Kieferorthopädische Speisekarte

Kieferorthopädische Spezialitäten aus aller Welt Angerichtet und serviert von Fachzahnarzt für Kieferorthopädie Dr. Ulrich Kritzler

Dr. Kritzler 1

Vorspeisen / Vor und Frühbehandlungen Dienen vor allem der Herstellung einer normalen Funktion durch die Beseitigung von Kreuzbissen, Rücklagen des Unterkiefers und Unterentwicklungen des Oberkiefers. Zum Einsatz kommen vorwiegend herausnehmbare Behandlungsgeräte wie der U-Bügel Aktivator nach Karwetzky zur Behandlung von Rücklagen des Unterkiefers, der Funktionsregler 3 nach Fränkel zur Behandlung von Unterentwicklungen des Oberkiefers, Aufbissplatten nach Schwarz zur Kreuzbisskorrektur.

21Budihardja: U bow activator

canine to canine. Protrusion bow extends from middle of canine to canine at the palatal region, made from 0.7 mm stainless steel wire. The height of these two components depends on front teeth movements that want to be achieved. Expansion screw is placed in the upper plate, at the height of P1 or dm1. U Bow made from 1.2 mm wire, placed at both sides at the height of M1. U bow activation will define the mandible reposition.4

There are three types of U bow activator developed by Karwetzky: a) UBA type 1. In type 1, the U bows are placed downward and this activator is used to correct class II malocclusion; b) UBA type 2. In type 2, the U bows are placed upward and this activator is used to correct class III malocclusion; c) UBA type 3a and 3b. The placements of the U bows are different between the right side and the left side. This type is usually used to correct asymmetry and functional midline shifting (Figure 2).

From these three types of UBA, the one that used most is UBA type 1 to correct class II malocclusion. Ehmer, with the dysgnathy classification, said that indication of using UBA type 1 are mandible retrognathy, maxilla prognathy, upper front teeth protrusion and or lower front teeth retrusion, deck bite (Angle class II div 2), and skeletal or functional asymmetry that accompany class II malocclusion.4,5

Just as other functional appliance, the optimal time of using UBA are during growth, between 8–11 years old. UBA can also be used earlier (4–7 years), usually in patients with class II div 1 malocclusion accompanied by extreme over jet. This kind of malocclusion can enhance the risk of front teeth trauma, caused negative functional pattern (lower lip is trapped behind upper front teeth and incompetence lip closure) and usually caused psychological stress to the patient (being mocked about appearance).4,5

Figure 1. U bow activator from Karwetzky.

Figure 2. Three types of UBA developed by Karwetzky.

23Budihardja: U bow activator

Figure 5. Intra oral photos before treatment.

Figure 6. Panoramic radiograph before treatment.

Figure 7. Cephalometry radiograph before treatment.

Figure 8. Intra oral photos after 15 months using UBA.

23Budihardja: U bow activator

Figure 5. Intra oral photos before treatment.

Figure 6. Panoramic radiograph before treatment.

Figure 7. Cephalometry radiograph before treatment.

Figure 8. Intra oral photos after 15 months using UBA.

24 Dent. J. (Maj. Ked. Gigi), Vol. 40. No. 1 January-March 2007: 20–26

CASE MANAGEMENT

Our treatment plan was using functional appliance to achieve anterior reposition of the mandible and to influence the growth of the mandible to reach its maximum. Functional appliance used was U Bow Activator type 1 from Karwetzky. The first construction bite made was 4 mm sagittal to anterior, vertical 4 mm and transversally lower midline was adjusted to midline of the face. Transversal expansion in upper jaw was also needed in this case.

During the first six months, patient’s cooperation was not so good. He lost his UBA once that a new one has to be made. After that incident, patient was motivated during his visits to the clinic, and since that his motivation became better. He wore his UBA regularly, all night and during day time as well. The UBA was activated 2 mm every 2–3 months and the expansion

screw once in a week. After 15 months using UBA (Figure 8), his over jet was reduced to 7 mm and he had no difficulties wearing the UBA at all.

