Changes in dental and basal archforms with preformed and customized archwires during orthodontic treatment

Abstract

ObjectivesTo evaluate changes to the dental and dentoalveolar (WALA Ridge) arch widths with preformed and customized archwires during orthodontic treatment. Methods20 patients treated with preformed archwires and 20 treated with customized archwires were recruited. Pre-treatment (T1) and post-treatment (T2) mandibular casts were used to determine the changes in dental and dentoalveolar arch width measured at the canine, premolar and molar areas. Ratios of transverse dental to dentoalveolar movements were also calculated. Results were compared to an untreated control group with mandibular casts taken at two comparable time points. Data were analyzed using ANOVA and t-test. ResultsSignificant changes in dental and dentoalveolar arch width were found with the preformed archwire group when compared to the control (p<0.05). However, no significant changes in dental and dentoalveolar arch width were found with the customized archwire group compared to the control. Significant correlations were found between the dental and dentoalveolar arch widths. However, the ratios of dental to dentoalveolar transverse change differed between the groups and indicated that the types of movements were contrasting between the preformed and custom arch forms as each expanded the dental arches. ConclusionsThe WALA Ridge is a stable landmark when archwires are customized or shaped to the WALA Ridge. Changes in the WALA Ridge are expected when preformed archwires are used which do not conform to the patient's dentoalveolar arch width defined by the WALA Ridge. This is probably accounted for by the different types of tipping combined with extrusion that both methods employ.