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The Differential Straight Arch Technique

INDIAN DENTAL ACADEMY Leader in continuing dental education

Introduction  Development of the Tip Edge Bracket.  Design Considerations of the Tip Edge Bracket  The Differential Straight Arch Technique  Studies with the Differential Straight Arch Technique  Conclusion  References. 

Introduction: 

The Edgewise mechanism with conventional, static archwire slots is the most popular appliance in the world today. However, the Edgewise bracket, which Edward Angle presented to orthodontics as “the latest and best”, 2 years before his death, reflects the non-extraction philosophy that he espoused in the later years of his career. It has no provisions to facilitate space closure in posterior segments, and its archwire slot also restricts antero-posterior correction of dental arches, compared to its precursor, the ribbon arch.

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Angle spent the last years of his life, attempting to perfect the Edgewise mechanism He suggested the use of second order bends in the archwire, to tip crowns distally.

Subsequent changes in the edgewise bracket such as wider, twin brackets and preadjusted archwire slots have increased and refined the level of tooth control.  However, they also produce an active strain on anchorage even before any attempt is made to retract teeth.  This stationary or "reverse" anchorage is the result of holding the roots of all teeth to be moved at distal inclinations throughout treatment.  Simple leveling with preadjusted brackets can cause undesirable mesial movement of an entire arch. 

Development of the Tip Edge Bracket ď Ź

An early attempt to modify the Edgewise bracket was made by Alexander Sved, who removed all mesiodistal angular control from the arch wire slot in 1937.

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The bracket never became popular, no doubt because it had completely lost its "edge."

In 1968, Peter.C.Kesling, concluded that differential tooth movement (crown tipping followed by controlled root uprighting) requires that each tooth tip freely, either mesially or distally, not in both directions. In his famous article, “Expanding the Horizons of the Edgewise archwire slot” AJO-DO 1988, he introduced a slot that had diagonally opposed surfaces that would permit initial crown tipping, controlled in both direction and degree, and final Edgewise torque and tip control with straight

. A, Edgewise bracket with conventional arch wire slot.

B, Diagonally opposed corners of the slot are chamfered to permit mesiodistal tipping in predetermined direction. C, Tip-edge bracket slot has ability to control desired tip angle through horizontal surfaces and torque from a rectangular wire between central ridges or pivots.

Parts of the Tip Edge bracket Tip-edge bracket for maxillary right canine. Internal components of the "propellor" slot include: A and A, crown tipping control surfaces; B and B, root uprighting control surfaces; C, vertical and torque control ridges or pivots; D, rotational control surface.

Central ridges and uprighting surfaces of the archwire slot are also preangulated to provide final labial or lingual crown torque, with a straight rectangular wire.  The slot is designed so that initial second order changes, (mesio distal crown tipping) can be carried out in the presence of a straight, round archwire and powered by light intra-oral forces- elastics or coil springs.  Forces for subsequent root uprighting, tip and/or torque are generated by auxiliaries, not by flexing of the archwires. 

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Design Considerations of the Tip Edge bracket: Elimination of undesired torque forces to promote rapid bite opening and prevent midline discrepancy The absence of directly opposed parallel surfaces in the arch wire slot reduces or eliminates the action of undesired mesial or distal root torquing forces during overbite correction. Such root torque frequently occurs when continuous, straight arch wires (even though relatively small and round in cross section) are initially engaged into conventional edgewise slots.

Tip-edge bracket on upper anterior tooth eliminates couples permitting relatively rapid depression and overbite correction with light, arch wire force (0.20 oz [6 gm] per tooth). B, Conventional edgewise bracket on same tooth. Engagement of arch wire creates undesired torque force that can interfere with bite opening and cause a dental midline discrepancy

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The central ridges of the arch wire slot provide pivot points for the arch wire that enhance free crown tipping and diminish lateral root apex displacement .

