Vol XVIII No. 1 Clinical Information for the Orthodontic ...€¦ · Invisalign® Aligners, and one orthodontist who advised her that Invisalign was not a good option for total correction

Satisfactionand Patient

Choices for Doctor

Register Early!

Featuring: • OklahomaTakesOntheIncognito™ Appliance System

by Dr. Clint Emerson 3

• ClassIIPushingCorrectorsandtheOcclusalPlane by Dr. Michel Di Battista 6

• TheForsus™ Fatigue Resistant Device 10 Years at Hard Labor (and still going strong) by Jim Cleary, 3M Unitek 11

• SecondMolarExtraction: Why Should Second Molars be Extracted? by Dr. Hugo Trevisi 13

• Pre-ProstheticTreatmentwiththe Clarity™SLSelf-LigatingApplianceSystem by Dr. Kirsten Nigul 14

• Clarity™SLSelf-LigatingBrackets:TheChoiceisClear by Dr. Anoop Sondhi 17

• WireSelectionforOptimalBiomechanic Efficiency in the MBT™ Versatile+ Appliance System by Dr. Dietmar Segner 20

• Transbond™IDBPre-MixChemicalCureAdhesive by David K. Cinader and Darrell S. James, 3M Unitek 24

• NowTHAT'SaWinningSmile(SpecialFeatureArticle) 26

Dr. Dietmar Segner

Dr. Kirsten NigulDr. Hugo Trevisi Dr. Anoop SondhiDr. Clint Emerson Dr. Michel Di Battista

Orthodontic Perspectives

Vol XVIII No. 1

Clinical Information for the Orthodontic Professional

MAY 2011

Message from the President

Bill Cruise President

As I look through this issue of Orthodontic Perspectives, I note a common theme among many of the authors: Change – where was I then; where am I now. We all know that change can sometimes be a long and difficult process. But the potential effects of the change may well be worth the effort.

Reading about the experience of colleagues, their decision processes, and the benefits and results of changes they made can be valuable input for those also considering change. Among the topics you will find inside, one author describes the reasons for switching from traditional to aesthetic self-ligating brackets; another decides to try a new way for Class II correction; and another takes an interesting look at the decision to introduce lingual treatment into the aesthetic mix at his practice.

On a personal note, reading and hearing of the benefits of the customized Incognito™ Appliance System led me to the decision to initiate treatment – a change I realize is overdue. I’ve been told by many orthodontists out there that I have “English teeth” and would be a great candidate for the Incognito System. And so this last February, I decided to “put my money where my mouth is”, so to speak, and was bonded with the Incognito System.

Like many people who didn’t have the benefit of having braces when they were young, and a little self-conscious now at having braces fitted, the Incognito braces solution is just perfect for me. They’re hidden, custom-made for my treatment, and invisible to others. And while it did take me a while to get used to having them in my mouth, a short time later I was able to make a presentation at a 3M Company event and no one could tell I had them on. (You can get the whole story and follow my progress at HiddenBraces.com.)

The quest to improve processes and offer innovative treatment options for orthodontic patients is ongoing at 3M Unitek. Consider where you and your practice are today and where you want to be tomorrow. Do you have questions about the opportunities presented by aesthetic lingual treatment, or the benefits of self-ligating brackets for your patients? How about the efficiencies of APC™ Adhesive or Forsus™ Class II Correctors? Ask a 3M Unitek representative for more information, and let us know when you are ready to write your article for Orthodontic Perspectives.

Orthodontic Perspectives

is published periodically by

3M Unitek to provide information

to orthodontic practitioners about

3M Unitek products. 3M Unitek

welcomes article submissions or

article ideas. Article submissions

should be sent to Editor,

Orthodontic Perspectives,

3M Unitek, 2724 South Peck

Road,Monrovia,CA91016-5097

or call. In the United States and

PuertoRico,call(800)852-1990

ext. 4399. In Canada call

(800)443-1661andaskfor

extension 4399. Or, call

(626)574-4399.Copyright

© 2011, 3M. All rights reserved.

No part of this publication may be

reproduced without the consent

of 3M Unitek. 3M, AlastiK, APC,

Clarity, Forsus, iBraces, Incognito,

MBT, SmartClip, Sondhi,

Transbond and Victory Series

are trademarks of 3M. Other

trademarks are property of their

respective holders.

Visit our website at

www.3MUnitek.com

3

The sun is slowly dipping into the late afternoon. A dense haze hangs over the city, trapping the sun’s rays and setting the skyline on fire. It is 80 degrees with a warm breeze gently blowing. Everyone is out in the city with one hand texting and the other holding a double latte. A blonde co-ed flies by me on a Harley, probably off to get another tattoo. Ahhhhhh, the L.A. life. But not L.A.; try B.A. – Broken Arrow, Oklahoma, to be exact. A quiet suburb of Tulsa, Broken Arrow is a family town that consistently ranks high among best towns in which to live in Oklahoma.

When I opened my practice doors in 2008, my vision was to create a friendly, fun atmosphere in which innovative technology was utilized to give the community great smiles. As people began filtering through our door, I noticed that teens and adults routinely wanted to know options for more aesthetic orthodontic treatment. Ceramic braces weren’t hidden enough and aligner treatment was case limited with difficulty predicting outcomes and treatment times.

I remembered hearing Dr. Cliff Alexander speak in 2003 about a lingual option called iBraces™, now the Incognito™ Appliance System. I did what every American does when they need information, I Googled the company. There were a number of questions that I felt needed to be answered before devoting time and resources to Incognito Braces. Questions such as: “Am I ready to take on a new, rather steep, learning curve?” “What will I charge?” And most importantly, “In this Midwestern suburb, who will buy this product?” After a certification process, I realized the value of Incognito Braces for my patients and implementation of this product in my practice.

I quickly found that treatment plans and mechanics with Incognito Braces were the same as those used to treat a labial case. For example, if you would extract, then extract. If the case needs expansion, then expand; even rules such as, “don’t tackle AP correction until you are in wires large enough to control unwanted side effects” applied. The major learning curve for Incognito Braces turned out to be the sensitivity of the technique. There are some unique systems, and getting my entire team to realize the importance of each step was my first goal. To name a few:

• The impression must be precise

• Immaculate tooth preparation for bonding is essential

• Complete wire engagement is crucial

• With a 100% customized appliance, any short cuts lead to an inferior result

3M purchased the company in 2007 and began making changes such as converting the product name to the worldwide recognized “Incognito” brand and injecting a robust amount of technology into the appliance. We received a myriad of training opportunities from 3M, including great “hands-on” seminars. As our office accepted the challenge of this new learning curve, our only limitation of honing our skills was educating patients to

Dr. Clint Emerson

has been

practicing

orthodontics in

the Tulsa area

since 2004

and opened his own practice in Broken

Arrow in 2008. Dr. Emerson is a 2002

dental graduate from the University

of Mississippi School of Dentistry and

completed his orthodontic training in

2004 at the Louisiana State University

Department of Orthodontics in

New Orleans.

In his practice, Dr. Emerson uses

innovative technology to deliver

comprehensive orthodontics to all ages

of patients. He has been using TADs

and a soft tissue laser since his practice

opened, and in 2008 he began treating

patients with the Incognito™ Appliance

System. He is currently treating over

100 patients with Incognito braces.

Dr. Emerson received the 2010 “Velocity

Award” from 3M Unitek for the largest

increase in case starts for that year.

Oklahoma Takes On the Incognito™ Appliance Systemby Dr. Clint Emerson

4

ligature free or ceramic brackets. These are all products most people aren’t even aware of, let alone know which one will get the best result for them. Don’t be embarrassed about offering more expensive, esthetic options. Let the patient make the decision if Incognito is affordable for their budget. Lastly, be flexible with your payment options. Make Incognito Braces accessible without being burdensome. Develop creative ways to receive a down payment that securely covers your overhead but is feasible enough for people to sign their name and produce payment at that first appointment. For my office, it is that easy; value, simplicity, flexibility.

A Perfect ExampleI am writing this perspective from an airplane headed to the AAO midwinter meeting in San Diego. I was seeing patients at the office this morning and Mark was a walk-in who came in to ask if he could make an appointment to have his old retainer checked. We had a cancellation, so the front desk asked if he could stay and be seen. Not the way you want to see your new patient room filled, right? An adult wondering if you can just place a few bends in his 20 year old Hawley retainer! We spent a few minutes talking about the small spaces that have reopened from his previous 4-bicuspid extraction treatment, a slight Class II bite, and the vertical step between his anteriors and posteriors, all of which didn’t seem to be of much concern to him. I held the Incognito Braces typodont and said, “If these are things you would like to correct, then this would be a great product for you.” Some time later, my treatment coordinator popped in my office as I was gathering my bag and heading to the airport. “Full upper and lower Incognito” – Mark had signed up! Empty chair becomes a retainer exam, which transforms into full treatment. Now that’s value, simplicity, flexibility.

A Case in ProgressPatient Samantha found my office through persistence. After deciding to align her teeth, she had several consults looking for a plan to align her teeth without anyone seeing her braces. As a nursing student, she was not comfortable wearing braces and, in her words, “looking like a teenager”.

