Interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups.

INTRODUCTION: The use of digital orthodontic setups has grown quickly. The purpose of this study was to test the interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups in OrthoCAD (Align Technology, San Jose, Calif). METHODS: Six clinicians made digital orthodontic setups on 6 digital models twice, with a minimum interval of 2 weeks and a maximum interval of 4 weeks. OrthoCAD software was used, and treatment goals were all set the same according to the American Board of Orthodontics Objective Grading System (ABO-OGS). Differences between the 72 setups were measured with the ABO-OGS scores. RESULTS: In comparing setups 1 and 2, the intraexaminer mean absolute differences in total ABO-OGS scores varied statistically significantly between 2.17 and 6.00 points. Interexaminer mean absolute differences varied statistically significantly between 4.77 and 5.56 points. All but 1 intraclass correlation coefficient (ICC) value showed significant excellent agreement (ICC, >0.8) for intraexaminer reliability. One ICC value was insignificant and showed moderate (ICC, 0.4-0.6) agreement. Interexaminer reliability showed significant good (ICC, 0.6-0.8) agreement. CONCLUSIONS: There is a significant difference in ABO-OGS score when using OrthoCAD. Although this difference was low, it could be clinically significant. Interexaminer and intraexaminer reliabilities are not redundant for general use of the 3-dimensional orthodontic digital setup in OrthoCAD.

The influence of cephalometrics on orthodontic treatment planning.

Since its introduction, cephalometrics, i.e. cephalometric radiography and analysis, has been used for orthodontic treatment planning. However, the effectiveness of this diagnostic method remains questionable. A randomized crossover study was designed to assess the influence of cephalometrics in orthodontic treatment planning of individual patients. Diagnostic records of 48 subjects (24 males and 24 females aged 11-14 years) were divided in two stratified groups and assigned to one of two combinations: A, dental casts only, and B, dental casts, cephalometric radiographs, and analysis. The records were presented to 10 orthodontic postgraduates and four orthodontists for formulation of orthodontic treatment plans containing a dichotomous decision regarding the use of a functional appliance (FUNC), rapid maxillary expansion (RME), and extraction (EXTR). The combination of FUNC + RME + EXTR was used as the basis of the outcome measure. Agreement on orthodontic treatment planning using all possible comparisons of diagnostic records of individual patients (AB, AA, and BB) was assessed and overall proportions of agreement (OPA) were calculated for orthodontic postgraduates and orthodontists separately. Median OPA were 0.60 (AB), 0.65 (AA), and 0.60 (BB) for orthodontic postgraduates and 0.50 (AB), 0.75 (AA), and 0.50 (BB) for orthodontists. Irrespective of the level of experience, neither consistency of orthodontic treatment planning between both combinations of diagnostic records showed a statistically significant difference (P > 0.05) using Wilcoxon signed rank test nor did consistencies and agreement of orthodontic treatment planning after the addition of cephalometrics. It appears that cephalometrics are not required for orthodontic treatment planning, as they did not influence treatment decisions.