eye and logical mind he picked out the six consistent features related to the clinical crowns, which were common to all the study models. He named these as the six keys to normal occlusion
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Terminologies
1.Andrews plane 2.Clinical crown
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FACC
For all teeth except molars, it is located at the mid-developmental ridge that runs vertically and is the most prominent portion in the central area of the labial or buccal Surface. www.indiandentalacademy.com
Andrews reexamined the treated cases applying the criteria for six keys. This study revealed that most of them failed to attain many, If not all. He started analyzing the causes for the above shortcomings and came to the conclusion that the standard edgewise appliance had too many deficiencies to obtain consistent results. These were in the form of 1. Variability in wire bending from operator to operator and even with the same operator 2. Deficiencies in the standard edgewise bracket design. 3. Variations in the bracket siting procedures. www.indiandentalacademy.com
The six keys The six keys to normal occlusion contribute individually and collectively to the total scheme of occlusion and, therefore, are viewed as essential to successful orthodontic treatment. Lack of even one of the six is a defect predictive of an incomplete end result in treated models.
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Key I. Interarch relationships The nonorthodontic normal models consistently demonstrated that The distal surface of the distal marginal ridge of the upper first permanent molar contacts and occludes with the mesial surface of the mesial marginal ridge of the lower second molar.
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-The mesio-buccal cusp of the upper first permanent molar falls within the groove between the mesial and middle cusps of the lower first permanent molar. - The mesio-lingual cusp of the upper first molar seats in the central fossa of the lower first molar. -The premolars enjoy a cusp-embrasure relationship buccally, and a cusp fossa relationship lingually. -Max. canine has a cusp-embrasure relationship with mand. canine & 1st PM. The cusp tip is slightly mesial to embrasure -Max. incisors overlap mand. Incisors & midlines of arches match www.indiandentalacademy.com
Key II. Crown angulation (tip) The degree of crown tip is the angle formed by the FACC and a line perpendicular to the occlusal plane. A “+ reading" when the gingival portion of the FACC is distal to the incisal portion. A “- reading" when the gingival portion of the FACC is mesial to the incisal portion.
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Each normal model had a distal inclination of the gingival portion of each crown, It varied with each tooth type, but within each type the tip pattern was consistent from individual to individual.
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Key II. Crown angulation (tip) Normal occlusion is dependent upon proper distal crown tip, especially of the upper ant. teeth ( longest crowns). Degree of tip of incisors, determines the amount of MD space they consume & has a considerable effect on post. occlusion as well as ant. esthetics.
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Key III. Crown inclination (torque) Crown inclination angle formed by a line which bears 90째to the occlusal plane and FACC (as viewed from the mesial or distal). A + reading is given if the gingival portion of the tangent line (or of the crown) is lingual to the incisal portion, A - reading is recorded when the gingival portion of the tangent line (or of the crown) is labial to the incisal portion www.indiandentalacademy.com
ANTERIOR CROWN INCLINATION. In upper incisors + crown inclination. In lower incisors - crown inclination The average inter-incisal crown angle - 174째.
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If the inclination of the anterior crowns is not sufficient, space, in treated cases, is often incorrectly blamed on tooth size discrepancy
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POSTERIOR CROWN INCLINATION— UPPER. A minus crown inclination for each crown from the U canine through the U-2nd PM. A slightly more negative crown inclination existed in the U-1st & 2nd molars POSTERIOR CROWN INCLINATION — LOWER. A progressively greater "minus" crown inclination existed from the lower canines through the lower second molars www.indiandentalacademy.com
Wagon wheel effect
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Key IV. Rotations Teeth should be free of undesirable rotations Rotated molar, would occupy more space than normal, creating a situation unreceptive to normal occlusion.
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Key V. Tight contacts Contact points should be tight (no spaces). Persons who have genuine tooth-size discrepancies pose special problems. Serious tooth-size discrepancies should be corrected with jackets or crowns, so the orthodontist will not have to close spaces at the expense of good occlusion.
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Key VI. Occlusal plane (curve of Spee) Depth of curve of Spee ranges from flat plane to slight concave surface (0- 2.5 mm) A flat plane should be a treatment goal as a form of over treatment. There is a natural tendency for the curve of Spee to deepen with time.
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A deep curve of Spee results in a more contained area for the U teeth, making normal occlusion impossible ď ŽA
reverse c.o.s is an extreme form of over treatment, allowing excessive space for each tooth to be intercuspally placed
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Key VII. Correct tooth size Bennett & McLaughlin If Andrews’ non orthodontic models have shown tooth size discrepancy, it would have resulted in either spacing or crowding in either of arches, until compensated by tip & torque in ant. segment. Discrepancy may exist prior to treatment but frequently not noticed until the finishing stage The potential need for interproximal reduction to ↓ tooth size in one arch or restorative procedure to ↑tooth size in opp. arch should be discussed with patient/parents before trt. www.indiandentalacademy.com
Conclusion -The 120 nonorthodontic normal models differed in some respects, but all shared the six characteristics. -Compromise treatment is acceptable when patient cooperation or genetics demands it, but should not be acceptable when treatment limitations do not exist. -When possible, six keys should be our measure of the static relationship of successful orthodontic treatment.
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Deficiencies in Edgewise Bracket The conventional edgewise brackets are identical for all teeth except some mesio-distal width differences. However different teeth have different relative prominences, angulations and inclinations. This necessitates giving first, second and third order bends in the archwire.
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The non programmed appliance A set of brackets designed the same for all tooth types, relying totally on wire bending (except possibly for angulation if the bracket is angulated) to achieve the optimal position for each individual teeth.
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Base point Slot base Slot point
bracket base
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base stem
Design shortcomings Bracket base perpendicular to bracket stem. Bracket bases are not contoured. Slots are not angulated Bracket stem are of equal faciolingual thickness. Maxillary molar offset is not built in. Bracket sitting techniques are unsatisfactory. www.indiandentalacademy.com
Bracket base perpendicular to bracket stem. Bracket base is perpendicular to the facio-lingual axis, and the slot is cut parallel to the facio-lingual axis. This leads to targeting the bracket slots to different inclinations and occluso–gingival levels, when placed on different teeth with varying curvatures. The latter may result in functional interferences
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Bracket bases are not contoured. Occlusogingivally the base of a nonprogrammed brackets is flat .
Ex: mandibular 1st premolars
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MESIODISTAL
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Slots are not angulated.
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Stems of equal prominence
Stems of equal prominence necessitate the first order bends such as the bends required between the upper central and lateral incisors
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Maxillary molar offset not built- in
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Bracket sitting techniques are unsatisfactory. Various authors have their own way of positioning the brackets. -Tweed recommends sitting brackets in specified number of millimeters from the incisal edge. -Holdaway advocates that the bracket sitting should altered according to the malocclusion www.indiandentalacademy.com
According to Jarabak bracket sites for inclination should be determined by the shape of the crown. Saltzman recommends except for the maxillary lateral incisor ,brackets should be located in the middle third of the crown.
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Fully programmed brackets Andrews designed brackets that are affixed to the teeth such that their bases should reflect the planes of the teeth crowns Hence he set about designing a new system of edgewise brackets.
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1. Every tooth type had a specifically designed bracket 2. Slots were cut at an angle to the vertical edges for attaining built- in angulation in the bracket. 3. The base of the brackets were inclined in order to effect the torque needed for a particular tooth type. 4. The thickness of the bracket stem was varied according to the facial prominence of each tooth. 5. The bracket bases were contoured. Thus it became possible to use unbent archwires in the appliance through www.indiandentalacademy.com most of the treatment.
