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    The BasicsTwo of the most important aspects of orthodontic treatment are bracket positioning and arch widthcontrol. First, let's discuss bracket positioning.

    Bracket Placement Review

    A prominent orthodontic educator recently stated that "In the 1960's, the best orthodontics wasdone by the best wire benders. Today, the best orthodontics is done by the best bracketpositioners." I couldn't agree more with this statement.

    Horizontal Positioning of BracketsVisualize center of tooth directly from the facial surface, then look down long axis of the toothMay need to use a mirror for bicuspidsPlacement errors lead to rotations

    Rotational(axial) errorsCause unwanted tippingKeep incisal edge of bracket parallel to incisal edge of toothuse same visualization techniques as for horizontal placement

    Excess bonding agent under the bracket may cause rotational errors To avoid these, push bracketfirmly onto tooth

    Vertical errorsCause excessive extrusion or intrusion

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    Check the same tooth on the other side of the arch and make sure the inciso-gingival position isthe same on both sides- this prevents occlusal plane tipping

    Mesio-distal positionPosition bracket on the mesio-distal center of the tooth for all upper and lower centrals, laterals,and cuspids

    -In most cases, position the brackets in the mesio-distal center of all molar and premolar teeth

    Inciso-gingival position

    Deep bite patientsPosition brackets 1 to 2 mm incisal to the center of the toothOpen bite patientsPosition brackets 1 to 2 mm gingival to the center of the tooth

    The pictures on the right show ideal anterior bracket placement for

    average bite (top), deep bite (middle), and open bite (bottom).

    Occluso-gingival placement of premolars

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    Deep bite casesPosition brackets 1 to 2 mm gingival to the center of the toothOpen bite cases

    Position brackets 1 to 2 mm occlusal to the center of the tooth

    Upper molar bracket (or band) positionAnterior portion of bracket bisects the MB cuspFinal band seat is accomplished with lingual pressureBracket in the occluso-gingival center for all cases

    Lower molar bracket (or band) positionBracket always placed in the center of toothFinal band seat is accomplished with buccal pressurePosted

    Blocked out teethIt is important to create space for blocked out teeth and get them into the arch very early intreatment. I start all my fully bracketed cases in either .014 or .016 nickel titanium archwires. Ipack coil (.010x.030 stainless steel) to create space for any tooth that does not have enough spaceto fit into the arch.Before I go into the details of packing coil, let's discuss this space creation. When packing coil,space is created by allowing the teeth to move anteriorly in the arch. If you are treating a case

    non-extraction, you must be willing to accept the fact that space will be gained at the expense ofanterior teeth moving forward. For every millimeter that teeth move forward, about 2mm of spacewill be gained. If you decide to use a non-extraction treatment approach, you must understand andbe comfortable with the fact that the anterior teeth will move forward during the initial aligning. Ifyou are comfortable with this forward movement, non-extraction therapy is a good choice.

    So, how do you pack coil? Here are the steps.1. Visualize the arch from an occlusal view. If a tooth doesn't have enough space to fit in the archform, you need to pack coil in that area.2. Pack a section of coil that is 2mm longer than the distance between the adjacent brackets. Forexample, if the lower right lateral incisor is blocked out, pack a piece of coil that is 2mm longer

    than the distance between the distal of the bracket on the central, and the mesial of the bracket onthe canine.3. See the patient in 4 weeks and evaluate. If the space create can accommodate the tooth,engage the tooth. If the space is not big enough, pack a piece of coil that is 2mm longer than theone previously used.4. Repeat step 3 until enough space is created.

    Arch Width Control

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    Along with good bracket positioning, good arch width control is one of the most important parts ofquality orthodontic treatment. Proper arch width control starts with a good diagnosis. Does thepatient require arch expansion, arch contraction, or maintenance of the existing arch form? Oncethis question is answered, some simple steps performed throughout treatment allow thepractitioner to reach the treatment goals.

    I alter all stainless steel archwires to help give the patient the desired arch form. If no expansion isdesired, here is how I co-ordinate archwires.

    1. Draw a line on the lower pretreatment model from the

    buccal cusps of the posterior teeth through the incisaledges of the anterior teeth

    2. Co-ordinate the lower wire so it is 3mm wider than this line throughout

    the circumference of the wire.

    3. Co-ordinate the upper wire with the lower.

    If no expansion is desired, make the upperwire 3mm wider than the lower.

    4. About 6mm of expansion (3mm per side)can be obtained with archwires alone. Simply expandeach stainless steel wire used to the desired amount of expansion. If expansion in only one arch isneeded (for example, correction of a narrow upper arch), just expand the archwires for that

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    particular arch.

    5. Any cases requiring more than 5-6mm of expansion need an expansion appliance (RPE,quadhelix, or Schwarz plate). This should be determined during the initial diagnosis.6. Molar area expansion is much less reliable than is bicuspid area expansion when using onlyarchwires. A future posting will describe techniques for expanding the molar area with archwire

    bends.7. Use a hollow chop pliers (or fingerpressure) when forming the wires. Thehollow chop is shown here.

    Good arch width control techniques result in good interdigitation of teeth as the treatmentprogresses. Less elaborate finishing techniques and faster treatment will be the end result if thesetechniques are used.

    Anchorage Control in the Early Phase of Bicuspid Extraction TreatmentIn extraction treatment, every effort must be made to prevent the anterior teeth from

    moving forward during initial leveling and aligning. As the teeth are aligned usinga flexible low-load deflection wire (such as a nickel-titanium alloy) the teeth tendto move forward (through air) rather than backward (through bone) into theextraction site. In addition, when using a pre-adjusted appliance,the tip built intothe bracket is also expressed while using the initial archwire. Tipped teeth takeup more space than do teeth that are upright. This space is also gained by theteeth moving forward.This forward movement and resulting increase in protrusiveness is one of threeaspects of the malocclusion that often worsen during the initial phase of

    extraction treatment.

    The second unfavorable side-effect that often occurs early in extraction cases isunwanted bite deepening. The canines often erupt in an upright position incrowded cases. If a light straight wire is placed into a canine bracket when thetooth is upright, placing that wire through the incisor brackets will cause overeruption of the incisors and hence bite deepening. This is contra-indicated inmost cases.The figure below demonstrates how this happens.

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    Third,the molar relationship often drifts toward Class II early in these cases. Thisis how it happens.When an archwire is tied in to all the brackets, friction between bracket and wireplus the elastic or steel ties make the entire arch behave as one unit. Since theupper anterior teeth have more total tip than the lower anterior teeth, the upperteeth will move anteriorly more than will the lower anteriors. As the uppers moveforward, they drag the molars with them (Remember, friction makes the arch actas one unit. The anteriors and posteriors move together.) The lower anteriors,because they have less tip, don't advance as much as the uppers, so the lowermolars don't advance as much as the uppers. As a result, the molar relationshipmoves toward Class II.These undesirable movements can be minimized by using anchorage control,which is defined as the maneuvers used to restrict undesirable changes duringthe initial phase of treatment so that leveling and aligning is achieved withoutthe key features of the malocclusion worsening.Two maneuvers make up anchorage control. The first technique is called abendback. To use a bendback, simply bend back the archwire distal to the lastbanded (or bonded) tooth. This keeps the amount of wire from molar to molarconstant, which helps prevent the teeth from advancing.

    The second, and more important anchorage control technique, is called alaceback. Lacebacks consist of .010 ligature wire tied in a figure 8 fashion aroundthe bracket on the last bracketed tooth up to the canine. The figure belowillustrates how a laceback is engaged.

    Lacebacks are tied in before engaging the archwire.Tie in the laceback, then tie inthe archwire over the laceback. Tighten the laceback so it exerts pressure on thecanine. This pressure not only prevents the canine from tipping forward (whichwould increase protrusiveness and deepen the bite) but also encourages thecanine to move distally against the periodontal ligament.This creates about 1mmof space in the quadrant where the laceback is used.This space is then used asthe teeth are aligned and correctly tipped. Clinically, light nickel-titaniumarchwires are capable of correcting about 2mm of crowding per month. This isexactly the amount of space one laceback in each quadrant will create. The

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    space,because it is close to the crowding, is available for relief of crowding.Clinically, the crowding is relieved by using this readily available space ratherthan the the teeth moving labially.

    After the canine is moved distally, the laceback loses its tension. This gives theteeth a chance to move into the created space. When the patient returns for a 4week recall, tighten the lacebacks. This will create another millimeter per side(2mm total), that will be used for aligning and tip control. The lacebacks are

    tightened at 4 week intervals until aligning is complete. When the patient isready for a wire progression, the lacebacks can be removed.

    The net effects of lacebacks are the use of the extraction sites to relieve crowdingand to allow the expression of tip, discourage bite deepening, and prevent themolar relationship from becoming more ClassII.

