EDGEWISE APPLIANCE
INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
Contents :Evolution / Historical perspective 1) Bandelette appliance 2) Angle’s E–arch 3) Pin &Tube appliance 4)Ribbon arch appliance 5) Edgewise appliance Attachments Modification of edgewise brackets Evolution of buccal tube
www.indiandentalacademy.com
Bracket placement &angulation Evolution of the technique -Primary edgewise -Secondary edgewise -Tertiary edgewise Ideal arch form Three orders of tooth movement Tweed’s philosophy of treatment Anchorage preparation Aims & goals of treatment Diagnostic facial triangle Growth trends General plan of treatment Merrifield’s modification
www.indiandentalacademy.com
Evolution of appliance First attempt at tooth movement in1728 by a French physician Pierre Fauchard Bandalette appliance-crude alignment of teeth by expansion of the dental arches Disadvantage : lacked stability no effective means of firmly fixing it in position
www.indiandentalacademy.com
1849-Dwinelle developed jack screw 1871-Magil introduced dental cements to attach bands on teeth 1866-Kingsley advocated the use of extraoral forces No attempt was made to correct malocclusion by placing teeth in a stable soft tissue environment Angle believed that teeth when moved into their correct occlusal relationship,stability would be assumed
www.indiandentalacademy.com
The E arch appliance(1880) First typical orthodontic fixed appliance Rigid framework –Molar bands with heavy labial arch wire soldered to them, Teeth tied to it by means of brass ligature wire Crown movement & simple anchorage Teeth were expanded into normal occlusion
www.indiandentalacademy.com
4 different designs: Basic E-arch Ribbed E-arch E-arch without threaded ends that fit into molar sheaths ,used with an attached ball for high pull head gear in the incisor area E-arch with hooks for intermaxillary elastics Also had a maxillo mandibular growth guidance Disadvantages :1) correction of axial inclination could not be accomplished 2)long term retention was required
www.indiandentalacademy.com
www.indiandentalacademy.com
The Pin &Tube appliance(1912) Ideal arch of E-arch was not there Arches were altered as tooth movement carried out progressing towards ideal archform Bands with tubes soldered on it Pins soldered on the archwire & made to fit into tube perfectly Change position of pin ,solder it again on archwire to a different position & fit into the tube again Disadvantage:difficult to solder & unsolder pins time consuming
www.indiandentalacademy.com
Ribbon arch appliance
(1915)
To overcome disadvantage of pin & tube Brackets with vertical slot introduced Archwire initially confirmed to malocclusion ,held in place by brass pins Rectangular wire with longer dimension vertical Overcame 2 major problems: 1) archwire placement 2) M-D movement of teeth Teeth were free to move along the archwire like strings of beads www.indiandentalacademy.com
Teeth could tip M-D ,even with lockpins Angle devised cleats to be soldered to archwire to contact the sides of the bracket Held the teeth upright ,but necessitates soldering new cleats at different locations Disadvantage:-relatively poor root control -mesial & distal tipping bends could not be incorporated - enmass movement of teeth in an anteroposterior direction was not easy
www.indiandentalacademy.com
The Edgewise appliance(1925) Solution to all problems –latest & best in orthodontic mechanism Changed the form of bracket located the slot in the center & placed it in a horizontal plane instead of a vertical Bracket wide mesio-distally Rectangular slot for rectangular archwire .022x.028 slot size ,Same size wire Archwire inserted in narrowest dimension -EDGEWISE Initially called open face or tie brackets Archwire held with brass ligature & S-S ligature later
www.indiandentalacademy.com
Accessories used in edgewise
www.indiandentalacademy.com
Types of headgear used:High pull :- intrusion of maxillary incisors increase the lingual root torque used with cl.II elastics Intermediate pull headgear :- distalise maxillary dentition when bite is not deep hold the maxilla during anchorage preparation Low pull headgear :- open bite case support mandibular dental arch in older patients The Kloehn cervical gear:- growth trend is type A or C restricting the maxillary growth so that mandible can catch up www.indiandentalacademy.com
Angle "malocclusion must be treated s.t.the denture is a self-sustaining ,self maintaining unit and all parts of denture exerting or sustaining forces must be perfectly balanced� 1) fully normal proximal contact relations of teeth 2) normal cusp & inclined plane relation 3) normal upright axial position & relation of teeth this is essential if the teeth are to balance with the muscles & sustain the forces of occlusion www.indiandentalacademy.com
