Since its development by the late Dr. Spencer R. Atkinson, the Universal Appliance has undergone periodic refinements without losing its essential characteristics In the original design, the lateral extending tabs or wings were too bulky and the central shaft was too narrow and shallow to accommodate the archwires and pins or ligatures comfortably.
The modified design is known as the 3-D Universal Appliance due to its tridimensional mechanical principal. The bracket is essentially a vertical hollow shaft with two lateral welding tabs. The central shaft has two slot openings. The horizontal one opens labially at the gingival third and will accommodate .008 up to .016 round wire. The vertical slot opens incisally near its base and extends gingivally one-third of the bracket height. It will accommodate a single wire, a double wire, a twisted bundle of round wires, or a single ribbon or flat wire ranging from .008 x .020 up to .016 x .028. The 3-D Universal Bracket is wider mesiodistally and deeper buccolingually than the original design.
The six basic movements achievable with the 3-D Universal Bracket are:
1. Correction of mesiodistal axial inclination with the gingival wire 2. Correction of rotation with the incisal wire 3. Torque to correct buccolingual axial inclination 4. Combination of the first three movements 5. Vertical or incisogingival movement 6. Horizontal or mesiodistal bodily movement
The archwire inserted in the incisal slot may be used alone or in combination with a wire in the gingival slot. The combination provides the appliance with full control in all the three planes of space, with one wire controlling the mesiodistal movements and the other the labiolingual and rotational movements. Hence, five archwire combinations are available:
1. Round gingival wire alone 2. Round incisal wire alone 3. Flat incisal wire alone 4. Two round wires used simultaneously 5. Round gingival wire and flat incisal wire used simultaneously
The Incisal Wire: The incisal wire whether round or flat, is used for the correction of rotations, for leveling and for torque. Archwires in the incisal slot are also used as a guiding rail when coil springs are used at the gingival level, producing a smooth bodily tooth movement.
The Gingival Wire: The gingival wire will correct mesiodistal axial inclinations, leveling, act as a guide when teeth are moved bodily in a mesial or distal direction and it performs as a fulcrum for labiolingual movements and lingual root torque.
Comparison of Previous Universal Bracket with 3-D Universal
Modular Self-Locking Appliance:
The Modular Self-Locking Appliance System was introduced by Maxwell Fogel and Jack Magill in the year 1976. It is a light wire system using a single pivotal bracket or twin self-locking low frictional attachments. The unique feature of this bracket system is the development of an adaptable receptacle, which makes possible the use of the combination technique. The bracket has a horizontal slot, which opens labially, and three vertical slots, which lie lingual to the receptacle. The horizontal slot has been added to accommodate the orthodontist who still desires the facility. Otherwise, the horizontal slot is not used during routine treatment.
Insert Bracket: The principal module is the insert bracket, which is made of a special soft stainless steel to withstand the various demands made upon it. It can be opened and closed as many times during treatment as necessary. The elements of the insert bracket are:
Archwire Chamber: The round archwires float freely in the .025 archwire chamber. The chamber is strategically placed in relation to the bracket wings permitting adequate tipping. Beaks: Beaks are flared forming a funnel shaped entrance for the wire. Beaks can be opened and closed for containment and release of the archwire. Insert Slot: Entrance formed by the shape of the beaks, facilitates easy access for the archwire. Slot Apex: Constricted portion of funnel, permits snapping in and retention of wire prior to closure of the beaks. Seat: Base of insert bracket, which rests in the grooved wing of the receptacle for stability Stem: Extension of the insert bracket fits into the vertical slot and holds insert bracket in position when bent at right angle.
Placement of Insert Bracket: The insert bracket is fitted into the vertical slot of the receptacle. The stem is cinched and bent laterally with a light wire plier or dull ligature cutter, pressed snugly under the wing and against the side wall of the receptacle.
Receptacle: The receptacle is made in three sizes- small, medium, wide and is contoured for specific teeth in the anterior and posterior segments. The three vertical slots accommodate insert brackets and auxiliaries. A single slot is used in the early stages and both mesial and distal slots are used in the finishing stages. It is suggested that the receptacle be placed towards the incisal edge of the band in order to provide sufficient metal backing for the insert bracket.
Insertion of Light Wire into Insert Bracket: The round archwire is snapped into the insert bracket with mild finger pressure. In situations involving major malpositions of teeth, a wire director may be used to guide the archwire into the insert slot. Closure of the insert bracket beaks is accomplished by gently using How pliers.
Removal of Archwire from Insert Bracket: Removal of the archwire is accomplished by opening the insert bracket with an insert spreader. The insert spreader, an .012” flat bladed instrument, is carefully fitted into the insert slot and simply pushed forward, opening the slot to its original dimension and preparing the release of the archwire. The wire is snapped out of the slot using a scaler.
Modernized Begg-Combination Technique: William J. Thompson
The rationale behind this approach was to develop a technique and a bracket system that uses the advantages of both Begg and Straight Wire at the same time minimizing the disadvantages. To understand the rationale behind the development of this appliance, one must understand the advantages and disadvantages of both the Begg and Straight Wire Appliance Systems.
Favourable Characteristics of the Begg Appliance are: 1. Rapid bite opening: The Begg appliance is superb in bite opening 2. Rapid anterior alignment 3. En masse retraction of the six anterior teeth 4. Anterior root torque is unlimited because it depends on the torquing action produced by the auxiliaries 5. Supportive extra-oral anchorage is not necessary as the posterior anchorage is not taxed because of stationary anchorage 6. Predictable molar and incisor positions
Unfavourable Characteristics: 1. Posterior root torque is difficult 2. Three dimensional arch coordination is difficult 3. Maintaining rotations is difficult because the single point contact tends to permit undesirable tooth movements 4. Finishing intricacies are difficult
Favourable Characteristics of Straight Wire Appliance: 1. Precision arch coordination is routine 2. Precision intercuspation is routine 3. Buccolingual root torque is routine 4. Simplified finishing wires are routine
Unfavourable Characteristics: 1. Rigid appliance due to increased interbracket distance 2. More friction with sliding mechanics 3. Additional supportive anchorage is necessary 4. Forward tipping of incisors in continuous wire leveling 5. Prolonged bite opening mechanics
Hence, the Begg appliance is rapid in early treatment but becomes more cumbersome in the finishing stages. The straight wire system is prone to complications in early periods of treatment but is efficient in the final finishing adjustments.