She saw two general dentists who had recommended Invisalign® Aligners, and one orthodontist who advised her that Invisalign was not a good option for total correction and that fixed ceramic braces would be needed for complete alignment and bite correction. Not satisfied with the options, Samantha found our office on the internet and was ecstatic to learn that the Incognito Appliance System was a viable option for her case. Having to travel 45 miles each direction was a small sacrifice to Samantha in order to receive the Incognito Braces treatment.

Patient Background

• 21.3 year old female

• No significant medical history

• Chief dental concern: “Missing tooth #29, bite, and alignment”

• Chief concern: “I don’t want braces”

make them aware of this new system. The learning curve wasn’t as steep as I had feared and looking back, our team’s initial focus on the details even helped improve our performance with our labial appliances:

• We see less loose brackets due to our commitment to more stringent bonding protocols

• Our patients are experiencing faster treatment results due to our focus on a more intimate wire to slot interface

• We go to great lengths to ensure patient’s wires are comfortable before they leave our office

If You Build It, Will They Come?I struggled deciding what I would charge for Incognito™ Appliance System. So, I made a few phone calls to find out what everyone else was charging for Incognito treatment. I heard a range of $9,500-$11,000. Let me tell you, in Broken Arrow, where the mean family income is just over $60,000 a year, that’s a new truck! I don’t personally charge that much, and to that point, if you are considering bringing Incognito Braces into your practice, I would find a number that is a comfortable starting point and then let that number move as patient acceptance dictates.

I then kept coming back to the question of “who will buy this product?” Was the Incognito system typodont going to sit on my shelf and be merely a bookend or a topic of conversation? I thought it would probably fit a narrow range of patients, like newscasters and models; people for whom aesthetics was essential in their life would buy Incognito Braces. I was wrong. Once offered, everyone bought Incognito Braces. The cases in my office included a myriad of types of patients including: housewives, band members, athletes, sales reps, teachers, widows, singers, hygienists, and medical students. Our patients range in age from 14 to 67. We have patients from different countries who speak different languages; we have males and females, brothers and sisters, and even a mom and her son in treatment. In fact, the only common link our Incognito Braces patients share is the desire for the smile they have always wanted.

Making Treatment AccessibleSo how did they afford it? The same way they afford cellphones, nice cars, vacations, homes, and flat screen TVs. We put value in the product and the patients realize the benefits greatly outweigh the sacrifice. For us, the product concept sells itself. I believe this is true because when a patient sits down and holds the Incognito Braces typodont or sees an advertisement or meets a patient who wears Incognito Braces, they immediately want it for themselves.

The key is converting this boiling pot of excitement into a signed contract with value, simplicity, and flexibility. Spend time putting value in the treatment and aesthetic benefits, not the cost of the appliance. Make your discussion simple about what appliances can be used for a patient’s treatment. Most patients like to hear what YOU think is appropriate for them, instead of receiving a laundry list of appliances such as removable aligners, lingual or metal brackets,

5

Samantha has been in treatment for 1.4 years and has completed 10 office adjustments. She is currently in 16×25 stainless steel wires upper and lower. Her Forsus corrector has been activated incrementally during the last three visits. Remaining treatment includes completion of Class II correction with the Forsus Correctors and the mesial/distal reduction of the space in the area of #29 for final tooth restoration.

Samantha is the typical Incognito™ Braces patient in my office. She wanted to get her orthodontic and dental problems corrected, but was reluctant to use traditional appliances. Once the option of hidden lingual treatment was presented, the decision to start treatment was easy.

Great for My PracticeI believe aesthetic treatment is no longer a trend in orthodontic treatment. It is what patients want and it is here to stay. They prefer brackets over bands, clear over metal, aligners over braces, and I believe lingual over labial. I made the prediction to myself in 2008 that a new wave of public interest in lingual was coming. Three years later, the market is brimming with lingual possibilities. I opened my doors with the vision of innovative technology and three years later, Broken Arrow, Oklahoma, is still reminding me that people will spend their money on exactly what they desire.

We have been privileged to be part of the transformation of this lingual appliance from iBraces™ to Incognito Appliance System as 3M began pouring its innovative resources into both the product and practitioners who will deliver it. Thank you to 3M for a commitment to develop and redevelop cutting edge technology. Thanks to my staff for the hard work they put in each day and their desire to learn new techniques, and to my patients who have entrusted their smiles to our office.

Case photos provided by Dr. Clint Emerson.

Orthodontic Diagnosis

• Class II division 1

• Retroclined Maxillary incisors

• Missing tooth #29

• #7 and #10 slightly smaller mesial/distal than normal

• 80% overbite; 4 mm overjet

• Maxillary spacing, mild Mandibular crowding

• Maxillary midline centered; Mandibular midline 4 mm right of center

Treatment Plan

• Extract ankylosed #T and obtain proper mesial/distal space for future implant

• Full Maxillary and Mandibular fixed appliances

• Forsus™ Fatigue Resistant Device placed one side only for correction of right Class II

• Patient elected not to open space #7 and #10 for cosmetic restorations

When setting up her case, I requested a band placed on #3 with a headgear tube for use with the Forsus corrector. I also asked for increased lingual crown torque on the lower incisors to prevent flaring during bite correction and increased palatal root torque on the upper incisors to achieve proper Incisal inclination (Figure 1).

After initial alignment, I placed the stainless steel wires and prepared Samantha for the Forsus corrector by placing a stop on the upper and lower wires distal to the first molars and creating a resting point in the anterior for the Forsus spring. This was accomplished by bending a .045 steel lab wire and using bracket adhesive to bond to #27 and #28. This was my first lingual case to use Forsus correctors, and to this point in treatment, the bond has not failed.

Figure 2A-H: Case in progress at 16 months.

Figure 1A-F: Initial case presentation.

2A

2G

1A

2D1D 2E1E 2F1F

2B

2H

1B 2C1C

6

I would like to thank Dr. Stephan Tisseront for his remarkable article and case report in the October issue of Orthodontic Perspectives: Forsus™ Class II Correctors: Is There an Age Limit? It has stimulated my willingness to share what I have learned over the last 15 years working with Class II pushing correctors.

It was back in 1996 that Dr. John P. De Vincenzo made Eureka Springs pushing Class II correctors available. The first patients I tried them on were half- to almost fully-corrected within 3 months. It was way too fast to be growth! It could only be a dento-alveolar phenomena, although the first cases were growing patients.

Consequently, I was soon using them in cases way over the growth period with amazing outcomes and very stable results (no dual-bite, no “postural orthodontics” and negligible CR-CO discrepancies).

Ten years ago, 3M Unitek launched the Forsus™ Fatigue Resistant Device. It did then, and still delivers, the same amazing results, but with significantly fewer breakages and emergencies. I use them exclusively now.

As mentioned by Dr. Tisseront, the treatment options regarding most Class II deep bite adult cases with mild to moderate crowding are: decompensation of the dental arches and mandibular surgical advancement (with or without genioplasty), or extraction of two upper premolars with a less favorable facial aesthetic outcome.

“Class II adult deep bite” is a very vague label. Periodontal status, lip seal, incisor showing, transverse dimension, tongue size, and sleep apnea, to name just a few, are among the individual data that weigh in the decision scale to elect either a combination of orthodontic treatment and maxillo-facial surgery or an alternative.

The purpose of this article is to provide additional information to support Dr. Tisseront’s article and confirm his findings that the treatment alternative employing Forsus Class II Correctors is not just a second best alternative, but THE treatment of choice in selected cases, all things and risks considered.

The following two case reports are adult Class II deep bite patients treated with the Forsus Fatigue Resistant Device without extractions and without maxillo-facial surgical procedures.

Case #1N.M. female 38 years old. She came in for a second opinion because she declined the surgery suggested by the previous orthodontist. Chief complaint: “I am hurting myself at the palate”.

It is with reasonable confidence that I suggested a non surgical treatment with the use of the Forsus Fatigue Resistant Device.

The patient was informed and agreed that a plan “B” would involve extraction of upper 5’s or surgical advancement of the mandible (Figure 1A-L).

Dr. Michel Di Battista

received his dental

(‘75) and Orthodontic

Certificate (‘79) at

the University of

Montreal and has

maintained a private practice in Saint-Bruno,

Quebec, Canada since 1979.

He is a member of The Angle East Society

of Orthodontists and has delivered

presentations at the AAO, NESO, CAO, QAO,

Angle Society and European meetings.

Class II Pushing Correctors and the Occlusal Planeby Dr. Michel Di Battista

7

The treatment sequence was the following:

07-05-30: Bonding upper arch (centrals 12° torque, laterals 8° torque, Clarity™ Ceramic Brackets). Final wire size .016×.022 SS.

08-01-21: Bonding lower arch (-5° torque on incisors). Final wire size .016×.022 SS.

08-05-27: Day of Forsus™ Correctors installation. 25 mm rods on both sides. An .016×.022 SS wire was inserted on lower arch. At this time the lower Curve of Spee is not totally flattened. The Forsus Correctors will assist the levelling of the lower Curve of Spee. Compression of the springs at initial insertion: 6.0 mm×18.5 g = 111 g per side (Figure 2A-H).

08-08-17: Forsus Correctors 29 mm rods each side, compression at 6.0 mm (111 g).

08-09-30: Measured activation; down to 4.5 mm per side as some correction has taken place. Addition of Forsus Correctors Universal split crimps on each side.