Angle introduced the bracket 2 yrs.before his death Proposed nonextraction treatment for all malocclusion Expansion of the dentition –method of teeth alignment Muscular balance was upset,teeth were moved to an unstable positions-------high frequency of relapse Little attention to establishment of anchorage
www.indiandentalacademy.com
Graduated from an Angle course given by George Hahn in 1928 Tweed diagnosed & treated cases under Angle’s guidance He held to Angle’s firm conviction that one must never extract - for 3 yrs. High frequency of relapse – discouraging Important observation1) facial balance &post treatment success related to upright mandibular incisors 2) to get lower incisors upright ,one must prepare anchorage & extract teeth
www.indiandentalacademy.com
His technique can be summarised as an anchorage technique While most operators were concentrating on how best to move teeth ,he focused himself on how not to move teeth To a great extent “cart has been placed before the horse�,Dr Tweed placed the horse where he belongs ,in front of the cart Angle gave orthodontics the edgewise bracket ,but Tweed gave the speciality the appliance
www.indiandentalacademy.com
Among his other contributions :a)Emphasized the four objective of orthodontic treatment with emphasis & concern for facial esthetics b)Developed the concept of up righting teeth over basal bone esp.lower incisors c)Made the extraction of teeth for treatment acceptable d)Enhanced the clinical application of cephalometrics e)Developed the diagnostic facial triangle to make cephalometrics a diagnostic tool & a guide in treatment & evaluation of results f)He developed the concepts of orderly treatment procedures &introduced anchorage preparation as a major step in treatment g)He developed a fundamentally sound & consistent preorthodontic guidance program using & popularizing serial extraction of primary & permanent teeth www.indiandentalacademy.com
Over the years several modifications in the appliance Angle advocated Non–extraction treatment Basic concepts which are cornerstones of modern edgewise orthodontics:1)Ability to obtain tooth movement in all 3 planes of space with a single archwire 2)The philosophy of treating to an ideal arch or to Angle’s concept of ‘Line of Occlusion’ The line with which ,in form and position according to type,the teeth must be in harmony if in normal occlusion.
3)The use of rectangular or square edgewise arches which if properly employed can control arch width ,arch form ,B-L crown inclinations,axial root inclinations & incisor crown-root torque www.indiandentalacademy.com
Types of head gears High pull:- Intrusion of maxillary incisors Increase lingual root torque Used with cl. II elastics Intermediate pull:-Distalize maxillary denture when bite is not deep. Hold the maxillary arch when using cl.III elastics during anch.preparation Low pull:- In open bite cases To augment anchorage in mandibular arch in adult patients The Kloehn cervical gear:-restricting maxillary growth to allow mandibular growth in growing patients www.indiandentalacademy.com
ATTACHMENTS Evolution of edgewise brackets Original bracket – soft gold , . 022 x .028 inch slot 1)Single width brackets original bracket .050 inch wide & soldered to the gold band material archwire rests on bottom of bracket slot instead of the band ineffective for tooth rotation because of the narrow width Angle devised gold eyelets to be soldered on bands www.indiandentalacademy.com
2)Twin brackets - two brackets on one base -“Siamese twin brackets” by Swain - space between two brackets was .050 inch (equal to width of one bracket ) Main advantage : - ability to effect tooth rotations without using auxiliaries Available in different widths: Extra wide Standard Intermediate Junior
www.indiandentalacademy.com
3)Curved base twin bracket curved bases to confirm to the curvatures of the canines & premolars Advantages of twin brackets : Offers a positive control Disadvantages: increased width decreases the inter bracket span ,thus decrease the resiliency
www.indiandentalacademy.com
4)Lewis bracket Developed by Lewis in 1950. To overcome the problem of efficient tooth rotation. He soldered auxillary rotation arms that abutted against the bracket itself thus, offered a lever arm to deflect the archwire & rotate the tooth. One piece bracket with integral rotation wings These wings do not interfere with occlusogingival deflections of archwire & do not decrease the interbracket span www.indiandentalacademy.com
