Urethane modules were previously employed in active appliances to hold the archwire in place within the confines of the bracket. Typically, the A-lastics are changed at every orthodontic visit, increasing the chair time at each appointment. Their binding force adds friction to the system requiring a higher force to move teeth. The rapid fatigue of the A-lastics can cause loss of rotational control of teeth requiring re-straightening of the teeth following major mechanics. A-lastics may discolor and can present challenges associated with oral hygiene.
Any orthodontic mechanical system wherein the archwire is seated totally against the base of the bracket. The combination of the archwire being seated against the base of the slot and the force being applied to the archwire increases binding and friction which requires a higher force to move teeth along the archwire.
Active Self-Ligating Brackets
A self-ligating form of an active appliance. The bracket contains a metal clip which is its own ligating mechanism. While no A-lastics are typically employed with this system the active clip binds the archwire into the base of the bracket effectively reducing the lumen of the slot. All of the same problems associated with tooth movement with the A-lastic systems are found in many phases of treatment using active self-ligating brackets.
Anterior Trapezoid Elastics
Elastic bands are used to close anterior open bites and settle final anterior occlusion and guidance. The elastics are 5/16 inch and 6 oz force. They are placed over the maxillary central incisors and to the class III hook positioned between the laterals and cuspids on the lower archwire.
The time span between orthodontic office visits allows for biological repair processes to occur. The longer appointment interval minimizes discomfort to the patient and actually allows the teeth to move at a more rapid, yet biologically sound rate. The passive self-ligating bracket appointment interval is usually ten weeks in duration during the early phases of treatment.
Bio implies working in conjunction with sound biological principles. Adaptive indicates the use of treatment mechanics which allow the clinician to assist the body in adapting the individual's physiologically determined tooth position and arch form. Bioadaptive treatment mechanics use extremely light forces that work with the orofacial complex—the muscles of the face, tongue, bones, and tissue- to allow the body to re-establish a natural balance.
Biozone or Optimal Force Zone
The level of force which are high enough to stimulate cellular activity without completely occluding blood vessels in the periodontal membrane. One must apply a force strong enough to stimulate cellular activity without adversely affecting the vascular or oxygen supply in order to maximize the potential for tooth movement in an orthodontic delivery system.
A coating is applied to a tooth during the bonding procedure after the teeth have been conditioned, but before the brackets are placed in order to improve the bond of the bracket to the tooth. The product is Solo (by Ormco) and is applied immediately before the placement of the brackets. It is lightly applied with a brush (less is more) and is not light-cured before bracket placement.
Critical placement of the bonds in the Damon System is essential for success in treatment. Refer to the bracket positioning guide chart for specific heights. When placing the brackets, care must be given to placing the mesial and distal outline of the pad in the long axis of the tooth rather than aligning the body of the bracket. The continuous archwire slot and the incisal edge of the pad are placed parallel to the occlusal plane. Care must be given to placing the upper and lower cuspid brackets at the height of the contour which tends to be toward the mesial 1/3 of the clinical crown.
Elastic bands are incorporated into treatment to close posterior lateral bites and settle posterior occlusion. These are utilized in the final archwire phase. The elastics are 5/16 inch and 6 oz. of force. They are placed over the hooks of the upper and lower first and second molars.
The distance a bracket protrudes labially when bonded to a tooth. Damon brackets have been carefully designed to make it a true straight-wire System. The upper and lower brackets have been designed to open down or away from the clinician seating behind the patient. This allows for greater visibility into the archwire slot to check archwire placement prior to closing the door. This feature also allows the lower brackets to be designed with a lower profile above the archwire slot lessening the chance of occlusal interference and bond failures. The interbracket distance and in-out position of the archwire enhances self-cleaning and minimizes decalcification.
Class II Elastics
Extend from the anterior hook on the maxillary posted archwire, typically mesial to the maxillary canine, to the hook on the mandibular first molar. Rarely are they extended to the second molars. Sizes are 5/16 inch 6 oz. force for non-extraction cases and 1/4 inch 6 oz. force in four bicuspid extraction cases. If the patient postures the mandible forward while sleeping, two elastics per side are recommended.