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Therefore, Tip-edge brackets permit anterior teeth to depress under light arch wire forces, which results in relatively rapid bite opening and subsequent correction of anteroposterior discrepancies through predetermined crown tipping.

The central ridges (CRs) provide upper and lower pivot points between the arch wire and slot. This unique feature in a horizontally facing slot permits full engagement of the arch wire on a tipped tooth with little or no vertical deflection.

One hundred percent inter-bracket distance ď Ź

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The Tip-edge bracket is the first edgewisetype bracket to provide automatic mesiodistal tip control and 100% interbracket distance. If malposed teeth are tipped mesiodistally, at different levels or rotated, interbracket distances become extremely important. Even if a small round arch wire is used, the force couples and associated torque influences created often are detrimental to attaining treatment objectives.

Neither ribbon-arch nor edgewise brackets can provide 100% interbracket distances for malpositions in both the vertical and horizontal planes. However, the Tip-edge bracket, with its propeller shaped arch wire slot, can provide 100% interbracket distance in both planes. A 0.016-inch round wire usually can fully engage the slot on each anterior tooth without deflection. This is due to both slot design (chamfered corners) and dimension (0.022 inch). The central ridges provide one-point vertical contact with the arch wire and the horizontally facing slot provides 100% interbracket distance in that plane.

Initial use of 0.016-inch round arch wire in 0.022-inch Tip-edge bracket slot creates a 36째 tipping range that permits arch wire engagement in most cases. This feature in a horizontally facing slot provides effective 100% inter bracket distance in both the vertical (A) and horizontal (B) planes.

Slot design automatically permits tipping or holds tooth upright to create anchorage

   The diagonally opposed crown tipping and root

uprighting control surfaces of the arch wire slot determine whether a tooth tips toward its ultimate position or remains upright to serve as an anchorage unit according to the needs of the case and the direction of the applied force. Another unique feature of the slot design is that the same set of brackets functions properly to correct Class I, II, or III malocclusions.

Tip-edge arch wire slots also permit the retraction of both dental arches as would be required in a Class I bimaxillary malocclusion with generalized spacing. For nonextraction correction of Class II or III malocclusions, the same brackets permit retraction of the malposed teeth of one dental arch while enhancing anchorage in the other. When full-sized arch wires are engaged in each bracket of a Class II malocclusion, the lower teeth can act as one large anchorage unit by resisting mesial tipping from Class II intermaxillary elastics. Simultaneously the upper teeth freely tip distally for correction of the overjet and other Class II relationships

In a Class III malocclusion, the application of Class III intermaxillary elastics automatically reverses these mechanics and retracts the lower dental arch while simultaneously restricting mesial movement of upper premolars and canines. Whether a tooth tips freely or serves as an anchorage unit is determined by the cross section of the arch wire, direction of force application, and the design of its Tipedge arch wire slot. Dental arches can be repositioned with light forces (2 oz) and differential tooth movement and still maintain final control over the torque and tip angulations of each tooth. Total three-dimensional control is not a constant but an option and is used only when required— usually near the end of

Retraction and/or space closure using light forces with minimal arch wire deflection ď Ź

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The arch wire slot of the Tip-edge bracket permits closure of extraction spaces or retraction of entire dental arches through tipping and subsequent uprighting with little or no vertical arch wire deflection. When Tip-edge brackets are used, only 2 oz per quadrant is required to retract six, eight, or even ten teeth in cases featuring extraction of first or second premolars or first permanent molars

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Tip-edge bracket permits retraction by distal tipping of the canine with little or no flexing of the wire. B, Retracting the same tooth with a standard edgewise bracket can actually result in distal crown tipping and simultaneously cause flexing of the arch wire and extrusion of anterior teeth. Relatively heavy forces normally used can also displace anchor molars.