An appliance that captures the advantages of both systems and reduces the disadvantages of both is the combination bracket. The new appliance enables the orthodontist to combine both the tipping and bodily movement principles of mechanics. The dual capability of the appliance is due to the combination design in which the lower third of the bracket is a type 256 Begg bracket and the upper two thirds of the bracket is a .018” x .025” straight wire slot with in-out positioning and preangulated and pretorqued.
The Begg slot will accept all auxiliaries and archwires used in Begg treatment and it performs as a typical Begg bracket in relation to tipping, bite opening etc. All Begg slot heights are dictated by the edgewise slot and as such are 1 to 1.5 mm more gingival than in a routine Begg set up. Free tipping is made possible by means of a specially tapered bracket slot. Begg molar tubes are kept gingivslly and can be obtained with convertible straight wire tubes on the lower molar . The second molars should not be incorporated into the Begg system initially. All Begg treatment should be built around the first molar as the anchorage unit. After the bite is opened and the retraction of incisors is complete, the second molars can be banded. Begg procedures should be carried completely through Stage I and Stage II and at least partly through Stage III. Use of the edgewise portion of the bracket is not begun till late Stage III.
Stage III is essential; the combination bracket is not intended as a substitute for this phase of treatment. Stage III mechanics should be continued until the occlusion approaches a fairly level plane and the edgewise slots are almost parallel within 5 degrees of the horizontal. When this level of alignment has been achieved, the Begg portion of treatment is discontinued and .018” x .025” rectangular wires are placed in the edgewise slot for finishing.
The Beddtiot Appliance: Richard Hocevar
Beddtiot Stands for Begg Edgewise Diagnosis Determined Totally Individualized Orthodontic Technique. These brackets are narrow, single-width (0.050 inch or 1.3 mm) edgewise brackets with 0.022 inch (height) x 0.028 inch (faciolingual depth) horizontal arch wire slots. On the lingual side of the bracket (that is, against the band or bonding pad) is a 0.020 x 0.020 inch vertical slot. Except for torque, the brackets are all identical. Therefore, they are interchangeable. Placed with its torque-indicator groove gingival, a bracket provides lingual root torque; with the groove occlusal, it provides lingual crown torque. The standard torques make up a set with a smooth progression— 0°, 5°, 10°, 15°, and 20°.
The brackets are small in all dimensions to ensure optimal appearance and minimal lip and cheek irritation. This also lessens occlusal interference, enamel surface involved in bonding, and problems with gingival proximity and oral hygiene. Narrow brackets have long, resilient spans of arch wire between them— a great advantage over twin edgewise brackets.
The dimensions of the arch wire slot allow considerable (but limited) mesiodistal tipping on undersized wires (10° distal crown tip on 0.016 inch, the usual working wire), as well as limited uprighting (5° mesial crown tip on 0.018-inch arch wire).
The vertical slot has many potential uses. It can accommodate ligatures, elastic hooks, rotation devices, and various other auxiliaries. If oriented horizontally, the "vertical" slot of the bracket can serve as a miniature buccal tube to gain control of partially erupted or impacted second molars. The attachment's size facilitates avoidance of occlusion. It also allows bonding where only a small area of tooth surface has emerged.
The basic buccal tubes are conventional 4.5 mm long, 0.022 x 0.028 inch "edgewise" tubes with 25° lingual crown torque for lower and 10° for upper first molars. The distal end of the maxillary tube is angulated outward 10° from the welding flanges to maintain the proper rotation ("toe-in"). In cases with deep overbites or moderate-to-severe anchorage requirements, an additional rectangular tube is carried diagonally across the buccal surface of the basic tube, its mesial end pointing gingivally.
The additional tube (outer tube) is like the basic tube. The outer tube crosses the inner tube at an angle of approximately 15° and is somewhat gingival to the inner tube. It carries the main (working) arch wires during the bite-opening and retraction phases of treatment, while rectangular sectional wires in the inner tubes and second premolar brackets lock molar and premolar teeth together so neither can tip independently; as a unit they provide tremendous anchorage for bite opening and retraction. The gingivally positioned and angulated outer tubes direct the arch wires away from the danger of distortion from mastication. They provide effective built-in "anchor bend" while the actual bends can be slight (usually about 25°). Sectional wires make the molar and premolar teeth, in effect, a single large tooth with its CR further mesial than the CR of the molar.
When the posterior teeth are used as anchorage for retraction, the molar cannot tip forward without intruding the premolar; nor can the premolar tip mesially without extruding the molar. Finally, the fact that the outer tube is rectangular and torqued like the inner tube makes it convenient to use rectangular wires when the orthodontist wishes to apply reverse torque to lower incisors that he is intruding.
Disadvantages: Control of rotations is difficult and requires the use of auxiliaries.
The Tip-Edge bracket was designed by Peter Kesling based on his experiences with differential tooth movement. These brackets are designed to cause distal tipping of all teeth except those distal to the extraction sites, which tip mesially. The face of the edgewise slot has been changed to permit free crown tipping followed by controlled root uprighting. Removal of diagonally opposed corners of a conventional edgewise slot creates the basic Tip-Edge bracket. The archwire slot is .022” x .028” has has the interesting feature of increasing in vertical dimension (up to .028”) as the crown tips.this permits stepping up to larger size archwires (from .016” to .022”) with no flexing or binding.
