Correlation between the Rotation of the First Molars and the Severity of Class II Division 1 Malocclusion

Figure 1

Determination of rotation of the first maxillary molar. (a) The defined points were initially marked on the scanned model. The three indicators were then calculated as follows: (b) indicator 1 (angle of Henry); (c) indicator 2 (angle of Friel); and (d) indicator 3 (line of Ricketts).

(a)

(b)

(c)

(d)