Thanks a lot :)

Thanks for appreciation. Usually we don't have to twist wires if we are retracting on heavy rectangular wires bcz of built in torques in bracket which is very high in MBT system nowadays. If we observe retroclination on retraction then it's clinical judgement to give twist/ torque bend/ curve or any other mechanics to create couple

Hiii. Yes usually in rectangular SS. Although it can be given in TMA too. Twisting of wire can be easily achieved by pliers. The way you rotate rubik's cube up and down, the same movement to be given to the wire. I am making a presentation on 3rd order bends for fixed appliance playlist. Soon I'll elaborate your query in that.

Hi. Rectangular wires can do torquing but sometimes space is deficient so space creation might be required

Later. After alignment is done with thin round wires

Elastics should be used along with rectangular wires right sir??what is the guage of the wire which we have to use when we start the treatment sir??

Yes preferably rectangular. 19x 25 SS better

500 / 0.45 = 1111 as per formula mentioned. Even if you want to calculate moment through other formula force x force arm then also the answer will be 1100 gms. How? Calculate individually : 1100 gms force applied lingually and distance from CRes is 10 = 1100. Same force magnitude applied labial direction but distance from CRes is 10.45mm as the height of bracket is 0.45 mm = 11495. Difference between both moment calculated is 495 this is the moment you need here. I have used exact figures from William profitts book so you can refer that too.

Initially there is uncontrolled tipping when there's no couple. Just moment is created which is 500gmmm in example. Then there's creation of couple and tooth doesn't tip anymore. Tooth will only move bodily now if the wire is strong and doesn't deflect or get deformed. For bodily movement, 100 gm is needed as the width of bracket is 5mm. This will produce couple of 500 gmmm and tooth will move further. Mc and Mf will get equal then I hope I cleared the query

Yes. 3rd order bending

@@irfansinstituteofclinicalortho thank you for your reply doc

For translation your moment of couple has to be equal to moment of force. Width of bracket is 5mm so to reach 500 gmmm (moment of force). Your couple should be 100 as the formula is force x distance between point of force application.

@@irfansinstituteofclinicalortho okay thanks for the clarification doctor, but what about in the second example at 8:07... how did you create a couple of 350? i suppose the distance is within the bracket right? if so then the distance is 0.45mm (as written on the picture)??

@@1996712 yes. Bcz bracket slot vertical height is either 18 mil which is equal to 0.45mm or 22 mil equal to 0.55mm. To achieve 350gmmm moment of couple you will have to apply approx 700 gm couple force.

When you keep on increasing force, a time comes when you start creating couple more and more. When couple reached 100gm (in example) then you will be able to generate moment of couple 500gmmm and bodily movement. Bcz width of bracket will always a constant, the only possible change is change in force. 250gmmm will not move tooth bodily.

There are many ways to produce couple. For example by twisting the wire, torquing arch, even RCS can do that if given in rectangular wire.

@@irfansinstituteofclinicalortho Ok sir but how do we know the values?

@@rekhabharadwaj8557 that's actually clinical judgement. Let's say in patients follow up visit you notice more tipping then you will have to create more couple by twisting the wire etc. And vice versa. Since We give couple in heavy wires, you have to give it little by little every time. Till you achieve your results. Although the are gauges like dontrix to measure forces but used to measure force of elastics and springs, not easy for wires.

@@rekhabharadwaj8557 secondly, the whole journey from standard edgewise to MBT is the gradual development of the bracket prescription in which you don't have to put your energy in wire bending and you achieve ideal bodily movements and tooth positions with least efforts. Whether you are achieving bodily movements with twisting or bending the wire or just bcz of built in couple in brackets, calculation number is the same which i mentioned in video

@@irfansinstituteofclinicalortho ok sir thank you so much. One more doubt sir , in the Mc formula you have taken the dimension of wire as the points of force..As the wire is twisted , the height will change , like isn't it so that the diagonal length about be taken?

Assumption to give concept same as given in profitt. Usually, this is the average distance where CRes is located.