The ability of Tip-edge brackets to retract teeth and close extraction spaces without arch wire deflection can be illustrated by the "treatment" of a Class II malocclusion featuring extraction of the four first premolars. The same set of brackets is used on the six upper and lower anterior teeth as is used for nonextraction treatment. However, the chamfers of the arch wire slots in the second premolar brackets are reversed to permit mesial rather than distal crown tipping. This permits the closure of extraction spaces through tipping from light forces but provides for control of final crown uprighting from springs

Differential tooth movement (crown tipping followed by root uprighting) normally does not subject anchor molars to forces sufficient to initiate their mesial movement until spaces are closed. At that point, they are restrained from moving mesially through the contiguity (proximal contact) of all teeth mesial to them and the reciprocal forces of mesial root uprighting— contiguously reciprocal uprighting.

Bracket design provides increase in slot size with mesial or distal tipping The chamfers or tipping surfaces of the arch wire slot are extended beyond one another. ď Ź Because of this, the slot automatically increases in width relative to the arch wire as the tooth tips mesially or distally ď Ź

Maxillary right canine bracket and arch wire. A, Slot dimension is 0.022 inch when uprighting surfaces are parallel with the arch wire. B, Slot can increase to 0.027 inch when distal tipping of canine occurs. This permits changing from 0.016 to 0.022-inch arch wires with no deflection

This is one of the most beneficial (yet least obvious) features of the Tip-edge bracket arch wire slot since it can facilitate placement of both initial 0.016-inch arch wires and subsequent larger wires— up to 0.022 inch in diameter. It also provides varying degrees of control ranging from initial one-point contact with a round wire to final, predetermined torque and tip angulations for each tooth with a rectangular wire.

Slot design can cause automatic shift from tipping to bodily movement


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The arch wire slot of a Tip-edge bracket can stop mesial or distal crown tipping at a predetermined inclination and concurrently increase the anchorage potential of a tooth.

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This automatic shift from tipping to bodily movement is an example of programmed differential mechanics at work.

In malocclusions with excessive spaces, such as those caused by congenitally missing or relatively small teeth, this feature prevents over retraction of anterior teeth.

Once the 25° crown tipping surfaces of canine brackets strike the arch wire, tooth movement automatically becomes bodily and is slowed proportionately.

If the other anterior teeth tip distally to their bracket limits (20°), the combined resistance values may then exceed those of the anchor molars and, with continued and/or increased forces, the molars will begin to move mesially.

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On the other hand, in first premolar extraction situations, anchor teeth (first molars) may for various reasons move forward excessively. The crowns of second premolars then can become mesially tipped to the limits of their slots with tipping surfaces then striking the arch wire. Subsequently, further mesial movement of these premolars must be bodily and the premolars can become anchor teeth themselves to help support the molars.

Side-Winder springs for concentrically powered uprighting. 

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Side-Winders are mesial or distal uprighting springs with power coils that are concentric with the desired axis of root uprighting. Have several advantages over standard springs with their gingivally positioned coils. Improve both esthetics and hygiene. Offer a choice of insertion from either the occlusal or gingival aspect Appear to be more efficient than standard springs.

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With the Side-Winder, the center of the power coil is concentric with the center of the bracket (the desired axis of uprighting) and the resulting force vectors are vertical at the contact points with adjacent teeth. This would seem to maximize the desired distal root positioning and minimize mesial displacement of the crown.

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However, when the center of the power coil is gingival to the desired axis (standard uprighting spring), the vectors of force at the level of the arch wire would tend to move the crown mesially to open space distally and/or apply undue pressure to the lateral incisor


Labial or lingual torque from a rectangular wire with the Tip-edge bracket 

The Tip-edge bracket slot can deliver torque force to the tooth through contact of its central ridges and/or root-uprighting surfaces with the flat upper and lower surfaces of a rectangular wire. While receiving labial or lingual torque force from a rectangular wire, the mesiodistal inclination of the tooth must be controlled by an uprighting spring or an elastomeric Tip-edge ring. The root will then tend to move along a compound curve created by the wire and the spring or ring.