After using UBA for 25 months (Figure 9 and 10), over jet was reduced to 2–3 mm and the profile changed significantly. Molar relationships on both sides were class 1. Both patient and parents were happy and satisfied with the treatment result and they did not want any further orthodontic treatment with fixed appliance. It was decided to go to retention phase and during this stage the patient is told to wear UBA only at nights.

After 15 months using UBA as retainer (Figure 11 and 12), the treatment result was stabile. Patient has stabile static and dynamic occlusion, nice profile, beautiful smile and his self confidence become better after orthodontic treatment. Patient and his parents were highly satisfied with treatment result.

Figure 9. Extra oral photos after 25 months using UBA.

Figure 10. Intra oral photos after 25 months using UBA.

Dr. Kritzler 2

Behandlungsbeispiel: Frühbehandlung einer Rücklage mit dem U-Bügel Aktivator nach Karwetzky

Frühbehandlung einer Anomalie des progenen Formenkreises mit dem Fränkelschen Funktionsregler 3

Aufheben eines einseitigen Kreuzbisses mit der Quadhelix nach Ricketts (links) oder der Dehnplatte nach Schwarz (rechts)

REFERENCES

1. Baik HS. Clinical results of maxillary protraction in Korean

children. Am J Orthod Dentofacial Orthop 1995;108:583-92.

2. Sung SJ, Baik HS. Assessment of skeletal and dental changes by

maxillary protraction. Am J Orthod Dentofacial Orthop 1998;

114:492-502.

3. Proffit WR, White RP. Surgical-orthodontic treatment. St Louis:

Mosby; 1991.

4. Moss ML. The functional matrix hypothesis revisited. Am J

Orthod Dentofacial Orthop 1997;112:8-11, 221-6, 338-42,

410-7.

5. Graber TM, Rakosi T, Petrovic AG. Dentofacial orthopedics

with functional appliances. St Louis: Mosby; 1997.

6. Frankel R. Maxillary retrusion in Class III and treatment with the

function corrector III. Trans Eur Orthod Soc 1970;249-59.

7. McNamara JA Jr, Huge SA. Functional regulator (FR-3) of

Frankel. Am J Orthod 1985;88:409-24.

8. Kohmura T, Tokuda N, Hara S. Effects of therapy using the

function regulator (FR III) on the cases with the reversed

occlusion. Jpn J Orthod 1986;45:693-711.

9. Ulgen M, Firatli S. The effect of the Frankel’s function regulator

on the Class III malocclusion. Am J Orthod Dentofacial Orthop

1994;105:561-7.

10. Loh MK, Kerr WJ. The function regulator III: effects and

indications for use. Br J Orthod 1985;12:153-7.

11. Kerr WJS, Ten Have TR. A comparison of three appliance

systems in the treatment of Class III malocclusion. Eur J Orthod

1988;10:203-14.

12. Kerr WJS, Ten Have TR. McNamara JA Jr. A comparison of

skeletal and dental changes produced by functional regulators

(FR-2 and FR-3). Eur J Orthod 1989;11:235-42.

13. Proffit WR. Contemporary orthodontics. St. Louis: Mosby; 2000.

14. Dahlberg G. Statistical methods for medical and biological

students. New York: Interscience Publications; 1940.

Fig 4. Intraoral photographs. A, pretreatment; B, 1 year 3 months after FR III treatment; C,postretention (2 years after treatment).

Fig 5. Lateral profile photographs. A, pretreatment; B, 1 year 3 months after FR III treatment; C,postretention (2 years after treatment).

American Journal of Orthodontics and Dentofacial Orthopedics

Volume 125, Number 3

Baik et al 301

verse relationship was achieved; no overcorrection wasproduced. The treatment result was retained for 6months. To prevent or compensate for buccal tipping,the appliance was adjusted for buccal root torque.