Lateral extensions (wings) on the bracket provide maximum rotational control even when the tooth is tipped. This permits the bracket body to be narrow for maximum esthetics. Each bracket has a vertical slot to accept rotating or uprighting springs, power pins and jigs for accurate direct bonding. The vertical slot is .020” x .020” with both the gingival and incisal ends chamfered to facilitate the insertion of auxiliaries from either direction. It can also be used to accept a ligature on a lingually displaced tooth.
Tip-Edge brackets are available in both extraction and non-extraction kits and with torque in the base or torque in the face. The Tip-Edge slot has two surfaces: tipping surfaces and uprighting surfaces. The tipping surfaces limit the degree of initial crown tipping. The uprighting surfaces determine the final degree of tip reached with an uprighting spring. These surfaces also control torque if an edgewise archwire is engaged after major uprighting and torquing have been achieved with auxiliaries.
Molar Tubes: Tip-Edge molar tubes are cast and have a .036” round gingival tube and a .022” x .028” occlusal tube with a removable cap. Usually only the first permanent molars are utilized for anchorage. Tip Edge kits are available as – 1. Extraction and non extraction kits 2. Torque in base /face 3. Over rotational bracket 4. With in/out compensations 5. Positing jigs 6. Tip edge rings
In/Out Compensation: Tip-Edge brackets are cast with in-out compensation to eliminate the need for lateral, premolar or molar offsets.
Overrotation Brackets: Brackets with special wedge shaped bonding bases are available for overrotating central and lateral incisors. They automatically rotate and hold the teeth with 8 degrees of overrotation with no need for first order bends.
Tip-Edge Rings: Tip-Edge rings are elastomeric ligatures designed to retain the archwire and prevent mesial or distal tipping. Lingually facing lugs on either end of a crossbar wedge between the archwire and the bracket to control the mesiodistal inclination of a tooth. Used to hold teeth upright during Stage III.
Advantage over original edgewise – 1. Adversely tipped teeth 2. Better Anchorage control
Advantage over ribbon arch- 1. Built inIn\out compensation. 2. Prevent distal crown tipping of cuspid
Combination Anchorage Technique (CAT) Brackets: William J. Thompson
The original combination brackets proved to be bulky, weak and esthetically unattractive. Although capable of Begg and Straight Wire mechanics, design deficiencies made them less effective. Problems with pinning, rotations, slot closure and occlusal interference were chronic irritants and were eliminated in the design of the new combination bracket.
The CAT bracket is comfortable and esthetically pleasing to the patient. It has a .022” x .035” gingival or ribbon arch slotand either a .018” x .025” or .022” x .028” straight wire edgewise slot. An enclosed vertical slot is also incorporated into the bracket for use with uprighting and rotating springs, elastic or surgical fixation hooks and for attachment of tandem or double archwires. All brackets are identified by colour coding dots at the distogingival aspect. Maxillary brackets are red and mandibular brackets are blue.
Maxillary incisor brackets can now be obtained with varying degrees of torque and maxillary canine torque has now been reduced to 0 degrees. This reduces the prominence of the canine roots on the labial plate. Torque on the lower premolar has been changed from 17 degrees on the first premolar and 20 degrees on the second premolar to 19 degrees for both the premolars, which reduces both the inventory requirements and identification problems. Molar attachments now have convertible double tubes to facilitate extending the straight wire into second molar tubes.
Bracket size and contour have been reduced. The new bracket is less buccolingually and on the peripheral edges. These changes have reduced lip irritation caused by bracket bulk and practically eliminated distortion of lower premolar tie wings caused by occlusal interference. A redesigned pin slot and bracket pad has simplified placement and retention of pins.
Phase I and II treatments are now completed with the same type of pin. New auxiliary extension pins, which permit fixation of tandem archwires, are now recommended for Phase III treatment. Extension pins are also used as surgical ligation hooks.
Begg-Ribbon Arch Combination System (BRACS): Nikhil S. Vashi
The Begg-Ribbon Arch Combination System is an appliance that combines the advantages of Begg appliance like rapid bite opening, use of light tipping forces for retraction with those of Edgewise and preadjusted appliances like precise finishing and total control over tooth movements.
The bracket has one gingival ribbon-wise slot (.018” x .027”) for round and rectangular archwires and two vertical slots for lockpins and ligature wires. It also has an incisal slot (.020” x .020”) for ligature wire or elastic modules. This slot can also be used for a stabilizing archwire if needed. The molar tube is rectangular ribbonwise for ribbon arch. It is placed at a 6 degree offset for distal rotation to achieve better molar control.
The bracket design is such that it would allow free tipping, controlled tipping or bodily translation of teeth as required. Different tooth movements can be obtained just by tying or pinning the archwire differently to the bracket. If the archwire is tied to the distal slot only, free distal tipping of the tooth would be obtained. If both the slots are used or if a single tie is used from mesial to distal then translatory movement would take place and controlled tipping would result if the archwire is loosely secured to the bracket.
BRACS has following advantages- 1. Rapid differential movements of teeth with better control and less friction. 2. Helps in proper finishing of the case. 3. Need for patient co-operation is minimal. 4. Eliminates the need for heavy elastics. 5. Eliminates complicated and unstable stage III mechanics. 6. Reduced the treatment duration
‘J’ Bracket- A new design of Begg (combination) bracket
The ‘J’ bracket was introduced by Dr. V. P. Jayade in 1991. This bracket attempts to harness the advantages of both the ribbon arch and edgewise brackets at the same time eliminating their disadvantages.