1.5 mm×18.5 g = +27.75 g additional per split crimp. Activation brought back to 6.0 mm (111 g per side).

08-11-17: Forsus Correctors 32 mm rods each side, compression 8.0 mm.

09-01-29: Reactivation with the addition of split crimps totalizing 148 g per side.

09-04-22: Forsus Correctors stopped when normal overbite and overjet is achieved (Figure 3A-C).

The Class II correction is held and stabilized with a decreasing wear of Class II elastics (6 mm – ¼") light 1.8 oz, latex per side from mesial of 3’s to lower 6’s.

09-08-10: Fixed appliances removal.

Fixed lingual retainers .016 round SS on #13 to #23 and #33 to #43.

10-09-22: Insertion of occlusal splint Biteplane full coverage type on the upper arch without occlusal contacts posterior to the lower canines.1

Active treatment time 3 years 3 months.

10-11-16: Final records; Upper incisors correction torque to occlusal plane = +30°.

Lower incisors to occlusal plane change = none.

Clockwise occlusal plane rotation: 6.2° (orig: Op/Sn = 12.2°, final: Op/Sn = 19.8°, Normal = 14.4°)2 (Figure 4A-C).

2A

2D

2F

2B 2C

3A 3B 3C

2E

2H2G

Figure 2A-H

Figure 3A-C

Figure 1A-L

1A 1B 1C

1F1E1D

1G 1H

1K1J1I

1L

Figure 4A-C

4A 4B 4C

8

11-03-23: Control visit: Overjet = 3.1 mm Slide CR-CO = 0.4 mm.

Patient very satisfied with results “The results are far beyond my expectations” (Figure 5A-M).

Case #2 LPFemale 53 years old. Chief complaint: “My teeth are crooked, my mouth and lips are going backwards, deeper and deeper”. She agreed upon a “long” 3½ year treatment involving the Forsus™ Fatigue Resistant Device. Teeth missing: #18, #24, #36, #37 and #46. Bridge on #35-#38 (Figure 6A-N).

5F

5A 5B 5C 5D 5E

5I

5K

5G 5H

5J

5M5L

The treatment sequence was the following:

06-08-22: Bonding upper only: Clarity™ Ceramic Brackets Standard Edgewise (0° torque, 0° ang.) brackets on #12 to #22.

07-08-16: Bonding lower teeth. (It has taken one year to decompensate the upper teeth torque = +28.5°.

08-05-13: Forsus Correctors 25 mm rod right, 29 mm rod left.

08-09-24: Class I correction achieved, stop Forsus Correctors, start Class II elastics.

Restorations done during treatment by the restorative dentist (Dr. Gilles Dulude) (Figure 7A-D).

10-07-15: Removal of fixed appliances.

Lingual fixed retainers .016" round SS, from #13 to #23 and from #33 to #43.

Treatment time 3 years and 10 months.

10-11-10: Final records. No clockwise rotation of the occlusal plane, Op/Sn original = 12°.

Op/Sn final = 14.40°, normal = 14.40°2 (Figure 8A-O, 9A-B).

11-03-24: Insertion of occlusal splint Bite Plane type, full coverage on the upper arch without occlusal contacts posterior to the lower canines.1

Overjet = 2.7 mm, CR-CO Slide = 0.2 mm.

Patient totally satisfied, “The treatment did not seem long!”

Some TipsAmong the factors that should be taken in consideration with the pushing Class II correctors force system are:

Case Selection

Generally Class II deep bite cases are the ones that respond more favorably to this force system. They exhibit a brachyfacial type and a favorable chin component. They are often characterized by a counter-clockwise canted occlusal plane and normally positioned or retroclined lower incisors.

Figure 7A-D

Figure 5A-M

7B

7D

7A

7C

6F

6I

6K

6G 6H

6J

6M

Figure 6A-N

6L

6A 6B 6C 6D 6E

6N

9

Class II pushing correctors are powerful clockwise occlusal plane rotators and upper arch distalizers. The less originally clockwise rotated the occlusal plane, the better the potential to correct the point A and point B to the occlusal plane relationship (Witts). Avoid, or use with extreme care, Class II pushing correctors, especially on patients who exhibit pronounced clockwise or canted occlusal plane with much vertical excess, and of course, on those with moderate to severe open bite.

Retroclined lower incisors and normal attached gingiva are positive prerequisites. As a result of using Class II pushing correctors, the lower incisors are being intruded (contributing to gingival build up) and anchored in the thick chin symphysis bone. (Use -5° prescription on lower incisors.)

The decompensation and three dimensional preparation of the dental arches before using the Class II pushing correctors

Both arches should be prepared and coordinated as in preparation for a surgery at the exception of the lower Curve of Spee. The Forsus™ Fatigue Resistant Device will assist the levelling of the lower Curve of Spee.

In Class II Div II cases, make sure the upper incisor's buccal torque is properly normalized or slightly overcorrected. A little opening of spaces mesial to the upper canines sometimes allows a good interdigitation and overcorrection of the buccal segments without anterior interferences (Figure 10). The mandibular arch should be

free to move to a Class I occlusion without any interference. I avoid overcorrecting to an edge-to-edge position. This traumatic situation may initiate root resorption and unnecessary attrition.

The minute magnitude calibration of the force system

The control of the level of force delivered by an appliance is of paramount importance, not only with regard to treatment efficiency and treatment time, but also “TO MINIMIZE ANY IAOTROGENIC EFFECT OF TREATMENT FROM THE USE OF TOO HIGH FORCE”.3

I would add, “to minimize breakages and bulky mechanics”.

The Forsus Fatigue Resistant Device can be compressed about 12.0 mm at a linear constant deflection rate of about 18.5 g/mm.

ATTENTION: THE FORCE IS NOT CONSTANT, BUT INCREASES CONSTANTLY BY 18.5 G FOR EACH MM OF COMPRESSION.

Ideally, I don’t have the Forsus springs compressed by more than 9.0 mm. Initially 5.0 mm to 8.0 mm of compression is fine, comfortable and efficient.

At each appointment, the activation of the springs compression is measured and kept between about 5.0 mm to a maximum of 8.0 mm, according to the amount of correction needed. The distance from the mesial part of the distal ring “A” to the mesial part of the spring “B” is passive at 28.0 mm and fully active at 16.0 mm for 12.0 mm of total possible compression. The distance is measured at 25.0 mm (Figure 10), so the compression is 3.0 mm. Activation of 3.0 mm to 4.0 mm is a good holding and stabilizing activation.

At about 5.0 mm to 8.0 mm of activation every two months, no upper lingual arch or RPE appliance is required to hold the upper first molars.

8F

8A 8B 8C 8D 8E

8K

8M

8G 8H

8L

8O

Figure 8A-O

8N

8J

8I

9A 9B

Figure 9A-B

Figure 10: Forsus™ Corrector spring compressed 3 mm.

Spaces mesial to canines.

10

10

However, the buccal inclination of the upper first molars has to be carefully monitored. The Forsus™ Corrector activation and the lingual crown torque expressed by the archwire on the first molars have to be coordinated.

Sometimes an additional -10° to -20° of lingual crown torque at #16 and #26 level may be bent on the .016"×.022" archwire.

By no means should the maximum opening of the jaw dictate the length of the push rods and thus the entire force system. Should a patient open beyond the length of the push rods, he can easily be instructed to re-insert them back into place.

Note: If the Forsus Corrector is compressed at 7.0 mm, it exerts a distal action force on the first molar of about 130 g, and as a reaction force, an equal amount of 130 g on the archwire hook stop at the distal of the lower canine.

The Condyle to Fossae Relationship

I do not use Class II pushing correctors as functional appliances in growing and non-growing patients. In my office, every time the Forsus Springs are employed, the patient should always be able to close back in centric relation and chew on his molars. The condyles are never permanently forced out of the fossae.4 This means no activation beyond 12.0 mm.

Some TricksThe fixed appliances I employ with the Forsus Fatigue Resistant Device can be shortly described as follows:

• Bracket size: .018"×.025"

• Wire size: .016×.022 stainless steel

• Torque prescription on #16 and #26: -14° (-14T/0° offset-/3M Unitek Victory Series™ Brackets)

• Torque prescription on #32 to #42 is -5°

Please Note: To prevent the lower incisors from flaring, the usual recommendation is to fill the bracket slot with a full-size stiff archwire. This may be good mechanics, but I’ve found it is less compatible with low physiologic forces and comfort if more adjustments are performed on the archwire during and after the use of Forsus correctors.

The “elastomeric torque” delivered by an Alastik™ Easy-To-Tie Ligature (3M Unitek, #406-884, silver) tied in an X-fashion, prevents any “play” of the lingual face of the archwire (0.16"×0.22") from the bottom of the bracket slot. This torque has been estimated at about 0.4 g-mm5 (Figure 11).

When the lower incisor torque changes, it is as a block with the occlusal plane, not off of it.

I always bond upper and lower 7’s when available.