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The arch wire slot can function also as a "shock absorber" to cushion the high levels of torque and mesiodistal uprighting force usually associated with the insertion of full-sized square or rectangular arch wires into standard edgewise arch wire slots.

If the crown of an anterior tooth is tipped distally and lingually, the design of the Tip-edge slot allows arch wire engagement with little or no vertical (second order) flexing. The arch wire slot also will be larger than the cross section of the wire, thus permitting engagement with less torsional (third order) flexing of the wire and, therefore, less torque force. After the upper and lower surfaces of the arch wire and the uprighting surfaces of the slot reach full contact and alignment, the crown is maintained at these predetermined tip and torque angles with a Tip-edge ring.

The hammock effect ď Ź

When a ligature, either steel or elastomeric, is used to retain an arch wire in a Tip-edge bracket, a "hammock effect" is created that tends to parallel the arch wire with the gingival and occlusal edges of the tie wing tips.

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This could influence mesial or distal crown inclination.

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The "hammock effect" from conventional elastomeric rings that normally are used as ligatures is relatively light and clinically insignificant.

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Tooth crowns are able to tip distally or mesially to the full range allowed by their arch wire slots from light elastic or arch wire forces in the presence of such rings.

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Steel ligatures usually are used only to reduce friction and facilitate sliding of teeth along the arch wires. They are tied loosely, which also reduces or eliminates the hammock effect to permit mesial or distal tipping. A large (0.012 inch or more), tightly tied steel ligature could inhibit tipping and might be used to stabilize or enhance the anchorage potential in a particular tooth. When a tooth is at its final position near the end of treatment, an elastomeric Tip-edge ring normally is used to maintain the desired crown tip.

Mesiodistal angular control from a Tip-edge elastomeric ring 

A Tip-edge elastomeric ring can effectively control the mesiodistal inclination of a tooth. The resilient crossbar and lugs wedge between the arch wire and the tipping surfaces of the slot. The tooth is urged gently toward, or held in, its final tip angulation with the arch wire

Differential Straight Arch Technique   

The Differential Straight Arch Technique takes full advantage of the Tip Edge brackets. Treatment is divided into 3 stages. Specific archwires and auxiliaries are employed during each stage.

Stage One: 

In contrast to conventional edgewise techniques, which tend to approach correction of each aspect of a malocclusion sequentially, Stage One of the DSAT initiates treatment by addressing the correction of all major aspects simultaneously.

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This includes existing over or under jets, crowding or spacing, and anterior deep or open bites.

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Stage One is the only stage of the DSAT in which archwires are used to directly generate tooth moving forces-especially for anterior alignment and bite opening. Goals of Stage One: Vertical correcton of deep/open bite. Horizontal correction of anterior over or underjet. Align anterior teeth to eliminate crowding or spacing.

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Correcting Anterior Overbite: Correction of anterior deep bite allows full expression of any potential mandibular growth in correction of a Class II malocclusion. Stage one archwires are formed from 0.016� high tensile stainless steel wire. In extraction treatment, archwires are generally straight ( no vertical loops) with bite opening bends placed several millimeters mesial to the molar tube. This allows distal sliding of the archwire as retraction of anterior teeth occurs.

Bite opening bends are placed to the degree that the anterior portion of the archwire lies in the deepest part of the muco-buccal fold when passive. It is important that the premolars not be bracketed and engaged at the start of treatment, as this dissipates the intrusive forces of the bite opening bends and turns them into molar tip back bends. Proper use of Class II elastics (1-2 oz. On each side) in conjunction with properly modified high tensile stainless steel wires will correct severe anterior overbites within 4-6 months of treatment. Note: Use of excessive elastic force , or use of overly resilient wires may worsen the deep bite rather than improve it.

Bite-opening bends displace anterior portions of 0.016 inch Australian arch wires gingivally to reduce anterior overbite.)

Initial 0.016-inch arch wires (Extra Special Plus grade of stainless steel by A.J. Wilcock) and 0.018-inch coaxial alignment auxiliaries and light (1.5 oz) Class ll elastics. Ribbon archtype brackets on canines were used for traction only.