Class III Elastics
Extend from the hook on the mandibular posted archwire, typically mesial to the mandibular canine, to the hook on the maxillary first molar. Rarely do they extend to the maxillary second molar. Sizes are 5/16 inch 6 oz. force for non-extraction cases and 1/4 inch 6 oz. force for four bicuspid extraction cases. The archwire is typically cut between the upper first and second molar to facilitate movement.
The system of brackets which has historically been used for decades in orthodontic care delivery which actively ties the archwire into the slot with A-lastic or steel ligature ties. Much like active self-ligation, the resultant friction and binding require higher forces to move teeth along the archwire in most phases of treatment.
Small tubes or one open-side tube are crimped on either side of an anterior bracket to prevent archwires from sliding side to side causing a wire to poke out the posterior tubes of the molars. The stops should always be placed anterior to the crowding on either side of a single bracket in an area where there is the least rotational deflection of the archwire. Some clinicians use light-cured composite (Revolution by Kerr) applied to the archwire on either side of a bracket to prevent the archwire from traveling.
Efficiency of Movement
Teeth move more efficiently if the force levels are not frequently interrupted. Activation of an appliance too frequently "short-cycles" the repair process which would have been prevented by a longer appointment cycle. The Damon System is designed to take advantage of longer appointment intervals and lower forces which allow for more biologically efficient and effective delivery of care.
Method of space closure whereby the six anterior teeth are ligated together and moved as a unit closing the extraction site. The anterior space is first consolidated via elastic C-chains (under the archwire if large spaces) on .016 x .025 or .014 x .025 CuNi-Ti or Ni-Ti SE archwires. After anterior space closure, this segment is ligated from cuspid to cuspid with .008 stainless steel ligature wire behind the archwire to prevent anterior spaces from opening. Posterior spaces are closed utilizing Ni-Ti coils or Pletcher stainless steel coils on a preposted .019 x .025 Stainless Steel archwire. The coil springs are placed over the end of the archwire cut distal to the first molar while the other end is activated with ligature wire to the hook on the archwire placed mesial to the cuspids.
The orbicularis oris and mentalis muscles maintain the AP (anterior-posterior) position of the anterior teeth while the crowding seeks the path of least resistance which is into the extraction sites. This is a very significant mechanical advantage since the crowding is alleviated without any demand on posterior anchorage. Taking advantage of these mechanics eliminates the need for individual cuspid retraction. Moving the anterior teeth en masse appears to have a positive long-term periodontal impact, particularly around the cuspids.
A .019 x .025 posted wire manufactured of either stainless steel or TMA. If minimal bending and detailing is required the "Major mechanics archwire" is left in the finish. If moderate or greater bending and detailing are required .019 x .025 TMA is recommended.
Finishing and Detailing Phase
The last phase of treatment. All leveling, aligning, crowding, bite opening, space management, and rotations have been completed. Final torquing and detailing are completed during this period of treatment. If minimal detailing is required the working archwire .019 x .025 Stainless steel is utilized. TMA is recommended if major detailing is required.
Method of Class II correction utilizing the Herbst®* philosophy of treatment. Round pivots are welded to maxillary stainless crowns and to a cantilevered lower arm extending anteriorly from the crowns placed on the lower first molars. The lower stainless steel crown/lingual arch/cantilever is cemented with Fuji Glass cement. The maxillary crowns are cemented with Ormco Gold Powder in case of severe trauma to the patient. The tube and shields are "flipped" onto the round pivots of the maxillary crowns. Rods are inserted into the tubes and then coupled to the lower pivots on the cantilever. If necessary, shims can be added for accurate mandibular positioning.
The advantages of the flip-lock Herbst®* are increased comfort and a shield effect similar to that gained with a Frankel appliance. They act to keep the buccal musculature away from the teeth via the appliance which allows for a more physiologic lateral development of the dental arches. The firmness of the rods prevents the "bowing" of maxillary molars typically associated with "add-on" mandible advancing appliances.
Initial advancement of 4 to 4.5 mm is designed into the appliance via a wax bite which aids in mounting the construction models on a simple articulator. Incremental advancements are made every 5 to 6 months and are not greater than 3 mm in length. The mandible is advanced to an edge-to-edge relationship and retained with a Damon splint until ready for full fixed appliances. The mixed dentition is often blocked out in areas of erupting permanent teeth. The average length of Herbst®* treatment is 14 to 16 months. A tomogram is taken to confirm condylar position prior to Herbst®* removal.