Two types of bracket configuration were originally made available. The vertical edges were always parallel to the FACC While the horizontal edges were perpendicular to vertical edges – square brackets At different angle – rhomboid shaped Fully programmed appliance- Slot-siting features - Convenience features - Auxiliary features www.indiandentalacademy.com
Feature 1- mid transverse planes of the slot stem and crown must be the same
Feature 2-base of the bracket for each tooth type must have same inclination as the facial plane of the crown. Feature 3-each bracket inclined base must be contoured occlusogingivally www.indiandentalacademy.com
Feature 4- mid sagittal plane of the slot stem and crown must be same. Feature 5 -the plane of the bracket base at its base point must be identical to the facial plane of the crown at the FA point. Feature 6 - base should match the mesiodistal contour of the tooth. www.indiandentalacademy.com
Feature 7 - the vertical component should be parallel to one another. Feature 8 – all slots point must have same distance between them and the crown embrasure line.
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Convenience features
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Bracket identification features Factor to be identified
identifying feature
Arch - maxillary mandibular
Dot on brackets face Dash on brackets face
Quadrant – maxillary mandibular
Dot on distogingival portion of bracket face Dash on ”
Class – maxillary incisors canines premolars
Least base contour Most slot angulation Prominent gingival tie wings
Mandibular incisors canines premolars
Greatest faciolingual thickness Most slot angulation Prominent gingival tie wings
Type Maxillary central from lateral
Central less faciolingual thickness Central 5°angulation lateral 9°angulation
Mandibular
www.indiandentalacademy.com Both are alike
Auxiliary features – Power arms Hooks Face bow tubes Utility tubes Rotational wings
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Tip and torque values of Andrew's prescription Non5/17 orthodontic Normal values
9/10
11/-7 2/-7
2/-7
5/-9
5/-9
Maxillary
Central incisor
Lateral incisor
canine
First premolar
Second premolar
First molar
second molar
Angulation
5
5
11
2
2
5class I 0classII
10-class I 0-classII
Inclination Class II Class I Class III
2 7 12
-2 3 8
-7
-7
-7
-9
-9
1.5mm
1mm
prominenc 1.8mm e
1.4mm
1.5mm
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1mm
Mandibular
Central Lateral incisor incisor
Canine
First premolar
Second premolar
First molar
Second molar
Angulation
2
2
5
2
2
2
2
Inclination Class II Class I Class III
4 -1 -6
4 -1 -6
-11
-17
-22
-30
-35
prominence
2.3mm
2.3mm
1.6mm
1.15mm
1.15mm
1mm
1mm
Nonorthodontic Normal values
2/-6
2/-6
5/-11
2/-17
2/-22
2/-26
2/-35
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Bracket siting procedures Andrews emphasized that the accurate placement of the brackets was an integral part of the straight wire appliance. He suggested a bracket siting procedure, which was aimed at targeting the slot within 2 degrees and 0.5 mm of the precise placement over the slot site. (This is the area on a tooth that would accept the bracket such that the bracket slot would receive a ‘straight’ arch wire passively when the tooth gets optimally positioned).
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He demonstrated that most of the people are able to mark the midpoint of a line about 10mm in length (a figure close to the length of FACC of a maxillary central incisor) to the accuracy of within 0.5 mm. Further, they can also judge the parallelism of two or more lines within the accuracy of 2 degrees Hence he reasoned that it should be possible for anyone with average skill to draw with a pencil the FACC of crowns of all the teeth, mark their midpoints and align the midpoint of the base of each bracket with the FA point in such a way that the sides of the brackets are parallel with the FACC. www.indiandentalacademy.com
Fully programmed translation brackets As the teeth are translated, they tend to tip mesiodistally and rotate into the extraction spaces since the force acts at the brackets away from the center of resistance, both in the lateral as well as occlusal perspectives. New features were added to counter these effects to an extent that would correct them.
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Translating problems Translation- “uniform movement of the body in a straight line”. For translation to occur, the force must be applied at the object’s centre of resistance However bracket is placed in wrong place in two waysIt is occlusal . It is located laterally . www.indiandentalacademy.com
Translation
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Translating solutions Levers Optimal lever lengths are dictated by the distance between the bracket site and tooth's centre of resistance.
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The slot of edgewise bracket should be thought of three levers. The levers that all edgewise brackets have in common are contained with in the slot activated by the arch wire.
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Counter rotation adjustments The slot siting feature for counter rotation involves rotating the slot in one of the three specified amounts around its vertical axis
Slot rotation+ mesiodistal slot length + archwire flex+ mesial www.indiandentalacademy.com Or distal force = counter rotation
Counter mesiodistal tip The slot siting features for counter mesiodistal tip involves Rotating the slot in one of three specified amounts in faciolingual axis
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Slot angulation+ mesiodistal length + activated archwire + power arm = counter mesiodistal tip www.indiandentalacademy.com
Counter buccolingual tip Rotating the base of the bracket in one of three specified amounts around its mesiodistal axis.
Base inclination+ faciolingual slot length+ archwire flexion + mesial or distal force = counter buccolingual tip www.indiandentalacademy.com
Translation bracket categories – Minimum translation brackets –requiring a translation of 2 mm or less Medium translation brackets – requiring a translation of more than 2mm but less than 4 mm Maximum translation brackets -requiring a translation of more than 4 mm.
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Maxilla
1
2
3
4
5
6
7 2(5+-3) 3(5+-2) 1(5+-4)
Angulation Medium translation Minimum Maximum
14(std11 5(2+3) + counter 3) 15(11+4)
-1(2+-3) 0(2+ -2) -2(2+-4)
2(5+-3) 3(5+ -2) 1(5+-4)
Rotation Medium Minimum Maximum
4 (0+4) 6(0+6)
4(0+-4) 2(2+ -2) -6(0+-6)
14(10+4) 14(10+4) 12(10+- 12(10+2) 2) 16(10+6) 16(10+6)
Inclination Medium Minimum Maximum
-7(std -7) -7 -7
-7 -7 -7
-14(-9+5) -13(-9+4) -15(-9+6)
4(0+4)
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-14(-9+5) -13(-9+4) -15(-9+6)
Mandibular L1
L2
L3
L4
L5
L6
L7
Angulation Medium Minimum Maximum
8(5+3) 9(5+4)
5(2+3)
-1(2+ -3) 0(2+ -2) -2(2+ -4)
-1(2+-3) 0(2+ -2) -2(2+ -4)
-1(2+-3) 0(2+ -2) -2(2+-4)
Rotation Medium Minimum Maximum
4(0+3) 6(0+6)
4(0+4)
4(0+4) 2(0+2) 6( 0+6)
4(0+4) 2(0+2) 6(0+6)
4(0+4) 2(0+2) 6(0+6)
Inclination Medium Minimum Maximum
-11(-11) -11(-11)
-17(-17)
-22(-22) -22(-22) -22(-22)
-30(-30) -30(-30) -30(-30)
-35(-35) -35(-35) -35(-35)
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Partly programmed bracketsBy definition partly programmed brackets are the one which lack at least one slot sitting feature because of which it would fail to fully direct each slot to its tooth slot site. 1. Slot inclination . 2. Slot angulation. 3. Slot prominence. 4. Horizontal base contour.
