The anchorage bend in the Begg technique

The anchorage bend is an essential feature of the Begg technique. The factors which affect the degree of the anchorage bend include operator preferences as well as certain mechanical features of the case being treated. A test jig was constructed so as to be able to measure on the bench the intrusive forces developed by an anchorage bend over the six anterior teeth for a selection of different archwires. The amount of force developed was proportional to the degree of anchorage bend and also to the diameter of the archwire. The jig was modified in order to measure the frictional resistance to distal movement generated by the anchorage bend. The resistance was found to be greater than the usually quoted forces designed to slide the upper archwire distally. An oval tube was placed on to the test jig and doubled back archwires used. A reduction in intrusive force for a particular degree of anchorage bend was seen although frictional resistance was not affected when using doubled back archwires.