Friction Per Bracket
The force required to pull an archwire through one bracket. This friction or binding diminishes the efficiency of orthodontic delivery systems to provide the most advantageous tooth movement over time. Conventional brackets tied with A-lastics produce 500-600 times more friction than passive self-ligating brackets (PSLBs). Those tied with stainless steel ligature ties showed approximately 400 times more friction than PSLBs. Active self-ligating brackets exhibited 216 times more friction than passive SLBs. (Voudouris JC, AJO 1997, Vol III, No 2)
Those modern archwires are made of alloys other than stainless steel and exhibit low deformation and high elasticity properties. The Damon System utilizes Nickel-titanium (Ni-Ti) archwires, Copper Nickel Titanium archwires (Copper Ni-Ti), and Titanium Molybdenum archwires (TMA) to affect tooth movement. Wire progression and sizes are referenced in the archwire sequencing section of this workbook.
Hi-tech Edgewise Phase
This phase is the "heart and soul" of the System. This phase starts working on torque, root angulations, and levels, completes rotation control, archform, consolidates space in the anterior segments, and prepares for the third phase of archwire sequencing. It is critically important to take a panorex and evaluate root and bracket position before proceeding to the major mechanics' phase of treatment.
The first wire was placed in treatment. Typically.014 CuNi-Ti (specially designed for the Damon System) is used to iNi-Tiate alignment, leveling, start rotational control and bite opening and prepare for the next archwire. The Damon System advocates using light archwires early in treatment for as long as possible. It is advised to resist the temptation to place the largest archwire the clinician "can get in" because of increased binding, friction, and higher force. If forces are applied out of the "optimal force zone" the impact on bone and tissue is altered. These initial archwires can be entire arch or sectional in nature and are left in to be evaluated at ten-week intervals. One or two ten-week intervals are a normal duration for this initial archwire depending upon the severity of the original occlusion.
Initial Light Round Archwire Phase
The first light round wire is carefully selected to minimize binding between the "tube" of the bracket and the archwire. This allows sliding of the teeth and brackets along the archwire as they start to level and align. The intent of the initial light round archwires is to apply just enough force to stimulate cellular activity without crushing the vascular supply in the periodontium. The intent of this archwire is not to remove all of the rotations but to align teeth and bracket slots just enough to move to the second phase of the archwire progression. This initial .014 CuNi-Ti archwire is designed specifically for this system and has more resiliency than conventional .014 CuNi-Ti archwires. This phase of treatment generally extends for the first 10-20 weeks of treatment.
A defined measurement of space from the distal of one bracket to the mesial of the next. The Damon System has an interbracket distance which is extremely positive in terms of promoting favorable tooth movement and rotational control. The combination of interbracket distance, a large lumen of the slot, and small dimension round archwires lower the applied force, particularly in the lower anterior segment.
The aperture is in a closed bracket which allows an archwire to pass through it. Three walls of a lumen are created by the base and two sides of the archwire slot are in the bracket. The final wall is created by the closed slide in the Damon bracket, the wire tie (A-lastic or steel ligature tie) in a conventional bracket, or the clip in an active self-ligating bracket. A small wire in a large lumen is most favorable for tooth movement as it diminishes the divergence of the angles in the archwire slot which allows freer, less friction-laden movement.
Major Mechanics Phase
The working portion or the third phase of archwire sequencing. This includes posterior space closure, antero-posterior dental correction (interarch elastics or Herbst®* application to the archwire), and adjusting bucco-lingual arch discrepancies. Stainless steel archwires are primarily used to maintain vertical and bucco-lingual control during this major mechanical phase of treatment. With low friction brackets, lighter archwires are not recommended for this working phase of treatment.
Mim-Metal Injection Molding
The process by which the Damon brackets are manufactured. It is the most precise technology available today to manufacture metal brackets. This process is needed to manufacture exceedingly small accurate parts that will allow movement of the slide and very close tolerances of the archwire slot.