Requisites of a Good Combination Bracket:
1. It must be capable of deriving all the advantages of the Begg appliance and at the same time eliminate its disadvantages. 2. It must permit the incorporation of straight wire concepts at the finishing stage but it should not have the disadvantages of preadjusted edgewise brackets. 3. It should preferably be a bracket with more than one slot to permit the use of more than one archwire simultaneously, which allows application of forces over different areas of the tooth to derive optimum mechanical advantage. 4. It should be economical.
Advantages of Multiple Slot Brackets over Single Slot Brackets: 1. A combination bracket with more than one slot is much more efficient than a single slot bracket because many of our treatment requirements are diametrically opposite. For instance, we want the bracket to allow free crown movements during the first stage while we expect it to fully control the crowns during the third stage to provide maximum crown stability. Again in the first stage a unipoint contact between the wire and the bracket is desirable to allow free tipping while in the same stage we would prefer a broader contact for controlling rotations.
2. They offer the possibility of applying forces to the teeth at different areas eg. One can apply crown-tipping forces to closer to the incisal margin and root moving forces closer to the cervical margin of the crowns.
3. Switching slots helps in altering or reinforcing anchorage
4. Segmental wires, which offer greater versatility in force distribution can be used whenever necessary. Tandem wires can also be used.
Rationale of Orientation of Slots in the New Design:
Orthodontic brackets are generally cuboid (not cubic) meaning their height, width and depth dimensions are not identical. Hence, if the orientation of the slot is changed from horizontal to vertical, the width dimension would remain the same while the height and depth dimensions would interchange. In the conventional edgewise brackets, height of the slot (.018” or .022”) is less than the depth (.030”) thus permitting less play in a horizontal direction and more play in a vertical direction. Therefore, a change in the orientation of the slots results in a substantial change in their potential to allow or restrict certain movements while other movements remain unaltered. By carefully choosing the orientation of the slots we can minimize their drawbacks with respect to certain movements without affecting other movements, thereby increasing the overall efficiency of treatment.
The movements, which remain unaffected by the orientation of the slot, are: 1. Intrusion or extrusion of teeth 2. Labio-lingual crown tipping using round wires 3. Labiolingual root movements using rectangular wires To quote Hocevar “ the torquing action of a rectangular wire remains the same whether it is used in the edgewise or ribbonwise manner. Twisting the same wire through an equivalent arc requires the same force and produces the same range of movement whether this wire is used ribbonwise or edgewise.
The movements, which are affected by changing the slot orientation are: a. Mesio-distal crown tipping b. Rotational control
Mesio-distal crown tipping: Freedom for mesiodistal tipping depends on the play of the wire in a vertical direction and it increases with the height of the slot and decreases with its width. Edgewise brackets, if oriented vertically, would give more mesio-distal tipping freedom because the height dimension would change from .018” or .022” to .030”. In case of a Begg bracket a much greater height of .040” and a width of 1mmmakes the mesio-distal tipping freedom excessive. Hence, optimum freedom for mesiodistal tipping would be obtained by a narrow (1mm) unipoint slot with .024” height sufficient to allow about 14 degrees of tipping. However, the slot is kept facing horizontally so that it automatically restricts further crown tipping.
Rotational control: Rotational control increases in single wide or twin brackets. When the slots are oriented vertically, the decreased depth dimension (.018” or .022”) permits less play in a horizontal plane thus increasing the rotational control.
Twin slot arrangement also has its peculiar disadvantages: 1. They drastically reduce mesiodistal tipping due to increased width 2. They reduce the inter-bracket wire span which reduces the working range of the inter-bracket section of the wire
Net effect of the changed orientation of the slots: 1. Permits adequate mesio-distal crown tipping but restricts excessive croen tipping 2. Affords good rotational control 3. Allows to fully utilize the torquing abilities of rectangular wires
‘J’ Bracket Configuration: 1. A single slot (.024” x 1mm) employed for permitting easy tipping to an adequate extent in the initial stages faces horizontally, which automatically restricts excessive tipping as the teeth move. It is placed incisally so that crown tipping forces are applied closer to the incisal region giving a mechanical advantage 2. The twin slots (.032” x .018” depth placed 3 mm apart) face vertically. This has the advantages of: a. Far better rotational control b. Possibility of using Begg uprighting springs and torquing auxiliaries during the third stage along with a .018” round base wire c. Possibility of using full torquing potential of rectangular wires up to .018” x .025” in the finishing stage 3. Using both the slots together when necessary, the advantages of a combination bracket can be derived. The two archwires will complement each other and help in overcoming deficiencies of each other.
Molar Attachments: When only the first molars are available for anchorage, the molar bands will carry a gingival rectangular tube in ribbonwise orientation and a round tube occlusally. When both the first and second molars are to be utilized for anchorage, the second molar will have such a combination tube, while the first molars will have twin rectangular attachments gingivally, and an occlusal round tube.
The first self-ligating bracket, the Russel attachment, was developed by a New York orthodontic pioneer, Dr. Jacob Stolzenberg in the 1930’s. this bracket had a flat-head screw seated snugly in a circular, threaded opening in the face of the bracket. The horizontal screw could be loosened or tightened with a small watch-repair screwdriver to obtain the desired tooth movement. Loosening allowed bodily translation on a round wire, while tightening allowed root torquing with a rectangular or square wire. Perhaps because Dr. Jacob Stolzenberg was ahead of his time, the concept of self-ligating brackets fell into obscurity until the early 1970’s.
In 1971, Dr. Jim Wildman of Eugene, Oregon, developed the Edgelok bracket, which had a round body with a rigid labial sliding cap. A special opening tool was used to move the slide occlusally for archwire insertion. When the cap was closed over the archwire with finger pressure, the bracket slot was converted into a tube. The rigidity if this fourth outer wall rendered the bracket “passive” in its interplay with the archwire.
Passive brackets are inherently imprecise in their ability to control tooth movements because of their total reliance on the fit between the archwire and the bracket slot. This means that tooth control is compromised with undersized archwires. The Edgelok bracket was the first passive self-ligating bracket, and the first to enjoy any sort of commercial success.
