A new accurate approach to the anterior ratio with clinical applications. Part II: a nomographic solution

Evaluating the anterior ratio is useful to forecast potential tooth mass discrepancies and related overjet or underjet. Because the arcs of the six anterior teeth have recently been described by the mathematical hyperbolic cosine function, it has permitted the design of a nomograph for ready use in clinical practice. A nomograph is a simple chart on which one can draw a straight line that will intersect three scales representing variables that satisfy an equation. A clinician may now evaluate and forecast the effects on overjet with purposeful alterations in the sums of the six maxillary and mandibular anterior tooth masses for various cross-arch canine widths with an accuracy of +/-0.5 mm.