Correlation of the arch forms of male and female subjects with those of preformed rectangular nickel-titanium archwires.

Introduction: This investigation was carried out to correlate the normal arch forms of male and female subjects derived mathematically by the beta function with commercially available preformed rectangular nickel-titanium archwires.

Methods: The mathematical beta function was used to derive planar projections of natural archforms by using the spatial coordinates of the labial bracket interfacing surfaces in the maxillary and mandibular arches of both sexes. Graphic planar representations of corresponding bracket base spatial coordinates of archforms of 30 popular rectangular nickel-titanium archwire-bracket assemblies (derived through the same mathematical function) were superimposed on relevant maxillary and mandibular arches.