Evaluation of conformity of preformed orthodontic archwires and dental arch form

Abstract

Introduction: The alterations in the arch form during treatment are dictated by the dimensions of the archwires. Objective: This study aimed to determine the mean arch dimensions of a sample of Pakistani subjects and to evaluate the conformity of preformed archwires with mandibular arch form. Methods: The dental records of 1,500 adult subjects were evaluated. The mandibular casts of 42 subjects (males = females = 21) with balanced facial profile, Class I occlusion, ideal overjet and overbite were included. Brackets were bonded on all teeth. Arch dimensions were evaluated at canines, first premolars, second premolars, first and second molars, with digital vernier calipers. The arch widths at the level of aforementioned teeth were evaluated on the digitized archwires, using the mean arch depths of the subjects. Results: In males, the archwires were found to be wider at canines and premolars, and significantly narrower at first (p< 0.001, 95% CI = 2.03 - 5.74) and second molars (p< 0.001, 95% CI = 2.29 - 7.73) as compared to the arch dimensions of the mandibular casts. In females, the archwires were significantly narrower at canines (p< 0.001, 95% CI = 1.4 - 3.97), and first (p= 0.02, 95% CI = 0.402 - 4.41) and second molars (p< 0.001, 95% CI = 1.76 - 6.13). Conclusion: No single commercially available archwires evaluated in the present study conformed to the arch dimensions of our subjects. Utilization of the currently available archwires may result in unwarranted modification of arch form, which may lead to unstable post-treatment teeth position.

Mandibular Clinical Arch Forms in Iraqi Population: A National Survey

“…In this investigation, a 2D scanner was used, and this method was also used in other studies [ 2 , 4 , 20 , 32 , 33 , 34 ] as it is simple and practical for the large sample size. Similarly, arch form templates were used in evaluating the mandibular arch forms as they have been commonly used in orthodontic clinics to choose orthodontic prefabricated archwires for patients [ 8 ].…”

“…One of the most common causes of relapse after orthodontic treatment is the alteration of the patient’s original arch form [ 1 , 2 ]. The tendency for post-treatment relapse will be higher if greater changes in the arch form occur during treatment [ 1 ].…”

“…The preservation of the original intercanine and intermolar width is critical for stability since it represents the position of the teeth that results from the muscular balance of each patient [ 3 ]. When the same archwire form is used for all patients, the initial arch form is likely to change, resulting in an unstable result [ 2 ]. Moreover, preformed superelastic archwires are difficult to adapt to each patient’s specific arch form [ 4 ]; so, having a variety of preformed archwires on hand is more practical [ 5 ].…”

Comparación del tamaño transversal de los arcos 0.012, 0.014 y 0.016 de NiTi de tres marcas

“…reportaron una profundidad de segundos molares de 40 mm. (15) Hedayati y cols. encontraron una profundidad de los molares de 27 mm.…”

The MH-WIRE, a novel coil-springe wire system: A prototype design

“…The desired properties of the ideal wire that every orthodontist dreamed of were ideal constant force, log range of action, shape memory, super-elasticity, weldability/joinability, formability, biocompatibility, low price, low friction, high esthetics, and high corrosion resistance. [ 5 6 ]…”