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Criticism on straight wire appliance The main drawback of the SWA is that it overlooks biological variations in the anatomy of teeth of different individuals. 1. Dellinger - the basic data should have been collected from individuals having malocclusion and not from ideal occlusion casts as was done by Andrews 2.One of the important features of SWA (and other PEA) is the torque built in the brackets, which ideally should eliminate third order bends in the arch wire. A uniform torque value in the bracket slots for any given tooth of all the patients is based on the premise that individual teeth of any given type would exhibit identical curvatures. Curvature could vary 5.2 to 10.4 for teeth with low variation www.indiandentalacademy.com 12.8 to 25.6 for teeth with high variation
3. Andrews had laid great stress on the consistency of the long axis (L.A.) point This is also not accepted by these authors. Dellinger found it erratic and inconsistent. Germane et al also questioned Andrews’ contention that the facial surface contour is more consistent when L.A. point is used to locate the brackets and that the clinicians can place the brackets within an error of +_2 degrees torque. 4. The collum angle i.e., the angle between the long axis of crown and the long axis of root differs from tooth to tooth and also for the same tooth in different persons. In class II Div. 2 cases the central incisors have a more acute collum angle than that seen inwww.indiandentalacademy.com Class II Div. I cases. Hence, even when
5. Different vertical growth patterns have different inclines of occlusal planes with respect to the cranium. The inclination values of the maxillary incisors are preadjusted with respect to the occlusal plane. a uniform built-in torque value for all the patients would place the upper incisors in positions other than optimum in high or low angle case 6. Not using full size archwires. 7. Abuse by the general dentist. It is not clear that “one appliance fits all� www.indiandentalacademy.com
New torqued appliance - Creekmore The basis for this technique is the Steiner spring wire bracket which is supplied with 0.018 and 0.025 channels.
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Creek more prescription maxillary
1
2
3
4
5
6
Torque
+7
+3
-7
-7
-7
-10
Tip
2½
5
2½ Distal root tip
0
0
Mandibular Torque
0
0
7
15
15
Tip
1½
2½
2 ½ distal root tip
2 – non extraction 5 – distal root tip2nd premolar extraction
2 mesial root tip – 1st premolar extraction
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23 or 30
1. All brackets are torqued except mandibular centrals and laterals 2. -Torqued brackets have a horizontal scribe line to identify the torque angle. For lingual root torque, the scribe line goes to Gingival. For labial root torque, the line goes to the occlusal. 3. Maxillary bicuspids have 0 angulation. 4. Mandibular bicuspids have two different angulations and are labeled extraction or non extraction right or left. 5. Mandibular incisor bands have angulations to tip the roots distally www.indiandentalacademy.com
6. - Maxillary molars can have the following choices; a. 0.018 .0.025 tubes with 10 torque, 6 rotation b. � tubes with 10 torque, 6 rotation plus 0.051 or 0.045 round tube with no rotation for face bow. 7. - Mandibular molar tubes are torqued 30, with 0 rotation, distal extension and mesial hook. 8. Attachments for first molars when 2nd molars are banded are torqued Lewis brackets with rotation levers. The mesial wing is removed on maxillary first molars to attain desired molar rotation easily. www.indiandentalacademy.com
Vari simplex discipline It is one of the pre adjusted edge wise system. It was introduced in 1978 by Dr. R. G . Wick Alexander.
The name vari – simplex discipline was chosen after very much thought “VARI” means the variety of bracket types used ( twin, lewis an lang) Simplex refers to the KISS principle. Discipline instead of appliance.
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In this archwire fabrication is simplified 1. with 1st, 2nd and 3rd order, effects placed in the bracket instead of bending them into arch wire. 2. simpler arch wire afford fewer arch wire changes, and easier ligation and activation. 3. This rarely employs multiloop arches, because they are time consuming, create food trap and often impinging upon the gingival tissue. 4. Hooks are usually not soldered to the archwire because soldering is time consuming and can reduce arch wire effectiveness. Ligature hooks or ball hooks attached to the brackets are used instead. www.indiandentalacademy.com
From Tweed to Vari simplex In the tweed technique, preserving anchorage of the posterior Teeth is of primary concern. Application of tweed concepts:1. Uprighting the mandibular 1st molars. (anchorage preparation) 2. In vari simplex 5 degree torque is placed in the mandibular central bracket to prevent incisors from flaring labially. 3. Retractor ( headgear) is an important element of the vari simplex discipline.
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Philosophical basis of the vari simplex discipline The general philosophy which spawned vari- simplex is based upon two key tenets. 1. E= R in all areas of life there are efforts and there are results. The strength of the effort is the measure of the result. 2. “ attruistic egoism� Orthodontist will perform treatment which is beneficial to the patient and rewarding to the doctor The basic goal of the vari – simplex discipline is to produce a quality result easily and efficiently as possible. www.indiandentalacademy.com
Vari- simplex appliance design Different bracket styles are employed on various teeth. The most important factors to determine the design of the Vari- simplex appliance are: 1.Sizes and shapes of the teeth. 2. Mesio distal width and curvature. 3.Selecting the proper bracket style to fit the size and shape to each tooth. 4. Accessibility of the tooth whether it is located in a curved or straight area of the arch. www.indiandentalacademy.com
Factors determining bracket system 1. Bracket types 2. Placement positions 3. Angulations 4. Torque 5. in/outs. The placement of these factors into bracket, as pioneered by Dr. Ivan lee Dr. Larrywww.indiandentalacademy.com andrews
Vari Simplex Discipline Brackets used in vari simplex 1.Twin bracket- Used on large flat surfaced teeth. -Mini –Diamond bracket in rhomboid design. Advantage – Flat surface . Easy accessibility . www.indiandentalacademy.com
Twin bracket on the lateral incisor are provided with additional tie wing for easy initial wire placement. Additional handles Patient comfort
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Lang bracketWas invented by Dr Howard Lang Used round surfaced teeth at the corners of the arch . Design-single bracket a flat rotational control wing -each wing has a circular hole . - Wedge shape in profile www.indiandentalacademy.com
Reasons for using Lang bracket on cuspids1.Twin bracket reduces the inter-bracket distance. 2.Better rotational control. 3.Full bracket engagement with a twin bracket is difficult on a round surfaced tooth. 4.Prevents attrition on the maxillary cuspid. www.indiandentalacademy.com
Lewis bracketThey are used for large round surfaced teeth that are not at the curve of the arch - bicuspids . Small flat surface teeth - mandibular incisors. www.indiandentalacademy.com
Design – Consists of fixed wing single bracket with built in labial curvature of the rotational wings . Bracket is wedge shape in profile view which puts the tie wing close to the tooth occlusally and far out gingivally.
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Advantages of using fixed Lewis wing over flexible Steiner wingAdditional force . Save adjustment time. Edges of the Lewis bracket are less sharp . Breakages are less . On a badly rotated tooth the wing in the direction of rotation can be removed. www.indiandentalacademy.com
Other attachments The twin bracket with a convertible sheath is used on each maxillary and mandibular first molar. Headgear tubes are placed occlusally on the maxillary first molar appliances. Ball hooks are attached to the upper and lower first molar brackets.
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Bracket height :each bracket is placed at a predetermined position on each tooth relative to the other teeth.