When anterior open bite - or edge to edge incisal relationship exists at the start of treatment, the maxillary archwire is kept straight. ď Ź Very mild bite opening bends are placed in mandibular arch (5-10°), serving only to prevent the molars from tipping mesially in response to application of Class II elastics (if overjet correction is required.) ď Ź

Correcting overjet or underjet  Accomplished simultaneously along with anterior

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vertical discrepancies through use of either Class II or III elastics depending on incisor relationships. Overjet or underjet in absence of anterior overbitecan be corrected with horizontal (Class I) elastics if space is available in the arch for retraction. Eliminates possibility of molar extrusion. Particularly important in high angle or anterior open bite cases.

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In patients who do not show compliance with elastics wear, an Outrigger appliance may be placed. This features two hooks that extend labially when the elastics are not worn, providing an uncomfortable but not painful reminder that elastics are not in place. Note: during Stage one , the resultant vector that intrudes and retracts the maxillary anteriors, may have a tendency to cause labial flaring of incisors. The ends of the wire are bent distal to the molar tube to prevent this. This is an example of differential tooth movement- pitting teeth that can only move bodily, against those free to tip.

Anterior Alignment: ď Ź

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When space is available distal to the canines, anterior alignment is achieved by using elastomeric ties to the archwire through the vertical slots of the Tip Edge brackets. The Tip Edge archwire slot allows adjacent teeth to simply tip out of the way as lingually displaced teeth are brought into position.

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When moderate to severe crowding is present at start of non extarction treatment, vertical loops are placed in the anterior segments of 016 inch archwires.

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Rotations are corrected using rotating springs inserted through the vertical slots of the brackets. These are over corrected whenever possible and held in these positions throughout treatment

Stage Two  Primary

goal is the closing of posterior

spaces.  It is the shortest of the three stages of Tip Edge treatment, usually completed in 2 to 3 appointments.  Patient is instructed to wear light (1.5-2 oz) Class II or Class III elastics as needed to maintain desired anterior tooth relationships.

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Goals of Stage Two:


Close remaining posterior spaces. Correct or maintain dental midlines. Correct posterior crossbites. Achieve Class I molar relation Over rotate severely rotated premolars. Level anchor molars. Maintain all corrections achieved in Stage One.

2. 3. 4. 5. 6. 7.

Stage Two Mechanics: 

For maximum control, 022 inch round steel wires are placed in both arches, with mild bite opening sweeps in case of prior deep anterior overbite.

In mild to moderate anchorage cases, the archwires are engaged through the occlusal rectangular molar tubes during Stage II.

This levels the premolars and molars early , easing the transition to Stage III.

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In maximum anchorage cases, where friction within the molar tube is of concern, it is preferred to insert the archwires through larger diameter gingival round tubes.



Automatic Canine Rotational Control During Retraction. With the Differential Straight Arch Technique, no canine rotation problem occurs during space closure. ď Ź This is because forces are applied not to the labial surfaces, but at the contact point with lateral incisors, which are moved distally along with centrals by the archwire. ď Ź

Braking mechanics in Stage Two 

In cases where abundant space is present in the mandibular arch, over retraction of the anteriors is not desired. Application of mechanical brakes, (Sidewinder springs on premolars, canines and incisors, in conjunction with 022” round wire or 0215x028 rectangular wire) prevents unrestricted lingual or distal crown tipping of anteriors. Relatively heavy (6-8 oz) horizontal force are applied between anterior resistance unit and posterior teeth.

Stage Three 

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The goal of Stage three is to bring all teeth to their final, desired axial inclinations either palatally / labially or mesio distally. Generally takes 9-12 months for extraction cases, and 6 months for non extraction cases. All mesio distal uprighting and labial/lingual torquing is accomplished by forces generated from auxiliaries. Wire used is either 022” round wire from Stage Two, or full size 0215x 028 rectangular wire.