Ni-Ti Coils—Nickel Titanium coil springs
Small segments of wound Ni-Ti wire are used for space opening or closing. The closed Ni-Ti coils for space closure are manufactured with small eyelets on each end which allow one eyelet to be inserted over the end of the .019 x .025 SS posted wire clipped distal to the first molar. This eyelet is bent at 90 degrees to minimize friction and binding. The other eyelet is tied with ligature to the soldered hook on the archwire between the lateral and cuspid. Where maximum anchorage is needed the first and second molars are tied together for greater anchorage and the Ni-Ti coils are placed from the hook on the first molar and tied with ligature wire to the hook on the archwire anterior to the cuspid. The coil spring force needed in this maximum anchorage situation is greater and Pletcher stainless steel springs are recommended. The coils are generally 9mm (medium strength) in extraction cases and 12 mm (medium strength) in non-extraction cases.
The open medium-light Ni-Ti coils used for space opening are manufactured in straight lengths, or on a spool, and are cut to the appropriate lengths which are 1 1/2 bracket lengths longer than the distance from the distal of the anterior bracket to the mesial of the posterior bracket or tube. They are then compressed between the two aforementioned brackets and left to exert their force to increase the arch length. Crimpable stops are generally added to the archwire on either side of an anterior bracket to prevent the archwire from slipping. Occasionally, in a very long span, the archwire may be left slightly longer (and cinched if necessary) to prevent it from being dislodged from the tube or longer tubes can be incorporated on the molar tubes.
The theory of treatment planning employs those mechanics which are most appropriate for a given case at a given time. The operator does not do the same thing for every patient but rather observes a clinical situation and utilizes those techniques which will take advantage of the particular biological environment available. Forces remain in the Biozone. Treatment continues favorably as the biology of the patient is working with the clinician rather than in spite of it.
Any high-tech archwire lightly tied over the labial and buccal surface of closed Damon brackets of the arch extending from the first molar to the molar. This overlay archwire then extends into tubes bonded on the second molars. It is used in situations where the clinician desires to align the erupting second molars while continuing to detail and finish. In these situations, the cases are near completion so little movement generally needs to take place other than the alignment of the second molars. Any frictional impact of the steel ties is minimal.
Passive Self-Ligating Brackets
The design of brackets utilized in the Damon System. These low-profile brackets are characterized by the absence of the need for auxiliary A-lastics and steel ties (as in conventional brackets) or clips within the brackets (as in active self-ligating brackets) to hold the archwire in place. The archwire in a passive self-ligating bracket is held in place by a labial sliding mechanism. The archwire is, therefore, not bound against the base of the bracket, and friction is minimized. The lumen of the slot is effectively larger, allowing the archwire to freely correct rotations as well as level and align well within the biological limits. The resultant effect is to provide the greater movement with less force applied. By taking advantage of this unique feature, the goal is to apply biologic forces to the teeth that do not negatively impact the vascular supply in the periodontal membrane. In conventional or active self-ligating bracket system the resultant binding and friction forces the clinician to use higher forces which make it more challenging to stay in the Biozone or Optimal Force Zone. By not needing to routinely change bracket ties appointment intervals can be safely expanded.
Taking for "Use what the body gives you to work with." The Damon light force System allows the evident forces to dictate the ideal physiological arch form. By balancing the forces of the lips, cheeks, facial muscles, alveolar and skeletal bone, tongue, periodontal membrane and tooth morphology the operator can retreat from those mechanics which are artificially influenced. Posterior expansion can be achieved without the use of mechanical expanders by adapting these forces, as can leveling, aligning and bite opening. By not overpowering the biomechanical system the body's own physiology sets the course to a more biologically adaptive and biologically normalized result which is patient specific.
A stainless steel (as opposed to Ni-Ti) coil is used for space closure. They are attached to the mesial hook of the posted .019 x .025 archwire and extended distal to the first molar. These deliver a greater force than Ni-Ti coils and are typically used in adult cases as well as those cases where the space desired to be closed has been evident for long periods of time (previous extraction spaces). All other mechanics are identical for space closure.
These are used during the major mechanics and finishing phases of archwire sequencing. (See archwire sequencing) These are .019 x .025 in size and are manufactured of either stainless steel or TMA. The posts can come pre-welded from the manufacturer or can be crimped-on mesial to the cuspid by the operator. The posts are used for space closure with coils springs, for space maintenance following space closure using tieback modules, and for interarch elastics.