Bicuspid bracket height is the key because its clinical crown height is so variable. Its normal bracket slot height is 4.5mm Maxillary arch:Mandibular arch Centrals – x Centrals – x-0.5 Laterals – x – 0.5 Laterals – x-0.5 Cuspids – x+0.5 Cuspids – x+ 0.5 Bicuspids – x Bicuspids – x First molars – x-0.5 First molars – x- 0.5 Second molars – x-1 www.indiandentalacademy.com
BRACKET ANGULATION
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Banding Bonding (Incisal edge (Long axis reference) reference) Centrals 3° 5° Laterals 6° 8° Cuspids 6° 10° Bicuspids and Molars 0° 0° Mandibular Arch Centrals 2° 2° Laterals 2° 2° Cuspids 6° 6° Bicuspids 0° 0° 1st Molars – 6° – 6° 2nd Molars 0° 0° www.indiandentalacademy.com
Bracket torque
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Bracket torque:-
Maxillary Arch Centrals -14° Laterals -7° Cuspids – 3° Bicuspids – 7° Molars –10°
Mandibular Arch Incisors – 5° Cuspids – 7° 1st Bicuspids– 11° 2nd Bicuspids – 17° 1st Molars – 22° 2nd Molars 0° or – 27°
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BRACKET IN-OUT Maxillary Arch Base Centrals Standard Laterals Thick Cuspids and Bicuspids Thin Molars Thinnest Mandibular Arch Anteriors Cuspids and Bicuspids Molars
Base Thick Thin Thinnest
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Salient features-3Ëš torque on maxillary cuspid No torque in the second molar tube. -5Ëš lingual crown torque in the mandibular incisors
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Extra oral forces The retraction ( headgear) is one of the most important elements of the vari- simplex discipline. The term retractor refers to a face in with inner and outer bows. It is the only appliance with which the orthodontist can control all three dimensions vertical, sagittal and transverse both skeletally and dentally.
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Roth’s prescription
( the straight wire appliance – 17 yrs later – Ronald H Roth Jco vol 1987sep(632-42) In 1968, R . H ROTH was introduced to Dr. L.F. ANDREWS. He started designing his own prescription as a clinical trial and error evaluation that lasted severed years. Cases were evaluated by the use of Intra oral photographs and Mounted models for tooth positions During treatment and at the end of appliance therapy www.indiandentalacademy.com
According to him teeth tend to relapse back from which they started. if counter-tip, counter-rotation, counter-torque, and leveling of the curve of Spee were applied to the SWA in every possible direction, then it should be possible to use primarily one prescription for most cases, and to finish to an "END OF APPLIANCE THERAPY" goal in which all tooth positions are slightly overcorrected and from which the teeth will most likely settle into non-orthodontic normal positions So with the concept of overcorrection he designed his comprehensive prescription using the available Andrews extraction brackets www.indiandentalacademy.com
In 1979, Roth introduced a bracket setup containing modifications of the tip, torque, rotations and in out movement of the Andrews standard setup brackets.
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The major difference :with the manner in which the teeth are moved and not necessarily the desired end result or the result attained. ANDREWS attempts to translate teeth throughout treatment without ever tipping teeth.. In the ROTH approach, tipping of teeth is allowed, by using round wires in the initial phase of the treatment, but the attempt is to keep the tipping to a minimum wherein it is not necessary to resort to complex mechanics to do the uprighting www.indiandentalacademy.com
Andrews' occlusion study was based purely upon anatomical measurements of tooth positions on untreated normals. According to him teeth should be positioned from an “ANATOMICAL STANDPOINT’” Roth’s occlusion study was based purely upon pantographically recorded and a large number of posttreatment orthodontic cases.
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what made Roth to modify Andrews SW appliance Inventory problem-To treat different cases clinicians were to buy band kits for all Andrews sets and series.. Anchorage loss -When mesially angulated brackets are placed on the posterior teeth, the teeth tend to tip mesially and migrate forward that resulted in anchorage loss. Problem in finishing - To achieve desired tooth positions with the standard SWA, it was necessary to finish the mechanotherapy phase of treatment by placing compensating and reverse curve in the upper and lower archwire www.indiandentalacademy.com
Roth's rationale for his bracket set up. ď ą The purpose of the Roth setup was to provide over corrected tooth positions prior to appliance removal that would allow the teeth in most instances to settle to what was found is non orthodontic normals studied by Andrews. With the appliance in place, it is virtually impossible, because of bracket interference, to position the teeth precisely into the occlusion shown by the non orthodontic normal sample.
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Play or tipping freedom - Due to the play between the archwire and bracket, the delivered tip, torque and rotation forces are less than the designated amount “built in” the slot which need over correction to compensate for play. The curve of Spee will return or deepen after appliance removal. Teeth adjacent to an extraction site will tend to rotate and tip towards the extraction site. As teeth in the buccal segments settle they will rotate and tip mesially, so if they are overcorrected and slightly tipped distally, they will tend to settle better than teeth that are already mesially inclined. As band spaces close, there is a corresponding loss of torque of the anterior teeth. www.indiandentalacademy.com
Extracted teeth with Roth Rx SWA brackets, showing over correction built in to the brackets Extracted teeth with Andrews SWA brackets showing non – orthodontic normal tooth position.
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ROTH SETUP Roth setup is available in both 0.018 and 0.022 slot Roth preferred 0.022 slot brackets because it offered more advantages 1.In terms of wire size selection, 2.In terms of stabilizing arches as anchor units and for orthognathic surgery and 3.For control of torque in the buccal segments, which is very important from the standpoint of functional occlusion.
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The Roth setup incorporated into it a member of hooks for various types of elastic configuration and also double triple and lip bumper tube for the use of auxiliary wires and attachments.
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Upper arch Central tip Andrews 5 Roth 5 Lateral Andrews 9 Roth 9
torque 7 12 3 8
rotation 0 0 0 0
If tip is increased the resultant axial inclination is esthetically and functionally undesirable The 5째 increase in torque improves Esthetics by preventing flattened profile, straight upper lip and obtuse nasolabial angle. www.indiandentalacademy.com
Andrews
Upper canine tip torque rotation 11 -7 0
Roth
13
-2
4
Tip is Increased because they are being retracted in most treatment. Less negative torque to offset the reciprocal effect of building more positive torque into the incisors.
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I&II PM (A) (R) IM &IIM (A) (R)
tip 2 0 5 0
torque -7 -7 -9 -14
rotation 0 2D 10 14D
Elimination of the mesial tip on all buccal segment teeth strengthened anchorage control significantly (but burning anchorage can be difficult).
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LOWER ARCH CENTRAL &LATERAL tip (A) 2 2 CANINE (A) 5 (R) 7
torque -1 -1
-11 -11
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rotation 0 0
0 2M
I PM (A) II PM IM
tip 2 -1 2 -1 2 -1
torque -17 -17 -22 -22 -30 -30
II M
rotation 0 4D 0 4D 0 4D
2 -35 0 -1 -30 4D Because these teeth settle more mesially than the upper and simultaneously rotate mesially thus necessitating extra distal rotation No change in the torque-To establish proper functional occlusion www.indiandentalacademy.com
ROTH TRU-ARCH FORM Roth Tru-Arch form was derived from his extensive clinical testing and recording of jaw-movement patterns in treated patients who were out of retention and had remained stable.
