Fig. 4From: The inflection point: a torque reference for lingual bracket positioning on the palatal surface curvature of the maxillary central incisorThe procedures done to calculate the torque angle value at any 0.5-mm increment are described here in four steps. All the equations mentioned here are found in Fig.Ā 3 and a specially formed Excel spreadsheet containing all these equations in addition to cubic and quadratic equation calculators, allowed all the procedures listed here to be doneBack to article page