The lower wire preparation:

• Crimped hook on the loop bend between the lower 7’s and 6’s to tie the archwire back (Figure 12A)

• Temporary step down bend just about 1.0 mm distal of #33 and #43 to stabilize the crimped hook acting as a bumper to the pushing rod (Figure 12B)

• A bent forward and outward ‘S’ modified crimped stop links the rod (modified) to the archwire (Figure 12B-C)

• An elastomeric ligature to stabilize the rod “elbow” bucco-lingually from flipping in the cheek or rubbing against the first premolar bracket. The ‘S’ part of the crimped hook is angulated bucco-lingually as required (Figure 12B-D)

ConclusionsSome Class II, full cusp adult cases can be treated without extractions or surgical advancement of the mandible. The dento- alveolar changes induced by the Class II pushing correctors Forsus Fatigue Resistant Device are largely sufficient to achieve superb and stable results in selected cases.

Case photos provided by Dr. Michel Di Battista.

References1. Peter M. Greco, Robert L. Vanarsdall Jr, Michael Levrini, and Richard Read,

An evaluation of anterior temporal and masseter muscle activity in appliance therapy, The Angle Orthodontist 1999, 69: 141-46.

2. Riolo M.L., Moyers R.E., McNamara J.A., Hunter W.S., An Atlas of Craniofacial Growth, 1974.

3. El-Sheikh, Moazz Mohamed. Force-Deflection characteristics of the fatigue-resistant device spring: An in vitro study. World Journal of Orthodontics 2007; 8: 30-6.

4. Popovich, Kurt. Effect of Herbst treatment on temporomandibular joint morphology. A systematic literature review. AM J Orthod Dentofacial Orthop 2003; 123: 388-94.

5. Michel Di Battista, The Elastomeric Torque and the Incisors, Lecture given at the AAO 101th Annual Session, Toronto, 2001.

Figure 12A-D

12B12A

12C 12D

Figure 11

11

11

Jim Cleary

is a Product

Development

Specialist and has

been with 3M Unitek

for over 28 years.

He is an inventor on 48 issued U.S. patents.

Over a decade ago, in response to customer input, 3M Unitek engineers began an evaluation of intraoral Class II devices as an alternative to headgear. With devices of this kind, a common issue was fatigue failure. Orthodontics is all about movement, but most of it happens slowly enough that the mechanics and appliance components used can be viewed as nearly static. A device that is connected between the upper and lower arches, however, operates in the most dynamic situation encountered in orthodontics. Any solution adopted must first and foremost be reliably fatigue resistant.

The result of the research also indicated that, besides fatigue failure, there were typically additional trade-offs that limited satisfaction with products in this category, including the need for lab work and varying degrees of installation difficulty.

The “FReD” project (Fatigue Resistant Device), as it was dubbed in the beginning, was started since it seemed that an approach could be developed which would meet the important 3M Unitek fatigue resistance goal. Developing this new product would also provide an opportunity to create a flexible, easy-to-use system, and possibly reshape the way Class II correction was done.

The result, as we know now, was the Forsus™ Fatigue Resistant Device introduced in 2001. It has now completed ten years of service to orthodontists and their patients.

A Brief Development HistoryThe spring module and the system built around it have evolved over that time. The system as originally launched provided an L-pin for the upper distal attachment of the spring module, and an assortment of auxiliary bypass wires for attachment on the lower. A range of push rod lengths used for both left and right mounting completed the hookup (Figure 2-3). The three part telescope design of the spring module with its push rod provided enough travel for full jaw opening, so many clinicians simplified installation by omitting the bypass wire, and connected the push rod directly to the lower archwire. This

The Forsus™ Fatigue Resistant Device 10 Years at Hard Labor (and still going strong)by Jim Cleary

Figure 1: Forsus™ Fatigue Resistant Device EZ2 Module.

1

12

Creative clinicians have embraced the Forsus Fatigue Resistant Device and have made it their own; they realized its versatility and have devised alternative hookups and custom attachment devices. For instance, reports from the field were coming back about the growing popularity of attaching the push rod distal to the lower first bicuspid bracket. Proponents of this method cited advantages such as less visibility and less cheek irritation than connecting distal to the cuspid bracket.

In many cases, however, an extra short push rod was required. A 38 mm push rod could easily be cut down to provide the proper length, but a push rod length one step down in the current size assortment was a better, easier solution. A push rod one step shorter would not allow space for a tubular stop, as used on the 25 through 35 mm rods, within the length limit of a fully activated spring module. Rather than adding rod length to accommodate a tubular stop, it was decided to evaluate a 22 mm push rod where the recurve bend would function as a stop. The system expanded again to include the 22 mm push rod, which has subtly modified bend geometry to assure smooth telescoping action.

Close to the time the 22 mm push rod was introduced, the first change to the spring itself was made. A second closed coil was added to the mesial end of the spring. This provided a more positive, solid seating of the spring on the mesial flange, and a more durable attachment.

That very dynamic, and, as patients continue to demonstrate, the often hostile environment in which the Forsus device operates drove the desire to make the EZ Module more robust. With the development and field experience of the original snap-in attachment, design options were explored. The one clear message in feedback from clinicians was to maintain the “easy part”. Armed with that prior experience, a whole new module was designed to increase the durability. Careful analysis was performed on CAD models to assure a snap-in function similar to the original. The new module was designed with integral posts on which to mount the spring module, and an integral gusset that snaps in lingual to the headgear tube to control buccal deflection of the assembly. The Forsus EZ2 Module was introduced at the end of 2008, and while still easy to install, is tougher against the many assaults encountered in service.

As the saga enters year eleven, the story has not ended. Ways of improving and expanding the system continue to be explored. And it can be expected that those friends of the Forsus Device within the orthodontic profession will continue to develop creative new applications.

For additional reading, the quest to design a spring module that would withstand the roughly half million cycles during the necessary treatment time was presented in detail in Orthodontic Perspectives, Vol. IX, No.1 which is available for review on www.3MUnitek.com. – Editor

preference led to the first major addition to the system, the Direct Push Rod, which was developed by Dr. William Vogt, Easton, PA (Figure 4). The recurve design and attachment loop orientation provided a more stable position of the push rod under load (Figure 5).

The original spring module was constructed with a cylindrical distal end fitting brazed to the larger of the two tubes within the module. To improve manufacturing, TIG (Tungsten Inert Gas) welding was implemented to join these components. Redesign of the distal end for this new process provided the opportunity to improve comfort as well with a smoother, rounded end fitting. Assembly was later switched to laser welding for greater productivity. Less visible improvements were also incorporated into the attachment of the spring module mesial end flange and the mesial end of the spring itself.

The Forsus™ Fatigue Resistant Device did its job well and has gained an ever-increasing following. But even greater efficiency and reduced chair time are constantly sought by clinicians, and users told us that threading the L-pin from distal of the headgear tube and bending the end could be a time consuming endeavor. Development of a quick and easy distal connection began.

3M Unitek had expanded MIM (Metal Injection Mold) capabilities in house, so a one piece MIM snap-in connector was proposed. Persistence and fabrication of working prototypes overcame the initial skepticism, and the Forsus™ EZ Module was added to the system (Figure 6). The L-pin still had its uses, such as with gingival or non-standard headgear tubes, but the quick and easy snap-in connector gained a strong following.

Figure 2: Original Forsus™ Corrector spring with L-pin.

Figure 3: Typical Forsus™ Corrector installed using archwire bypass.

2 3

Figure 5: Forsus™ Fatigue Resistant Device with Direct Push Rod design.

5

Figure 4: Dr. William Vogt.

4

Figure 6: Forsus™ Fatigue Resistant Device EZ Module featuring a snap-fit connection to the buccal tube. Note a 22 mm push rod installed distal to the first bicuspid bracket.

6

13

A large proportion of the routine work of an orthodontist is treating sagittal Class II malocclusion, which is the most common malocclusion among patients seeking orthodontic treatment. Class II malocclusions are frequently accompanied by compromised facial aesthetics, which is best dealt with in the mixed dentition. However, patients do not always seek treatment in mixed dentition. Rather, they postpone treatment to adolescence, a period which is often associated with poor patient cooperation. In such adolescent cases, second molar extractions offer a valid alternative treatment option for Class II treatment.

The main goals of a second molar extraction treatment are preventing third molar impaction and making it easier to upright first molars. These extractions create some space distal to the archwire, isolating the third molar from the remaining teeth, enabling its anterocclusal movement and its eruption in contact with the distalized first molar (Figure 1A-C, 2A-B). A third molar of good shape and size is an ideal substitute for second molars.

Case photos provided by Dr. Hugo Trevisi.

Dr. Hugo Trevisi

received his dental

degree in 1974

at Lins College of

Dentistry in the

state of São Paulo,

Brazil. He received his orthodontic training

from 1979 to 1983 at that same college.

Since that time he has been involved in

the full time practice of Orthodontics in

Presidente Prudente, Brazil. Dr. Trevisi has

lectured extensively in South America,

Central America, Portugal and Spain and

has developed his own orthodontic teaching

facility in Presidente Prudente. Dr. Trevisi

has over 20 years of experience with the

pre-adjusted appliance. He is a professor

at the Department of Orthodontics at

the University of Cuiabá – UNIC, Brazil,

and a member of the Brazilian Society of

Orthodontics and the Brazilian College of

Orthodontics.

Second Molar Extraction: Why Should Second Molars be Extracted?by Dr. Hugo Trevisi

Figure 1A-C: Panoramic radiograph of a patient who underwent orthodontic treatment with upper second molar extractions. The spaces created enabled optimal eruption of the third molars.

