Objective vs subjective analyses of arch form and preformed archwire selection

Can 3D imaging and digital software increase the ability to predict dental arch form after orthodontic treatment?

“…By use of the RMS, the difference between the corresponding points on the dental arch and the archwire can be calculated. Similar to the current study, Nouri et al 9 used the RMS to quantify the subjective data, such that the polynomial curve was drawn and the least distance between the CBPs and the fitted polynomial curve was measured. The RMS was also used to find the best-fitted archwire.…”

“…The ICC values are interpreted as follows: 0-0.2: weak agreement, 0.3-0.4: fair agreement, 0.5-0.6: moderate agreement, 0.7-0.8 strong agreement and .0.8 almost excellent agreement. 13 Since the interobserver reliability of the 3 orthodontists who participated in this study had been previously calculated and confirmed on both normal occlusion casts and in use of the software, 9 only the intraobserver reliability of the first orthodontist in use of the software was calculated in the present study. For this purpose, the first orthodontist was requested to select the best-fitted archwire for 10 casts for the second time after a 2-week interval by the digital method.…”

“…Comparison of the numerical value of difference between the archwire and dental arch of patients revealed that in the digital method, the difference between the primary and final wires was around 0.5 mm, which is clinically negligible. 9 Also, use of digital method informs the orthodontist about the exact numerical value of difference between the existing wires and the patient's dental arch, which leads to more accurate decision making and lower human errors. As shown in our study, the digital method increased the agreement among the orthodontists.…”

“…6 In orthodontic treatment planning, the dental arch form of the patient should be initially determined and further preserved during treatment to achieve optimal esthetics, function, and stability. 7,8 Nouri et al 9 showed that the software environment enables a better fit of archwire with the dental arch and agreement of orthodontists is higher in the selection of archwires for regular occlusion patients.…”

Agreement of the clinician's choice of archwire selection on conventional and virtual models

“…8 The therapeutic arch form should be designed by considering the original arch form of the patient and treatment objectives. 9 A survey by McNamara et al 6 revealed significant variation in archwire selection methods among orthodontists. Most orthodontists selected archwires subjectively by visual assessment of the adaptation of the archwires to the facial axis or facial surface of the teeth, incisal edges and cusp tips, or the facial portion of the proximal contacts.…”