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Torquing as well as mesio-distal uprighting are self limiting. Patient can go for 3 to 4 months or longer between adjustments, without any adverse effects. Uprighting auxiliaries: Side Winder Springs are employed for mesiodistal uprighting. Torquing Auxiliaries: Most commonly used torquing auxiliaries are the nickel titanium Torque Bars which are curved ribbon arch sections of 022 x 028 ” Nickel titanium formed with 20 or 30 degrees torque.

Rectangular torquing auxiliary. Cross section through auxiliary illustrates built-in 20째 of torque. Auxiliary placed lingual to main 0.022-inch round arch wire, which provides

For use of Torque Bars, special Deep Groove Brackets are used on the maxillary central incisors.  These feature conventional preadjusted Edgewise archwire slots cast into the bottom of Tip Edge archwire slots.  A cap fills the Deep Groove in Stages One and Two. This is removed at beginning of Stage Three , and a Torque bar ligated tightly lingual to the round base archwire. 

A. Standard Tip-Edge bracket. B. "Deep Groove" version for maxillary incisors, featuring conventional edgewise slot that is filled with special cap to keep archwire in outer slot during Stages I and II. C. Cap is removed for Stage III and deep groove used to engage nickel titanium torquing auxiliary under main archwire.

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For torquing of individual teeth, an Individual Root Torquing Auxiliary is used. These are often used with Ceramic Tip Edge brackets, which do not have the Deep groove feature.

Stage three Anchorage control: 

Unique aspect of Tip Edge technique is the ability to control timing of anchorage strain.

This occurs only during Stage Three when occlusion is already in Class I and there is no spacing mesial to the anchor molars.

The relatively heavy forces from uprighting springs and torquing auxiliaries are applied to the teeth only after all teeth are in proximal contact, or contiguous.

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When the crowns of teeth are inclined distally, these reciprocal forces will reinforce anchorage as the teeth are initially urged distally against the anchor molars during the early phase of uprighting.

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Kesling refers to this as Contiguously Reciprocal Uprighting.

Round wire or rectangular wire for finishing?  

Round Wire Approach: Reseved for severe A-P skeletal discrepancies, as they permit maxillary and/or mandibular teeth to assume compensating labiolingual inclinations. Also used when patient does not need molar torque or selective labiolingual root positioning of canines or mandibular incisors. In such cases, torque to maxillary incisors could be provided by Torque bars.

Rectangular Wire  

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Their practicality in Stage Three was demonstrated by Richard Parkhouse. Strongest indications are: Generalized and individual torquing requirements, such as for molars, canines, mandibular incisors. Molar torque is nearly impossible to achieve with round wire. Placement of Sidewinder springs on all other teeth in conjunction with rectangular wire, automatically torques them. For full torque expression, full size rectangular wires, 0215 x 028 ” are used.

Studies using the Differential Straight Arch Technique. ď Ź

Canine retraction: A comparison of two preadjusted bracket systems. Lawrence P. Lotzof, Howard A. Fine, George J. Cisneros. (AJODO 1996). The purpose of this study was to compare the time required to retract canine teeth by using two different preadjusted bracket systems (Tip-Edge, TP Orthodontics, LaPorte, Ind., versus A-Company straight wire, Johnson and Johnson, San Diego, Calif.) in a human sample. Anchorage loss as a result of this movement was also evaluated.

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All patients required the removal of first premolars in one or both arches as a part of their orthodontic treatment. Each subject received two different brackets placed on opposite canine teeth within the same arch. There was no statistically significant difference in the rates of canine retraction. The mean anchorage loss was 1.71 mm for the Tip-Edge bracket, and 2.33 mm for the straight wire bracket.

