About Forsus/Twinforce

From: Marco Tribò [mailto:marco.tribo@tribo.ch]
Sent: Wednesday, December 22, 2010 2:53 AM
To: ‘The Electronic Study Club for Orthodontics’
Subject: About Forsus/Twinforce

Welcome back to the sleeping beauty Esco Digest!

About Forsus/Twinforce

We have been using both with the following results:

1. Both works
2. Twinforce is about 1.8 x more expensive (in Switzerland)
3. Considerably less breakage with forsus
4. Both are easy to handle
5. Twinforce offers a version that can be fixed to the upper and lower wire (no need of Bands on upper first molars)
6. Forsus slides on the lower wire and rests on the cuspid bracket. This can cause problems: rotation of cuspids and the brackets can be detached.

So finally it is a personal preference and depends also on the type of appliance/patient that you are treating. As we all know we have patients that are very careful and then we have others…

Merry Christmas and a Happy New Year to all out there!

Marco Tribò

12 responses to “About Forsus/Twinforce

  1. Like your post… I do not recall ever hearing of the twinforce. Who makes it? I have used the Forsus for some time with mixed results. The Forsus design and structural integrity has been greatly improved since it’s earlier days.

  2. I haven’t used Twin Force, I have been using Forsus for a few years now. Switched to them after I got tired of Eureka springs breaking all of the time. They break also, they all break, but you can usually get the job done with Forsus. If you place crimpable stops on the lower wire distal of the 3s, and bend back your lower wire, you will not have the 3s break or rotate. I have had maybe 10% of my Forsus patients undergo significant unwanted maxillary posterior expansion. I don’t know why it happens on some but not others. Still 10% will ruin your day, so I now place transpalatals on all of them, to be safe. The rep said this problem is unknown. However, I am curious if anyone else has had this problem. As a side note, I have used them for class III correction with uncooperative patients. I place an LLA just to be safe. A lot of work but they have gotten me out of some binds. Best of luck,
    Rob Kazmierski

  3. For what its worth:

    I have been using Forsus for several years and as my colleague noted, there were difficulties with canine brackets becoming detached UNTIL I read of the following modification;=:

    1. use of a shorter (25mm?) curved arm extending to between the premolars and not the canines. Far, far less breakage.

    2. use an elastic module (X2 from Unitek?) that is a thick 2 module chain elastic that ties the curved arm back to the molar bracket. This serves to reduce force on the premolar bracket while compressing the spring….molar distalization!

    Google Miller Orthodontics>online forms> lecture videos for more.

    Best wishes for the New Year!

    Tom Forrest

  4. I have been using the Forsus for at least 10 years now. I love it, but I also understand that even with cinching wires, I get a great deal of molar distalization. I have also used the appliance on multiple occasions unilaterally with much success. I love the appliance, but use it for full class II molar and some non-coop patients. Years ago, I would fabricate a lower archwire with helices bent into the wire for Forsus attachment to eliminate bracket breakage. But, since using the bumpers by on the canine brackets, breakage is minimal. I use the shorter rods to the premolars on some patients, but prefer to longer rods to the canines to avoid vertical side effects (much like the class II elastics to the 2nd molars).

    For those looking to use the appliance, make sure that you fill the slot in the lower arch for full torque control on the lower incisors before going to the Forsus. I have a negative 6 degrees in my lower incisors. I also start out with a rod shorter than I know I will need and gradually increase length by adding sleeves to the rod. Average wear time is 8 months. You can remove it, see if the patient is stable, and simply hook it back up if you get any relapse. We always shoot for end-to-end incisor and let them seat over the next month. Turning distal to the U7’s is difficult but necessary to maintain level marginal ridges.

    Great tool, but it is not cheap.

    Mark Lively

    • Mark, when you use unilaterally, do you include a “passive” rod on the Class I side? I’ve found that when I only use one rod I get a significant bite opening side effect on that side.


      • Hi Dave:

        Yes I have, but it closes down rather quickly. not. Quite honestly, the first few that I used an asymmetric approach were done due to issues with trauma to the cheek on one side or for multiple broken springs on the same side. I just removed the traumatizing or broken spring and just left the other side on. It still seemed to get the job done. So, I then started using the appliance on one side for the asymmetric bite secondary to a lateral shift. I do this less frequently, as for those patients, I usually place a RPE to disrupt the “bite, eliminate the lateral shift (most of the time), center the midlines, and run class II elastics to correct a symmetrical end-on class II bite.

        For those that are using the Forsus asymmetrically, it is in for no more than 4 months, so this may be why I have not had a big issue with the open bite. Mark

  5. I agree with Marco. My personal preference is the Forsus because of the construction in two pieces. This can be a plus and a minus but I choose the plus side.


    PS I have used the Advansync since it was introduced. Does anyone have comments? Did everyone know that the miniscope now comes in 4 retractable sleeves which makes it smaller( similar to Advansync). Besides the learning curve of the manufracturing of Advansync, I have found that in a few cases that it has a vertical displacement of the mandible rather than the horizontal displacement. I had to switch to a longer mandibular arm to get the horizontal displacement.

  6. Hey, Blair, great to hear from you. Happy Holidays!

    I have not used the Twin Force appliance. Like you I am a big FORSUS guy.

    Now Nanda has a relationship with Ortho Organizers so that explains part of what he does. On the other hand, Nanda is a bright fellow (I keep buying his books for a reason), and maybe Twin Force is a better way to go. Maybe someone else has an idea on this issue

    Do you do XBows?

    Something to ponder.

    Merry Christmas and Happy New Year!

    charlie ruff

  7. Nazan Kucukkeles

    Hi! Everybody,

    I tried jasper jumper, twin force and forsus (and I did my PhD with Herbst years before) .Twin force is more rigid than the others (which is good for a jumper) but the screws those attach the system to the wires fail frequently so patients keep coming. I like the forsus best because it is user friendly, doctor friendly (easy to place and remove) and very effective. For more skeletal results place TPA in the upper and lingual arch in the lower, cinch the wires and make sure you have 17X25 SS in slots.I wish you luck and happiness in new year..

    Nazan Kucukkeles

    • Question on FORSUS: when I use the 22 mm arm, I attach it between the lower 4,5 area. Very nice because it is less conspicuous. If it needs activation after 6 weeks, it cannot be activated since there is no stop on the arm. If I try and crimp a stop it slides forward. I could take the arm off and solder a stop but that is a lot of effort so I usually just switch to a 25 mm arm. Any other ideas? How about using K modules like Bob MIller recommends?

      It is reallhy nice to see everyone again.

      charlie ruff

  8. Marco,

    While it is true there is a version of Twinforce that does not require the use of bands for attachment ( i.e. the TwinLock version where there are clamps for both upper and lower ends ), it is still useful to have bands to allow placement of a TPA -otherwise you get significant flaring of the molars. Nanda fees that the advantage of the TwinLock version is that the distalising force is applied mesial to the first molar and along the line of the arch, rather than distal and through the headgear tube – therefore the force acts closer to the centre of resistance.

    I have no experience of using Forsus but plan to do so this year.

    Owen Crotty

  9. I think Forsus is a useful appliance but it has some negative effects over the lower incisors.
    We investigate CBCT images of the patients who use Forsus,
    we realize that in some patients forsus pushing forward the lower incisors aggressively.
    The question is “What will be happen in the long term ?”

    I prefer to fabricate a by-pass archwire in order to prevent canine bracket breakage
    And also cinching bypass arch back to the molars.
    I attached a photo.

    Pamir Meric
    Dicle University
    Faculty of Dentistry
    Department of Orthodontics

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