5)Curved base Lewis bracket Curved base confirms to the canine ,premolar surface Wings lie close to the tooth throughout their length ,so less trapping of food
www.indiandentalacademy.com
5)Vertical slot Lewis bracket Incorporation of .020 x .020 inch vertical slot Possible to use uprighting spring to correct axial inclinations if needed Advantages of Lewis brackets: 1) complete rotational control 2)do not reduce the interbracket span
www.indiandentalacademy.com
Steiner bracket Given by Cecil C Steiner in 1931 Incorporated flexible rotation arms & so did not rely on the resiliency of the archwire for tooth rotation Introduced tie wings for ease of ligation
Broussard bracket Designed by Garford Broussard for use in the Broussard technique Addition of a 0.0185 x 0.046 inch vertical slot to accept a doubled 0.018 inch auxillary wire www.indiandentalacademy.com
Evolution of edgewise buccal tube Original appliance had .022x .028 inch gold or nickel silver tubing soldered to the molar band Length –3/16 or ¼ inch Notched distal ends- to facilitate a tie back ligature Hook –gingival to buccal tubes ,soldered on the bands for placement of elastics Inconel tube- gold buccal tubes were discarded Stamped buccal tube with welding flanges or Inconel tube which could be soldered to the band www.indiandentalacademy.com
www.indiandentalacademy.com
Combination buccal tubes Incorporates a round tube for insertion of a face bow Fairly close tolerances must be maintained between archwire & tube for effective transmission of torque to the tooth
Triple buccal tube additional rectangular tube for auxillary sectional & base archwire
www.indiandentalacademy.com
Bracket & tube placement Angle“goal of correct bracket & tube placement is to produce an ideal occlusion at the end of treatment with flat ,straight ,ideal archwires Tweed advocates – millimeter measurement from bracket slot to the incisal edge UPPER ARCH LOWER ARCH Centrals –4.5 Laterals –4.0 Canines –5.0 Premolars-4.5 Molars –3.5
Anteriors-4.0 Canines-4.5 Premolars-5.0 Molars-4.0
www.indiandentalacademy.com
Bracket angulation Brackets –parallel to the long axis of the tooth Holdaway (1952) described three uses for bracket angulation a) as an aid in paralleling roots adjacent to extraction spaces b) as a method of setting up posterior anchorage units into tipped back or anchorage prepared positions c) as a means of obtaining correct axial inclinations or artistic positioning
www.indiandentalacademy.com
Evolution of technique Primary edgewise *as described by Angle in 1929 *fully banded technique-gold bands ,soldered soft brackets *flat ideal arch wire -to provide normal occlusion *original arch was of .022 X .028 in.gold wire *to be adapted passively to all malocclusion *if space had to be made ,loops are soldered onto main arch *if space closure required , spurs & tie backs used *involves all the teeth to be brought under control so,treatment should be initiated after eruption of canine & premolar www.indiandentalacademy.com
www.indiandentalacademy.com
Secondary edgewise *to avoid the making archwires passive *use of round wires in the initial stages *gold was replaced by a more rigid alloy *frequency of extractions increased *bands with prewelded brackets *in 1940s round .045in.tubes were also soldered on the upper molars for a face bow
www.indiandentalacademy.com
www.indiandentalacademy.com
Tertiary edgewise or Tweed’s edgewise *stressed on the importance of anchorage preparation *advocated the use of cl. III elastics & extraoral traction *vigorous forces were now employed *space closure was done by simple vertical or horizontal open loops bent into the archwire or by push coil tie -backs
www.indiandentalacademy.com
Tweed’s philosophy Based on the following :a)
Practically all malocclusions are characterized by a forward adjustment of teeth in relation to their basal bones --- this is due to deficiency between the basal bone & tooth material
b)
The establishment & maintenance of a stable anchorage should be the initial concern of the operator & is a fundamental factor in successful orthodontic treatment
c)
Teeth like inanimate objects ,best resist the force of displacement when tipped to the angulation that offers the most advantageous mechanical against the pull of dislodging forces .they are best stabilized when they overlie the basal bone www.indiandentalacademy.com