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ROTH’S CONCLUDING STATEMENT “I have tried to present a philosophy of treatment with the concept of overcorrection, based on the specific set of goals stated at the outset, taking in to account existing conditions, facial types, and reaction to treatment mechanics. Naturally there are always exceptions to the way one approaches treatment”
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MBT PHILOSOPHY (Systemized orthodontic treatment mechanics McLaughin Bennet . Trevisi)
The MBT philosophy of orthodontic treatment has been developed over a twenty yr period of time and has involved the combined efforts of its three principle clinicians, Dr. Mc Laughlin, Dr. Bennett, Dr. Trevisi Their philosophy places emphasis on 1. Treatment mechanics 2. The preadjusted appliance 3. Bracket placement technique 4. Arch form and arch wire sequencing. www.indiandentalacademy.com
The old mechanics and heavy force levels, developed for standard edgewise brackets, simply did not transfer to the new, sophisticated bracket systems ROLLER COASTER EFFECT:-
-Another frequent observation was in the area of the premolars and canines which tend to tip and rotate into the extraction sites. www.indiandentalacademy.com
MBT appliance bracket system Tip specifications:Reduced upper and lower anterior tip
5 2 2 Original SWA
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MBT
Upper posterior tip:0 of tip , as opposed to 2 of tip, was selected for all upper bicuspid brackets to place the crowns in a slightly more upright position. The buccal groove shows a 5 angulation to a line drawn perpendicular to the occlusal plane
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Lower posterior crown tip:For the lower premolars, the 2 of mesial crown tip in the original SWA brackets works well, keeping the crowns inclined forwards in a class I direction
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Torque specifications Expression of torque:torque is not efficiently expressed by the preadjusted bracket System, due to two mechanical reasons. 1.The area of torque application is small, 2.In order to slide teeth, it is normal practice to use 0.019/ 0.025 steel wires in a 0.022 slot, because a full- thickness wire prevents sliding.
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Incisor torque It is helpful clinically to have torque which moves upper incisor roots palatally and lower incisor roots labially. This treatment requirement is necessary for many types of malocclusion.
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Canine torque The finding of -7째torque for the upper canines has proved to be satisfactory for most cases, but the original SWA value of -11 torque for the lower canines has not been satisfactory, as it tends to leave the lower canine roots in a prominent position in most cases. Versatility is needed for canine torque values. A range of -7, 0, +7 torque is therefore available for the upper canines and -6, 0, +6 for lower canines.
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Upper premolar and molar torque
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Lower posterior torque
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In –out modifications The in-out feature of preadjusted brackets is 100% fully expressed, because the archwire lies snugly in the slot . The labio- lingual movement is rapid, and normally occurs in one visit.
But the upper premolar bracket has been provided with additional 0.5mm thickness. www.indiandentalacademy.com
MBT versatility 1. Inversion of upper lateral incisor brackets 2. Same tip and torque in lower incisor brackets
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Canine brackets are available in 3 prescriptions 3. Inversion of cuspid brackets with prominent cuspid roots +7 upper and+6 lower brackets are used. 4. 0 cuspid brackets with hook for extraction cases 0 brackets tend to maintain the canine roots in cancellous bone. 5. Inversion of upper cuspid brackets when cuspids are in the lateral incisor position +7 upper brackets are used. www.indiandentalacademy.com
6. Same tip and torque in upper bicuspid brackets 7. Additional 0.5mm of in-out in upper second bicuspid brackets 8. Upper second molar bands and brackets on upper first molars in non- headgear cases. 9. Lower second molar bands and brackets on lower first molars.
10. Lower second molar brackets on upper first and second molars of opposite side when finishing in a class II molar relation The lower molar bracket has 10 of torque which place the class II upper first molar in a correct relationship www.indiandentalacademy.com
Bracket placement When preadjusted appliance was developed, the center of the clinical crown became the vertical reference for bracket placement The brackets were placed by visually selecting the center of the clinical crown. unfortunately, this method resulted in significant errors relative to vertical placement. for example:gingival variations, such as partially erupted teeth, labially and lingually displaced roots , and gingival inflammation led to placement errors. www.indiandentalacademy.com
2. Large teeth ( upper central incisors) and small teeth ( upper lateral incisors) within the same patient led to obvious errors when brackets were placed in the centre of the clinical crown.
3. Incisal and occlusal fractures and wear, as well as teeth with extremely tapered and pointed cusps, led to bracket placement errors.
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The use of a bracket placement chart was developed in 1994, as well as Dougherty gauges, dramatically reduces bracket placement errors in the vertical dimension.
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Bioprogressive therapy (Robert Murray Rickets, Bench et.all, Hilgers) In this new approach, priorities were sought and hierarchies of movements were selected in keeping with the forces of occlusion, the forces of growth and the forces of nature. “bio� being used to suggest the strong biologic implications to be constantly born in mind with this technique.
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One of the principles put forth by Rickets was mainly based on growth. Basically calculating expected growth we can determine the amount of anchorage needed or not needed as growth is utilized. The second feature is the orthopedic movement. -Bioprogressive therapy – applies the principle of cortical anchorage in stabilizing teeth where limited movement is required. www.indiandentalacademy.com
Lower molar anchorage enhanced by expansion of molar roots into cortical bone. Upper molars that are adjacent to the zygomatic ridge, maxillary sinus and cortical bone shelves of the alveolar process needs to be anchoraged and stabilized for in orthopedic alterations.
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Linear dynamic system
(Bioprogressive simplified – the linear dynamic system –Jco- vol 1987 oct(716-734) ) Hilgers using recent advances in metallurgy and casting process have created a miniaturized generation of brackets called linear dynamic system. He designed linear dynamic system in the percept of “ begin with the end in mind” The objective of the linear dynamic system is to allow the dentition to be moved directly toward final positions by establishing a mandibular occlusal table as early in treatment as possible. Key to class I – proper positioning of the lower 1st molars. www.indiandentalacademy.com
The criteria for each tooth are 1.Ideal orthodontic tooth position 2.Anticipated rebound and required overcorrection 3.Appliance design features that contribute to patient comfort, clinical simplicity, and optimum utility.
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Mandibular first molars:Main slot Auxiliary Slot
Torque – 27° 0°
Tip Rotation – 5° 12° distal – 5°
Thickness Thinnest
0°
A slight distal crown tip of 5° uprights the lower molars to allow distal seating of the upper 1st molar and counteract the forces of retraction mechanics and elastics. The 12 distal rotation in the slot coordinates with a 15° maxillary molar rotation to avoid conflicting inclined planes and eliminate the need for bicuspid and molar offsets. www.indiandentalacademy.com
The main archwire torque should be sufficient to maintain anchorage created by natural tooth position against cortical bone of the external oblique ridge The auxiliary tube should not be torqued, so that a 90 bend of the auxiliary arch wire will avoid the soft tissue. In class II deepbite cases:The lower 1st and 2nd molars tipped mesially - deepens curve of Spee. If the lower 1st molar is left mesially rotated, the inclined plane effect of the lower molars will tend to rotate the upper molar mesially and re establish class II
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Maxillary 1 molars st
Torque Main slot -10° AuxiIiary 0° slot
Tip 0° 0°
Rotation Thickness 15° distal thinnest 0°
The upper 1st molar is rotated 15 distally, so that a line drawn through its distobuccal cusp would point at the distal of the opposite cuspid.