1A 1C1B

Figure 2A-B: Occlusal view at the end of the corrective treatment with the third molars fully erupted, showing perfect alignment and establishment of the contact points with the first molars.

2A 2B

New Textbook Available: If this topic is of interest to you, second molar extractions are covered in depth in a new textbook (available in June 2011), “State-Of-The-Art Orthodontics: Self-Ligating Appliances, Mini-Screws and Second Molar Extractions” by Drs. Hugo Trevisi and Reginaldo Trevisi Zanelato, published by Mosby Elsevier.

The section on second molar extractions includes the following topics:

• Development of second molars and third molars

• The benefits of second molar extractions

• When second molars should be extracted

• Characteristics of patients who undergo second molar extractions

• Management of the distalizing mechanics in second molar extraction cases

• Eruption of third molars after second molar extraction

• Clinical case examples

Contact your 3M Unitek representative for more information. – Editor Dr. Hugo Trevisi Dr. Reginaldo Trevisi Zanelato

14

Kliinik 32, Tallinn, Estonia, is a private dental clinic specialized in interdisciplinary dentistry. The various specialists in the clinic include general dentists, periodontists, endodontists, prosthodontists and an orthodontist. The close proximity of the specialists makes it easy for patients and doctors to be involved in interdisciplinary dentistry.

About 50% of my orthodontic patients are adults who need treatment from different specialists. I have been using bracket systems from 3M Unitek since 2005 and have found that a majority of adults prefer aesthetic orthodontic appliances. I started to use 3M™ Self-Ligating Appliances when the Clarity™ SL Self-Ligating System was released in 2007. Currently, I also use the SmartClip™ SL3 Self-Ligating Appliance System and Incognito™ Appliance Systems in my treatment.

Orthodontic treatment is often a part of interdisciplinary care. Most patients who benefit from interdisciplinary treatment usually first visit a prosthodontist or periodontist and come to orthodontist on the recommendation from these specialists. Often times, the option of orthodontic treatment comes as a surprise for them. However, orthodontic involvement as part of interdisciplinary care allows for minimally invasive treatment, saving the patient’s own tooth material, making less prosthetic work and reducing the need for surgical treatment.

When choosing a bracket system, patients are interested in aesthetics, treatment time and comfort. The Clarity SL system is aesthetic and remains so, even if the patient loves to drink coffee and tea, due to the absence of discoloring elastics. Self-ligating brackets also give the possibility to make longer intervals between visits during some treatment phases. Additionally, brackets with variable prescriptions allow a more precise focus on a patient’s individual problems, and give the possibility to reduce treatment time and wire bending.

Following is an example of a Kliinik 32 interdisciplinary case which I treated with the Clarity SL appliance system.

Patient CasePatient

Female, 40 years 10 months.

Chief Complaint and History

The patient was worried about wearing of her teeth and treatment aesthetics. She had been in another dental clinic where an ‘instant smile’ treatment plan was offered with crowning of all the teeth. She did not want to sacrifice healthy dental structure and looked for other options.

Diagnosis

The patient had a convex profile with slightly distal lower jaw. She had a deep overbite. The posterior occlusion on her left side was Angle Class 1; on the right side Class 2; the mandibular center line had deviated 2 mm to the right side. This was due to a long time missing lower second premolar which was replaced by an implant, but the implant is too narrow for the space. Her maxillary incisors where lingually inclined. She had significant wear of her maxillary anterior teeth and the central incisors where shorter than the lateral incisors. The teeth had erupted and brought the gingival margins incisally (Figure 1-2).

Dr. Kirsten Nigul

is associated in

private practice

at “Kliinik 32”, an

interdisciplinary

dental clinic in

Tallinn, Estonia. She is a 1998 graduate of

the University of Tartu, Faculty of Medicine,

Dentistry, DDS, and also received her

Specialist in Orthodontics from there.

In 2005 she received the Royal College of

Surgeons Edinburgh, MOrth, Overseas Gold

Medal. Dr. Nigul has been working with the

MBT™ Versatile+ Appliance System since

2005, and with 3M™ Self-Ligating Appliances

since 2007. Current interests focus on

interdisciplinary treatment, perio-ortho

patients, adult orthodontics and aesthetic

treatment with Clarity™ SL Self-Ligating

Appliance System and Incognito™ Appliance

Systems. She has lectured for orthodontists

and dentists in Estonia and at Baltic

Orthodontic Congresses.

Pre-Prosthetic Treatment with the Clarity™ SL Self-Ligating Appliance Systemby Dr. Kirsten Nigul

15

2nd Visit at Week 14 (8 weeks later)

Inserted Stainless Steel .019×.025" into lower arch.

3rd Visit at Week 20 (6 weeks later)

Inserted Nitinol Classic .019×.025" into upper arch.

4th Visit at Week 26 (6 weeks later)

Introduced open coil in lower arch to create room for implant crown.


Inserted Stainless Steel .018" into upper arch with step bends to correct gingival margin discrepancies. Self-ligating braces give the possibility to make activation visits shorter and more comfortable. Memory wires and exact positions of brackets allow working with straight wires from start to finish. While treating worn dentition, small teeth do not allow bonding the bracket into the ideal position, therefore bending of wire is necessary to get teeth into ideal positions. Clarity SL brackets allow easy and exact bending of the wire. While keeping the wire engaged in some brackets, you can freely see the activation amount of other teeth and easily add activation when wire is steadily held by clips in other brackets. The clip allows easy removal of the wire and reactivation. Activation intervals during that period are usually 4-5 weeks (Figure 4).


Make temporary restorations with composite. Orthodontist removes archwire while restorative dentist adds restorations. Orthodontist will continue with archwire activation according to restorative dentist’s goals.

Approximately 10 Months after Beginning Treatment

Brackets are removed from lower arch and fixed lingual retainer was placed on lower 4-4 anteriors to keep even levelled Curve of Spee.

Inserted Stainless Steel .018" into upper arch to create more room for canine restorations. Next 4 months were used to detail the final

Treatment Alternatives

The profile change and Class 1 bilateral occlusion would have needed bilateral sagittal split osteotomy. Patient did not desire any change in her profile and we decided to concentrate on the patient’s main problem and restore the maxillary incisors to create better aesthetics.

Treatment Plan

Advance upper incisors to allow for the advancement of lower incisors. Procline lower incisors to help correct deep bite, retain normal overjet and create more room to put normal size implant crown. Intrude upper incisors to move the gingival margins apically to the correct level with canines. This will create room in vertical plane to restore abraded crowns with prosthetic work.

Treatment ProgressBonding Appointment

Clarity SL brackets in the upper arch, Clarity™ Ceramic Brackets in the lower arch (Clarity SL lower arch brackets were not yet available at the time of this case). APC™ II Adhesive pre-coated brackets, MBT™ Appliance System prescription with .022 slot using a direct bonding technique and Transbond™ Self-Etching Primer. Initial archwires were .014" Nitinol SE on upper arch and Nitinol HA .016" on lower arch.

1st Visit at Week 6 (6 weeks later)

Inserted .016×.022" Nitinol SE into upper arch and Nitinol HA .019×.025" into lower arch. Rectangular wires were used to correct the inclination of upper front teeth. During alignment with Nitinol archwires, it is possible to keep longer periods between activations, usually 8 weeks (Figure 3).

Figure 1: Wear on maxillary anteriors; midline deviation.

Figure 2: Mandibular arch with implant in lower second premolar.

21

Figure 3: Wire change 6 weeks into treatment.

3

Figure 4: Step bends in upper arch.

4

16

ConclusionsBracket treatment often gives the possibility for minimally invasive treatment and the chance to preserve the patient’s own healthy tooth structure. There are many adult patients who would prefer not to receive orthodontic treatment. However, with careful explanation of benefits of orthodontics in interdisciplinary treatment, combined with a convenient and aesthetic bracket choice, orthodontic treatment acceptance increases dramatically. Kliinik 32 has seen a lot of success in offering the Clarity SL appliance system in interdisciplinary treatment as an aesthetic option.

Case photos provided by Dr. Kirsten Nigul.

positions of teeth. Close cooperation between the restorative dentist and orthodontist is very important during this period of treatment (Figure 5).

Approximately 14 Months after Beginning Treatment

Brackets are removed from upper arch and fixed lingual retainer was placed on 3-3 anterior teeth. On the same day composite restorations were detailed and impressions for new implant crown were taken (Figure 6-7).

Six months later, upper fixed retainer was removed and final full ceramic crowns were placed on upper 3-3 anterior teeth. Maxillary nightguard use is required while sleeping to retain the position of the teeth after final restorations. This helps to retain the vertical relationship of front teeth and to prevent further abrasion (Figure 8A-C).

Figure 5: Temporary restorations on upper incisors.

5

Figure 6: Completion of treatment. Figure 7: Open space for implant.

76

Figure 8A-C: Full ceramic crowns placed on upper 3-3 anterior teeth.

8B8A

8C

Forsus™ Fatigue Resistant Device Users Meeting

September 23-24, 2011Newport, Rhode Island

The 2011 Forsus™ Fatigue Resistant Device Users Meeting offers

learning opportunities for both new and advanced Forsus Corrector

users through the sharing of key clinical techniques, practical

hands-on applications and evidence-based literature.