    Here is an example of a laceback.

    Lacebacks not only inhibit forward canine movement, but they are an effectiveway of distalizing the canines. This occurs because the lacebacks tip the canines

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    at the gingival aspect of the alveolar crest. Due to the leveling effect of thearchwire,the tooth rebounds as the roots tip distally.(1) A study by S N Robinsonof 57 extraction cases showed lacebacks result in a net distal movement ofincisors during resolution of crowding. This movement averaged over 1mm(remember, crowding was also relieved).In extraction cases without lacebacks theincisors moved forward almost 2mm.The bottom line is that lacebacks make additional molar support (headgear,TPA's, or lower molar anchorage) unnecessary in most cases. Six to seven mm ofarch length discrepancy can be corrected using this technique.

    Questions1) If the force exerted by a laceback cause the canines to move distally, why don'tthe molars move mesially because of the reciprocal force?Answer- Clinically, it has been found the molars just don't move forward. Theforce level provided by the laceback is not enough to affect the large molar teeth.

    2) Why not just use a chain elastic? It sure is a lot easier to tie in a piece of chaininstead of having to manipulate the long steel ligature tie.

    Lacebacks are effective because they don't produce continual forces. The space iscreated, then they stop working until they are re-activated. This light,intermittent force is probably the reason the molars are unaffected. Also, theheavier forces produced by chain will cause teeth to tip into the extraction sites(see photo). Lacebacks do not cause this worsening of the malocclusion.

    Basic Considerations for Orthodontic TreatmentIt is always beneficial to review the basics. A firm understanding of the basic tenets of orthodontictreatment enables the practitioner to achieve excellent results in most cases. The following rules

    are based heavily on the treatment philosophy of Drs. Bennett, McLaughlin, and Trevisi, who arethe architects of the MBT treatment system.

    Basic #1- Emphasis on dento-alveolar changeOrthodontic treatment predominately affects dento-alveolar structures. Growth modification (evenif accomplished with functional appliances) results primarily in dento-alveolar development. It istrue that some patients experience orthopedic changes, but the majority of change is still dento-alveolar.

    Basic #2- The use of Light, Continuous ForcesIntermittent forces move teeth inefficiently. Heavy forces have been shown to damage rootstructure. Therefore, light, continuous forces maximize treatment efficiency. How can a practitioner

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    be sure that he/she is using light, continuous forces? First never, never try to speed up treatmentby forcing a wire into the bracket slot. Second, use a light, flexible wire until teeth are completelyaligned (one of the most common mistakes I see is practitioners abandoning nitinol beforealignment occurs). And third, use a wire progression that provides a slow increase in wire diameterso no wires are forced into the bracket slots.

    Basic #3- Leveling and AligningIf cases are leveled and aligned properly, mechanics become more efficient. About 1/2 thetreatment time in a typical case is used to level and align (this includes bite opening or closing-seebelow). The following techniques aid in the leveling and aligning process:-Use of nickel titanium archwires to relieve crowding.-Use of bendbacks and lacebacks to control forward movement of incisors in extraction cases.-Use of open coil springs to create space for blocked out teeth. When using open coil with the initiaarchwires, use only enough coil to provide a light force (the coil used is about 2mm wider than thespace between the brackets where the coil is used). This will minimize distortion of the arch form.-Early establishment and maintenance of arch form.

    Basic #4- Overbite controlGetting the bite opened to the desired level before initiating other mechanics is a basic that manypractitioners do not do. Strict adherence to this basic will really improve treatment results. Thefollowing procedures help the practitioner control overbite:-Differential bracket positioning can account for about 5mm of bite opening, or 3mm of biteclosing.-In deep bite cases, bracket the 2nd molars early in treatment.-Use of reverse and compensating curve (rocking chair curve) when the overbite is 6-9mm.-Use tipbacks in a 2x4 or 2x6 set-up when the overbite is 10mm or greater.-Be aware that in most cases, leveling and bite opening are not complete until rectangular wireshave been in place for at least one month.-Avoid leveling the Curve of Spee in open bite cases. Differential bracket positioning will greatly aidin maintaining the Curve of Spee.

    Basic #5- Space ClosureA .019x.025 rectangular wire in a .022 bracket slot enables the practitioner to use slidingmechanics while minimizing archwire deflection and loss of torque control.In most cases, en-masse space closure is preferred over canine retraction.Many effective ways of providing force for space closure exist; elastics, chain, coil springs, and tiebacks are most commonly used.

    Basic #6- Overjet CorrectionClassII correction is accomplished by using a combination of ClassII elastics and functionalappliances.ClassIII elastics work well for mild to moderate ClassIII discrepancies.Continuous forces on the dento-alveolar processes provide the best opportunity for overjetcorrection.

    Basic #7 Finishing and RetentionFinishing involves correction of mistakes made earlier in treatment, particularly bracket position.Let cases settle in light wires for at least 6 weeks prior to debanding.Many practitioners advocate removing archwires for an additional 4-6 weeks to help determineretention needs for the case.Retention is usually accomplished by using bonded retainers for the lower anterior segment, andacrylic full coverage upper retainers.Wrap around upper retainers are used in cases that need additional settling; retainers with biteplanes are use to retain deep bite corrections.

    Final Considerations

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    #1 Position brackets properly. Pay attention to bracket positioning. Reposition brackets twiceduring treatment- after leveling and aligning (6-9 months into treatment) and before beginningfinishing (4 months before removal).Use a panographic x-ray to evaluate bracket position whenrepositioning.

    #2 Control arch width. Be aware of what you are trying to accomplish with arch width control(expansion, contraction, or maintenance of arch width). Co-ordinate all stainless steel archwires toaccomplish your desired goals.

    Comments on Space Closure

    I often receive questions on space closure mechanics; I will take this opportunity to address issuesregarding space closure.First, and most important, the biology of tooth movement is more important in determining therate of space closure than the particular technique used. Osteoclasts and osteoblasts must do theirjob; human premolar and molar roots can move bodily through bone at the rate of about 1mm permonth. In most cases, movement faster than this amount means teeth are tipping into theextraction site. This type of movement is usually counter-productive.

    Second, the arch must be completely leveled before space closure can occur. That means thepractitioner must leave the working wires (usually .019x.025 st.steel in a .022 slot) in the archpassively for at least a month. Once the arch is leveled, space closure can commence.

    Third, many practitioners inform me they prefer to close space on a round working wire (mostcommonly .020 st. steel in a .022 slot). They claim that friction due to the rectangular wire fillingthe slot inhibits space closure. I believe this is false. Closing space on round wire is usually notindicated for the following reasons:1) Loss of torque control. Torque is the weak link of the pre-adjusted appliance. Closing spacewithout torque control uprights anterior teeth. This gives the completed extraction case arabbitted appearance- the teeth end up too upright. This is especially problematic in upperbicuspid extraction cases, as the uprighted maxillary anteriors can occlusally interfere with thelower anteriors.2) Speed of space closure. The rate of ostoblastic and osteoclastic activity, not the amount offriction, determines the speed of space closure. (1) Controlled force levels on a rigid wire eliminatenearly all of the potentially deleterious side-effects associated with space closure mechanics.Remember, if the rate of space closure exceeds 1mm per month, the teeth are probably tippinginto the extraction site. This is detrimental to the orthodontic result.

    Fourth, many practitioners ask what is the best force system to use. Many systems work well, asthe big issue is to provide adequate amounts of force after the arch has been leveled. I prefer en-masse space closure (moving the 6 anterior teeth as 1 unit) to canine retraction. En-masse closuretakes full advantage of the principle of sliding mechanics, which is one of the big advantages of thepre-adjusted appliance. As for force application, many effective methods exist. Nitinol coil springsor active tie-backs are very effective. However, I like to use elastics. The proper force is usuallyprovided by " medium Class I elastics when the exraction site is larger than 4mm.When the siteis 2-4 mm wide, switch to 3/16" medium. For the last mm or 2 of space closure, use chain elastic.My patients wear the elastics full time and change them every 12 hours. They attach the elasticfrom the hook on the canine bracket to the hook on the last bracketed molar. The anterior 6 teethare held together (as 1 unit) by chain elastic or a figure-8 steel ligature tie.

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    Using elastics to close space provides the practitioner the flexibility to deal with many situationsthat arise during space closure. For example, if the molars are a little Class II, space closure can beaccomplished by applying the elastics in a Class II direction. In fact, the practitioner can apply theelastics in virtually any configuration to close the space in the manner required in the individualcase.