The expansion plate consisted of acrylic with anexpansion screw and stainless steel clasps on thedeciduous and permanent first molars (Fig 3). The platewas activated 0.2 mm once a week by the patient untila normal transverse relationship was achieved; noovercorrection was produced. The dentist thoroughlyinstructed the patient to use the plate day and nightexcept for meals and tooth brushing. Treatment pro-gression was evaluated every 4 weeks, and the resultwas retained for 6 months.

The composite onlay technique was based on thetheory that bite raising will inhibit the forced lateralmovement and consequently allow the maxilla to growand develop in the transverse dimension without lock-ing the mandible in occlusion.13 The bite raising wasachieved by bonding composite (Point Four, 3MUnitek) on the occlusal surfaces on both mandibularfirst molars (Fig 4). The composite onlay was checkedevery 6 weeks and removed after a year. In none of thepatients did the composite onlay need improvementprocedures.

The untreated control group received no orthodon-tic treatment during the 1-year observation period.

Twenty randomly selected study casts were mea-sured at 2 separate times. No significant mean differ-ences between the records were found by using pairedt tests. The method error according to the Dahlberg22

formula did not exceed 0.2 mm for any measuredvariable.

Statistical analysis

The sample size for each group was calculated andbased on a significance level of ! " 0.05 and a power

(1-#) of 90% to detect a mean difference of 2 mm($1.5 mm) in expansion between the treatment strate-gies. The sample size calculation showed that 12patients in each group were needed, and, to increase thepower even more and compensate for possible drop-outs, it was decided to select 15 patients for each group.

The data were statistically analyzed by using SPSSsoftware (version 15.0, SPSS, Chicago, Ill). The Fisherexact test was used to calculate the success rate. Fornumerical variables, arithmetic means and standarddeviations were calculated. Analysis of variance(ANOVA) with the Tukey post-hoc test was used tocompare treatment effects and active treatment timewithin and between groups. Differences with probabil-ities of less than 5% (P %0.05) were consideredstatistically significant.

RESULTS

A total of 61 patients were invited to enter thestudy, but 1 did not participate. Thus, 60 patients wererandomized into the 4 groups, and all patients finishedthe trial (Fig 5). Group A comprised 9 girls and 6 boys(mean age, 9.1 years; SD, 1.03), group B included 9girls and 6 boys (mean age, 8.7; SD, 0.82), group C had8 girls and 7 boys (mean age, 8.3; SD, 0.70), and groupD included 8 girls and 7 boys (mean age, 8.8; SD,0.70). There were no significant differences betweenthe groups in age or crossbite side, and all 60 patientshad a midline deviation to the crossbite side. Nosignificant difference in any variables used in the studywas found between boys and girls, and, consequently,the data for the sexes were pooled and analyzedtogether. The baseline transversal measurement vari-ables of the jaws are summarized in Table I, and nosignificant differences were found between the groups.

All patients in the quad-helix group were success-fully corrected (Table II). In the expansion plate group,

Fig 2. Occlusal view of the quad-helix appliance. Fig 3. Occlusal view of the expansion plate.

American Journal of Orthodontics and Dentofacial OrthopedicsVolume 133, Number 6

Petrén and Bondemark 790.e9

Dr. Kritzler 3

Hauptmenue Hauptbebehandlung

Eine kieferorthopädische Behandlung beim Jugendlichen wird meist erst dann begonnen, wenn alle oder fast alle bleibenden Zähne durchgebrochen sind aber noch genügend Wachstumspotential vorhanden ist, um auch eventuelle Kieferfehlstellungen ausgleichen zu können. Weil Wachstum und Zahnwechsel aber sehr individuell sind, kann es von dieser Regel auch Ausnahmen geben.

Der richtige Moment, um mit der Behandlung zu beginnen, muss daher ganz individuell bestimmt werden, um den Patienten nicht unnötig lange zu behandeln aber auch nicht nicht den besten Moment zu verpassen.