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The roots of upper first molars should be inclined slightly to the lingual, so that forces of occlusion will then be directed across the heavy cortical bone of the palate and back through the buttress of the key ridge. The upper 1st molar triple tube incorporates several features. The entire upper buccal segment should have 10째 of buccal root torque to compensate for the occlusogingival curvature of the crowns of these teeth The auxiliary tube, which is offset to the buccal to avoid tissue impingement, has 0째 torque and 0째 rotation. This allows for selective torque and rotation of the upper first molar with initial utility arches, and it helps in placement of auxiliary arches. www.indiandentalacademy.com
Second molars Torque Tip Rotation Maxillary -10° 0° 12° distal Mandibular -27° -5° 12° distal
Thickness Thinnest Thinnest
The lower 2nd molar should be tipped distally during treatment Because it will settle mesially as the disto buccal cusp of the upper first molar settles into the lower first and second molar embrasure
As the lower arch comes in contact with each sequentially erupting tooth, the forward-growing mandible, the inclines of the mandibular teeth and the musculature act to "block in" the upper molars and allow them towww.indiandentalacademy.com settle in the most functional position.
Mandibular 2 bicuspids nd
Torque – 17°
Tip 0°
Thickness Thin
The lower second bicuspid should have buccal root torque symmetrical with the lower first and second molars, because their main cortical bone support is through the external oblique ridge. The bracket should have a wedge shape to minimize interference with the upper bicuspids, and the bracket base should be as thin as possible to accentuate the buccal offset of the lower first molar. In extraction cases it is helpful to have a 5° mesial tip for root paralleling. www.indiandentalacademy.com
Mandibular 1 bicuspids st
Torque Tip Thickness – 11° 0° Thin Transition tooth of the lower arch Root support of the lower first bicuspid is mainly from the lingual. (Root support of the lower second bicuspid is mainly from the buccal.) Even so, there must be buccal root torque in the bracket to passively accommodate the greater buccal crown curvature. Wedge-shaped brackets prevent occlusal interferences.
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Mandibular cuspids Torque 7째
Tip 5째
Thickness Thin
The root of the lower cuspid should contact the lingual planum alveolare, which is the bony buttress supporting disarticulation. Such a position is difficult to create if the lower cuspid root is vertical or supported primarily from the labial (0째 to -10째). Lingual root torque is also advantageous mechanically as the lower cuspid is moved mesially or distally. This is especially true in extraction cases. www.indiandentalacademy.com
Mandibular incisors Torque Tip Thickness – 1° 0° Thin The ideal torque of the lower incisor— as with the upper incisor— varies with facial type. However, a torque of -1° allows enough flexibility for increase or decrease in torque as required by dolichofacial or brachyfacial types. Bracket height should be somewhat incisal in deep bite cases to assist in bite opening and intrusion
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Maxillary bicuspids Torque – 7°
Tip 0°
Thickness Thin
Ricketts called the upper second bicuspid the "key to occlusion” because of its importance in the seating of the upper buccal segments. with the maxillary first molar, buccal root torque assures that the roots can be slightly to the lingual and supported by the dense cortical bone of the palate— particularly when expansion is part of the treatment mechanics. A mesial root tip of -5° in extraction cases facilitates root paralleling. www.indiandentalacademy.com
Maxillary cuspids Torque 7°
Tip Thickness 10° Thin
Inter canine angle – 134, the upper cuspid should be torqued slightly Lingual.
From esthetic point , the labial inclination Of the upper cuspids is important in supporting the corners of the mouth and the caninus complex. www.indiandentalacademy.com
Maxillary incisors Lateral Central
Torque Tip 14째 8째 22째 5째
Thickness Standard Standard
Palatal root torque is necessary to achieve an interincisal angle of 126. Not all cases should be torqued to such an angle, but this built-in torque permits it when a full-size edgewise archwire is engaged. Torque depends on the facial type. Both have standard thickness www.indiandentalacademy.com
Tip edge bracket system - 1986 ( Tip-edge orthodontics Richard Parkhouse) Introduced by Peter Kesling based on his experiences with differential tooth movement and thesis written in 1968 Based on the rationale that each tooth has to tip freely either mesially or distally –not in both directions . Keeping this in mind the appliance was designed to provide all the benefits of differential tooth movement plus pre determined degree of final crown tip and torque
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The Rx- 1 bracket Basic design consist of-removal of diagonally opposed corners of a conventional edgewise slot -slot size is .022 x.028 -lateral extensions or wings -vertical slot .020 x.020 - deep grooves
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BRACKET DESIGN
Vertical slot – 0.020” square www.indiandentalacademy.com
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Cut out surfaces – tip limiting surfaces Intact surfaces – finishing surfaces Central ridge - vertical control
A Dynamic slot ;-
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Molar tube are designed – .036 round gingival tube .022 x .028 occlusal tube Use of round tubes – bite opening in the initial stages Rectangular tube – space closure, root uprighting
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Maxillary
Maximum crown tip During translation
Final crown tip
Final root torque
U1
20 distal
5
12
U2
20 distal
9
8
U3
25 distal
11
-4
U4
20 distal or mesial
0
-7
U5
20 distal or mesial
0
-7
L1
20 distal
2
-1
L2
20 distal
2
-1
L3
25 distal
5
-11
L4
20 distal
0
-20
L5
20 distal
0
-20
Mandibular
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Advantage over original edgewise – Adversely tipped teeth Anchorage control Advantage over ribbon archIn\out compensation. Prevent distal crown tipping of cuspid
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Outrigger appliance
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Evolution of straight wire appliance
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By – Dr. I. Rohini
Combination anchorage technique - four stage light wire appliance - 1988 ( combination anchorage technique – Thompson vol 1988 Ajo-do may 363-79) CAT in its early structure was principally a four stage Begg light wire system, the fourth stage being the straight wire finally. The concept was to use a light wire appliance system to establish the early organization of the malocclusion and to finish the treatment with more rigid and precise straight wire appliances. What was originally believed to be modernized Begg was actually a true combination anchorage technique. www.indiandentalacademy.com
BRACKETS DESIGN IN CAT Two slots 1. Vertical slot Gingival slot True begg ribbon arch type. 2.Edge wise slot : Horizontal slot Uses of two slots. • Simple and efficient • Movement -Tipping -Bodily • Technique -Light wire -Straight wire www.indiandentalacademy.com
IMPROVEMENTS IN BRACKET DESIGN The original combination brackets was Bulky Weak esthetically unattractive Problems with pinning, rotations, slot closure and occlusal interferences These problems were eliminated in new bracket design Improvement in bracket design course from ideas and suggestions from experience with several brackets designed for combination treatment
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CAT BRACKET DESIGN •Clinically excellent for both light wire and straight wire treatment. •Comfortable. •Esthetically pleasing to the patient. •0.22 x 0.35” gingival or ribbon arch slot. •0.018 x 0.025” or 0.022 x 0.028” straight wire slot. •Vertical slot is also incorporated into the bracket for use with up righting and rotating springs, elastic, hooks, double arch wires. Color coding dots are used to identify the brackets. Maxillary brackets are – Red in colour Mandibular brackets are – blue. www.indiandentalacademy.com Color coding dots are placed distogingival aspect.
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MODIFICATION IN BRACKETS DESIGNS Maxillary incisor brackets – varying degrees of torque Maxillary canine torque has been reduced to 0 to reduce the prominence of the canine roots on the labial plate. The torque in the lower 1st premolar was 17° and for lower 2nd premolar was 20°.It has been changed to standard 19° for both. Molar attachment have convertible double tubes It facilitates extending the straight wire into round molar tubes. Redesigned 2nd molar tubes have reduced occlusal interference on short crowned 2nd molars. www.indiandentalacademy.com
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Molar tube offset 7° to facilitate proper rotation – when straight continuous arch wire are used. Redesigned pin slot and bracket pad have simplified placement and retention of pins. So that phase I & II can now be completed with the same type of pin.