d)Teeth are most readily moved when their property & power of mechanical resistance has been primarily reduced e) All forces emanating from an orthodontic appliance must be synchronized if they are to be most effective in the mass stabilization or the mass movement of teeth f) Nature being an expert mechanic herself ,offers biologic compensations & adjustments when teeth are placed in position of mechanical advantage for force resistance g) The dental units will best resist forward displacement when the buccal teeth are in mild distal axial position & the incisor teeth are in mild lingual axial inclination & overlying a substantial bony foundation “placing the incisors on the ridge� www.indiandentalacademy.com
Every malocclusion exemplifies a denture that is stabilized by balanced muscular forces & this muscular balance must be preserved in treatment if stability in the end result is to be accomplished ( Strang & Thompson )
www.indiandentalacademy.com
Facial types Tweed divided the facial types into following types:TYPE A :-Maxilla & mandible show forward & downward growth -ANB angle remains the same -Prognosis is good -Treatment not indicated during mixed dentition if ANB angle does not exceed 4.5 TYPE A Subdivision:- ANB angle greater than 4.5
www.indiandentalacademy.com
TYBE B :- Maxilla & mandible grow downward & forward with maxilla growing more rapidly than mandible - When ANB angle is 4.5 or less prognosis is favorable - Extraoral appliances should be used immediately after extraction TYBE B Subdivision :- ANB is large & found to be increasing -Undesirable growth trend, treatment long & difficult
www.indiandentalacademy.com
TYPE C :- -Maxilla & mandible grow downward & forward with mandible growing more than maxilla -ANB increasing -Growth is favourable & treatment is facilitated by growth TYPE C Subdivision :- mandible grows more than maxilla but only to a little extent
www.indiandentalacademy.com
Tweed’s Diagnostic facial triangle Basis for diagnosis & treatment planning Consists of the following :1) FMA –the Frankfort mandibular plane angle 2) IMPA –the incisor mandibular plane angle 3) FMIA – the Frankfort mandibular incisor angle
www.indiandentalacademy.com
www.indiandentalacademy.com
Angle FMA Visual 25 cephalometric 24.57 Range 15 – 36
IMPA 90 86.93 76 – 99
FMIA 65 68.20 56 – 80
For successful treatment triangle should be attainable Aim should be to obtain:FMIA of 70° – 75° ( when FMA = 20 ) FMIA of 65° ( when FMA = 30) When FMA is less than 20° FMIA should be more than 70° & IMPA should not exceed 94°
www.indiandentalacademy.com
He showed that in well balanced faces – IMPA was 90°±5° For every degree that FMA was in excess of 25° .the incisor mandibular angle IMPA would have to be decreased by 1° Treatment objectives :Facial balance & harmony Stability of the post treatment dentition Healthy oral tissues Efficient mastication
www.indiandentalacademy.com
Anchorage preparation Stable anchorage –important to prevent forward movement of mandibular denture when cl.II intermaxillary force is applied On histological basis Brodie (1937) believes that the strongest anchorage is provided by stable fixation of teeth –to allow as little movement as possible Tweed – anchor teeth best resist the dislodging forces when their vertical axes are parallel to the direction which offers the most advantageous mechanical resistance against the pull of dislodging forces
www.indiandentalacademy.com
Strongest anchorage is provided by tipping back the crowns of the teeth so that they will have a disto-axial inclination that will resist a forward pull First & most important step in treatment - Anchorage preparation If anchorage preparation is not done -the action of intermaxillary elastics cause elevation of terminal molars & depression of mandibular incisors. Thus,canting of occlusal plane, increase in FMA , point B drops downward & backward , entire mandibular denture is tipped & displaced forward into protrusion www.indiandentalacademy.com
Classification of anchorage preparation First degree- minimal anchorage preparation, -applicable to all malocclusion with ANB =0 to 4 , -total discrepancy does not exceed 10 mm, -terminal molars must be uprighted & or maintained in an upright position to prevent their being elongated when cl. II intermaxillary force is used . www.indiandentalacademy.com
Second degree-for malocclusions with ANB more than 0° to 4° -facial esthetics requires to move point B anteriorly & point A posteriorly i,e cl. II cases -usually accompanied by type A, type A subdiv.,type B & type B subdiv. -degree of distal tipping of mandibular molars more severe than first degree anch.prep. –they should be tipped so that their distal marginal ridges are at gum level www.indiandentalacademy.com