Contact 3M Unitek for more information.Register online at www.3MUnitek.com

Dr. Lisa Alvetro Dr. William Vogt

17

Dr. Anoop Sondhi

received his

dental degree

from the Indiana

University School

of Dentistry, and

his post-graduate certificate and MS in

Orthodontics from the University of Illinois

in 1977. Following his graduation, he was

on the graduate faculty of the Department

of Orthodontics at Indiana University.

During his full-time academic appointment

at Indiana University, he maintained a

part-time private practice. Since 1988, he

has been in full-time private practice in

Indianapolis, and continues to be a Visiting

Professor for several graduate programs in

Orthodontics. He has presented seminars

and continuing education courses to several

dental and Orthodontic organizations in

the United States, and has been invited to

give courses in Canada, Central America,

South America, Europe, Asia, South Africa,

Australia and New Zealand.

IntroductionA bracket is a bracket is a bracket (with apologies to Gertrude Stein), and as long as a bracket helps move teeth the way we want it to, there is really not much point in getting excited about one over the other. After all, we’re all orthodontists, and can move teeth with bailing wire if we have to. How often have we heard that one?! True to a certain point, I suppose, but such a misguided way of thinking.

You can certainly get from point A to point B in a Yugo (am I showing my age here?), or you could traverse the distance using something more efficient, reliable, and speedy – one of the spiffy crop of automobiles that I have been dreaming about. Sure, we’ll get from point A to point B in both scenarios, but there is a huge difference in how reliably, how quickly, how efficiently, and how comfortably we will get there.

Making the ChoiceAs of January 1, 2010, the appliance of choice in our practice is the aesthetic Clarity™ SL Self-Ligating Bracket for the maxillary arch. While we also use Clarity SL brackets in the mandibular arch, we frequently choose SmartClip™ SL3 Self-Ligating Brackets for the mandibular arch.

Now, anyone who has heard me lecture over the years, as well as long-term members of my staff, will recall when I was not enthusiastic about using aesthetic brackets at all. Indeed, I used the traditionally ligated Clarity™ Metal-Reinforced Ceramic Bracket quite sparingly, although it was an extremely aesthetic bracket. My reasons, at the time, were simple. While the Clarity bracket was definitely aesthetic, the increased inter-bracket distance exacted a penalty in efficiency, and we incurred additional visits, more often with adults, with a request that discolored elastic ties be changed. So while the bracket was certainly effective in expressing tooth movement, it gave up some efficiency when compared to metal brackets.

That is what has changed. With self-ligation, the Clarity SL bracket presents all of the efficiencies that SmartClip brackets brings to our practice, and none of the penalties that aesthetic brackets previously had.

The Impact on Our PracticeWhen we made the decision to make the Clarity SL bracket the appliance of choice in treating our patients, that decision was coupled with our campaign to position our practice as an “aesthetic practice”. While this would obviously have been desirable even earlier, we had been reluctant to compromise on treatment efficiency in order to adopt that moniker. Once we recognized that the Clarity SL bracket system was delivering treatment results as efficiently as SmartClip brackets, the campaign to reposition our practice went into full swing.

Clarity™ SL Self-Ligating Brackets: The Choice is Clear by Dr. Anoop Sondhi

18

of the packaging and delivery system available in VPO with Clarity SL appliances, we have found that the transition to the Clarity SL appliance system was almost seamless. The same familiar color codes that are being used with the SmartClip SL3 appliance system are also available with Clarity SL which makes inventory management simple. Further, because of the packaging and delivery developed for Clarity SL appliances, ordering and restocking is literally a breeze (Figure 2).

Hygiene and ComfortIt is now well understood, of course, that eliminating elastomeric ties decreases plaque retention, and all of the consequences that come with it. While that has become one of the accepted advantages of changing to self-ligation, there hasn’t been much discussion on the issue of comfort.

It has long been understood, and well accepted, that tooth movement should be achieved by forces that are as light as possible. The literature is replete with data to support the use of light forces to minimize root resorption, patient discomfort, etc. However, reducing force levels is always a greater challenge in ligated treatment systems, since some of the force is required to overcome the friction introduced by the ligature. In the absence of such friction, we are now able to initiate treatment with extremely light archwires, and it is not uncommon for us to begin the initial leveling with an .012 Nitinol archwire.

In marketing and positioning our practice in this community, we have always eschewed the conventional marketing strategies that most marketing consultants employ, and most doctors are familiar with. Conventional strategies involve all of the standard variables that have been used for years, such as location, hours, participation in specific insurance plans, etc. My partner, Jeff Biggs, and I have always operated on the understanding that patients will go the distance if they are convinced that there is a difference in the treatment that they will receive. Therefore, rather than following the normal marketing mantras of location, evening and Saturday hours, etc., our mantra has always been that “Choosing an Orthodontist is a Serious Decision”.

We give patients the clear reasons why they should choose to be treated in our office. The slogan, therefore, became “The Choice is Clear”, and that dovetails very nicely into our conversion to aesthetic appliances because of the obvious double entendre. The theme now is: it is clear that they should choose our practice, and equally apparent that they should choose “clear” braces. Patients, young and old alike, are quite pleased when we show them the typodonts to demonstrate the kinds of brackets that will be placed on their teeth.

Indirect Bonding and VPOOne of the questions we originally had involved the impact on our bonding appointments, since all of our full arch bondings are done exclusively with indirect bonding. It became very clear to us, as we tracked our progress in this transformation, that the indirect bonding system worked extremely well with Clarity SL brackets. Indeed, we have not seen any increase in bond failures, bracket breakage, or any of the other concerns that are sometimes mentioned.

At this point, I should explain our reasons for not using Clarity SL brackets consistently in the mandibular arch. Although we are treating several patients who are bonded completely with maxillary and mandibular Clarity SL appliances (Figure 1A-E), the readers of this article may be familiar with the fact that, over the past few years, I have focused sharply on the concept of using Variable Prescription Orthodontics (VPO) to enhance the effectiveness and efficiency of treatment.

The Clarity SL system is available in the complete spectrum of torques and angles that are a part of the VPO armamentarium in the maxillary arch. While several of the mandibular Clarity SL brackets are available, the entire spectrum is not currently available. For that reason, and for that reason alone, we are incorporating the Clarity SL appliance system into the mandibular arch gradually. Over time, it is our intent to make Clarity SL appliances our choice for both the maxillary and mandibular arches.

VPO and Inventory ManagementEvery orthodontist knows that any change in clinical inventory causes some concern, because existing, tried and tested systems sometimes get disturbed in the process, and the resulting turbulence in the clinical protocol is undesirable. However, because

Figure 1A-E: Patient bonded with Clarity™ SL Appliances upper and lower.

1A

1D

1B 1C

1E

Figure 2: APC™ Adhesive Coated Appliance System inventory management system with VPO color-coded bracket packaging.

2

19

ConclusionOur decision to transition from ligation to self-ligation, and now to Clarity SL brackets as the chosen instrument of self-ligation, has proved to be extremely positive, and well received by our patients. Indeed, the transition progressed so smoothly that we almost surprised ourselves. It is gratifying to be able to let the patients know that they have a choice and that, if they choose our clear braces, there will be absolutely no compromise in either the efficiency or the outcome of treatment.

Case photos provided by Dr. Anoop Sondhi.

Our follow-up with our patients has indicated a definite reduction in the overall level of pain and tenderness as a consequence of the change to lighter forces. Likewise, we have recorded a substantial reduction in the discomfort associated with removal and insertion of archwires. Because of the significant reduction in the force required for removal and insertion of archwires in the SmartClip SL3 clip that is incorporated in the Clarity SL bracket, the actual archwire appointments are simply not a source of discomfort in the way they used to be. Debonding has also proved to be easy. We are perfectly happy being recognized in our community as the guys whose braces don’t seem to hurt as much!

3M Unitek Holds “Future of Intelligent Orthodontics – Adult Orthodontics” Symposium in DubaiThe second 3M Unitek “Future of Intelligent Orthodontics” Symposium took place March 4-5, 2011 in Dubai. Featuring the topic “Adult Orthodontics”, the scientific agenda featured a broad range of topics and workshops by highly renowned speakers including Prof. Birte Melsen, Dr. Lars Christensen, Dr. Davide Mirabella, Dr. Francesco Amato, Dr. Jean-Stephane Simon, Dr. Jason Cope, Prof. Dietmar Segner, Dr. Dagmar Ibe, Dr. Leandro Fernandez, Dr. Colin Melrose, Dr. John Scholey and others.

Facilitated by Dr. Fredrik Bergstrand of 3M Unitek, more than 550 participants from 48 countries participated. Venue of the symposium was the Mina A'Salam hotel at Madinat Jumeirah, and a gala dinner was held the evening of March 4 at Al Hadheerah, a famous camp in the middle of the desert.

More than 150 participants also attended an Incognito™ Appliance System User Meeting, which followed the Symposium on March 6.

Facilitated by Dr. Magali Mujagic, highly renowned speakers like Dr. Julia Tiefengraber, Dr. Leandro Fernandez, Dr. Robbie Lawson, Dr. Anna-Kari Hajati, Dr. Skander Ellouze and Dr. Esfandiar Modjahedpour lectured about the latest developments of the Incognito System.

