Aligner (Invisalign) Biomechanics: The Hidden Truths

This video presentation discusses the key biomechanical components of aligner-based orthodontic treatment. These features are not often discussed but are clinically critical for optimum performance of treatment. Here Dr. Madhur Upadhyay has presented a 'first principle' based understanding of the biomechanics of aligners, firmly supported by the available literature. He has shared biomechanical concepts, clinical tips, relevant literature, patient treatment & easy to understand illustrations.
Timestamps
00:00 Intro
00:14 Knowledge & Experience
01:41 Case 1
03:46 My journey (outline)
04:30 How big is the aligner industry? (Invisalign)
06:03 What are the tools of aligner mechanics?
09:43 How aligners treat different malocclusions?
10:00 Deep bites
13:36 Open bites
18:28 Case 2
19:22 Space closure
24:36 How good are aligners at moving teeth?
36:49 Force delivery
38:39 Stress relaxation
44:00 Case 3
46:33 Why are aligners so ridiculously inefficient?
46:43 Modulus of elasticity
52:13 What can go wrong with aligners?
54:31 What did we learn? Helpful tips!
Want to know more about how biomechanics works in orthodontics. Sign up for an online course at courses.orthob...
Get notified as soon as it arrives. A course that will dive deep into the fundamentals of clinical biomechanics in orthodontics with over 9 lessons & 25 modules of power-packed knowledge in the form of detailed videos, Q&As, notes, live interactive sessions and more.
The course has been meticulously prepared and delivered by Dr. Madhur Upadhyay, Associate Professor & Clinical director at the Division of Orthodontics, University of Connecticut, USA. He has over 15 years of experience in conducting courses, seminars & workshops on biomechanics.
Find out more about him at:
www.orthobites...
/ madhur-upadhyay-a99738126

[@hiralsavani]

Thank you doc for the eye opening information that you shared about aligner mechanics and materials. It clearly states that why someone is struggling with aligner for the difficult tooth movements. highly recommended..

[@revsen6405]

Excellent lecture.. learnt a lot about basics of aligners

[@Asathai1]

Great lecture and presentation. Thank you so much Dr Madhur Upadhyay

[@divyajadhav4291]

Very well demonstrated and explained sir... Thankyou so much for this 🙏

[@87gn199]

Great lecture... Did you have an engineering or heavy classical physics undergrad experience? Biomechanics? Would love to hear how you approached this early in your quest to understanding, thank you.

[@corazon7408]

Thank you so much Doc

[@eric-h6y]

Very impressive lecture. Great job !

[@kazmeensayyed3068]

Great lecture. Honest one.

[@bonesl5465]

Excellent lecture

[@bacsichinhnhathacsinguyenp9123]

Thanks a lot Doctor

[@rafaelborelliortodontia2249]

Great lecture! Thank you for sharing!

[@orthobitesorg]

You are welcome! Sign up to get notified as and when we post similar lectures/ courses on biomechanics. www.orthobites.org/subscribecontact

[@draitazazulhaq]

32:57 Is just like roller-coaster effect if we use NiTi 0.016. Or 0.018 or NiTi rectangular wire Instead of using SS wire we get this effect and its called rolorcoster effect same is coming with these aligners from my opinion if we use 2mm sheet with power riges on incisers on gingival area we can get translation movement

[@ortodr.g5002]

most studies are quite old. isn't it possible that the technology of the aligners has changed the information in the video?

[@orthobitesorg]

Thank you for the comments. A couple of things: the basic material for aligners for years have been polyester, polyurethane or co-polyester, polypropylene, polycarbonate, ethylene vinyl acetate, and polyvinyl chloride, among others. These have not changed much over the years, which implies that the fundamental mechanical properties have not either. Second, the new research either clinical or in vitro in summary has not shown any change in behavior.

[@Dentrovert]

Great presentation Thank you so much for sharing really appreciate it!

[@jihadsaleh9004]

Hi Doctor Thank you for this great presentation.. did the aligners closed the space in the case you started to treat ? Do you provide mentoring services to general dentists in doing orthodontics treatment ?