Third degree –severe discrepancy cases –14-20mm or more -ANB does not exceed 5° -generally cl.I bimaxillary cases -sliding jigs are necessary -2nd ,1st molars & 2nd premolar must be tipped to such an extent that the distal marginal ridges are below the gum level also called total anchorage preparation
www.indiandentalacademy.com
Ideal arch form-
orthodontic arch is the form which moulds the dental arch with every bend reflected in the position of the teeth Angle “ if an archwire is placed in brackets with uniform slot depths,it must take the form of the outline of the buccal & labial surfaces of the teeth” Unique alignment of upper lateral incisor –thinner labiolingually & short crown length
www.indiandentalacademy.com
Contact points lie on an ellipsoid curve There is a straight line from canine to mesio buccal cusp of first molar,but the beyond that it curves inward progressively Bonwill-Hawley diagram is widely used to decide arch form
www.indiandentalacademy.com
Bonwill-Hawley diagram is widely used to decide arch form
General pattern 窶電ecided by studying the original models & of the muscle behavior of the patient rather than based upon widths of teeth themselves www.indiandentalacademy.com
Three orders of tooth movement Movements necessary to bring the teeth into the line of occlusion –first ,second ,third orders First order bends-horizontal change relative to the line of occlusion -also called in -out bends -do not alter the horizontal plane of the wire -the action & reaction of these bends affect expansion or contraction -used to move individual teeth -the interaction of bends can affect the third order position of the teeth if expansionary forces are used www.indiandentalacademy.com
Second order bends -represent a vertical change -also called tip/angulation -used to tip posterior teeth mesially or distally-may be tip back or tip forward bends
www.indiandentalacademy.com
Third order bends -torsional change (with the line of occlusion serving as axis) -also called torque or inclination movement -used to obtain axial changes in the buccolingual or labio-lingual root & crown axis on one or more teeth There are two types of torque 1)passive 2)active www.indiandentalacademy.com
Tweed summarised his philosophy on which his appliance therapy is based:i) Normal occlusion is best maintained with the mandibular incisors in their normal axial inclination when related to the F-H plane approx. 65째(FMIA) ii) The ultimate in balance & harmony of facial esthetics is achieved only when the mandibular incisors are positioned over the basal bone iii) The normal relationship of the mandibular incisors to their basal bone is the most reliable guide in diagnosis & treatment of cl. I ,cl. II &bimaxillary protrusion cases and also in attainment of balance & harmony of facial profile & permanence of tooth position
www.indiandentalacademy.com
General plan of treatment Treatment divided into 3 phases:a)Anchorage preparation b)Distal enmasse movement of maxillary buccal segments c)Establishing correct denture form & completing treatment objectives Anchorage preparation involves:1) placing mandibular incisors upright 2) changing axial inclinations of the maxillary incisors, to make them less resistance to distal movement 3) changing the axial inclinations of buccal teeth to a more distal axial inclination www.indiandentalacademy.com
Extaction treatment a)Leveling of arches .o18 in. wire with molar stops /tie back spurs at the molar tube & distal tip back bends in posteriors cl. III elastics & headgear Working arches U/L .019 X . 025 in. with mild second order bends Uprighting of canines-horizontal loops soldered mesial to second premolars
www.indiandentalacademy.com
Uprighting of canines-horizontal loops soldered mesial to second premolars Canine bracket is not engaged in the wire
www.indiandentalacademy.com
Anchorage preparation .021 X .028 stabilization wire with mild second order bends in upper arch .019 X .028 in working wire in lower arch with tip back bends & sliding jigs to bear pressure on 2nd premolar bracket cl. III elastics are worn Once anchorage preparation done – reverse the mechanics cl. II elastics are worn
www.indiandentalacademy.com
Distal movements of canines & incisors U/L .019 X .025 archwires with second order bends & open coil springs compressed mesial to canines are inserted cl. III elastics aid in distal movement of mandibular canine Headgear applied to upper arch aids in upper canine retraction
www.indiandentalacademy.com
Incisor retraction Using .019 X .025 archwire with closed Bull loop distal to canine –activated 1mm every 3 wks. Mandibular incisors are retracted to an FMIA of 65° in cl.I cases & 70° in cl.II cases Maxillary incisor retraction completed –heavier .021 X . 027 in.wire ,reduced posterior to lateral incisors & passed free of canine Strong lingual root torque in upper anteriors for bodily retraction