About 2 years later, Dr. Franz Sander of Germany introduced the Mobil-lock. The Mobil-lock required a special tool to rotate the semicircular labial disc into the open or closed position. As with the Edgelok, the passive outer wall transformed the bracket slot into a tube.
At about the same time, Dr. Herbert Hanson of Ontario was working on the prototype of a new self-ligating bracket that by 1976 became the basic Speed design. The SPEED bracket was introduced into the market in 1980. SPEED stands for spring-loaded precision edgewise energy delivery.
The SPEED appliance consists of a narrow single width bracket body. The bracket body is multislotted with three main horizontal slots- a pre-torqued archwire slot, an auxiliary slot and a spring retainer slot. The archwire slot is available in either.018 x .025 inch or .022 x .028 and can accommodate round, rectangular, square or SPEED shaped archwires.
The .016 inch square auxiliary slot is designed to accommodate a variety of preformed hooks, segmental archwires or a ligature or elastomeric thread. The spring retainer slot houses the recurved tip of the spring clip. The slot is made deep enough to house the spring clip during most of the severe transient stresses. The Spring Clip: The most identifiable component of the SPEED bracket is the unique roll-shaped, flexible spring clip. The highly resilient spring clip opens and closes in a vertical manner to permit arch wire removal and insertion. Its shape has evolved to eliminate any possibility of an accidental archwire release through the incorporation of a recurved tip. The labial arm of the spring clip forms the fourth flexible wall, which not only contains the archwire but also actively interacts with it to bring about various tooth movements. This set the SPEED bracket apart as the only “active” design in its category at that time.
SPEED Appliance Function:
The SPEED appliance is unique in its manner of operation due to the presence of the flexible spring clip. The spring clip is responsible for controlling tooth movement in all three planes of space through rotation, tip and torque. Rotational Control: On archwire engagement, the SPEED spring clip is automatically activated by its displacement from it’s the resting position. The inherent nature of the spring clip is to return to its resting position. Any rotational correction is achieved through the torsional component of the deflection of the spring clip. This deflection creates a rotational couple consisting of a fulcrum and a spring clip force. Tip Control: The inclination and resiliency of the spring clip ensures full tip control. Any required tip correction is achieved through the labial deflection and subsequent return of the spring clip to its resting position.
Torque Control: The geometry of SPEED’s torque control lies in the combination of the mechanical action of the archwire in the slot with constant force application of the spring clip. The synergistic effect of these two components ensures the full expression of the built-in torque. The efficiency of this action is further enhanced through the combined effect of the spring clip and the uniquely beveled SPEED archwires. SPEED shaped archwires take full advantage of the inclined plane created by the SPEED spring clip.
In 1986, Dr. Erwin Pletcher designed the Activa bracket. The Activa bracket had an inflexible curved arm that rotated occlusogingivally around the cylindrical bracket bpdy. The arm could be moved into a “slot-open” or “slot-closed” position with finger pressure alone. Once closed, the rigid outer wall of the movable arm converted the bracket slot into a tube. The passive configuration of the Activa bracket limited its interplay with the archwire.
Drawbacks such as the ease with which the patients could open the bracket and a large mesio-distal bracket width eventually led to its commercial demise.
In 1995, another self-ligating model was introduced by Dr. Wolfgang Heiser of Austria called the Time bracket. The Time bracket was similar in appearance to the SPEED bracket but its design and mode of action are significantly different. The Time features a rigid, curved arm that wraps occlusogingivally around the labial aspect of the bracket body. A special instrument is used to pivot the arm gingivally into the slot-open position or occlusally into the slot-closed position. The stiffness of the bracket arm prevents any substantial interaction with the archwire, thereby rendering Time a passive bracket.
The Twin Lock bracket, a second endeavor by Dr. Jim Wildman, was introduced in 1998.Its flat, rectangular slid, housed between the tie wings of an edgewise twin bracket, is moved occlusally into the slot-open position with a universal scaler. It then slides gingivaly with finger pressure to entrap the archwire in a passive configuration.
Similar self-ligating brackets were introduced by Dr. Dwight Damon known as the Damon SL I and the Damon SL II. Both these are twin edgewise brackets. The difference between these two generations is that the first featured a labial covered that straddled the tie wings while the second incorporates a flat, rectangular slide between the tie wings. In both versions, the slide moves incisally on the maxillary brackets and gingivally on the mandibular brackets. Special opening and closing pliers are required to move the slide.
. In ovation brackets It is self ligating bracket system consisting of a twin bracket for rotational control and has an active clip for seating arch wire .
Manufactures claim that the bracket design not only combines all the important features of an effective self ligating system ,it goes even further to provide the highest level of versatility ,function and comfort Backet has the following features- Low profile Four full tie wings Slot blocker Horizontal V Slot Compound contoured base Torque in base
Advantages of Self-Ligating Brackets: Self-ligating brackets allow greater patient comfort Shorter treatment time, reduced chairtime and more precise control of tooth translation. Numerous studies have demonstrated a dramatic decrease in friction for self-ligating brackets compared to conventional bracket designs. Such a reduction in friction can help shorten the overall treatment time especially in extraction cases. Self-ligating brackets reduce the incidence of precutaneous injury to the index finger or thumb, which are sustained with steel ligatures when using conventional brackets
Brackets Used in Lingual Orthodontics
Lingual Light Wire Technique: Stephen F. Paige
With the advent of bonding of attachments directly to the teeth, the elimination of the band material kindled a desire for even more cosmetic appliances, which first resulted in clear plastic brackets and tooth-colored ceramic brackets. A current approach has been bonding brackets directly on the lingual surfaces of the teeth.