Daher werden geeignete Standardunterlagen erstellt, um eine präzise Diagnose und die geeignete Therapieplanung durchführen zu können. Der “kieferorthopädische Check-up” besteht meist aus einem Übersichtaufnahme der Zähne, dem Panoramaröntgenbild , einer seitlichen Fernröntgenbild des Schädels mit genauer Analyse, einer Fotoserie und Abdrücken des Ober- und Unterkiefers oder einem oralen Scan der Zähne. Diese Unterlagen fertigen wir direkt in unserer Praxis an. Im besonderen Fällen benötigen wir eventuell ein dreidimensionales Röntgenbild (DVT) für dessen Anfertigung wir die Patienten jedoch in überweisen.

Auf der Basis dieser Unterlagen werden dann geeigneten Lösungsmöglichkeiten erarbeitet und in einem ausführlichen Gespräch mit dem Patienten und seinen Eltern besprochen.

Dr. Kritzler 4

Festsitzende Behandlungsgeräte (Multibandapparatur)

Selbstligierende Brackets werden mit umlaufenden Behandlungsbögen aus speziellen Metalllegierungen miteinander verbunden. Nach Durchlaufen einer Reihe von aufeinander abgestimmten Bögen unterschiedlicher Größe und aus unterschiedlichen Materialien sind die Zahnbögen ausgeformt.

Durch das zusätzliche Einhängen von Gummiligaturen kann auch die Bisslage korrigiert werden. Beilagen Als zusätzliche Behandlungsmittel können spezielle vorgeformte Behandlungsbögen, Mini Schrauben zur skelettalen Verankerung, das Herbst-Scharnier oder die Forsus Apparatur ompliance Therapie einer noch vorhandenen Rücklage des Unterkiefers und Federn zur Wurzelaufrichtung eingesetzt werden.

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that greatly assists in keeping forces effective, blood vessels fromtotally occluding and tooth movement consistent. In Damonmechanics, wire play is not just a calculation; it is fundamental toits many benefits.

The Advantages of Variable TorqueWith regard to rectangular wires, there are three primary meansof creating the torque required to achieve an esthetically pleasingfunctional result: employing pretorqued brackets, adding torqueto archwires or both. Dr. Dwight Damon is a strong proponent ofemploying variable-torque brackets (rather than primarily relyingon placing torque in wires) for a number of reasons. One is thatdoing so introduces torque correction gradually, beginning withthe first light rectangular wires, which keeps forces effectivethroughout all stages of treatment while sustaining the bloodsupply around teeth for consistent tooth movement. I’ve learnedthat employing variable torque:

• Allows roots to begin uprighting early during the rectangularwire-leveling phase.

• Maintains anterior torque during major mechanics, avoidingthe trauma and time of round-tripping teeth.

• Permits selective torque for individual teeth.

• Maintains posterior torque during maxillary width increasesand bone adaptation.

• Minimizes the guesswork of adding, then duplicatingtorquing bends to different sizes and alloys of finishing wires.

• Enhances the quality of case results while minimizing timeand appointments.

• Can improve final root position, which supports greaterstability.

Expanding Torque Options without FurtherExpanding Bracket InventoryNote: I wrote this article from my experience with Damon 3 andDamon 3MX (D3/D3MX), both of which offer variable torque and havedramatically reduced the need for adding wire torque. Ormco has recentlylaunched Damon Q™ (DQ) with new torque values that are intended tofurther lessen the need for adding wire torque as well as minimizing oreven eliminating some of the techniques described in this article. Through-out the article, I specify when I am referring to D3/D3MX or DQ, andhow the new DQ torque values address specific torque challenges.

Even with the number of variable torque options that D3, D3MXand DQ prescriptions provide (Fig. 2), some cases may requireadditional means of torque. Three options include: (1) employinga bracket on a tooth different from its intended placement on thesame side of the arch; (2) switching a bracket from its intendedplacement in one arch to the same or a different tooth in theopposing arch; and (3) inverting a bracket 180º on the sametooth for which it is intended.