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MODIFICATION OF PINS IN CAT Lock in used in the technique are Phase I & II retention pin Phase III retention pin Tandem,, hook pin By pass clamp Special pins – Reduce friction during tipping movement of an arch wire in the gingival slot. New auxiliary extension pins have been contoured for lip comfort and modified to hold an elastomeric ring or an elastic. Stainless steel extension pins are recommended for use with surgical fixation ligatures. They are strong and with stand the tension of these ligatures.www.indiandentalacademy.com
1.Phase III retention pin 2.Phase I and II retention pin 3.Tandem, hook pin 4.Bypass clamp
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BRACKET AND TUBE PLACEMENT similar to that of straight wire appliances like edge wise slot parallel and at the same level as the interproximal contact point of the teeth in normal occlusion. Molar tube can be banded or bonded. Remaining brackets are bonded on the anterior and premolars keeping the molar tube as guide line. Molar tube placement rectangular tube 3.5 mm from the molar cusp tip. Other teeth are at the same level except canine and lateral incisor If maxillary molars are interfering in static of functional occlusion, -position have to be altered. Canines edge wise slot should be 4mm Maxillary lateral incisors 3 mm from the incisal edge. Non extraction case – mandibular I premolar – 4mm www.indiandentalacademy.com
BRACKET AND TUBE PLACEMENT
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ADVANTAGES OR FAVORABLE FINDINGS IN COMBINATION SYSTEMS Time factor Stage III can be altered because of the shortening of the usual uprighting periods by finishing and uprighting and torque in the rectangular slot. In class I extraction cases – those stages II closure may be minimal and uprighting of canines, stage III may be completely eliminated and only rectangular finishing may be needed. It is often possible to enter the rectangular slot with the main wire very early in the non extraction cases and to control most of the uprighting and torque with only the straight wire type and angulated and torqued slot. www.indiandentalacademy.com
Variable anchorage straight wire technique EJO – 27 2005(180-185)
The combination of begg and straight wire technique was improved by 2nd generation of combination brackets developed by Thompson(1995) and the idea was to improve the possibilities to adopt and vary intra-arch anchorage need of individual patient. a study was done to compare the results of combination anchorage technique and SW technique.
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Both VAST and SW technique seemed to produce same treatment results. In the hands of experienced orthodontist, the VAST required no extra oral traction and fewer scheduled appointments than the SW technique.
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CONCLUSIONS CAT Approach with modified brackets has been efficient, effective, and esthetically pleasing, satisfactory to the patient. CAT has provided optimum anchorage control and tooth movement in any given situation. Finally: What we think we know today shatters the errors and blunders of yesterday and is tomorrow discarded as worthless.
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BEDDTIOT Begg's - edgewise diagnosis determined totally individualized orthodontic technique Richard.A.Hocevar “ The intent was to incorporate the important advantages, features, and capabilities of many fixed appliances and minimize deficiencies, making the most of current understanding of orthodontic biomechanics and technology �. -Hocevar (July 1985, AJO-DO) www.indiandentalacademy.com
Beddtiot Philosophy
Begg principles are employed in some cases; various edgewise techniques in others. A wide variety of combinations may be employed easily.
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BRACKETS
Brackets are narrow, single-width edgewise brackets with 0.022 inch (height) ´ 0.028 inch (faciolingual depth) horizontal arch wire slots. On the lingual side of the bracket is a 0.020 ´ 0.020 inch vertical slot. www.indiandentalacademy.com
The arch wire slots are ''torqued" (cut at such angles to the brackets that they will be oriented parallel to the plane of the arch when the teeth are positioned properly)
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Except for torque, the brackets are all identical. Therefore, they are interchangeable; any bracket may be used on any tooth. Placed with its torque-indicator groove gingival, a bracket provides lingual root torque; with the groove occlusal, it provides lingual crown torque.
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Buccal Tubes - 4.5 mm long, 0.022 ´ 0.028 inch "edgewise“ tubes - 25° lingual crown torque for lower - 10° for upper first molars - Distal end of the maxillary tube is angulated outward 10° from the welding flanges to maintain the proper rotation ("toe-in") www.indiandentalacademy.com
Deepbite or moderate-to-severe anchorage requirement cases – An additional rectangular tube is carried diagonally across the buccal surface of the basic tube, its mesial end pointing gingivally www.indiandentalacademy.com
Outer tubeIt carries the main (working) arch wires during the biteopening and retraction phases of treatment Inner tube – carry heavy rectangular sectional wires to lock molar and premolar teeth together( prevents tipping, anchorage control) www.indiandentalacademy.com
Correction of Rotations Mild corrections - offset the bracket slightly toward the side of the tooth that is displaced lingually. Simple engagement of the bracket on the arch wire with a small elastomeric ligature will correct the rotation. Moderate to Severe corrections -gentle ligature or elastomeric thread may be used to tie the bracket to the arch wire. - Bayonet bends may also be used
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Modified Uprighting spring Original Uprighting spring Helix is farther from the arch wire, - Hook arm is slightly longer
- Less bulk. - More hygienic, - Less likely to impinge
upon or irritate the gingiva, www.indiandentalacademy.com -
“ BEDDTIOT was designed to facilitate application of the best modality in every situation, to handle any case, whether it would be treated best with Begg-like biomechanics or one of the many Edgewise approaches � - Hocevar
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Level anchorage system ROOT began using the angulated appliances of Holdaway in 1954 and since that time, he included the anchorage needed to reduce ANB angle, correct class II molar relationships, close extraction space, and level curve of Spee. In 1975 Root began using a completely preadjusted appliance, varying the amount of angulation in the buccal segment by severity of the malocclusion
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He uses more accurate timing of each step in therapy and more treatment control by means of periodic selfchecks. This is what he called “level anchorage system�
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15 10
0 10
0 -7
0 6 -7 0
10 25
6 22
4 11
4 11
7 7
6 0
Low fit = 17www.indiandentalacademy.com
4 15
2 0
2 0
tip torque
Tip torque
BRACKET PLACEMENT
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There are two choices of distal crown tip for the mandibular buccal teeth Regular:- mandibular 2nd premolars – 4 distal crown tip mandibular 1st molars – 6 mandibular 2nd molars – 10 Major:- mandibular 2nd premolars – 6 1st molar – 10 2nd molar – 15 Choice depends on the severity of malocclusion www.indiandentalacademy.com
The unique quality of LAS is predictability. If this system of orthodontic care has value , it lies in five primary areas. To fully state a problem is more than half way to its solution. A precise and repeatable treatment plan is mandated by defining the problem As treatment progresses the practitioner can periodically run a self-check. Predictability Applicability of special brackets and bands automatically coordinated with a straight arch wire. www.indiandentalacademy.com
Bioefficient bracket system (Atlas of advanced orthodontics: a guide to clinical efficiency - Anthony D. Viazis)
It is a modification of preadjusted system introduced by Viazis. The bracket prescriptions were designed to overcorrect malocclusion and to make it possible to work with the largest possible wires from the start of the treatment . www.indiandentalacademy.com
Rationale behind the bracket design isďƒ˜ maximum potential of any archwire is achieved when the largest possible wire is used. The archwire between a narrow single bracket will have less stiffness and greater flexibility
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BRACKET DESIGN
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The bracket is designed to fulfill following requirements1. Conformity to the crown anatomy and gingival outline
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2. Ease of useif the ball indicator is towards the centre of curvature of the gingiva, the vertical member automatically lines up along the long axis of the tooth.