www.indiandentalacademy.com
Stops are soldered 3mm mesial to 2nd premolar brackets Coil springs compressed against the stops
www.indiandentalacademy.com
Correction of cl. II relationship Now , mand.arch -.021 X .028 in. max.arch -.019 X .025 in. with accentuated tip back bends Mand. arch tied back to receive cl. II elastics 窶田ontinued till normal cusp relation is achieved
www.indiandentalacademy.com
Completion procedure Final space closure & detailed tooth positioning -.019 X .026 in. max. & mand.ideal arches ,coil springs compressed mesial to 2nd molar tubes until space closure is completed Vertical elastics are used for seating cusps if bite is open
www.indiandentalacademy.com
cl. II div.1 –non-extraction treatment Preparation of anchorage in the lower arch Preparation of anchorage in the upper arch Distal enmasse movement of maxillary arch Detailed positioning of teeth ANCHORAGE PREPARATION Initial leveling & alignment - .016 or .018 round wires Working arch wire .019 X .025 in. with coordinated tip back bends cl. III intermaxillary hooks soldered mesial to canine Loop stops are made mesial to molar tubes but the archwire not tied to molar anchor teeth
www.indiandentalacademy.com
Upper arch is stabilized -.021 X .028 in.wire with mild tip back bends Intermediate pull headgear mesial to canine is used to augment the anchorage - min. 14 hrs./day Distal pull by headgear –twice as much as mesial pull on the arch by cl. III elastics During day – light cl. III During night –heavy cl. III Distal tip back bends increased slightly every 2-3 wks.
www.indiandentalacademy.com
Stabilization arch -.021 X .028 in. wire with same degree of tip back bends as in working archwire Passive in mandibular incisor region Total time required – aprrox. 4 mons. Anchorage preparation in upper arch Excessive inclination of the proclined upper incisors is reduced by using .018 in. round wire Important – this provides unfavorable stationary anchorage & resist distal / lingual movement of the teeth Heavy stabilization wire with mild second order bends is placed www.indiandentalacademy.com
Enmasse distal movement of maxillary arch Upper arch wire -.021 X .028 in. reduced distal to lateral incisors Mild lingual crown torque if incisors are proclined Intermaxillary hooks on archwire –patient put on cl. II elastics Watch out for mandibular anchorage –any signs of mobility ,increase the tip back bends After 3 wks. –tip back bends in the maxillary arch are increased ,stronger elastic force is applied until normal relation of teeth attained Mild palatal root torque in anteriors Continue till incisors in edge –edge relation & posteriors in good occlusion www.indiandentalacademy.com
Detailed positioning of teeth Proper seating of cusps is obtained by fitting correlated U & L ideal arches carrying vertical spurs for vertical elastics between them
www.indiandentalacademy.com
Bimaxillary dentoalveolar protrusion Two types of cases:1)Axial inclinations of all the teeth in the arch inclined abnormally forward (both in cl.I & cl. II cases ), Dental arches are more or less well aligned 2) Axial inclinations of teeth in buccal segments fairly upright ,irregular & crowded Steps in treatment: Anchorage preparation in lower arch Anchorage preparation in upper arch Extraction of four premolars Multiple loops .016 in. archwire U/L used for alignment Space closure done using looped archwire www.indiandentalacademy.com
Treatment of cl.III malocclusion Objective:1)To correct abnormal buccolingual inclination of all posterior teeth in both arches 2)Constrict the mandibular arch which is too broad 3)Expand the maxillary arch which is too narrow 4)Move maxillary arch forward enmasse ,using mandibular arch as stationary anchorage
www.indiandentalacademy.com
Steps in treatment Initial .016 in. round wires After 2 wks. ,.021X .027 in. U/L ideal arches Brass wire hooks mesial to canine Mandibular archwire is bent considerably narrower than the ideal & torque is placed in the buccal segment Step forward 2nd order bends placed in maxillary posterior segment (direct opp.of tip back bends) Intermaxillary elastics from lingual of maxillary molar to hook mesial to mandibular canine When cross bite is corrected –archwires are reshaped to the ideal Treatment continued until the maxillary teeth have moved forward enmasse into occlusion with teeth in mandibular arch.
www.indiandentalacademy.com
www.indiandentalacademy.com Leader in continuing dental education
www.indiandentalacademy.com