Presentation Blocks: 03-22-2018 - Thursday - 11:00 AM - 12:15 PM

Title: Intra- and Inter-examiner Reproducibility in Irregularity Index Measurements


Fatma Demir, Izmir Katip Celebi University
Ersat Irezli, Izmir Katip Celebi University
Mucahid Sahin, Izmir Katip Celebi University
ASLI BAYSAL (Presenter)
Izmir Katip Celebi University


Objectives: The aim of this study was to assess intra-examiner and inter-examiner reproducibility of irregularity index measurement.

Methods: Twenty plaster casts of moderately crowded arches were randomly selected and five contact point displacements (CPD) at lower anterior segment (through #33 to #34) was recorded using digital calipers on two different time points by three examiners to determine irregularity index (sum of five CPDs).
To evaluate intra- and inter- examiner differences, paired t-test and analyses of variance were used, respectively. Correlation analysis were performed between examiner pairs, the corresponding intraclass correlation coefficients (ICC) and associated significance determined. Statistical significance was set at p ≤ .05.

Results: Only a few of the repeated measurements of examiners showed significant differences (p ≤ .05). All researchers were consistent in repeated measurements (p=.000) and ICCs ranged between 0.916-0.986 Just for one CPD measurement, statistically significant difference was detected among examiners (p=.011). High correlation was found for inter-examiner repeatability (p<.05) and ICCs ranged between 0.739-0.984. But when the difference of 1.5 mm among measurements was set as clinically significant, the percentages of these values were 15%, 5% and 45% for examiner 1, 2 and 3, respectively. These were 25%, 80%, 65% for examiner pairs.

Conclusions: Irregularity index may be a misleading tool for determination of anterior alignment especially when measuring small contact point displacements.