Clarence E. Shelton, Jr., DDS, George J. Cisneros, Stanley E. Nelson and Paul Watkins. ( AJO DO 1994) compared the treatment time in Class I non extraction cases between 28 cases treated with the Begg technique and 25 cases with the Tip-Edge appliance. The average treatment time for the Tip-Edge group was 12.80 months versus 20.89 months for the Begg group. The Tip-Edge appliance may thus reduce treatment time in Class I nonextraction therapy

Employing Tip-Edge brackets on canines to simplify straight-wire mechanics.R.T.Rocke AJO-DO 1994 

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The author reported two premolar extraction cases in which Straight Wire brackets were used in conjunction with Tip Edge brackets only on the canines. The canines were retracted by tipping backwards followed by uprighting with Sidewinder springs. The advantage was that there was no deflection of the archwire during canine retraction and no resulting deepening of the bite.

Comparison of Standard Edgewise, Preadjusted Edgewise and Tip Edge in Class II extraction treatment. Ramos, Killiany, Kesling. JCO 2001 The efficiency of these three appliances was retrospectively evaluated in the treatment of 105 similar malocclusions by 8 experienced orthodontists. Treatment time was significantly different among the three groups,with standard edgewise patients treated in a mean 31.1 months,TipEdgepatients in 27.1 months, and preadjusted edge -wise patients in 26.0 months.

Tip-Edge patients had the fewest appointments (19.4),followed by preadjusted (27.6)and standard edgewise (33.9) patients. The number of arch wire changes was also significantly different,with the preadjusted group showing the most changes (a total of 12wires), the standard edgewise group next (10wires),and the Tip-Edge group the least (7 wires). Also Headgear wear was not required in the Tip Edge cases.

Kaku etal ( J Clin Orthod 2004) reported the use of Tip Edge brackets in a case following molar distalization with Greenfield Molar Distalizer, in order to allow the anterior teeth to tip back and close the spaces without taxing molar anchorage. In addition, the anterior teeth were not forced to come forward during leveling and aligning due to absence of opposing moments acting on them. This further reduced the anchorage requirements.

Conclusion ď Ź

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The use of Tip Edge brackets in conjunction with the Differential Straight Arch Technique, provides the orthodontist with the advantages gained by free initial crown tipping, as well as the final luxury of automatically achieving predetermined tip and torque angles. The use of light gentle forces results in kind treatment of the teeth as well as less taxation of anchorage.

References   

Kesling,P.C.:Expanding the horizons of the edgewise arch wire slot,Am.J.Orthod 1988;94:26-37, Kesling,P.C.:Dynamics of the Tip-Edge bracket, Am.J.Orthod. 1989.96:16-28, Kesling PC, Rocke RT, Kesling CK. Treatment with Tip Edge brackets and differential tooth movement.AJO DO 1991; 99: 387-401. Kesling CK. The Tip Edge concept: eliminating unnecessary anchorage strain.J Clin Orthod 1992;26:165178. Rocke RT. Employing Tip-Edge brackets on canines to simplify straight-wire mechanics. AJO DO 1994;106:34150. Shelton C, Cisneros G, Nelson S. Decreased treatment time due to changes in technique and practice philosophy. AJO-DO 1994; 106:654-57.

Lotzof L, Fine H, Cisneros G. Canine retraction: A comparison of two preadjusted bracket systems. AJODO 1996;110: 191-196. Galicia-Ramos, Killiany D, Kesling PC. A Comparison of Standard Edgewise, Preadjusted Edgewise,and Tip-Edge in Class II Extraction Treatment. J Clin Orthod 2001;35:145-53. Parkhouse R, Parkhouse P. The Tip Edge torquing mechanism: a mathematical validation.AJO DO 2001;119:632-639. Kaku J, Arimoto H, Sinohara N, Greenfield R. Use of Tip Edge Brackets to reduce posterior anchorage requirements after molar distalization. J Clin Orthod 2004;38; 320-324. Orthodontics:Current Principles and techniques. Ed.TM Graber, RLVanarsdall Jr, 3rd edn, Mosby, 2000. Pp.721748. Leader in continuing dental education

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