Moving a bracket from one arch to the opposing arch requiresswitching placement to the other side of the arch and takingthe differences in angulation into account. Some clinicians havethe mistaken idea that inverting brackets also requires switchingplacement to the other side of the arch but that is not so. Main-taining inverted brackets on the same side of the arch keeps theroot tip the same mesiodistal.2

Switching brackets from one arch to the other or inverting brack-ets on the same tooth changes positive torque to negative andvice versa, thus increasing the number of torque options avail-able. For example, in a case such as is depicted in Fig. 3, rootmovement of a palatally inclined maxillary lateral incisor will lagsufficiently behind crown movement, a situation which warrantsa torque value lower than the available +3º of the lowest torqueD3/D3MX lateral incisor bracket. Inverting a low- (+3º) orstandard-torque (+8º) D3/D3MX bracket on this tooth offerstwo additional low-torque options (-3º and -8º). DQ offers a -5ºlow-torque option designed to address most of these situationswithout inverting brackets. I admonish clinicians that invertingbrackets comes with inherent risks. It is imperative that inverted

Figure 3. Inverting a low- or standard-torque bracket (which changes the +torque to -) generates greater labial root movement than the lowestD3/D3MX lateral torque option available for upper laterals (pictured). TheDQ low-torque value (-5º) is designed to bring the root of a palatallyinclined maxillary lateral incisor labially with crown movement.

Figure 2. Damon 3/3MX and Damon Q Torque Options

Maxillary D3 DQ D3 DQ D3 DQ D3 DQ SL Ti

High/Super +17º +22º +10º +13º +7º +11º — — — —

STD +12º +15º +8º +6º 0º +7º -7º -11º -18º -27º

Low +7º +2º +3º -5º — -9º — — — —

Mandibular D3 DQ D3 DQ D3 DQ D3 DQ SL Ti

High/Super — — +7º +13º — -5º — — — —

STD -1º -3º 0º +7º -12º -12º -17º -17º -28º -10º

Low -6º -11º — 0º — — — — — —

1/2 3 4 5 6 7

1 2 3 4/5 6 7

5

recommended finishing canines relatively upright for improvedfunction and esthetics with the canine positioned from 0º to -2ºrelative to the occlusal plane, depending on its labial surfacecontours.

Pretreatment and Ideal Tooth PositionsDetermine Incisor and Canine TorqueExcept where countering major mechanics, I always base maxil-lary incisor and canine bracket torque selections on the pretreat-ment tooth positions and prescribed final tooth positions, factor-ing wire play into the determinations. As with any technique,experience and training are critical to making these judgments.

To maintain maxillary incisor and canine positions when thereis no need to counter the negative effects of major mechanics,standard-torque brackets are usually adequate. On the otherhand, uprighting lingually inclined maxillary incisors and caninesoften requires high-torque brackets, which, even when factoringin wire play, are usually satisfactory although I occasionallyengage Ni-Ti archwires with 20º of built-in anterior torque oradd torque to the stainless steel archwire. The increased DQmaxillary incisor and canine torque values are designed to up-right lingually inclined anteriors without the need to use wireswith built-in torque or add torque to the stainless steel wire.

To correct maxillary lateral incisors that are blocked out lingually,not only must the crown be moved labially but also extra labialroot torque is almost always required. In such situations, thelowest D3/D3MX torque option (+3º) is usually not enough.Given that we generally need to factor in overcorrection, flippinga low- or standard-torque D3/D3MX lateral incisor bracket(which offers two additional options of -3º and -8º) is often nec-essary to provide the additional labial root torque (as shown inFigure 3). DQ offers a low-torque value of -5º that is designed toprovide the additional labial root torque required in most situa-tions. At the discretion of the clinician, additional wire torquemay be added as needed.

If I have inverted brackets, as soon as the crown and root are inan overcorrected position, I either downsize the wire (increasingwire play and stopping active torque) or reflip the bracket andrebond it or rebond with a standard-torque bracket. Note thatovercorrection applies to root positions as well as crown positionsin all three planes of space. Determining when root position hasbeen adequately overcorrected is difficult to quantify and requiresexperience.