Posterior Expansion or Adaptation
The impact of the orofacial muscles on alignment and arch development. By balancing these forces the expansion of the arch is of a posterior nature which alleviates crowding through a balance of the delivery system, blood supply, and muscles. This phenomenon allows the operator to treat non-extraction cases without the flaring of anterior teeth or forcing these anterior teeth through the cortical bone as previously associated with aggressive non-extraction techniques. Anterior-posterior positions of the anterior teeth stay stable while a noticeable and measurable posterior adaptation of the buccal segments. This phenomenon is very similar to the observed "Frankel effect" generated by the Frankel appliance.(These adaptive changes have been shown to be as stable as other types of treatment involving extraction therapy) The clinical impact of this routine clinical observation allows for far more cases being treated with Face Driven Treatment Planning.
Basically three types
a .016 x .022 Bond-a-Braid (Reliance) wire is bonded to the palatal surface of the four maxillary anterior teeth using Revolution (Kerr).
.026 round stainless steel wire adapted to the lingual surface of the six mandibular anterior teeth is bonded using Transbond (Unitek). A "landing pad" of composite is injected onto the teeth and the .026 steel wire is inserted into the pad of composite on the teeth. Once cured, a layer of Revolution (Kerr) is injected around the wire and the pad forming a "ski jump" contour or additional bond security and food deflection.
- Interarch retention:
The Damon Splint/retentive splint—typically used following Herbst®* to hold the jaws in position while waiting for the full fixed appliance phase. It is also used in cases with severe posterior crossbites, lateral tongue thrusts, severe class II's corrected with elastics or a Herbst®* with springs, or any patient with severe muscle dysfunction (Bucco-lingual coordination challenges). It is constructed of two, clear Biocryl or Essix "slipcover", 1 mm full arch retainers bonded together with lab acrylic in the advanced position (as determined by a wax bite). The upper and lower slipcovers are bonded together from the posterior molar to the mesial of the upper cuspid tip leaving the anterior section open for an airway.
Reverse Curve Ni-Ti Wires
017 x .025 or .019 x .025 in size. Manufactured by Orthodontic Specialties with 20 degrees of torque built into the archwire from lateral to lateral. The reverse curve in design is manufactured of Nickel titanium. These archwires are particularly effective in severe Class II, Div. II cases. They are placed in the upper arch following the initial phase of archwire sequencing. If only intrusion is desired, the same dimension of archwires is used without the additional 20 degrees of torque.
The ability of an orthodontic delivery system to favorably influence rotated teeth into the proper position. It is typically affected by:
- depth of bracket slot — a critical range of depth exists
- usable bracket width — the amount of the bracket that contacts the wire for rotational forces
- horizontal wire dimension — a critical wire dimension exists
Rotations are not removed by binding the wire against the back of the bracket. The play between the wire and the slot should be within .002" to.003" for ideal rotational control. Realizing that this bracket depth dimension is critical to rotational control the depth of the Damon passive self-ligating bracket is reduced from .028 to .027.
Final rotation control should be achieved following the second phase or High-Tech edgewise phase of archwire sequencing. The System is designed to use no less than .025" bucco-lingual edgewise archwires to achieve rotational control. By achieving final rotational control early in treatment (and not losing rotation control during treatment) the teeth can be maintained in their final rotational position for a long period of time which usually enhances stability.
A segment of wire (typically .014 Ni-Ti) is inserted in a rotated segment of the arch in order to align teeth prior to placing a larger dimensioned archwire. Sectional archwires are commonly used to prevent light archwires from being displaced by heavy posterior occlusal forces.
Following anterior space consolidation in the High-Tech edgewise phase of archwire sequencing, the six anterior teeth are ligated together under the archwire with .008 stainless steel ligature wire. A pre-posted .019 x .025 Stainless Steel archwire is inserted with the hooks placed between the laterals and cuspids. Medium Ni-Ti (9 or 12 mm.) springs are placed over the end of the slightly protruding archwire clipped distal of the first molars. The other end of the spring is attached to the hook on the archwire with ligature wire. The springs are usually activated at approximately 2/3 of their original length. (Please see en masse retraction for other options used)
The process of gathering anterior space between teeth prior to en masse retraction. Chain elastics are used from lateral to lateral or cuspid to cuspid depending on the amount of space needed to close. If major space is present, care is given not to round trip the cuspids. (In this situation, space would be closed lateral to lateral) Only close anterior space on .014 x .025 or .016 x .025 Ni-Ti archwires in the second phase of archwire sequencing. Closing space on round archwires will cause rotations. If major anterior space is involved the chain elastics are placed prior to insertion of the archwire, thus minimizing friction. (On occasion elastic thread is utilized to control the force of the space closure) It is preferred to consolidate space distal to the cuspids prior to en masse retraction of the anterior segment. Space closure is easier if the force vectors are parallel to the major mechanics' posterior archwire. All rotations should have been corrected prior to posterior space closure.