    Delays in space closureA couple of reasons exist which can cause delays. Often, upper premolar brackets are placed toogingivally. This results in over eruption of the premolars, resulting in occlusal interferences. Also,gingival tissue can build up in the extraction site, causing delays. In addition, dented or bent tubesor bracket slots can inhibit sliding. So if the space is not closing appropriately, check these threeitems. Chances are, you will discover the problem.

    Important Orthodontic Studies

    For anyone practicing orthodontics, keeping up with the literature is essential. There are manyways to do this, but one of the easiest methods is to subscribe to Practical Reviews inOrthodontics. (http://www.cmeonly.com/programdetails.cfm/2/44/2) Each month you receive anaudio CD and a written synopsis of the most germane orthodontic articles from all the majororthodontic journals. The reviewers do a great job of summarizing all that is new and important inthe orthodontic literature. Try this service; you will not be disappointed.

    The orthodontic practitioner should not only keep abreast of current orthodontic literature, but alsobe aware of the studies that have shaped how orthodontics is practiced today. I believe the study

    performed by Professor Arne Bjork while he was the chairman of the Orthodontic Department ofthe Royal College of Dentistry in Copenhagen is the single most valuable study ever done in thefield of orthodontics.

    Professor Bjork practiced orthodontics for about 20 years before accepting the previouslymentioned teaching position in 1950. For the next 15 years, he worked on this study. Bjork placedtitanium implants in the maxillas and mandibles of 240 children. He then took yearly records,performing no other treatment on these patients. This research is valuable because it can never beduplicated. Todays medical ethics prevent researchers from placing implants for observation only.In addition it is now unethical to watch and not treat severe malocclusions. Because the scope ofmedical ethics was so different in the 1950s than it is today, Bjork was able to provide the

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    orthodontic community with a valuable body of data.

    So, whats the big deal? Why is this information so precious? Well, by superimposing cephalometricx-rays on the implants, Bjork was accurately able to determine how faces changed with growth.When superimposing cephs without implants, it is nearly impossible to discern the differencebetween growth and bone remodeling.

    Interpretation of Bjorks data lead to some interesting conclusions. The driving force responsible fofacial growth seems to be the condyles. If cellular proliferation is near the anterior surface of thehead of the condyle, the mandible rotates in a forward direction (counter- clockwise, if one viewsthe chin in profile). See figure below.

    If cellular proliferation is near the posterior surface of the head of the condyle, the mandiblerotates in a backward (clockwise) direction. See figure below.

    As the mandible moves due to the cellular proliferation, the sling of muscles that encapsulate themandible are responsible for pressures and tension directed onto the bone. These forces result inapposition and resorption of mandibular bone. Therefore, mandibular morphology is different forforward and backward mandibular rotation.

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    Because of the way the muscles act (as well as some other factors), forward rotators are referredto as strong muscled patients, and backward rotators are called weak muscled patients. Almost allorthodontic mechanics result in extrusive forces on the teeth. Strong muscled patients resist thisextrusive tendency, while weak muscled patients tend to not resist this tendency. This leads us toa very important concept: the same brackets, bands and wires will produce different treatmentresults in different patients. Muscle strength (which can vary by a factor of 6 between strong andweak muscled patients) is the main reason for these variable treatment responses.

    So, how do we use this knowledge to improve treatment? Weak muscled patients tend to be openbite patients; the extrusive component of orthodontic mechanics is often expressed. Conversely, itis often very difficult to open the bite in strong muscled patients (who tend to be deep bitepatients). By looking at the shape (morphology) of the mandible, the practitioner can determine ifbite opening or closing will be a problem. A specific treatment plan for the individual patient canthen be devised.

    Some other facts stemming from Bjorks work are very important. First, the distribution of growthcells on the head of the condyle follows a bell shaped curve. That is, not all patients are entirelystrong or weak muscled. About 85% of patients are predominately strong muscled (good thing,because weak muscled, open bite patients are difficult to treat). Many patients have some strong

    and some weak muscled characteristics. The most difficult cases are the very strong, andespecially very weak muscled patients. These cases are often easy to pick out because themandibular morphology is very diagnostic. The difficult part is to monitor the borderline cases tosee if vertical control becomes problematic. Graber states in his textbook that controlling verticaldimension in borderline patients is one of the most important aspects of good treatment.

    Second, forward or backward rotation is a highly genetic phenomenon. Condylar growth directiondepends on the location of the growth cells; this is an inherited trait. However, growth patterns canbe affected by the environment. For example, airway blockage, habits, allergies, etc. can change

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    the normal position of the mandible, allowing different parts of the growth center to be more fullyexpressed. So, according to Bjork, environment influences growth while genetics controls it.

    Bjork used knowledge of apposition and resorption of bone based on muscular pressures andtensions to determine muscle strength based on mandibular morphology. I like to use fivecharacteristics to point out the morphological differences between strong and weak muscledpatients. Not all these characteristics are visible on all patients, and previous growth direction doesnot insure that future growth will continue in the same direction. But despite these limitations,mandibular morphology is a useful predictor of both future growth and response to treatmentmechanics.

    Lets explore the specific morphological characteristics I use. First,the gonial angle will be more acute in strong muscled patients and more obtuse in weak muscledpatients. Second, the shape of the lower border of the mandible is a good predictor. In weakmuscled patients, apposition below the symphysis and resorption anterior to the gonial angleproduces a concavity throughout the lower border. In strong muscled patients, anterior rounding isabsent. In addition, notching occurs anterior to the gonial angle. This results in an "S" shaped curveon the lower border. The third predictor I like to use is the density of bone at the symphysis. A thicksymphysis indicates strong muscles, while a thin symphysis means the muscles are weak. Fourth,the inclination of the symphysis is a reliable predictor of muscle strength. In strong muscledpatients, the inclination is relatively acute, while the norm for weak muscled patients is a moreobtuse inclination. The final indicator I use is the inclination of the condyle.In strong muscledpatients, the condyle will incline anteriorly, while in weak muscled patients, the condyle will have aposterior inclination. This trait is not always visible on the ceph because of superimposition ofstructures over the condyle on ceph x-rays.

    There are many other predictors of mandibular growth rotation.Many clinicians rely solely onmandibular plane angle to predict muscle strength (and, hence, treatment response). Althoughweak muscled patients usually have higher mandibular plane angles than do strong muscled

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    patients, this measurement can be deceiving. If the clinician uses more than one measurement toarrive at a diagnosis, the diagnosis will probably be more accurate. Using all the available data willhelp insure that the patient will receive the best diagnosis possible.

    In addition to maxillary and mandibular growth rotation (the maxilla follows the same basicrotational pattern as the mandible), Bjork also described the intramatrix rotation. He defined theintramatrix as the maxillary and mandibular teeth and alveolar processes. Bjork described threetypes of intramatrix rotation, two which can occur in strong muscled patients, and one whichoccurs in weak muscled patients. To understand intramatrix rotation, one must understand Bjork'sdefinition of the fulcrum. The fulcrum is simply the most anterior contact point of teeth inocclusion.Type I intramatrix rotation occurs in strong muscled patients when the fulcrum exists at the incisaledges of the maxillary and mandibular anterior teeth. This combination of mandibular andintramatrix rotation leads to normal downward and forward growth of the cranio-facial complex.This results in the best possible growth for the patient.Type II intramatrix rotation occurs when mandibular rotation is forward without an incisal edgefulcrum. This lack of incisal edge fulcrum often results from tongue or lip habits, or from earlyexfoliation of primary teeth.The fulcrum now exists in the middle of the arch. This pattern leads toover eruption of maxillary and mandibular anterior teeth, a deep bite, and collapse (lingualmovement) of the maxillary anterior segment-a classic Class II, Division II malocclusion.Type III intramatrix rotation occurs in weak muscled patients where the fulcrum is on the posteriorteeth. If sufficient eruption occurs in the anterior segments, the result is a long face with goodocclusion. If something (tongue, lip, fingers) interferes with anterior eruption, an open bite results.

    Understanding cranio-facial growth rotation leads to many interesting diagnostic conclusions. InType I and Type II intramatrix rotation, teeth move forward and laterally on the alveolar processes.The opposite occurs in Type III intramatrix rotation. Therefore, expansion and arch length gainingtreatment may be more successful in Type I and II intramatrix rotation than in Type III intramatrixrotation. Crowding that can be corrected by expansion in a strong muscled patient may requireextractions in a weak muscled patient. In fact, every decision you make regarding a patient'streatment will be influenced by the patent's muscle strength. Extraction vs. non-extraction, bracketposition, composition of arch wires used, and type of retainer used are all greatly influenced by a

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    patent's muscle strength. It is clear that an understanding of Bjork's research will change the wayyou look at orthodontic diagnosis.Posted byJim P

    Frequently asked questionsIn space closure, if after a couple of months of space closure, we still have a couple of mm of spacein the upper anteriors and no spacing in the lower arch, the occlusion is a solid ClassI with little orno overjet, is it correct to assume that we have a tooth size discrepancy? There seems to be 2

    ways to deal with this remaining space, either bond composite to the upper teeth to close it orperform ARS on the lowers? What would you do in this situation?