When maxillary lateral incisors are minimally blocked out to thepalate, it’s a judgment call whether to use a low-torque (+3º) orflip a low-torque D3/D3MX bracket for a torque value of -3º

(Fig.10). The DQ max-illary lateral incisortorque value of -5º isdesigned to managemost laterals that areminimally blockedout to the palate with-out the need to invertbrackets.

In situations whereteeth are blocked outeither labially or lingually, the strategy almost always includestying in the blocked-out tooth at the initial bonding. You canemploy Kaplan hooks, embed a ligature wire in light-curedcomposite or consider cutting a bracket in half. Includingblocked-out teeth creates the best opportunity to optimize forcesand moments. Two situations that preclude tying in blocked-outteeth at initial bonding are: (1) when incisors are in an anteriorcrossbite and cannot be engaged because of the deep bite; and(2) when space must be opened prior to bringing blockedoutcanines into the arch.

Lingually blocked-out mandibular incisors (Fig. 11) often needconsiderable labial root torque, even more than the lowest torque(-6º) that the D3/D3MX prescription provides. Shifting a stan-dard- or high-torque D3/D3MX maxillary lateral incisor bracketto a mandibular incisor changes the positive torque to negativefor much lower effective torque values (-8º and -10º). DQ offersa -11º low-torque option that is intended to foster appropriatelabial root torque in such situations without the need to invertbrackets. If more torque is required, make adjustments to theappropriate wires.

Figure 10. With a minimally blocked-out upperlateral, use a low-torque or invert a low-torqueD3/D3MX bracket.

Figure 11. Bonding a high-torque D3/D3MX maxillary lateral incisor bracketto a ligually blocked-out mandibular incisor (which changes the +10º to-10º) generates greater labial root torque than the lowest torque D3/D3MXmandibular lateral incisor.

+10º

-10º

3

brackets be carefully monitored and when the intended torqueis achieved, reflipped and rebonded or the tooth rebonded withanother appropriate torque bracket. Regardless of appliance, itis necessary to palpate roots at each appointment to monitormovement.

Using Torque to Counter Major MechanicsCorrecting Class II and Class III malocclusions requires selectingproper variable-torque appliances to help offset torque loss dur-ing correction, maintaining inclination (both anterior and poste-rior) and avoiding the trauma and time of round-tripping teeth.I’ll address the counterbalancing protocols of variable torque formajor mechanics in cases being treated nonextraction (Fig. 4)before discussing torque selection for individual tooth positions.

In mildly crowded Class I cases where no significant incisorinclination discrepancies exist, standard-torque D3/D3MX orDQ brackets on the incisors are sufficient to maintain existingtooth inclinations.

For Class I cases with moderate to severe crowding, low-torque incisor brackets on both arches help resist proclination as

teeth start to unravel (Fig. 5). Beginning in the round-wire phase,lip pressure helps drive transverse arch development to the poste-rior. When moving into rectangular wires, low-torque incisorbrackets help resist proclination. In these situations I often finishin .016 x .025 stainless steel archwires.

Depending on the severity of the crowding, the narrowness ofthe arch and the degree of lip pressure, inverting maxillary low-torque D3/D3 MX brackets (which changes +7º and +3º for thecentral and lateral incisors to -7º and -3º, respectively) offers evengreater resistance to labial crown proclination. Once crowdingis resolved and incisor inclination has been established, eitherI leave the brackets in this position, reflip and rebond them, orrebond brackets with different torques. In such situations, wireplay may work to our advantage by decreasing the need to reflipbrackets or rebond teeth with other torque values. DQ offerslow-torque incisor values (+2º and -5º for the maxillary centraland lateral incisors, respectively) that are intended to addresssuch situations without inverting brackets, although there maycertainly be exceptions.

