A computerized software for selecting the most appropriate shape and size of archwires

The achievement of a stable, functional and esthetic archform has long been one of the prime objectives of orthodontics. A fundamental question is how the practitioner makes the correct design for the arch or how he selects the appropriate archwire. The goal of this study was to program a computer software for selecting the most appropriate shape and size of preformed archwires according to each patient dental arch. Methods & Materials: 100 Upper and lower dental casts were scanned by a conventional scanner. Then midbuccal tooth points were digitized on computer screen. By means of sixth degree polynomial function, archforms were generated for each sample by our software. Moreover, in order to select the best NiTi archware to fit the archform, we scanned five shapes of prefabricated 018 NiTi archwires. The software results were compared to the fitness of these shapes with each sample archform. The software results were compared to the consensus of seven orthodontists’ archwire selection by means of Kappa statistics. Intra and inter examiner reliability was assessed by means of one sample T-test, ICC and Dahlberg formula. The mean measurement error was 0.1mm and in the form of magnification. Intra-examiner error was 0.1mm and inter-examiner error although significant was 0.05mm. Kappa was 0.413 between the gold and the first suggestion of software. (64% similar to gold in upper arch, 59% in lower arch). Agreement (Kappa score) between gold’s was 0.429 at best. Considering the first and second suggestion valid, Kappa was calculated to be 0.91 (94% similar to gold in upper and lower arches). The accuracy of measurement is acceptable clinically and the reliability and validity was also good. The first and second suggestions of the software seemed clinically similar to the orthodontists’ suggestion. Therefore our software is an appropriate tool for selection of best fit NiTi archwires to planned arch form for the patient.