    Studies show that in 60% of cases, there is a tooth size discrepancy where there is more toothmass on the lower arch than on the upper. This is usually due to small upper laterals or large lowerlaterals. We call this the 60% problem. The solution to this is to do what you suggest. In 20% of allcases, there is excess tooth mass on the upper. This is called the 20% problem; it can also becorrected by IPR, but in this situation, it is the upper arch that is reduced. In my practice, I often dothe ARS on the premolars because stripping in that area does not affect the esthetics as much.The interesting point about this discussion is that only 20% of all cases have no tooth size- archlength discrepancy, so the problem you describe is present in a lot of cases. However, in manycases with a discrepancy the problem is too small to be clinically relevant, so not all of the cases

    with a discrepancy need interproximal tooth reduction or bonding.

    If we are to call the diagnostic arch length the existing mandibular form, taken from the molarbuccal cusp tips and anterior incisal edges, and not expand, how do we substantial crowding?Another way to put my question-when we unwind all of the crowding, don't we need a longer archlength, or distal drive the molars? Creating a Roman arch form and advancing anteriors will notstrictly maintain this existing arch length, right?

    If you keep your arch length the same, the only way you can relieve crowding is to remove toothstructure. Tweed wrestled with this problem 70 years ago and ended up extracting 4 bis in 90% ofhis cases.We base our arch width on a line 3mm wider than the cusp tips/incisal edges to account for bracketthickness. We can change arch form (expand or labially advance teeth) to relieve crowding. Howmuch of this can you do? Different practitioners will alter arch form different amounts. The moreyou change arch form, the less stable the final result will be, but the more you alter arch form, theless extractions you have to do.From a philosophical standpoint, I am not a big fan of distalization, especially on the lower. I don'tlike pre-determined arch forms, and I don't like to do a lot of expansion. This is why I extract teeth.Over the last 15 years, I extracted some combination of bicuspids in a little over 21% of my cases.This is a little bit lower than the 26% national average as reported by the AAO, but as a GP doingortho, I do refer some of the more difficult cases that present in my office. These difficult cases areusually extraction cases, so factoring in these cases to my overall percentage would bring myextraction percentage closer to the national average.

    I have evaluated cases involving Class II elastics and I remember what you said about the use ofClass II elastics,that is, Class II elastics really work but if you use them you may be "selling yoursoul because of some of the side effects that may occur. I've looked at a few of my cases and Ithink you meant Class II elastics may distort everything we've worked to achieve up to this point intreatment. I see mostly lateral open bites, especially molars out of occlusion. So what should orcould we do to remedy the ill effects of Class II elastics? Do we use single elastics on each side anduse less aggressive means (I've been using 2 elastics on each side 3/16 med full time wear)? Dowe accept this problem as side effects of Class II elastics and deal with it after the Class II has beencorrected? I'm thinking using Class II finishing elastics with vertical elastics on the 6's or maybe

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    even bracketing the 7's. What are your thoughts on this matter?

    There are certainly many side effects associated with Class II elastics. To minimize the side effects,I try to use them only in .019x.025 st steel with the bite opened to the desired level. Then,theelastics act as minor repositioning devices. This, hopefully, will eliminate the lateral open biteproblem. If lateral open bite still occurs, go to a lighter wire after the Class II is corrected and theocclusion should settle.I like to use medium elastics, with full time wear. This provides a constant repositioning forceand maximizes the speed of correction. If correction doesnt occur with this force, I increase theforce by using 2 elastics per side, but this may lead to the side effects you described, especially inweak muscled patients. Vertical finishing elastics are a good way to close lateral open bites;bracketing the 7s in cases that can tolerate the bite opening will also help.The bottom line is Class II elastics are a good way to correct Class II, IF you can stand the sideeffects. Many ways exist to handle the side effects, but these ways may be a bit mechanicallycomplex.

    I noticed that a case of mine has a tooth size discrepancy, with wide mand lateral incisors, andwide mand second bi's. Much more crowing exists on the lower than the upper, and the molars areClass I, but with only 2 mm of overjet in the anteriors. Initial leveling and aligning will probablyadvance the lower anteriors. Do we wait to do IPR on these type of cases after crowding androtations are relieved, or can do IPR before initial aligning? She is not a weak muscled patient, but Istill would prefer not creating edge to edge in anteriors and opening the bite. But I guess that itcomes with the territory that the teeth may look worse before they look better.

    Good job in picking out the tooth size discrepancy before treatment starts. I like to align before I doIPR, even if it means the occlusion will be edge to edge for awhile. The reason I do it this way isbecause when the teeth are aligned, it is easier to strip the contact points and shape the teethcorrectly. When crowding exists it is tough to get at the contact points accurately. In addition younever quite know how the leveling and aligning will play out, so I always like to get things lined upbefore I do something irreversible. So, get into at least .016st steel before doing any reduction.

    Temporary Anchoring Devices or mini implants are something we've never talked about. They aregaining in popularity among orthodontists. Are you currently using them? Do you think this willdecrease treatment time? What kind of cases are they indicated, deep bites cases, open bite cases?What are your feelings towards TAD?

    TAD's are all the rage these days. They are easy to insert and remove and provide reliableanchorage. They are used for space closure, distalization, intrusion, as well as attachment pointsfor interarch elastics so the mechanical advantage of the elastics is greater. They are often usedfor bite opening and bite closing. I see their use greatly increasing over the next few years.Posted byJim Prittinen,

    Frequently asked questions, part 2I'm using lacebacks on an extraction case. One question: when the lacebacks are tied in, with thewire on top, is there enough room around the brackets for elastic ties or would you have to use theligature ties to tie everything in place?

    I use elastic ties when engaging the wire. There is plenty of room on the bracket tie wings for boththe laceback and the elastic tie.

    What kind of burs do you use for IPR?

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    I use Essix burs. Find them here- http://www.essix.com/orstore/default.aspx . The specific burs I likeare the 55000 for anterior reduction and the 699LC and 848MD for posterior teeth.

    An issue that I am struggling with is re-bracketing. In the first scenario, a patient breaks a bracket,say in the 020 or rect wire stage. Some tooth movement seems to have occurred since the break.How far do we have to go back in wire progression to catch up? I have found that I'm often using016 Niti to get the new bracket and tooth in line. But what then? Second, after repositioning forsecond order movement in mid-course, I'm going to 016 Niti, but then can't seem to get right tothe rect niti next month because it won't fit that tooth position. Is there a certain way to repositionbrackets that will speed the process? What if a patient is breaking brackets every otherappointment? Biting fingernails?

    The first rule in re-bracketing or repositioning is to be efficient. In your 1st case, even if you were in.020, I would re bracket that tooth at the same time I repositioned. If I had time, I'd do it that day.If not, leave the tooth unbracketed and schedule a longer appt. for repositioning in a month. One ofthe beauties of ortho is you can delay or speed up things depending on your schedule at thatparticular time. This is not the case with most other dental procedures.To answer your 2nd question, if you can't go directly to 019x025 niti from 016 niti, use an 016 ststeel wire for a month. Again, not all patient's teeth move exactly the same way, so sometimes wehave to adjust on the fly. Position the brackets correctly (there is no magic here) and use the wiresyou need.

    Breaking brackets is a whole different issue. Poor coop takes all the fun out of ortho. Look in my"policies" handout which I gave out in the last course. We charge the pt $20 per bracket after theyhave broken off 10 (most orthodontists start charging after 5). You will be surprised how quicklythe situation improves after the parents get a few extra bills.

    1) The bracket on LR4 has come off between just about every adjustment; however no otherbracket has come off! FYI, I do have a few ortho cases going and haven't had problems withbrackets coming off...this is starting to frustrate me! Any troubleshooting advice? (I have evenplaced a NEW bracket, just to be sure)

    2) Do you have any info on how to place koby hooks?

    3) According to USDI guidelines, the consolidate stage is to close posterior spacing, so if it's a non-extraction case, do you generally skip this stage? And are lacebacks your preferred method ofclosing space? I have heard of k-modules, chain elastics, etc. Which ones work best in whichsituations?

    Brackets consistently coming off is a frustrating problem. It's usually related to occlusion. Whenyou re bracket, make sure it is not interfering. You can relieve interferences by adjusting thebracket (usually a tie-wing is the culprit) and by also doing a minor adjustment on the opposingtooth.