The process of altering the course of treatment by changing an extremely crowded situation into a non-extraction case. Ideally, this is performed in the late mixed dentition stage prior to the eruption of the cuspids. A four-tooth sectional .014 wire is placed in the anterior segment to align and control severe rotations. Following the initial phase, a .014 x .025 or .016 x .025 Ni-Ti wire is placed with a compressed Ni-Ti coil spring extending from the lateral incisor to the first molar. Great care is given to only activating the spring approximately 1 times the width of the bracket. (Too much activation will overpower the lip bumper effect of the orbicularis oris and mentalis muscles. Crimpable stops are placed on either side of a central bracket to prevent the archwire from sliding. The patient is reappointed at an appointment interval, usually 10 weeks, that will not allow the archwire to slide out of the first molar tube. NOTE: This procedure can be performed in conjunction with Herbst®* therapy by welding a wire tube to the maxillary stainless steel crown and aligning the anteriors as described above. It is also advisable to weld a long molar tube in an attempt to prevent the archwire and spring from becoming dislodged from the molar tube between appointments.
Space Management Phase
The intermediate period of treatment. This phase generally starts with the consolidation of anterior space with .014 x .025 or .016 x .025 Ni-Ti and elastic chains to control spacing and ends with the .019 x .025 posted wires to close posterior space en masse.
The auxiliary was added to the Damon System to keep spaces closed. They come in a variety of sizes and strengths (Recommended: Heavy — Unitek). These are placed on a .019 x .025 archwire and extend intra-arch from the posted hooks on the wire, passing incisal to the first bicuspid in the same arch, ending on the hooks of the first molars.
The method whereby closed spaces in the arches are kept from re-opening during the later phases of treatment. Once all spaces are closed, modules, elastic chains, or ligature wires are employed to keep all spaces closed. This typically occurs in the major mechanics and final stages of treatment with the .019 x .025 archwire in place. Tiebacks are strongly recommended in this low force-low friction system since is it very easy for space to open.
It has been noted that the tongue can play a dramatic role in influencing the course of orthodontic treatment. In severely crowded cases it appears that the activity of the tongue previously suppressed due to the extreme crowding and lack of space "wakes up" during treatment once the crowding has been alleviated and lifts to assume a more normal position. The base of the tongue, being in a higher position can splay out and begin to occupy interocclusal space between the maxillary and mandibular first and second molars, creating a lateral posterior open bite. Corrective action includes recognizing this phenomenon and counteracting the presence of the tongue with "V"-elastics or box elastics.
The elastic pattern is employed to counteract lateral posterior open bites. Moose (Ormco) elastics are positioned from the posts on a .019 x .025 maxillary archwire, extending under the hook on the gingival of the mandibular first bicuspid bracket and terminating on the first molar hook in the maxillary arch.
Working Phase Wire
The .016 x .025 Ni-Ti (.014 x .025 Ni-Ti-see archwire sequencing) archwire was employed after the initial leveling and aligning phase with .014/.016 Ni-Ti wire and preceding the major mechanics and final phase .019 x .025 posted archwire. Termed the "heart and soul" of the system because it completes leveling and rotational corrections, consolidates spaces, furthers archform development, and starts torque control. One visit following the introduction of this archwire a panoramic radiograph should be taken to evaluate root positions and final bracket position. Corrections should be made prior to managing spaces and finishing the case. Note the faciolingual dimension (.025) of the workhorse wire is the same as that of the final wire (.025) to give a dimensional match. Patients experience very little discomfort if the proper sequencing is employed as the workhorse wire prepares the case for the final wire.