Fujita confirmed that orthodontic treatment with brackets placed on the lingual is possible and that there was an obvious improvement in esthetics and increased patient acceptance for this form of treatment. Patients who would not normally have had orthodontic treatment may now seek treatment, because of the esthetic nature of lingual treatment.
There is not only a very positive attitude toward the improved esthetics of the lingual appliance, but a uniquely improved patient comfort. With few exceptions, patients seem to be able to adapt quickly, with no trauma to the tongue. Another advantage is that the precise positioning of the teeth becomes more obvious without the distraction of the brackets and wires, and lip posture is seen correctly and not artificially positioned in front of the anterior teeth.
Enamel decalcification is a risk with any orthodontic treatment and can only truly be controlled with proper oral hygiene and fluoride therapy during treatment. The use of lingual brackets will not reduce the risk, but the lingual location can minimize the undesirable esthetic effects of decalcification. Oral hygiene procedures may be more difficult because of more limited accessibility, but Fujita has shown that patients with lingual appliances can maintain proper oral health. An obvious disadvantage to the lingual appliance is the difficulty of insertion and removal of archwires.
Bracket Design Criteria:
The first important factor to be considered in designing lingual attachments is that interbracket distance is reduced on the lingual. Therefore, the bracket must be designed to be as narrow as possible mesiodistally.
Secondly, as a consequence of decreased bracket width, mesiodistal root control becomes more difficult. Cuspid and bicuspid uprighting after closure of extraction spaces requires efficient mechanisms for uprighting. A possible solution to this problem is the use of vertical slots for arch auxiliaries.
The third factor to consider is the topography of the lingual surfaces of the maxillary and mandibular anterior teeth. The lingual contours of the anterior teeth seem to vary a great deal. Because of the concave and convex surfaces, the amount of torque supplied to the tooth by the bracket will be very sensitive to its occlusal-gingival placement. A very small change in the occlusal-gingival placement can produce a large change in root torque. This problem could be solved by indirect bonding procedures.
A fourth factor for consideration would be ease of insertion, ligation, and removal of the archwires. A very satisfactory solution is the incisal/occlusal placement of the archwire. The use of vertical slots could permit the use of pins to increase ease of ligation.
The author initially chose the Begg bracket because it satisfies these design criteria nicely and was available from many manufacturers. It is as narrow as possible and has a vertical slot for use of auxiliaries. Lingual tooth contours on the maxillary and mandibular teeth are much less of a factor because torque control can be achieved by properly shaped torquing auxiliaries, much like conventional Begg mechanotherapy. Ligation can be achieved with steel ligatures, elastic modules, or pins. The slot can be oriented in an occlusal-incisal direction to ease archwire placement and removal. Placement of the bracket is sensitive only to the incisal-gingival placement because angulation and inclination can be achieved with the use of auxiliaries.
Subsequently, the author switched over to the Unipoint combination bracket (Unitek), with the slot oriented in the occlusal-incisal direction. The horizontal slot of this bracket is not routinely used during treatment. The author used the horizontal slot in the early phases of treatment to aid in unraveling of crowded anteriors, but it is not usually necessary. The reason he switched to the Unipoint combination bracket was because of the need to have a gingival "wing" to place elastic modules on continuous elastic chains.
Molar Tube Design:
A conventional oval tube with a mesiogingival hook is used. Initially, the reasoning behind the oval tube was to allow for double-back bends to prevent irritation to the tongue. However, the discovery that the distal end could be bent in a buccal direction negated the need for a double-back bend. The oval tube has some advantages in that it increases patient comfort, allows molar control, and will accept a ribbon arch.
Lingual Begg Light Wire Technique: Peter K-J Yen
Peter Yen developed an alternative lingual technique that uses regular Begg light wire and labial brackets.
In this technique, TP 256-500 mini-mesh lower incisor labial brackets, which have narrow bonding bases, are used for both upper and lower incisors. The brackets are adapted to the study models to conform to the lingual surfaces of each tooth. The mini-mesh may be ground to make it narrower.
Upper lateral incisor labial brackets are adapted to the cuspids, and the curved upper cuspid labial brackets to the bicuspids.
To provide proper interbracket distance in Stage I, the vertical slots of the brackets should be directed incisally for incisors and cuspids and occlusally for bicuspids. For Stage II and Stage III, a new set of brackets must be bonded with the vertical slots directed gingivally.
Molar Tube: A .036" tube with a mesiogingival hook is soldered to the lingual surface of each molar band. The tube should be centered occlusogingivally and placed slightly to the mesial of the band. A tube can be welded to the buccal surface of the band for crossbite elastics or space closure during Stage II.
Archwire: The mushroom-shaped archwire should have horizontal loops for elastics distal to the cuspids. Offset bends are usually necessary at the bicuspids and molars. A toe-out bend is generally used in the lower arch and a toe-in bend in the upper, depending on the amount of constriction or expansion needed. The distal ends of the archwire can be annealed to permit easy bending into the embrasures and prevent tongue irritation.
The Conceal System: Thomas Creekmore
An acceptable lingual orthodontic appliance system must include the following key elements: a. A mechanical appliance that aligns teeth from the lingual aspect as efficiently as a labial appliance b. A means of positioning brackets precisely to create a "near" straight-wire appliance on the lingual aspect c. A consistent and accurate indirect bonding technique d. A selection of preformed arch wires complete with canine-premolar offsets e. Specially designed pliers with longer handles and offset beaks
The Appliance: The foundation of the design is the opening of the arch wire slots to the occlusal aspect rather than to the lingual aspect. The occlusal approach makes arch wire insertion, seating, and removal easier than arch wire insertion with lingually opening slots.
The first 1 mm of the molar tube opens to the occlusal aspect, providing direct guidance for insertion of the arch wire occlusal to the arch wire plane. As the ends of the arch wire are inserted into the tubes, the rest of the arch wire moves gingivally directly into the occlusal opening of the bracket slots.