    I usually place Koby hooks under the archwire. Then you don't have to remove them on every wirechange. Just tie it in like you would a steel tie. Be sure to pull tightly on the pigtail as you twist.After tightening, deflect the hook to where you want it to go by using a ligature director. Then tiethe wire in as usual over the hook. The Koby hook gains stability when the wire is tied in.Lacebacks are used early in extraction cases to control anchorage (that is initial retraction ofcuspids into the extraction site without any forward molar movement) so, technically, they are nota method of space closure. Any elastic force can be used to close space. Power chains, k-modules,elastics, open coil springs, etc. all work. Use what works best in your hands. Personally, I useelastics (1/4" or 3/16" medium ) until the space is about 2 mm. Then I use power chain. I think thearchwire used is more important than the type of force. To maintain good torque control, I like touse heavy rectangular wire during space closure.Finally, if there is no space to close, consolidation is essentially complete, so, yes, you technically

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    skip this stage in those situations.

    What are the things to look for in the prefinishing check list?

    Prefinishing Checklist

    Name _________________________ Date ___________

    Initial bracketing date ____________

    1. Goals of treatmenta. _________________________ accomplished yes ___ no ___b. _________________________ accomplished yes ___ no ___c. _________________________ accomplished yes ___ no ___d. _________________________ accomplished yes ___ no ___

    Explanation of no answers______________________________________________________________________________________________________

    2. Static Occlusion 6 keysa. molar relationship......acceptable yes ___ no ___b. tip.....................acceptable yes ___ no ___c. torque..................acceptable yes ___ no ___d. rotations...............acceptable yes ___ no ___e. spaces..................acceptable yes ___ no ___f. curve of Spee...........acceptable yes ___ no ___

    Explanation of no answers______________________________________________________________________________________________________

    3. Functional occlusiona. Left lateral working ______ balancing interferences ___________b. Right lateral working _____ balancing interferences ___________c. Protrusive ______________ interferences ___________________

    Is functional occlusion acceptable yes ___ no ___ CR = CO? yes ___ no ___Equilibration required yes ___ no ___If unacceptable, why? _____________________________________________________________________________________________________________

    Ready for de-banding? Yes ___ no ___If no, how long? ______________Fee paid yes ___ no ___If not, how much is owed? ____________

    I have some anterior open bite cases I'm treating. In some of these cases the bite closes by justgoing through the wire progression while others require 019x025 nitinol rocking chair curve (RCSwire) coupled with heavy elastics from upper to lower canines. The problem with this is patientcooperation; patients will not apply the heavy anterior elastics because they hurt and instead of

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    closing anterior bite we now have more bite opening. So, I'm wondering instead of using the RCSwire maybe I can use just a regular 19x25 nitinol with lighter anterior elastics (1 or 2 elasticsinstead of 3) . So, if the patient doesnt wear the elastics the open bite wont worsen. Would thiswork? What do you think?

    Welcome to the wonderful world of ortho. One of the advantages of GP ortho is you get to pick thecases you want (and don't want) to treat. With diagnostic experience comes the ability to pick outthese tougher cases before you begin treatment. You can then either charge more or refer.If you have an open bite in the bicuspid area as well as in the anterior, a flat wire will not easilysolve the entire open bite problem. In these cases, there is no way around the difficult mechanicsof RCS plus heavy elastics. However, if the bite is closed (or nearly closed) in the bicuspid area,then lighter anterior elastics on a wire without curve should do the job.

    Remember, a little (1 to 1.5mm) lateral open bite may respond to differential bracket position. Getthose bis bracketed gingivally, and eruption (and hence lateral open bite closure) may occur. Thatbeing said, RCS plus heavy elastics is still one of the most reliable methods of open bite closure.Posted byJim Pr

    More QuestionsI want to ask you how to correct a bilateral crossbite in a 42 year-old patient. I do not think I can

    use a palatal expander. Is there any way to correct it?

    These situations are tough. You can't split the palate without surgery; the sutures are too mature.That leaves us with tipping teeth. You can probably get about 3mm per side of expansion bytipping. If the amount of crossbite is 2mm or less, expanding the archwires during the wireprogression may do the trick. If the amount of crossbite is approaching 3mm, a Schwarz plate(which I personally don't like to use) or a quad helix (which I like) will get you to your goal. In anyadult crossbite case, always consider leaving the patient in crossbite. Sometimes the best answeris the most simple.

    One other question: I have some patients' moms discussing ortho in their young kids, who stillhave many deciduous teeth. Is it usually best to wait until these have exfoliated? I understand thatgrowth curves favor early intervention, but waiting for permanent bis to erupt may prolongtreatment. Do orthodontists routinely wait for all the deciduous molars to exfoliate prior to startingortho? Are there certain malocclusions that most practitioners treat early?

    You are touching on a very controversial topic. Many practitioners swear BY early treatment-theysay it is always better to treat early- while many practitioners swear AT early treatment- they say itis worthless. The answer is probably somewhere in between. The more severe the malocclusion,the more early intervention seems to help. FYI, most of the orthodontic literature demonstratesthere is not a whole lot of value in early (two phase) treatment as compared to more traditionalsingle phase treatment. The bottom line is that with experience you will develop a treatmentphilosophy that probably will include some early treatment.

    When are vertical (triangular) elastics used in the finishing phase? Would that be in weak muscledpatients? Do you routinely use elastics for finishing, or mainly rely on settling forces and arch wirebends?

    I use finishing elastics in about 20% of my cases. They tend to be helpful on weaker muscledpatients, where the muscles are unable to provide adequate settling forces. I try bends beforeadding elastics in most cases. If the bends provide good interdigitation, I'm done; if not I addelastics.

    I am finishing up a case in which all teeth interdigitate well with the molars in solid Class I

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    occlusion. I had the patient use Class II elastics for 3 months. However, some overjet remains inthe anterior. Since all teeth are in contact, I do not think it is a good idea to do IPR on the anteriorteeth and retract them with chain elastics. I might improve the overjet, but teeth might notinterdigitate well as a result. What is your call on this?

    I think you are faced with a tooth size discrepancy. Upward of 80% (that's right 80%) of patientshave some sort of discrepancy. This case probably has excess tooth structure in the maxillary. Thisoften presents as good posterior interdigitation combined with overjet. In these cases I often do alittle ARS in the upper. I usually strip 1mm distal to each cuspid. Then I close the space with 6-6chain. I find that this retracts the anterior segment a bit without changing the posterior occlusion.Because the space closure is minor, it can be done on the finishing wires (.018st steel), although itis always better to close spaces on .019x.025 stainless steel wires.

    I have a case in which I could not close the space of about 1 mm between the bicuspids with elasticchain. I am thinking of using closing coil; however I have never used it. I learned that there are nitiand stainless steel closing coils. These coils can be purchased in spools, or in different lengths withhooks at the ends (to engage the hooks on brackets). I prefer spools of stainless steel coil. I havenot ordered any and want your recommendation. Please recommend the type and the steps of howto choose the length of the coil for a particular span from one bracket's hook to another. If youhappen to recommend the one that comes in a spool, please advise me how to form a "hook" atboth ends of the coil, so I am able to engage it on the bracket hooks.

    When I use closing coil (which is rarely), I use stainless steel coil off of a spool. I like to stretch thecoil about 1.5 times its resting length measured from the distance between the two attachmentpoints. I use a bird beak and grab the last link of the coil, turn it up 90 degrees, and shape it tomake a loop at right angles to the rest of the coil. (If you experiment with this, you will find this tobe very easy to do.)I then use a Koby hook on the bracket of the teeth to be engaged if it doesn'talready have a hook on the bracket. Stretch the coil, and slide the loops over the hooks.Remember, any method of force application should work. I would be more inclined to look at whythe space is not closing, not changing the method of space closure. Some possible culprits:1) overbite is too deep2)bracket position is off3) sinus on the upper is low-cortical bone of sinus wall is interfering with root movement4)friction in space closing set upUsually, for the last mm or so, friction is the culprit. You could have a bracket whose tie wing isbent, a slot that is a bit constricted, or numerous other issues. I usually will try (if I have eliminatedthe other above possibilities)going to .020 stainless steel and closing the remaining space on roundwire with chain. I know this violates one of my rules, and we are risking the expression of side-effects, but for a mm or so in a stubborn case, the risk is worth it. Remember, you have to knowthe rules before you can break them.

    I have always bracketed all upper teeth at same height from the incisal with the cuspids andcentrals .5 mm longer than the laterals. I know you position brackets by finding the center of theteeth. I am just not too comfortable at doing it your way. I read old lectures, not yours, and cameacross one that said to bracket all teeth at same height from the incisal with the laterals .5 mmshorter. What are your thoughts on these different ways of bracket positioning?

