May 21, 2006
Microimplants are temporary anchorage devices (TAD’s) that looks like a fancy albeit miniature version of a screw.
A common example of orthodontic anchorage (relatively immobile blocks of teeth) is the situation when the orthodontist wants to pull in your front teeth that are sticking out. He uses the back molar teeth to help him because they are large, multirooted, and move very little when they are used to pull back the front teeth. The molar teeth are well anchored in your jaw.
Another simple way to think of anchorage: A fisherman is sitting in a row boat and has just caught a very 150 pound fish. if he has thrown an anchor overboard, and is strapped into the boat, he can, in time, reel the fish (tooth) in toward the boat without being pulled out to sea, or being pulled out of the boat, or the boat moving from its original position. Woe to the fisherman if he failed to anchor and was close to a waterfall.
What if the patient has no back teeth? Solution…the orthodontist places two microimplants, one on each side of the jaw toward the back where the molars used to be and attaches rubber bands to the front teeth he wants to move back.
The screw is about the about half the size of the width of your thumbnail, and no wider than the width of the head of a pin. It looks like this: @— .It is generally made of Titanium steel, and is placed painlessly either with a mini-”screwdriver” or a mini-ratchet wrench following the painless creation of “starter” hole in the bone. See Tomas page 1 and Tomas page 2.
The microimplant screw is removed when orthodontic treatment is completed. It takes less than a minute to remove it, and causes no pain.
In the last 3 years much attention has been paid to this subject as witnessed by an ever increasing number of journal articles and presentations by multiple speakers who have given a host of presentations on the subject at the international meeting of the American Association of Orthodontist from during 2004, 2005 and just recently in May 2006 in Las Vegas.
Like a forest fire burning out of control orthodontists are coming to use them more and more to enable them to move teeth in ways they never could before.
It will not be long before the use of the microimplant (miniscrew, TAD) is being taught and used in every post graduate orthodontic school in the country here and abroad.
They are placed into a variety of locations in the patient’s jaw bones usually between the roots of the teeth as well as other locations nearby the roots of the teeth and on the palate.
An article in the AJO-DO vol. 130, n. 2., Aug 2006 provides the reader with the thickness of the soft tissues and cortical bone at the most common areas of placement of pins in the maxillar alveolus and the thickness of the soft tissue at the mid-sagittal suture of the palate. I am sure that soft and hard tissue depth measurements will be forthcoming from the authors in relation to the common implant sites in the mandible. [See the article.]
Their use has made infinitely easier the movement of teeth in certain cases, that heretofore was accomplished with only the greatest difficulty.
The placement of the microimplant is becoming one that more and more frequently is being done by the orthodontist. However, there are many orthodontists who prefer to have their colleague, the oral surgeon, do it for them.
The procedure takes about 20-30 minutes and is accomplished painlessly since the patient is provided with local anesthesia.
You might think that driving a screw into the bone is very painful, however, bone in fact has no nerves inside it, so once the “operator” passes the screw through the skin that covers the bone, which is about as thick as this (H) it is done without any sensation except that of some pressure.
Dentaurum is without doubt one of the leaders in this field. Their principle spokesman for their microimplant “TOMAS” (Temporary Orthodontic Micro Anchorage System) is Professor Axel Bumann. He lectured at the AAO conference in Las Vegas, 2006. (www.dentaurum.com), E-mail: email@example.com. This company has published some excellent material on this subject and you can request it as well as their DVD on the subject.
Imtec is another leader in the field: www.imtec.com (click on “Products” then see “Orthoimplant”.) You will find the Imtec catalogue on microimplants to be most instructive.
The following articles will provide the reader with a brief overview of the subject:
Thiruvenkatachari B, Pavithranand A, Rajasigamani K, Kyung HM
Department of Orthodontics, Rajah Muthiah Dental College and Hospital, Annamalai University, Tamil Nadu, India. firstname.lastname@example.org
INTRODUCTION: The purpose of this study was to compare and measure the amount of anchorage loss…
|Universal Skeletal Anchorage SystemThe Leibinger Micro Implants Universal Skeletal Anchorage System is intended to be placed in the mouth for use as an anchor in orthodontic procedures. The system encompasses three different styles of implants to give a comprehensive selection when facilitating tooth movement….|
By JOHN W. GRAHAM, DDS, MD, AND JASON B. COPE, DDS, PhD
How to manage potential complications of using temporary anchorage devices
As has been demonstrated in numerous case reports, miniscrew implant (MSI) placement is predictable and stable.1–5 However, implementation of the procedure by clinicians without adequate training in the basic biological and biomechanical fundamentals germane to miniscrews may lead to less-than-ideal treatment results or even complications. The goal of this article is to present potential complications that clinicians may encounter in the routine placement of miniscrews, and how they may be avoided and/or treated.
Inadequate Primary Stability
Primary stability refers to the movement, or the lack thereof, of a miniscrew upon initial placement. A lack of primary stability almost routinely leads to overt miniscrew mobility, with subsequent failure. Recent evidence suggests that the majority of primary miniscrew stability comes from cortical bone, with lesser stability coming from medullary bone.6…
Temporary Anchorage Periimplantitis…
Poor Miniscrew Emergence…
Undesirable Tooth Movement…
Postremoval Complications …
The Case For Microimplants
By Gaby Bahri, DDS
An orthodontist tells how he came to adopt this new technology, and how it can help your practice
Microimplants have become part of the standard of care in my practice today. I praise myself for having made the decision to include this treatment a few years back after reading an article by Kawamura.1 Since then, my team and I have offered solutions to a wider variety of orthodontic problems with more confidence and with a higher degree of certainty.
I remember the time when I left this technique for others to try on their patients and make the mistakes at their own expense; I regret every minute that I spent waiting to start on my first patient. This feeling repeats itself over and over when I hear that in Europe, like in Korea and Japan, microimplants and miniscrews are actually being used routinely by a great number of orthodontists.
Hurdles to Overcome…
Solving Day-to-Day Problems…
Common Uses of Microimplants…
ASK an honest question to yourself, how many of your cases outcome is compromised because of loss of anchorage ? How much of your energy/time/money is wasted in planning anchorage ? Half of orthodontic learning involves how to manage anchorage. No more of these Headaches, After Edward Angle the NEXT revolution is here. Call it Microimplant screw anchorage, Skeletal achorage (SAS) or Temporary Anchorage devices (TAD), name does not matter, but it sure has revolutionised orthodontic treatment.
Temporary Anchorage Devices – (TAD).
Some useful links to various manufactures websites:
Temporary Anchorage Devices
cases were shown where TADs were used to assist in the correction of antero-posterior and vertical discrepancies. In one case, TADs were used for direct inter-maxillary fixation following orthognathic surgery. However, a common concern was the stability of skeletal correction using TADs. Surgical correction is more likely to change neuromuscular imbalances, leading to a more stable correction. However this can not be proven at this time because of the lack of studies in this area. The group called for long-term stability studies using TADs. In category of correction of dental discrepancies, applications of TADs were shown for: (1) antero-posterior tooth movements, (2) molar uprighting, (3) intrusion/extrusion of single and multiple teeth. In most cases TADs were used to supplement dental anchorage, however in some applications TADs were used as the sole source of anchorage. Overall the group felt that there are many possible indications and applications for TADs and they serve as an invaluable component of the orthodontic armamentarium. In addition, it was noted that biomechanics need to be design to optimize the use of TADs.
The question re growing vs non growing patients was issued with voice of skepticism from some participants on placing TAD`s on young growing patients.