[@doorzcos3367]

Great lecture but I am still amazed when I hear root movement or tooth translation cannot be done efficiently using aligners specifically invisalign. Building gable bends for the teeth being translated in your clincheck combined with a vertical lingual attachment and a bevelled horizontal offset attachment on the buccal will yield predictable results all the time. All these side effects can be negated by overcorrections in the opposite direction. Cannot extrude posterior teeth you might say? Well how about building a reverse spee wire into the clincheck and having the right attachments, not breaking the aligner biomechanics rules, and see how fast you climb out of a deep bite. It works you just need to micromanage every single tooth.

[@orthobitesorg]

Thank you for sharing your tips! Based on the current evidence, these are some of the steps should take to counter the drawbacks of aligners. Hopefully researchers can identify similar measures, apply & evaluate them in retrospective or prospective studies. This will then tell us how effective they are.

[@emalieth8220]

Indeed, very interesting lecture. I think that the literature on which this presentation is based is quite old in some cases, older than SmartTrack for example. That could explain some discrepancies in current observed results.

[@mojtaba1348]

What a great lecture.

[@orthobitesorg]

Thank you!

[@ortholee72]

Thanks for sharing your lecture.

[@orthobitesorg]

You are welcome! Want to know more about how biomechanics works in orthodontics. Sign up for an online course at courses.orthobites.org/course...

[@animasharma6192]

Sir, can we apply PAOO in aligners too. Kole's procedure.

[@orthobitesorg]

Yes, of course. Aligners are one of the many appliances that are used to move teeth. PAOO as it claims is used to accelerate tooth movement. However, as you will experience faster tooth movement, the aligner side effects will get exaggerated too. (orthobites.org).

[@stefantodorovikj420]

thank you

[@orthobitesorg]

You are welcome!

[@orthobitesorg]

Sign up to get notified as and when we post similar lectures/ courses on biomechanics. www.orthobites.org/subscribecontact

[@aqilkavkhayev2268]

So is it true that there is no point in using aligners instead of braces? I was just about to start studying aligners to use in my practice

[@orthobitesorg]

Aligners have utility based on patient, malocclusion, tooth movement, compliance However, it is not as broad as the companies or aligner 'gurus' make it appear. It is important to study them so that as a clinician you know when, where & how to use them.

[@printbally1130]

🙏

[@maikyst.photography]

I have a question , so when you mention the % in the tipping , you show a teeth with a torque movement , I do not know if its a language difference cuz my native language is Spanish , so this movement that you show is tipping or torque ? It confuse me cuz I want to know when I need to use thicker aligners , for torque movement or tipping movement

[@orthobitesorg]

Broadly tipping comes in two forms: uncontrolled ( root moves in one direction and crown in the other) & controlled tipping ( minimal movement of the root). The tipping movement shown at 25:20 is more toward uncontrolled tipping (UT). Here there is no torque being used ( because that is the classical definition for UT). CT needs some control over the so there is little torque used. Thicker aligners might help with torquing movement, however the evidence is not there.

[@maikyst.photography]

@@orthobitesorg thank you for your answer

[@angelc4794]

I need your help! My dentist had me change trays everyday (I didn't know this was unusual) but he had 0.056 mm activation per tray maybe even more for a total of around 1.4 mm. :( 25 trays in 30 days with IPR between tray 15 and 16. No one can help me decide if more damage than just my incisor dying happened because no one knows how the force was applied/compounded. I manage to get my tooth movement table and the staging should be even over all teeth over all 25 trays. 0.392 mm/week velocity attempt with 1.4mm/month total Would you consider this excessive or dangerous? Would you help me figure out what happened on some level?

[@orthobitesorg]

Appreciate the details that you have (assuming you are not a dentist yourself ?). There are many things, that go, into planning an orthodontic tx. To understand the dynamics of your treatment we will have to look at many details. However, in general, an optimal rate of tooth movement will be around 0.4 mm-1.2mm/month. Tipping movements will be on the higher side while pure root movements on the lower and everything else in between. So was the movement in your case excessive! Maybe? However, a 1. 4mm /month movement will not cause loss of vitality.

[@ivancastro365]

Yo is it harmful for reproductive help???