    You are touching on the art vs. the science of orthodontics. Any consistent way to get bracketspositioned properly is vital to getting a good result. Changing how brackets are positioned will giveyou different smile lines and esthetics. Understanding this means you are starting to understandthe art of orthodontics. Positioning the anterior brackets a little incisally will result in someintrusion and, therefore, a little less tooth display than positioning the anterior brackets more

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    gingivally. So each of these techniques may be appropriate in different situations. Incisalpositioning may look a little nicer in a patient who already has excessive gingival display. Gingivalpositioning may be appropriate for a patient who doesn't show a lot of teeth while talking orsmiling.My point is each case is different, and if you truly want to provide the best results for your patientsyou must, at times, deviate from the ideal. Understanding how different bracketing techniquesresult in different esthetic results will allow you to change bracket positions with confidence.

    I find that I'm spending a lot of time coordinating my 19x25 stainless steel. When I try to conformthe 19x25 steel to my initial wire I use my fingers to match the wire. Do you use pliers to do this?On one case I elected to leave the 19x25 niti because my steel was not accurate. If I do leave the19x25 niti instead of the steel how long should I wait? If the 19x25 niti fits passively after 2 to 4months is that a sign that it has served its purpose?

    I coordinate .019x.025 st steel with a hollow chop pliers(in the Ortho Organizers cat. it is Endura#201-401). It is tough coordinating these, but with practice, it can be done. In some cases, I don'tuse .019x.025 stainless steel when there are no mechanics to do. If there is no space closure,midline shift, or Class II or Class III correction, I often skip the .019x.025 st steel and stay in .019x.025 niti. This has to stay in at least 3 months to provide torque expression. When it ispassive, it has done its job. However, don't do complex mechanics on niti, because the side-effectsof these mechanics are more easily expressed on the low-load deflection archwires.

    Thank you for the reply, regarding the wire progression. Mechanics should not be done with any19x25 niti wire at all? What about space closure and elastics use?

    The low load deflection arch wire (niti) is not strong enough to overcome the side-effects ofcommonly used orthodontic mechanics. For example, if you use Class II elastics, the patient usuallyhooks the elastic to the hook on the lower 1st molar band. The elastic provides a vertical force onthe molar. The low-load deflection niti wire will be overpowered by the elastic, resulting inextrusion of the molar. The result is loss of vertical control. If the same mechanics are done with .019x.025 stainless steel wire, the strong arch wire will prevent extrusion of the molar. The resulthere is better vertical control.

    I have two concerns. First,I have a case which I expanded both upper and lower arches due tosevere lingually inclined teeth. After the teeth are uprighted, do I need new upper and lowermodels to coordinate the wires? How do I coordinate arch wires, lower 3 mm wider than what isindicated on the new model and upper 3 mm wider than lower? Or do I make the lower arch width6-7 mm wider than what is indicated on the new model,with the upper 3 mm wider than lower?Second, you said Class II elastics will reduce about 4 mm of overjet. I'm using Class II elastics on acase that needs 8mm of Class II correction. After correcting 4 mm of overjet (I still need 4 mmmore of overjet correction),can I hold the bite where it is after the first correction of 4 mm overjet

    for six months, to give the condyle and the fossa time for bone remodeling and muscleadaptation?. Then, after the rest period,can I use a second round of Class II elastics for theremaining 4 mm of overjet correction? I'm referring only to using Class II elastics, with no othermeans of Class II correction, such as extraction or ARS.

    When coordinating arch wires,I look at how much expansion is needed (for this look at pre-treatment models) and coordinate all my stainless steel arch wires to this position. In the exampleyou gave, I would not take another model just for the purpose of arch wire coordination. If my archwidths are where I want them , I simply continue to coordinate based on the pre-treatment model.Because the arch widths are correct, you are using the correct arch width coordination. There is noreason to complicate matters by changing how you are coordinating the arch wires.

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    I rarely use Class II elastics for more than 5mm of Class II correction, even in very strong muscledpatients. The issue is not a TMJ issue-the condyle and fossa can adapt to the new condylar positionIn fact, when using repositioning appliances, we expect condyle and fossa adaptation for evenlarger horizontal corrections. The issue is the side effects that Class II elastics cause to theocclusion. For example, if you try to correct 8mm of overjet with Class II elastics, the vertical forcesplaced on the lower molars will extrude them. This will result in occlusal plane tipping anddownward and backward rotation of the mandible, tipping of the upper occlusal plane inferiorly inthe anterior, which results in increased gingival display. A rest phase does not change the totaltime you need to use Class II elastics; the net side effects will still be there.The bottom line is this: Class II elastics are very effective in correcting small and moderateamounts of Class II, especially in strong muscled patients. But, the side effects are real, and canruin an otherwise nice result. Don't fall into the trap of using Class II elastics in severe Class IIsituations in an effort to avoid more difficult treatment options that may be better for the patient.Be aware of potential side effects, and understand which patients will not respond well to theelastics. Also understand what specific side effects will be detrimental to the patient that is beingtreated with Class II elastics, and watch carefully for the first signs of the particular side effects.Posted byJim Prittinen,D

    Another Round of QuestionsWhat should be corrected first- overjet, overbite, or midline discrepancies? Do you correct one at a

    time or all at the same time?

    Answer:1) Always correct overbite before overjet. Overbite is corrected during the wire progression(.014,.016, and .020 stainless steel). Use curve if the pre-treatment overbite is 6mm or greater.2) Overjet, midline correction, space closure, and other aspects of the malocclusion (except foroverbite, which is done earlier) are corrected in the mechanics phase- after the wire progression.Correct these aspects of the malocclusion in .019x.025 stainless steel, because this wire providesvery good control. By following these guidelines, most malocclusions can be corrected efficiently.

    I have created enough space by using coil springs and have engaged the crowded teeth. I haveused .016 Niti for 3 weeks since coil springs were removed. The lower centrals have flaredexcessively. This concerns me. I have used .016 Niti for 5 months. Is this too long? Also, should I bedoing anything at this point the get those lower centrals back where they belong? How do I do this?Do I use power chain?

    Answer:You were probably a little too aggressive in your use of coil springs; that is, the coil springs youused may have been a little long. Short term excessive flaring of the lower incisors is usually not aproblem, unless anterior gingival recession occurs. If recession has occured, use chain to retractthe anteriors. If no recession is apparent, align the incisors (remember to use steel ties if the wireis not fitting passively into the slot when you are using .016 niti), then begin the wire progression.The incisors may settle back on their own. Don't use chain until you are in a much heavier wire(.019x.025 stainless steel is best) because the force levels exerted by chain are very high. Fivemonths is not too long to be in .016niti- a mistake I often see is doctors progress out of niti tooquickly. Remember, open coil spring is used to tease the teeth apart; you don't need to pack a lotof coil to gain space. As a general rule, the coil is 2mm longer than the distance between theadjacent brackets. Every month, use a spring that is 2mm longer than the coil used in the previousmonth. Discontinue coil and engage the tooth when there is enough space in the arch to fit thepreviously blocked out tooth.

    After using 016 niti for 6 months, I started a wire progression on a 13 yr old patient. Everything

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    looks OK on the upper (coil springs to create space). But the lower left lateral, even after all thistime, still is rotated. Additionally about 1.5 mm of crowding still exists. I was not sure what to do,so I started a wire progression (.014 ss). The wire is slightly kinked in (I had to push it slightly to fitinto the bracket slot). I know that the wire has to be passive to maintain arch integrity. As of now,the crowding will not allow the LL2 to fit in the arch. Did I not create enough space with the opencoil? Should I have done IPR before progressing to 014ss? Did I progress to .014stainless steelprematurely? Could I pack coil later, say in .020 stainless steel, and create space? Does thismethod create space too late? Is it as efficient as creating space in .016 niti?

    Answer:If, as you say, there is still 1.5mm crowding, you have not yet created enough space to bring thistooth into the arch. Use coil to gain more space. Rotations are nearly impossible to correct if thereis not enough space in the arch. If there is enough space, it is much easier to engage the toothwith niti. Then the correction of the rotation will proceed uneventfully.Many doctors will progress up a wire progression, bypassing severely rotated teeth. Once they getto a heavier wire (.016 stainless steel or heavier), they will pack coil a little more aggressively tocreate enough space for the rotated tooth. Then after enough space is created they will step backto niti and engage the rotated tooth. This method results in less arch distortion, but it takes a littlelonger. You never want to kink a stainless steel wire. It will not return to its original shape so it willnot move the teeth efficiently.IPR is an option in this case. If the tooth is thinner, it will fit into a smaller space. The problem withIPR on rotated teeth is the inability to access the contact point, which is the area where you wantto do IPR. So do the IPR only after space is created and you can get at the contact point.