20

Dr. Dietmar Segner

earned his specialty

in orthodontics

from Hamburg

University, Germany,

and also received

his PhD from that institution. He worked as

professor of orthodontics at the university

clinic and now works in his private practice

in Hamburg specializing in the treatment of

adults using aesthetic appliances. For two

decades he has lectured all over the world

on adult orthodontic treatment, and results

of his research into biomechanical and

ortho materials.

It is the wire that drives or guides the teeth, no matter how advanced the brackets may be, or whether they are self-ligating or not. The sensible selection of the archwires during the different treatment phases has therefore a major influence on the treatment efficiency.

This article will show the principle and give the clinician a guide to select the right wire at the right time. It should be pointed out that due to the variety of malocclusions and the variability of individual tissue reaction, it is not possible to give fixed time frames for changing to the next archwire. Rather, it is an important clinical decision if the tasks of a certain treatment stage are resolved and the treatment can progress to the next stage and next archwire.

What is the Archwire’s Task?The tasks of archwires during an orthodontic treatment can be split into two, which I will call Mode 1 and Mode 2 (Figure 1-2). In the first mode, the wire is in its active state. Activation of the wire is carried out by ligating the archwire to the irregularly positioned teeth. Energy is stored by pushing the elastic wires into the bracket slots. After this activation, the archwire uses this energy to move the teeth. Such an operating mode is typical for the aligning and leveling stages. It would also be relevant in all situations where the orthodontist inserts loops or other active elements into the archwire through bends, as for example retraction loops. As these applications are not used on a regular basis in the MBT™ Versatile+ Appliance System, they will be excluded from the further deliberations.

In the other application of an archwire (Mode 2), the archwire is used as a guiding track for the mesial or distal movement of teeth along the arch. Here the archwire is initially passive and its stiffness and elasticity only comes into play when the teeth start to show side effects such as tipping or rotations. Then the wire creates corrective forces and moments and assures that the teeth do not deviate from the intended track and angulations. The activation is achieved by elastomeric chains, super-elastic springs, inter-maxillary elastics or similar. These auxiliaries store the energy for the tooth movement. This application mode is typical for the working and retraction phases. In this mode the wire should have a significant stiffness in order to keep the undesired rotations or tipping to a minimum.

DimensionDuring the alignment phase there is no need for a tight fit of the archwire in the bracket slot, as the differences between the archwire dimension and the slot dimension are up to 0.15 mm, while the positioning precision during the first alignment stage needs to be only about 0.5 mm. For a number of reasons, it is even desirable to have undersized wires in the alignment stage. The play between archwire and bracket slot reduces friction and potential binding with severely irregularly positioned teeth. Also the force-deflection curves of thin super-elastic wires are usually better because they show the correct force level immediately

Wire Selection for Optimal Biomechanic Efficiency in the MBT™ Versatile+ Appliance Systemby Dr. Dietmar Segner

Figure 1: Wire in an active state. Figure 2: Wire in a passive state.

21

21

until the deflection falls below 0.35 mm, so with one single archwire we achieve almost perfect leveling if we just leave the wire in and give it a chance to express itself fully, which might take anywhere from 5 weeks to 5 months.

In order to optimize the biological response, and avoid the risk of force that is too high, the initial archwire should be super-elastic and its force level should be significantly below 100 g of force. The optimal wire therefore is the 14 Nitinol Heat Activated both for the 18 system and the 22 system (Figure 4).

After the alignment phase, the slots will be quite well aligned. If a second archwire is necessary for the leveling stage, the deflection of that archwire due to misaligned bracket slots will be below 0.5 mm. Since none of the super-elastic archwires has a plateau of constant force below 0.5 mm, the aspect of superelasticity becomes unimportant for the second and all following wires of the treatment. Now it becomes crucial that the wire has the correct dimension to get full expression of the bracket prescription as described above.

at the beginning of the deactivation while thicker super-elastic archwires can show rather high forces during the first days after the ligation. It is also important to note that the slot dimension does not play a major role in selecting the first aligning wire. The same dimension is suitable for the 18 and 22 slot system.

During the leveling stage and also later in treatment the wire dimension becomes important. For de-rotation in self-ligating brackets and for effective torque effect, the wire dimension needs to be adjusted to the slot size. To get the standard designed torque effect the vertical dimension of the (rectangular) archwire needs to be 16 in the 18 slot and 19 in the 22 slot. Another requirement is that the horizontal slot dimension needs to be 25 in both the 18 and 22 slot systems for good rotational control. It is therefore clear that in the MBT™ Versatile+ Appliance System, the standard working wire as well as the finishing wires should be 16×25 in the 18 system and 19×25 in the 22 system.

It should be kept in mind that an increase in wire dimension results in a stronger expression of the torque built into the prescription of the MBT system, resulting in additional torque angulation. Using a 17×25 wire instead of a 16×25 in the 18 system or a 20×25 instead of a 19×25 in the 22 system increases the torque value by about 3°. Of course the same is true for undersized archwires: using a 14×25 wire instead of a 16×25 wire in the 18 system decreases the torque angle by 6°, using a 17×25 instead of 19×25 in the 22 slot system will decrease the torque effect by 7°.

Stiffness and Force LevelsIn the active Mode 1 of archwires, the force acting on the teeth depends mainly on the archwire used. Super-elastic archwires have a major advantage in that the force is almost constant no matter how irregularly the teeth are positioned or how short the inter-bracket distance is, in clear contrast to the twisted wires, braided wires or non super-elastic Nickel-Titanium wires. In the graph (Figure 3) we compare a 16 super-elastic nickel-titanium wire (Nitinol HA) and a 16 non super-elastic Nickel-Titanium wire (Nitinol Classic). We easily see that the super-elastic wire develops significantly less force. The difference is shown by the combination of the red and yellow areas in the graph.

But even if we try to reduce the force of the non super-elastic archwires by selecting a thinner wire (14 Nitinol Classic) we see that for all deflections above 1.2 mm, the thicker but super-elastic wire develops lower forces that are also constant over much of the deflection range. Below 1.2 mm deflection, the force of the non super-elastic wire, decreases so much that it becomes less than the super-elastic wire, and eventually it would not move the teeth any more, and an archwire change needs to be conducted. On the other hand, the super-elastic archwire continues to exert constant forces

Figure 3: Force associated with 3 archwires.

3

Figure 4: Force characteristics of Nitinol HA (HANT) in dimension 14 round.

4

22

In many cases, the initial alignment wire from the upper jaw can be transferred to the lower jaw and added to the alignment wire already present there. Often it would also be possible to transfer a lower alignment wire to the upper jaw and let this second wire run only up to the first molar.

Special Treatment ObjectivesIf there are special tasks during the leveling stage, the use of additional archwires may increase treatment efficiency. Typical examples would be the leveling of a pronounced Curve of Spee. Here round stainless steel archwires of the dimension 18 in the 18 slot system, or of the dimensions 18 or 20 in the 22 slot system, might enhance the efficiency. A number of orthodontists like to use a Nitinol SE reversed curve archwire of the dimension 16×22 (18 slot) or 19×25 (22 slot) for the same task. For transverse arch form adaptations, stainless steel wires would also be beneficial.

If the special application of torque is required, the use of non super-elastic nickel-titanium should be preferred over the super-elastic nickel-titanium variant. With super-elastic rectangular wires, the torsional moments are in the range of 200 to 500 gmm, which is on the low side of effective torque application. With non super-elastic wire materials, the torsional moment depends on the amount of activation and can be adjusted to up to about 1500 gmm. For the 18 slot system, a 16×25 Nitinol Classic, and for the 22 slot system, a 19×25 Nitinol Classic left in the mouth a sufficient amount of time will effect the specific torque requirements efficiently. Up to 2.5° per month can be achieved.

Wire SelectionTo make the selection of wires for an optimal biomechanic efficiency easier, a table has been assembled that lists the recommended wires for the different treatment stages in the MBT appliance system (Table 1). The table has columns for the 18 system as well as the 22 system. Also, the special requirements of self-ligating brackets in the MBT system are addressed in the table. In the rightmost column, suggestions for special treatment tasks are given. These wires are only needed in certain cases to make the treatment easier and more efficient for the patient. Listing a strict, non-negotiable order of archwires or recommended time intervals for the archwires to reside in the mouth has been purposely avoided. Such inflexible cookbook-style recommendations violate clinical experience as well as common sense and would be contrary to the philosophy of the MBT system.

During the working stage the wires operate in the passive Mode 2. They should have sufficient stiffness to counteract any undesired movements or rotations. Since the leveling phase achieved perfect alignment of the bracket slots, insertion of such a stiff archwire should not present a problem. Only wires of Beta III Titanium or stainless steel provide sufficient stiffness. Especially in extraction cases, steel is to be given preference.

Making BendsAlthough the philosophy of the MBT appliance system is to avoid bending as much as possible, by achieving perfect bracket positioning through indirect bonding and – if required – early repositioning of brackets in the leveling phase, it sometimes might be necessary to implement bends, especially during the finishing phase.

When a corrective bend is applied, it is usually to achieve a change from the previous situation. This means that in this moment the archwire is changing into Mode 1 again, the active mode. In addition to the property of accepting precise bends, the archwire material should also deliver the stored energy with physiologic forces. Especially in the 22 system even small corrective bends in a stainless steel wire exert significant amounts of force. To decrease the force level and associated pain for the patient, it is of benefit to use the lower modulus of elasticity of the Beta III Titanium material. The same corrective bend in the same dimension archwire will exert only 50% of the force in comparison to a stainless steel wire. Therefore, the Beta III Titanium material is the recommended material for finishing wires.