To counter the negative effects of Class II mechanics, whichcause maxillary incisors to incline lingually and mandibularincisors to procline, I place high-torque brackets on maxillaryincisors and low-torque on mandibular incisors but the latteronly if using a MARA or a Herbst®3 (Fig. 6). The same torque val-ues apply whether the Class II case is mildly or severely crowdedas long as the treatment plan is nonextraction, although I don’trecommend low torque on the mandibular incisors if the patienthas periodontal issues.

In regard to DQ, the low-torque incisor bracket (-11º) is particu-larly recommended for cases involving Herbst and Mara appli-ances but not for those with extensive crowding and/or thinattached labial tissue. As with all cases, evaluation of attachedtissue plays an important role in torque selection.

Figure 5. CL I moderate to severecrowding: To prevent incisorproclination, use low torque onboth arches.

Figure 6. To counter side effects of CL II mechanics on incisors,use high-torque on MX and low on MD.

Large blue arrowsindicate the directionof the root movementfrom the bracket torquethat counters the effectsof the mechanics.

Small blue arrowsindicate the movement ofthe incisal crowns that isa side effect of the CL IImechanics.

Flip maxillary incisor brackets toresist flaring even further whenusing D3/D3MX brackets.

Figure 4. Incisor Torque Based on Mechanics (Nonextraction)

Case Type/Mechanics

TorqueProblem

Torque Solution

Class I MildCrowding None Standard Standard

Class I Modto SevereCrowding

MX/MDIncisor Proclination

Low or flip MX lowfor even greaterlabial root torque

Low

Class IIMechanics

(Elastics, Herbst,Mara, ect)

MX IncisorLingual Inclination

High andadd wire torque

if neededSuper

MD IncisorProclination

Low if using Herbst orMARA and no perio

issues exist

Low if using Herbst orMARA and no perio

issues exist

Class IIIMechanics

(Elastics, ReversePull Facemask)

MX IncisorProclination Low Low

MD IncisorLingual Inclination Standard Standard

D3/D3MX DQ

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Because of wire play, even when finishing in .019 x .025 stainlesssteel archwires, high-torque D3/D3MX maxillary incisor brackets(+17º and +10º for the central and lateral incisors, respectively)may not provide enough inclination control so I routinely add10º of lingual root torque to the working archwire. DQ offershigh-torque maxillary values of +22º and +13º for the centraland lateral incisors, respectively, which are intended to addresssuch situations without adding wire torque.

To counter the negative effects of Class III mechanics, whichoften cause maxillary incisors to procline and mandibular inci-sors to tip lingually, I typically use low-torque brackets on themaxillary incisors and standard torque on mandibular incisors(Fig. 8). DQ offers low-torque maxillary incisor values (+2º and-5º for the central and lateral incisors, respectively) that are evenmore effective than D3/D3MX values in such situations.

Selecting Torque Values for Individual TeethThe orthodontic profession has long accepted Dr. LarryAndrews’s research that determined standards for optimal toothpositioning relative to the occlusal plane: e.g., +7º for the centralincisor (Fig. 9). Andrews’s conclusions were derived from 120natural occlusions that he deemed most favorable based on hard-tissue considerations only. The range for the maxillary centralincisor inclination in his optimal occlusion sample spanned from-7º to +15º with a standard deviation of +/-4º. With such a widerange and relatively large standard deviation as was the case withall tooth positions deemed optimal in the study, Andrews’sbenchmarks offer considerable opportunity for clinician discre-tion in determining tooth inclinations.

The Damon philosophy emphasizes the paramount importanceof smile arc4 and soft tissue to treatment planning, recognizingthe importance of lip and midfacial support for esthetics, espe-cially as we age. Keeping this in mind, ideal central incisor posi-tion (AP, SI and inclination) is not an arbitrary number butshould be based on each patient’s unique needs. I have found,however, that with the patient’s head in a natural position, themaxillary central incisor is usually in optimal position when it isbalanced under Glabella, which is best determined at the initialexamination with the patient in profile, smiling.

