The orthodontic literature shows diversity in adopting a reliable and definitive method for determining the shape and dimension of the dental arch form. Several visual, linear, geometric, and mathematical methods were employed in order to sort the form of the arch wire to fit a given dental arch. The consensus among researchers and orthodontists is that there is no general shape for the arch form and that the original mandibular arch form should be preserved. This concept has been translated through several vendors (Ortho CADs) for fabrication of the treatment arch wire for a patient, using pretreatment study cast. In addition, the Insigna and Sure Smile systems produced arch wires made-up for each patient. The method of Andrews and Andrews (2000) to determine the mandibular individual arch form (WALA ridge) seems promising and a recent study showed a positive correlation between this method and arch form shaping of treatment arch wire [jad1]s.
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