    After full banding, can we give the patient a bite plane until an anterior crossbite is corrected, or isit OK just to let the braces move the teeth?

    Answer:In general terms, a bite plane will, because it eliminates interferences, allow the teeth to movemore quickly. In my experience, patients in braces don't wear bite planes very well. The teethmove a little, and, as a result, the bite plane doesn't fit. That being said, a lot of orthodontists usebite planes. I prefer to open the bite by bonding composite to the occlusal surface of the lowermolars. The bonding can be done quickly, it is not removable by the patient, and it is easilyremoved by the doctor after the occlusion improves. Kids tolerate the change in occlusion well, butadults hate it. So I'm a bit more discriminating when I'm considering this on adult patients.

    I've been putting second molar brackets on my patients, and find that they report a lot of softtissue irritation. I know about using ortho wax, and I always encourage patients to use it tointercept problems before irritation occurs. Do you have soft tissue problems with second molarbrackets, and do you use the smaller ones, or the larger first molar brackets to get more surfacearea for bonding?

    Answer:I usually use the smaller bracket because of irritation issues. Remember, on the upper it's OK to

    use 1st and 2nd molar brackets interchangeably, but on the lower it is not. The prescription isdifferent on the lower 1st and 2nd molars-more lingual crown torque is present in the lower 2ndmolar brackets than the lower 1st molar brackets.

    How do I change the molar relationship from a full cusp (8mm) ClassII relationship to a ClassI molarrelationship in a non-growing patient?

    Answer:In a non-growing patient, it is very difficult to change a full cusp (8mm) Class II molar relationshipto ClassI molar relationship. So most of the time we dont try (don't fight molar relationship,especially in non-growers, is a statement with which most orthodontists would strongly agree).Usually in these kinds of cases, keep the molars in ClassII. Do this by taking out only the upper 1st

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    bicuspids and retracting the anterior segment. The molars stay in ClassII, but the canines end up inClassI and the overjet is corrected. Typically in these cases, the upper anteriors are protrusive, sotaking out upper bicuspids provides space for retraction of the upper anteriors. Often, problemsarise with these cases if the bite is deep. It is more difficult to open the bite in extraction casesthan in non-extraction cases.Anchorage control is very important in upper bicuspid extraction cases. The molar relationship isClassII, so additional mesial movement of the upper molars is contraindicated. In addition tolacebacks in the initial stage of treatment, some method to prevent this forward upper molarmovement must be used during space closure. Trans-Palatal Arches, Nance buttons, headgear, andbanding or bonding the upper 2nd molars are all treatment modalities that are used to increaseposterior anchorage during space closure.

    What do you use to rotate a tooth? Recently, I bought some rotation wedges. Do you recommendusing these and how do you use them?

    Answer:I'm not a fan of rotation wedges. They are tough to put in and they don't stay in very well.I preferto create space with coil, then after space is created, while still using a flexible arch wire such as .016niti, tie the tooth in tightly with a steel tie.

    I have a case where tooth #7 was in lingual cross-bite. I brought the crown into the arch, but theroot did not translate- that is,the root is still facially inclined. First, I repositioned the bracketseveral times and I placed a .016x.022 stainless steel wire, but the lingual root torque has notoccurred. How do I correct the root torque? I think some doctors place the lateral brackets upsidedown in these situations. I did that for a few months in the .016 niti, but the root just did not movelingually. This is very frustrating. Do you have any thoughts on this?

    Answer:You need lingual root torque on the lateral. The lateral incisor bracket that I use has 10 degrees oflabial crown torque (which is the same as -10 degrees of lingual root torque) so the bracket will notmove a root lingually very easily (the bracket prescription does not encourage lingual rootmovement). If you put the lateral bracket on upside down, the torque changes to -10 degrees,which results in a situation that encourages lingual root movement. Remember, for torque to beexpressed, you must use a rectangular wire. You cannot torque teeth on a round wire. Even a .016x.022 does not fill the slot enough to affect torque very quickly. Get into .019x.025 (preferablystainless steel) and torque will be expressed.

    I have a patient that started with 7mm of overbite. I curved the upper wires, and the bite has notopened enough. Should I use .016x.022 rectangular wire with curve?

    Answer:As a rule, I don't like to curve rectangular wire. If the bite needs further opening, try curving the .020st steel a little more, and use .020 stainless steel with a little deeper curve on the lower as well

    Stubborn deep bites are the result of an incomplete leveling of the curve of Spee. Lower curves willsolve this. If, after a couple of months, the bite is not open, bracket the 7's (I usually direct bondthem). Erupting 2nd molars often is the best way to get the bite opened. A word of advice: do notdo any other mechanics until the bite is opened. Do what it takes (and be patient!) to get the biteopened before progressing in the case. You will save a ton of time in the long run.

    SATURDAY, AUGUST 8, 2009Still More QuestionsI'm treating a 12 yr old female with mild crowding, ClassI dental and skeletal, deep overbite, somerotations, and a low mandibular plane angle. I've bracketed and banded, with differential bracketplacement, and propped the bite open slightly with composite on the occlusal surface of the lowermolars to accommodate the mandibular brackets. Ive used 016 Niti for a couple of months. Now I

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    notice the second molars are in crossbite. Do I bracket these now or wait? Any problems withmerely bracketing these 7s at the next appointment? Or should I make some type of temporarybite plate to unlock the occlusion while I move them?

    I would bracket the 7's asap, because not much will happen as far as correction of the deepbite/crossbite until you have control of the 7's. This happens a lot, and bracketing the 7's will solvethe problem. There are no problems with waiting a month, but you are just not making anyprogress toward finishing if you don't bracket.

    I have a question regarding differential bracket placement. I noticed that there is a line inMcLaughlin's book outlining this, but in general he does not routinely use this procedure. Don't wewant the brackets to be placed ideally relative to the incisal edge at the end of treatment toachieve a flat curve of Spee and ideal marginal ridge alignment? His technique seems to imply thatideal placement will usually flatten the curve and open the bite appropriately by that procedureonly, perhaps followed by reverse curve in rectangular ss if needed. Is there a disadvantage toplacing brackets differentially at the start of treatment?

    McLaughlin does not use differential bracket positioning as much as I do. However, the last time Isaw him speak (18 mo ago) he said he was leaning toward more differential bracket positioning,especially in the anterior. If you wait long enough, a flat wire with ideal bracket position will levelthe curve. In strong muscled patients, this may take a long time. I don't like curving rectangularwire (this does level the curve very quickly) because of the side-effects it produces.I have found no disadvantages to differential bracket positioning. I continue to use this techniqueas I have for the last 20-plus years. In fact, I probably place my anterior brackets a little incisally onmost cases, even those that do not require bite opening. My bias toward incisal anterior bracketpositioning is due to the fact that the more incisally the bracket is placed, the more torque(positive labio-lingual inclination) is expressed. Since torque expression is the "weak link" of thepre-adjusted appliance, this incisal bias results in helping solve the most difficult problem (torqueexpression) in using the pre-adjusted appliance.

    I heard a comment at a seminar regarding "round tripping. I'm thinking that I should have usedmore bendbacks to inhibit the mandibular incisors from flaring forward. Do bendbacks inhibit openbites and excessive anterior flaring? If we want to control the mandibular arch length and shape,maybe bendbacks are appropriate. McLaughlin mentions bendbacks, and also mentions IPR.Perhaps he is thinking about preventing flaring of the mandibular incisors.If we do bendbacks, how do we correct rotations and crowding especially if we use open coilsprings? The space has to be gained somewhere! Maybe he's doing an arch length analysis, thenIPR immediately in non-extraction cases, rather than gaining space through anterior tipping of theincisors, unless a more protrusive appearance is called for. You have said that you like to be incontrol. Maybe I need to control this incisor position more effectively, particularly in the mandibulararch during the first step. But how is this done?

    When you treat a case non-extraction, you must be willing to accept the fact that to unravel thecrowding, the teeth will move forward. If you don't want the teeth to move forward, then you must

    gain some space some way- stripping, extraction, expansion and/or distalization. Each of thesemodalities has problems associated with it. Moving teeth forward to unravel crowding is not roundtripping, because, if the diagnosis is correct, you will not plan on moving the teeth back to theiroriginal position.The big issue is diagnosis-where will the teeth end up with the plan you choose and is this right forthe patient? There are many ways to get the teeth where you want to get them, but figuring outwhere they belong is the most important part.

    I just started a case with an RPE. Last week the appliance fell out and the patient waited a coupleof days to come in the office. I had a very difficult time recementing the appliance. Is this due torelapse? Patient activated appliance for 2 weeks and it is now passive. The appliance may fall out

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    again. What should I do in this situation?

