Page 23 - orthodontic lecture reivew

• Suppose you want to apply a moment of 2000 g in

counterclockwise direction, in order to loosen this

screw. There are different ways to get the same

effect.

• If you apply two opposing forces of 100 g

considering that they are 20 mm apart from each

other, you will produce your desired moment of

2000 g .

• You will get exactly the same result if you

choose to apply two opposing forces of 200 g at

different points, and at distance of 10 mm

between them.

• Since the magnitude and direction of the moment

of the couple are the same, the final effect on the

screw will be suchlike .