This is in contrast to lingually opening slots that require insertion of the arch wire distally beyond anterior brackets, constriction of the arch wire lingually to engage premolar slots, and then bringing of the arch wire mesially to fully engage the anterior brackets.
The occlusal design approach did have potential problems that had to be solved: specifically, a design of premolar and molar brackets that would provide effective ligation, a design of anterior brackets for a better quality of ligation, and a design of all brackets that would provide adequate tip control.
A critical breakthrough was the design of premolar and molar brackets, with occlusal tie wings projecting mesially and distally instead of labiolingually. These tie wings change the direction of the ligature pull by 90°, effectively seating the arch wire in the bottom of the slot. Anterior brackets use this same design feature to enhance the quality of their ligation.
Each Conceal bracket has three different slot widths for the three different functions of tip (A-B), torque (E-F) and rotation (C-F or E-D).
Tip control in an occlusally inserting system is analogous to rotation control in a labial system. Both depend on the length of the lever arm and the quality of the ligature tie to seat the arch wire in the bottom of the slot. For twin brackets, the length of the lever arm is the width of the bracket. From labial experience, we know that adequate rotation control requires a minimum lever arm about 0.100 inch in length. The floor of the slot for all of the Conceal brackets is about 0.100 inch, which provides excellent control in the tipping plane.
Rotation control in an occlusal-slot system results from the engagement of the arch wire in the slot and does not depend on the ligature tie. It is analogous to tip control in a labial system. Control or lack of control (play) is a function of the size of the arch wire relative to the size of the arch wire slot and the width of the slot.
Torquing play is a function of the size of the rectangular or square arch wire relative to the size of the rectangular arch wire slot. Width of the slot is not a factor in torquing play. The slot could be the width of a razor blade and its play would be the same as an extra wide slot with equivalent arch wire/slot sizes. Conceal's torquing play with a 0.016 x 0.016 inch square arch wire is only 3.5°.
For anterior teeth at the level of the arch wire slot, space available for brackets on the lingual surfaces is about two thirds of that available on the labial surfaces. The resulting decrease in interbracket distance means that smaller arch wires must be used to develop proper forces. The Conceal system slot is therefore 0.016 inch horizontally and 0.022 inch vertically.
In addition to the occlusal opening and optimum slot design, Conceal meets the difficult challenge of small working space. Since the lingual anterior tooth surfaces are inclined about 45° to the occlusal plane, the space available for brackets is smaller gingivally than occlusally. Anterior brackets have a Y configuration, with a single tie wing projecting gingivally and twin tie wings projecting occlusally. This design provides the same selectivity of ligation as a regular twin bracket, but it is easier to ligate.
The Elan and Orthos Systems: Craig Andreiko
The Elan and Orthos Systems are two new appliance systems that represent the first time modern CAD/CAM [computer-aided design/computer-aided manufacturing] technology has been applied to both human anatomy and appliance design in the orthodontic field.
Elan: Elan is the first system to integrate the treatment plan and the appliance for a specific patient. It begins with digitizing the skeletal and dental entity of the patient. The system then proceeds to design an occlusion, based on the practitioner's treatment plan and on algorithms developed to mate the three-dimensional positioning of the dentition to the skeletal framework. Next, the system designs and fabricates brackets, wires, and bracket-positioning devices that are essentially reverse-engineered from the desired final results for that individual patient.
This system allows the practitioner to concentrate more on treatment planning and less on adjusting for the mismatch between the appliance and the patient. As Ricketts said, "Begin with the end in mind.
The Elan system begins with an analysis to determine the medullary center of the mandibular bone. This is converted to a mathematical equation called the Mantrough— the keystone of the analysis.
Next, the mandibular teeth are placed on the curve such that the crown long axes are at specified inclinations, as opposed to the facial inclinations that have been used to date. The centric stops (buccal cusps) of these teeth are aligned on another smooth equation derived from Mantrough, such that the roots of the teeth are centered in the bone. The maxillary teeth are then placed in occlusion with the already-set mandibular teeth. Maxillary posterior teeth are placed with respect to centric stops and calculations for molar rotation. The maxillary anterior teeth are placed from calculations to provide either group function or cuspid rise parameters.
Orthos: Orthos is a new average prescription and appliance design based on computer analysis of more than 100 cases derived from the Elan technology. It is a coordinated system of brackets, buccal tubes, and wires. Some of the features of this system are:
• Lower anterior brackets have been reduced in the faciolingual dimension while, at the same time, the 1st-order relationship between lower cuspids and anteriors has been corrected.
• Mandibular posterior segments have less negative torque than prior designs to keep these teeth from being inclined lingually.
• Orthos archwire forms are taken from skeletal studies and are also "coordinated" mathematically.
• Molar rotations are calculated from actual anatomy for the first time.
• The mandibular arch has more progressive tip to aid in root paralleling.
• Mandibular bicuspids have distal root tip to level marginal ridge contacts.
• Upper second bicuspids have distal tip to level marginal ridges between the second bicuspids and the first molars, and they are thicker than the first bicuspids to reduce the need for bayonet bends.
• Upper posterior segments have more buccal root torque to keep the dangling lingual cusps from causing balancing interferences with the prominence of today's expansion mechanics.
Straight Wire- The Next Generation: Thomas D. Creekmore and Randy L. Kunik
Frequently, the anticipated results of treatment are not achieved by using preadjusted appliances and straight wires. This is due to inaccurate bracket placement, variations in tooth structure, variations in the maxillary/mandibular relationships, tissue rebound, and mechanical deficiencies of edgewise-orthodontic appliances. Clearly, one preadjusted appliance prescription cannot fit all orthodontic patients.