Self-Ligating BracketsIn principle, treatment with self-ligating brackets in the MBT system can proceed with the same wires as with conventionally ligated brackets. The only difference of significance is the rotational control in the leveling phase. All self-ligating brackets have a fixed slot depth of 0.0275" (0.027" for the lower anteriors) defined by the clips or slides. In order to be able to effect de-rotation or control undesired rotation, the archwire needs to fill this slot depth with a play of not more than 0.0025". Therefore a single round wire will not give perfect rotational control without adding a ligature on the tooth in question.

Two options are available to the orthodontist: the first is to finish the leveling with an archwire that has a 25 for the horizontal dimension. For the 18 slot dimension, archwires of the dimension 14×25 and 16×25 were introduced, while in the 22 system 17×25, 18×25, and 19×25 wires have been available for a long time. The second option is to fill the slot in the buccolingual direction using two round archwires, which is called the Tandem Archwire Technique. For the 18 slot system this would be two 14 Nitinol HA archwires, while in the 22 slot system it could either be also two 14 dimension wires or a 14 and a 16 Nitinol HA wire used in tandem. The latter variant might activate the clip a bit, leading to some pressure of the clip on the wire(s) (Figure 5).

Figure 5: Tandem Archwire Technique examples.

5

23

MBT™ Versatile+ Appliance System Treatment Phases and Wire Requirements

Treatment StageRecommended Wire Products and Variations

MBT™ System Brackets 18 Slot MBT™ System Brackets 22 Slot

Aligning Stage 14 HANT Variations:

14 NCL with push coil and not all teeth ligated

14 HANT

then for self-ligating only:

14+16 HANT Tandem

Variations:

14 NCL with push coil and not all teeth ligated

Tasks:

• Activating cellular reaction

• Initial slot alignment

• Initial de-rotation

Requirements for Wire:

• Low forces, especially with large irregularities

• Force limitation desirable (force limitation by superelastic plateau)

• Avoid binding

• Torque effect initially usually not desirable

Leveling Stage Self-Ligating:

14×25 HANTor14+14 HANT Tandem

Non-Self-Ligating:

16 Australian

then16×25 Beta III Titanium

Variations:

If torque matters• 16×25 NCL

For additional vertical leveling:• 18 SS• 16×22 NSE

reversed curve

Self-Ligating + Non-Self-Ligating:

19×25 HANT

Variations:

If torque matters• 19×25 NCL instead of

19×25 HANT

For additional vertical leveling:• 18 SS• 20 SS• 19×25 NSE

reversed curve• 19×25 Beta III Titanium

Tasks:

• Final de-rotation/ re-establishing correct contact points

• Establishing torque

• Correcting angulations

• Leveling Curve of Spee


• Not too high forces

• Elasticity to correct angulations/tip

• Good rotational control

• Dimension needs to fill slot height for torque effect

• Stiffness to level Curve of Spee

Working Stage 16×25 SSor17×25 SS Hybrid

(with crimp hooks)

Variations:

If no space closure required:• 16×25 Beta III

Titanium

19×25 SS

(with crimp hooks)

Variations:

Optional: 21×25 hybrid

If no space closure required:• 19×25 Beta III Titanium

Tasks:

• Closing of extraction spaces

• Closing of other spaces

• Retracting anterior teeth with torque control


• Enough stiffness to avoid vertical and horizontal bowing



• Low friction

Finishing Stage 16×25 Beta III Titanium

Variations:

If already in place:• 17×25 SS hybrid• 16×25 SS

19×25 Beta III Titanium

Variations:

If already in place:• 19×25 SS

Tasks:

• Correct midlines

• Root alignment

• Overbite/overjet

• Functional occlusion


• Corrective bends possible without too high forces



• Enough stiffness to hold or fine-tune arch form and overbite

Settling Stage 16×22 Braided Alternative would be using a positioner

19×25 Braided Alternative would be using a positioner

Tasks:

• Maximizing intercuspidation


• Allows minor tooth movement by occlusion and elastic traction

Table 1: Recommended wires by treatment phase, MBT™ Versatile+ Appliance System. Note: Wire selection should be made on a case-by-case basis. NCL: Nitinol Classic; NSE: Nitinol Super-Elastic; HANT: Nitinol HA; SS: Stainless Steel.

24

David K. Cinader

received a BS

Degree in Chemical

Engineering from

Michigan Tech

University in 1994

and a PhD in Chemical Engineering in 1999

from Northwestern University. He joined

3M Unitek Research and Development in

September 1999 and has been involved in

orthodontic bonding development including

Transbond™ Plus Self-Etching Primer,

APC™ II and PLUS Adhesives, and

Transbond™ Supreme LV Adhesive.

Darrell S. James

is Senior Technical

Service Engineer

at 3M Unitek. He

has worked at

3M Unitek since

1985, primarily being involved in adhesive

development. He received his Bachelor of

Science Degree in Biology from Kent State

University in 1983.

IntroductionIndirect bonding has been practiced for many years, beginning with the “clean base” method of Silverman et al.1 and progressing to the “custom base” method of Thomas2. These techniques have in common the pre-positioning of appliances on a working model of the dentition and the use of a transfer tray to capture the appliances and convey them to the patient’s mouth. The custom base method offers the advantage of reducing the amount of excess adhesive flash by allowing the use of less highly filled adhesives.

The increased interest in lingual orthodontics has brought about more comfortable, customized systems such as the Incognito™ Appliance System3,4. Indirect bonding is especially attractive for lingual cases since the access is limited. In addition, the Incognito system requires a robust bonding solution, able to cure under the relatively large bonding bases where the curing light may not penetrate, and in the gaps between bonding base and tooth that may arise from tooth movement between taking the initial impression and fitting the transfer tray. In response to these needs, we have developed Transbond™ IDB Pre-Mix Chemical Cure Adhesive (Figure 1).

Transbond IDB adhesive is delivered in vials for familiarity of use and for the ability to adjust the dispensed amount. The dispensing tip was chosen to assure uniform, bubble-free drops. A fumed silica filler imparts the ability to fill gaps as well as resist slumping, running, or drifting from the bracket base prior to placement in the patient’s mouth.

To provide the strength associated with Transbond brand adhesives, its resin consists of the dimethacrylate monomers Bis-GMA and TegDMA.

Laboratory FindingsThe most important requirement of any adhesive product is bond strength, so Transbond IDB Adhesive is designed to have equivalent bond strength to Sondhi™ Rapid-Set Adhesive and Reliance Maximum Cure®, which are commonly used for indirect bonding (Figure 2).

Transbond™ IDB Pre-Mix Chemical Cure Adhesiveby David K. Cinader and Darrell S. James

Figure 1: Transbond™ IDB Adhesive is delivered in vials.

1

25

Another important aspect of an adhesive product is the set and work times, especially for the finite values of a chemical cure adhesive. The initiator concentrations were carefully chosen to offer a long working time without unduly extending the cure time. The work and set times are shown in Figure 3, and can be adjusted by using the product at refrigerated or room temperature.

For a no-mix adhesive such as Sondhi™ Rapid-Set Adhesive, the working time in the clinic is essentially unlimited, since the two resins are not in contact with one another until the point that the indirect bonding tray is placed into the mouth.

Customer EvaluationCustomer Acceptance Testing of Transbond™ IDB Adhesive was conducted in two phases. Initial samples of Transbond IDB Adhesive were sent to Incognito Appliance System users in Chile, Europe and the UK. Evaluators were asked for a wide range of feedback including comments on viscosity, work and set time, bond strength, bond failures, etc.

These users were comparing Transbond IDB Adhesive to their experience with Maximum Cure® Sealant (Reliance Orthodontic Products, Inc.) since that was the recommended adhesive for the Incognito System at that time.

Initial evaluators were asked to track bond failures over a 6 month time frame and to submit a satisfaction survey on Viscosity, Working Time, Setting Time, Dispensing, Color and Overall Satisfaction. The evaluators that continued to use the product and submit surveys

rated the Transbond IDB Adhesive more highly than Maximum Cure Sealant in every category.

Based on feedback from the first evaluation, Transbond IDB Adhesive was reworked to further improve the viscosity and work and set times. A new dispensing tip was identified and evaluated. The second evaluation version of Transbond IDB Adhesive offered more accurate dispensing.

The improved version of Transbond IDB was sent to a limited number of evaluators in the U.S. and Europe and included both Incognito system users as well as traditional labial bracket indirect bonders. The evaluators found this version to be preferred over the first version. The bond failure rate over a three month period was 3.3% overall (1261 brackets bonded). Labial and lingual indirect bonders achieved nearly the same bond failure rate at 3.5% (847 brackets bonded) and 2.9% (414 brackets bonded) respectively.

SummaryTransbond IDB Adhesive is a new chemical cure adhesive with work/set time, rheology, and delivery specifically designed for indirect bonding. The low bond failure rate recorded in a customer evalu

Vol XVIII No. 1 Clinical Information for the Orthodontic ...€¦ · Invisalign® Aligners, and one orthodontist who advised her that Invisalign was not a good option for total correction

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