molars, a twin-wire appliance was designed to provide alignment of these teeth. Constructed with two 10-mil steel archwires, its delicate features were safeguarded by lengthy tubes stretching from molars towards canines. Despite its efforts, it had limited capacity for movement without further modifications - rendering it obsolete in modern orthodontic practice. Begg's Appliance Returning to Australia in the 1920s, the renowned orthodontist, Raymond Begg, applied his knowledge of ribbon arch appliances, which he had learnt from the Angle school. On top of this, Begg recognised that extracting teeth was sometimes vital for successful outcomes and sought to modify the ribbon arch appliance to provide more control when dealing with root positioning. In the late 1930s, Begg developed his adaptation of the appliance which took three forms. Firstly, a high-strength 16-mil round stainless steel wire replaced the original precious metal ribbon arch. Secondly, he kept the same ribbon arch bracket but inverted it so that it pointed toward the gums instead of away from them. Lastly, auxiliary springs were added to control root movement. This resulted in what would come to be known as the Begg Appliance (Fig 10.19).5 With this design friction was decreased since contact between wire and bracket was minimal, and binding minimized due to tipping and uprighting being used for anchorage control (see Fig 8.26), which lessened contact angles between wires and corners of bracket Tip Edge System Dr. Begg's influence is still seen in modern appliances, such as Tip-Edge brackets. This type of bracket incorporates a rectangular slot cutaway on one side to allow for crown tipping with no incisal deflection of an archwire; allowing teeth to be tipped during space closure and then uprighted through auxiliary springs or even a rectangular wire for torque purposes in finishing. )At initial stages of treatment, small-diameter steel archwires should be used when working with Tip-Edge brackets. Contemporary Edgewise systems Throughout time, there has been a shift in which appliance is favored by dentists. In particular, during 1960s, when it was introduced, Begg appliance gained wide popularity due to its efficiency compared to edgewise appliance of that era; it could produce same results with less investment from dentist's part. Nevertheless, since then there have been advances in technology and sophistication of edgewise appliances which led to an opposite conclusion: nowadays, edgewise is more efficient than Begg appliance thus explaining why it is commonly used. Major steps in the evolution