Andrews’s research on maxillary canine inclination found thatthe optimal torque value to be -7º with a range from -17º to +10ºand a standard deviation of +/-4.2º. Dr. Damon has always

Figure 8. To counter side effects of CL III mechanics on incisors, use low-torque on MX, standard on MD.

Large blue arrowsindicate the directionof the root movementfrom the bracket torquethat counters the effectsof CL III mechanics.

Small blue arrowsindicate the movementof the incisal crownsthat is a side effect ofthe CL III mechanics.

Figure 9. Andrews’s Study of 120 Optimal Occlusions*

MaxillaryTooth

OptimalTorque

AverageTorque Range Standard

Deviation

Central +7º +6.1º -7º to+15º +/-4.0º

Lateral +3º +4.4º -6º to+17º +/-4.4º

Canine -7º -7.3º -17º to+10º +/-4.2º

1st Premolar -7º -8.5º -20º to+5º +/-4.0º

2nd Premolar -7º -8.8º -20º to+3º +/-4.1º

1st Molar -9º -11.5º -25º to+2º +/-3.9º

2nd Molar -9º -8.1º -25º to+12º +/-5.6º

MandibularTooth

OptimalTorque

AverageTorque Range Standard

Deviation

Central Incisor -1º -1.7º -17º to+16º +/-5.8º

Lateral Incisor -1º -3.2º -19º to+15º +/-5.4º

Canine -11º -12.7º -26º to+2º +/-4.7º

1st Premolar -17º -19.0º -35º to-1º +/-5.0º

2nd Premolar -22º -23.6º -45º to-8º +/-5.6º

1st Molar -30º -30.7º -55º to-9º +/-5.9º

2nd Molar -35º -36.0º -60º to-9º +/-6.6º

*Numbers rounded to the nearest tenth.

Countering Negative Effects of Curve of SpeeCorrectionLeveling the curve of Spee often causes mandibular incisorproclination; low-torque brackets counter this effect.Adding labial root torque to the .019 x .025 stainless steelfinishing wire controls mandibular incisor torque evenfurther if using D3/D3MX. If finishing in a .016 x .025stainless steel archwire, consider the need for additionallabial root torque to counter the increased wire play.

Figure 7. To counter lower incisor proclination whileleveling curve of Spee and with CL II mechanics,consider using low torque on MD.

Large blue arrows indicate the direction of theroot and crown movement from the brackettorque that counters the effects of the mechanics.

Small blue arrows indicate the root and crownproclination from leveling the curve of Spee andCL II mechanics.

Dr. Kritzler 5

Desert / Ausklang Langzeitstabilisierung Retainer

Der festsitzende Retainer im Unterkiefer dient der Langzeitstabilisierung der Unterkiefer-frontzähne und sollte mindestens bis zum Erreichen des 30. Lebensjahrs belassen werden.

there, rather than with the Orthodontist. In addition, ifthe General Dental Practitioner is going to be checkingthe retainer then they should be informed and advisedhow to check it, and if required, repair it.

Conclusion

We have shown in this article that fitting a lower bondedretainer is an easy procedure if the step-by-steptechnique, we have suggested, is followed. It can becarried out at the chair side without any laboratorywork involved.

References

1. Little RM, Riedel RA, Artun J. An evaluation of changes in

mandibular anterior alignment from 10 to 20 years

postretention. Am J Orthod Dentofac Orthop 1988; 93:

423–8.

2. Little RM. Stability and relapse of dental arch alignment.

Br J Orthod 1990; 17: 235–41.

(a)

(b)

Figure 7 (a) Composite being applied with a Teflon-coatedinstrument and (b) with a foam sponge

Figure 8 Cutting the elastic with a ligature cutter

Figure 9 A probe is used to check that the junction between thetooth and composite is smooth

Figure 10 The lower bonded retainer in place after debonding

JO September 2005 Features Section How to … place a lower bonded retainer 209

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