There are at least five reasons why current preadjusted orthodontic appliances do not achieve ideal tooth positions with the use of "straight" wires:
1. The most frequent reason is inaccurate bracket placement. Balut et al evaluated the variations in bracket placement by 10 orthodontic faculty members. A mean of 0.34 mm for the vertical discrepancies and a mean of 5.54° for the angular discrepancies were found in placement of orthodontic brackets.
2. Variations in tooth structure, such as irregular facial surfaces, crown-root angulations, and unusual crown shapes require variations in their tip, torque, rotation and height parameters to achieve optimum results.
3. Variations in the vertical and anteroposterior jaw relationships require variations in the positions of maxillary and mandibular incisors. Compared with Class I skeletal frameworks, maxillary incisors are more procumbent and mandibular incisors are more upright in Class III skeletal frameworks; whereas, mandibular incisors are more procumbent and maxillary incisors are more upright in Class II frameworks.
4. Need for overcorrections: Overcorrections for tissue rebound or relapse tendencies should not be limited to rotations but should include overcorrections for heights, tips, and torques as well.
5. Edgewise orthodontic appliances have at least three significant mechanical deficiencies: (a) force application to teeth through brackets located away from the center of resistance, (b) play between the arch wire and the arch wire slot, and (c) force diminution.
a. By necessity, brackets cannot be placed at the center of resistance of a tooth. Consequently, the application of a force to a tooth by an arch wire also produces additional forces on the tooth. For example, teeth distal to an extraction space will tip and rotate mesially, whereas those mesial to the extraction space will tip and rotate distally as the space is reciprocally closed.
b. Play between the arch wire and the arch wire slot is required if arch wires are to be removed and reinserted. Wires and slots cannot be made precisely every time. Manufacturing tolerances result in 0.022-inch slots ranging from 0.0220 to 0.0230 inches. The 0.018-inch dimension in arch wires is actually 0.0178 inches. Play can never be eliminated, but it can be minimized in the tipping, torquing, and vertical planes by "filling" the slot as much as possible. Rotational play is minimized by using brackets with adequate rotational lever arm lengths and ligating with sufficient force to keep the arch wire seated in the bottom of the slot.
c. Force diminution is the reduction in the force produced by an arch wire, deflected within its elastic limits, as it returns to its original shape. A minimum threshold of force is required to cause tooth movement. The force produced by an arch wire deflected to engage a malpositioned tooth will diminish as the tooth moves until the minimum threshold of force is reached. At this point, tooth movement will stop before the arch wire has completely returned to its original shape
The Slot Machine:
The Slot Machine is not really a bracket placement device in the traditional sense of bracket placement. Rather, it orients the arch wire slot of the bracket relative to the facial surface of each tooth on the model. This is accomplished by holding the arch wire slot stationary while manipulating each tooth to any tip angle, torque angle, rotation angle, and height through the use of orientation templates and a rotation guide.
Each parameter can be selectively varied independently of the others. Once the labial surface is oriented as desired; the bracket, while being held stationary by the arch wire slot, is attached to the tooth with bonding material that fills in any gap between the bracket base and the tooth.
This customized base maintains the orientation of the arch wire slot when the brackets are transferred to the patient's teeth by indirect bonding procedures. For example, a standard edgewise canine bracket that has 0° torque, 0° tip, and 0° rotation can be oriented with a Roth prescription.
1. Graber T.M. Development of a concept. in : Graber T.M, ed. Orthodontics principles and practice, 3rd Edn. Philadelphia : W.B. Saunders Company; 1992. Pg 1-27 2. Graber T.M, Swain B.F. Orthodontics current Principles and Techniques. St. louis C.V. Moshy Company; 1985. 3. Graber T.M, Vanarsdall R.L. Orthodontics current principles and techniques. St. louis C.V. Mosby Company; 1994. 4. Proffit W.R. Contemporary orthodontics. St. Louis. Mosby, Inc; 2000. 5. Begg P.R, Kesling P.C. Orthodontic appliances. in: Kesling H.D, ed. Begg orthodontic theory and technique, edn. Philadelphia : W.B. Saunders company; 1977. pg 87-142 6. Roth R.H. : Five year clinical evaluation of the Andrew Straight wire appliance. J Clin Orthod 1976; 10: 836-850 7. Thompson W.J. Combination anchorage technique an update of current mechanics. Am J Orthod Dentofac Orthop 1988; 93: 363-379 8. Thompson W.J. Begg and straight wire. A combination approach to the treatment. Am J Orthod Dentofac Orthop 1987; 79: 591-609 9. Maijey R. Smith D.C. Time savings with self ligating Brackets. J Clin Orthod 1990; 24: 29-31 10. Herbert Hanson G. The speed system: A report on the development of a new edge wise appliance. Am J Orthod 1980, 78: 243-265 11. Berger J.C. The influence of the speed brackets self-ligating design on force levels in tooth movement. Am J Orthod Dentofac Orthop 1990; 97: 219-228 12. Herbert Hanson G. On the speed Bracket. J Clin Orthod 1986; 20 No3: 183-189 13. Wildman A.J. Edge lok Bracket. J Clin Orthod 1976; 6: 613-623 14. Kesling P.C. Dynamics of the tip edge Bracket. Am J Orthod dentofac Orthop 1989; 96: 16-25 15. Kesling P.C. Expanding the horizons of the edge wise arch wire slot. Am J Orthod dentofac Orthop 1988; 94: 26-37 16. Kesling C.K. The tip edge concept: Eliminating unnecessary anchorage strain. J Clin Orthod 1992; 26: 165-178 17. Kesling P.C, Rocke T.R, Kesling C.K. Treatment with tip edge brackets and differential tooth movement. Am J Orthod dentofac Orthop 1991; 99: 387-401 18. Bennett J.C, Mclaughlin K.P. Revista Expanola de Orthodoncia. Special English edition 1999; 29 Supplement 2: 2-46
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