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3. Minimum friction;the single slot contact produces the least amount of wire –bracket contact and thus the lowest possible friction.
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4. Tip control:In this bracket design, as soon as a tooth begins to tip (as in space closure), the archwire contacts the side elbows, and the single slot momentarily becomes a wide twin slot that produces root movement before any further crown movement. Thus, the tooth "walks" back in a zigzag fashion.
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5. Rotational control-narrow ,elongated configuration of the bracket ,with the wings moved towards the mesiodistal surface of the teeth provide maximum rotational control
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6. Vertical slot :- uprighting springs can be used. 7. High torque in anterior brackets:
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The Next Generation :Straight Wire Appliance ď Ž
This concept was introduced by Creekmore and Randy in 1993 AJO
ď Ž
Frequently anticipated results are not achieved by using a preadjusted appliance and straight wire .
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1.
2. 3.
There are atleast five reasons – Inaccurate bracket placements –a mean of .34 mm error in vertical plane and 5.54˚ for angular placement is observed - Balut et.al Variations in tooth structure Variations in ant –post and vertical jaw relations require variations in the position of the max and mand incisors. www.indiandentalacademy.com
4.
Need for overcorrection
5.
Mechanical deficiencies of the edgewise appliance –force application away from CRes. -play between arch wire and slot. -force diminution. www.indiandentalacademy.com
The Next Generation :Straight Wire Appliance THE SLOT MACHINE
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Advanced Preadjusted Appliance Fabrication Torque –with the use of an incisor Torque Template (Creekmore Enterprises ). Tip -can be adjusted taking in consideration the anchorage requirement . Rotations- rotations can be accurately measured by using rotational guides
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ď Ž
Height – more precise height measurements are possible
All this requires proper planning of individual tooth movement so as to determine exact amount of torque ,tip , rotation and height parameter for each tooth www.indiandentalacademy.com
The Élan and Ortho's system (Jco interviews Craig Andreiko on the elan and ortho’s system Jco – 1994 aug 456-468)
This was introduced by Craig Andreiko(1994) These are two appliance system that represent the first modern CAD/CAM technology for appliance design in orthodontic field.
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Elan is first system to integrate treatment plan and appliance for a specific patient. Elan system begins with digitizing the skeletal and dental entity of the patient . The system then proceeds to design an occlusion based on the practitioners treatment plan and on algorithms developed to mate the three dimensional positioning of the dentition to the skeletal framework.
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Based on all these the system designs and fabricate brackets ,wires and bracket positioning devices that are essentially reversed engineered from the desired final results for that individual patient .
Begin with the end in mind
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•Mandibular brackets are placed as occlusally as possible for hygiene and assuring clearance from the buccal cusp •Maxillary bracket are placed fairly central due to absence of interference . •Currently the system is available only in the twin bracket configuration with both 018 and 022 .
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Advantages – Highly individualized treatment . More efficient. Fewer appointments Allows the operator to spend more time on designing treatment plans and less time bending wires . www.indiandentalacademy.com
Orthos system is a new average prescription and appliance design based on computer analysis of more than 100 cases derived from the Elan technology. It consist of a coordinated system of brackets ,buccal tubes and wires .
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Prescriptions incorporated in the appliance design are meant for a particular race . Asian version of ortho’s will soon be available .
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The Butterfly system - S. Jay Bowman Aldo Carano- Jco may 2004 The butterfly system has several unique features designed to improve upon existing preadjusted appliance concepts. It is based on a new low profile, twin –wing bracket. The bracket’s reduced profile, its miniature twin-wing design and rounded tie wings, and the elimination of standard hooks results in an appliance that is more comfortable, esthetic and hygienic. www.indiandentalacademy.com
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Versatile vertical slot : elimination of ball hooks a simple hook pin or T-pin can be inserted a stainless steel ligature or elastic thread can be placed to engage teeth that are blocked out.
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Butterfly system prescription maxillary
1
Torque
2
3
4
5
+14 +8
0
-7
-8
Angulation
+5
+9
+9
0
+3
Rotation
0
0
0
0
0
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Conservative anterior torque:for class II div 2 cases which often have lingually tipped incisors. Central incisor labial crown torque of 14 appears to be sufficient for a class II div 2, a class III Patient or even an extraction case. To prevent lingual displacement of the canines this prescription has no torque in the maxillary canine brackets. To match with the reduced progressive posterior torque the mandibular canine features a moderate – 3 torque www.indiandentalacademy.com
Progressive posterior torque:many bracket prescriptions contain an extreme amount of mandibular posterior lingual crown torque, intended to obtain cortical anchorage. compounding this problem there is popular use of over expanded arch and bracket prescriptions having limited maxillary posterior lingual crown torque. This combination tends to tip the upper posterior teeth to Buccal and “roll in� the lower posterior teeth to lingual, resulting in - prominent maxillary palatal cusps, - inappropriate interdigitation of the maxillary buccal cusps, - increased occlusal interferences -accentuated curve of Wilson www.indiandentalacademy.com
Progressive posterior torque was designed into the Butterfly system prescription
the maxillary posterior brackets have -14 of torque to help Prevent buccal tipping of 1st and 2nd molars Reduced mandibular posterior torque -10 to improve Intercuspation and posterior overjet, flatten curve of wilson, and reduce interferences.
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Angulated first molar attachments The butterfly system incorporates -6 tip of the attachments welded to the first molar bands to compensate for the difference in marginal ridge heights. The bands are fitted evenly at the mesial and distal ridges, Prominent disto buccal cusps result when 1st molar bands are fitted to marginal ridges instead of placing molar attachments parallel to buccal cusps.
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Mandibular:Torque
Angulation
Rotation
Central incisor Central incisor lateral
-5
+2
0
-10
+2
0
-5
+5
0
Lateral
-10
+5
0
canine
-3
+6
3D
1st premolar
-7
0
0
+3
0
2nd premolar -9
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Preventive mandibular anterior torque:Al Qabandi and colleagues reported 6-7 of lower incisor flaring simply from - leveling and aligning - class II elastics - clockwise rotation of mandibular plane - extrusion of maxillary incisors The lingual crown torque of -5 – is intended to resist the incisor tipping inherent in leveling mechanics. -10 preventive torque to counteract additional tipping from class II elastics www.indiandentalacademy.com
Butterfly bracket system is mainly based on modifications to the 2nd generation preadjusted edge wise system The intent was to take best from the past and to avoid common problems, thus producing more efficient treatment and more favorable results.
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Cannon Ultra Bracket System James .L. Cannon
A
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Summarizing so far‌ All the above prescriptions globally reflect the treatment philosophy of their different authors.
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Incisor torque
Andrews
Roth
Alex Root Bennett Hilgers
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Canine position
Andrews Andrews Roth Max
Alex
Root Bennett Hilgers
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conclusion The real value of PEA becomes apparent in finishing, the more accurate the appliance, the less time and effort required in this stage. Even though not required in initial stages ,in most cases some wire bending is required in finishing stage to precisely position teeth.
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