Comparison of commercially available preformed archwires with average natural arch forms

To compare the dimensions of commercially available preformed archwires with natural arch forms of Pakistani subjects.

The cross-sectional study was conducted at the Department of Orthodontics, Armed Forces Institute of Dentistry, Rawalpindi, Pakistan, from September 2019 to February 2020, and comprised maxillary and mandibular dental casts of orthodontically untreated subjects that were evaluated to obtain arch dimensions at the canines and first molar levels with the help of digital Vernier calipers. Bracket-archwire assembly was constructed to accurately measure widths from bracket-slot points at both the canine and molar levels in an attempt to mimic clinical archwire-bracket interface. Canine and molar depths were also recorded for accurate estimation of the digitised archwire widths at the aforementioned levels. Data was analysed using SPSS 25.

Of the 52 subjects, 26(50%) each were males and females with age ranging from 12years to 35 years. The archwires evaluated for maxilla were significantly wider at canines and first molars compared to the canine and molar dimensions of the dental casts obtained from the subjects (p<0.05). For mandible, significant differences were found at the canine level where archwires exhibited greater dimensions than mean intercanine widths of the subjects (p<0.05).

Commercially obtainable preformed archwires were inconsistent with diverse arch forms manifested in subjects with almost ideal occlusion. Therefore, utilisation of these archwires may create unwarranted wider dimensions of the arch form, especially in the intercanine region which can influence post-treatment retention, stability and facial aesthetics.