    If you can' t get the appliance to fit well, first determine if the problem is lack of space for themolar bands. You could try placing spacers for a day or so before attempting recementation. If theactual expansion relapsed, turn the screw backwards for a couple of turns, then recement. If youare satisfied with the amount of expansion you currently have, make a Hawley retainer. Have thepatient wear it full time for a few months. Then, bracket as usual.

    I have a question regarding reverse and compensating curve. I placed curve in the maxillary arch.A month later, after I took out the 014ss there was no curve on the wire. Does the curve disappearafter a month? Is there supposed to still be a curve after I take it out? There is a small spacebetween 8 and 9; I take it that is from the flaring so I assume that the curve did do something. Itried to think back to your lectures but could not remember if you mentioned what the wire wouldlook like after removing it.

    Often the lighter wires will straighten out a little because they are held in a straight position (tiedin) for a month. I would be more concerned with results- reduction of overbite- than how the wirelooks when it is removed. That being said, the biggest problem most doctors have when usingcurve is they don't put enough curve into the wires, especially the lighter wires. Bottom line- whatyou have is probably OK. Just make sure you curve the .014's enough.

    I'm working on a 4-bi extraction case. One of the max 2nd molars is partially buried with a 45%angle to the distal of the first molar. Do I attempt to bracket this now, and upright with Niti, or waituntil space closure? Should I use another uprighting procedure? Will this issue resolve itself withslight mesial movement of the molar during space closure?

    If the case is moderate anchorage, close the extraction space and the space gained in theposterior will allow for eruption. If it needs to be aligned, bracket the 7 during finishing.

    I have a question regarding intraoral elastics. For Class II correction, what size do you usually use?

    I most often use 1/4" medium, 1 elastic per side, full time wear, patient changes elastics every12hrs, and eating with them in is optional.

    When is the correct time to start the wire progression? What if brackets are improperly positioned?Do you reposition brackets before starting the wire progression?

    Begin the wire progression when the niti arch wire fits passively into all slots. If brackets areimproperly positioned, don't worry yet. You will reposition after a few months of wire progression.Your goal is to progress to larger arch wires. When the bracket slot is full (or nearly full), you will beable to see malpositioned brackets. It is much more efficient to reposition all brackets that need it

    at once, rather than doing one now, one next month, etc.

    I find that I'm spending a lot of time coordinating .019x.025 st. steel. When I try to conform the19x25 st. steel to my initial wire I use my fingers to shape it. Do you use pliers to do this? BecauseI am having a hard time accurately coordinating these wires, on one case I elected to leave the19x25 niti in for the mechanics phase. If I do use 19x25 niti instead of the steel how long should Iuse it? If the 19x25 niti fits passively after 2 to 4 months, is that a sign that it has served itspurpose?

    I coordinate .019x.025 st steel with hollow chop pliers. (In the Ortho Organizers cat. it is Endura

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    Pliers #201-401) It is tough coordinating these, but with practice, it can be done.Often, I don't progress to rectangular stainless steel when there are no mechanics to do. If, forexample, there is no space closure, midline shift, or Class II or Class III correction to do, I often skipthe .019x.025 st steel and stay in .019x.025 niti. This has to stay in about 3 months to providetorque expression. When it is passive, it has done its job. However, don't get into the habit of doingcomplex mechanics on niti, because the side-effects of these mechanics are more easily expressedon the low-load deflection archwires.

    More QuestionsHow do you decide when to use arch wire curves as opposed to tip-back bends when the biteneeds to be opened?

    The amount of gingival display often dictates what method of bite opening to use. If the patienthas a gummy smile I would rather intrude incisors (tip-backs do this more efficiently than curves)which results in a reduction of gingival display. If the smile is not gummy, erupting molars (curvesoften do this more efficiently than tip backs) will open the bite without reducing the gingivaldisplay.

    It is easy to envision that a toe-in bend for maxillary molars helps correct the mesio-lingual rotationof the molars. But how does the toe-in bend applied to the mandibular molars counteract thelingual movement which is often a consequence of eruptive forces produced by tip backs? Also, doyou do the toe-in and tip-back bends together or one at a time?

    A toe-in results in buccal crown movement. An eruptive force (the tip back) in one plane of spacebecomes a buccal force (the toe in) in another plane of space. Look at the photo, courtesy of Dr.Tom Mulligan.

    Although some practitioners use both bends simultaneously, I don't. I like to keep my forces assimple as possible. The toe in is used to counter the potential negative side effect of bite opening,which is lingual crown movement. If the side effect isnt expressed when using the tip back, thereis no need for a toe-in. So I wait to see if I need it.Remember, when using toe-in or tip-back bends, for eruptive(tip-back) or horizontal (toe-in) forcesto be produced, the bends must be asymmetric. In other words, the distance between where thewire is bent and where the wire is first engaged must be different on both sides of the wire.If thiscondition is met, use Mulligan's long and short segment rule (see photos or go tohttp://www.commonsensemechanics.com/CourseContent.htm )to determine the forces that will beimparted by the wire.

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    Now Im a little confused. The toe-in is used to prevent rolling in of the mandibular molars. Whydoes this rolling in of the mandibular molars occur?

    A side-effect of molar eruption (or any extrusive force for that matter) is lingual crown torque. Thisforce often results in lingual molar movement. Because the wires used for tip backs (usually .016or.020 stainless steel) are round, in a .022 slot no torque control occurs. Additionally, if rectangularwires are used, the pre-adjusted appliance prescription for the lower molars has lingual crowntorque built in. These factors contribute to rolling in, or lingual tipping, of the lower molars. A toe-inbend counteracts these tendencies by providing a buccal force. Ideally, the "bad" forces arecancelled by the "good" forces and the net result is a molar that is upright, not rolled in.

    I have another question for you: Why do practitioners who use utility arches expand the upper archby 5-10 mm by flattening the anterior bridge to correct ClassII Div 1 and 2 patients? Is the

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    expansion necessary?

    Upper arch expansion combined with distally rotating the upper molars has been a technique usedto correct Class II for over a century (It is often done when using headgear by adjusting the innerbow). The expansion creates the environment where the lower arch can be positioned forward(many ClassIIs are the result of a narrow upper arch which results in the lower arch beingpositioned, or trapped, distally). This is combined with distal rotation of the upper 1st molar, whichplaces the palatal cusp of the upper 6 in a more anterior position. In ideal occlusion, the upper 6palatal cusp occludes with the central pit of the lower 6. When the upper 6 palatal cusp ispositioned more anteriorly, the lower molar (and hence the whole lower arch) is guided forward.The expanded upper arch allows the mandible to reposition forward, which results in Class IIcorrection.

    Whats the easiest way to flare lower incisors forward to gain arch length?

    You can do this by manipulation of a utility arch, which has been popularized by Dr. Len Carapezza(http://www.igdpd.com). You could also use a straight wire, leaving the 3's, 4's and 5'sunbracketed, packing coil between the 2's and 6's. Make the coil about 2mm longer than thedistance between the distal of the bracket on the 2, and the mesial of the bracket on the 6. Theforce will push the anteriors forward and the molars back. The anterior teeth move forward muchmore easily than the molars distalize, so the net effect is forward incisor movement. Every month,pack a new piece of coil which is 2mm longer than the coil used in the previous month. Continueuntil the incisors are where you want them. The same effect can also be achieved by placing stopsin the arch wire near the molars so there is a little extra wire length from molar to molar. If you doit this way, you must change the arch wire to gain additional forward movement of the incisors, sothis method may be more cumbersome than packing coil.

    I have a question about molar uprighting. I have a few adult patients that have lost their lower firstmolars and I would like to upright their 2nd molars. In order to do this could I simply place a tipback bend just distal to the 2nd premolars rather than just mesial to the molar band? Anysuggestions you have on how to upright molars would be greatly appreciated.

    Molar uprighting is tough. In theory a center bend (technically an occlusally directed gable bend)will parallel the roots and all vertical forces will cancel. In reality it is very difficult to make thebend a center bend because the bracket position- and hence wire angle of entry- is different on theteeth adjacent to the bend (one bracket is relatively straight, the other is tipped). This contributesto making the bend asymmetric. Unlike a center bend, where vertical forces cancel, theasymmetric bend leads to expression of vertical forces. The big challenge in molar uprighting is toprevent eruption of the molar which often contributes to unwanted bite opening.Uprighting without eruption occurs with a center bend. You may also get eruption because thebend is usually not precisely a center bend.. Occlusal adjustments must be made so the bite

    doesn't excessively open. Often, the molar needs to be crowned because so much eruption occurs.Orthodontists have designed uprighting springs that mitigate the eruptive forces. They are kind ofhard to use. Many are now using temporary anchorage (TAD's) to get a more direct force on themolar.All in all, uprighting is tough. Don't promise your patient much,