Reliability of the moiré method in study of tooth and palatal morphology

The purpose of the present study was to determine reproducibility of the photographic technique, intra- and inter-examiner reliability of the moiré method for investigating tooth and palatal morphology as well as the agreement between the moiré method and the palatometer in measuring palatal height. Intraclass correlation coefficients (ICC) of 0.88 to 0.95 for three separate photographs for each of the same 40 casts taken by three examiners and measured by a single examiner exhibited high reproducibility of the photographic technique. For studying tooth morphology, the moiré lines were counted from the cusp tips to the mesiobuccal and distolingual fossae. ICC of 0.92 to 0.99 with 95% confidence limits for triple measurements and Pearson correlation coefficients of 0.92 to 1.00 for double measurements showed high intra- and inter-examiner consistency, respectively. For palatal height at the level of the first maxillary molars ICC with 95% confidence limits for triple measurements was 0.98 and correlation coefficient between two examiners 0.98, respectively. Correlation coefficients between the moiré method and the palatometer were also high, with a value of 0.98. In summary, with careful calibration before use, the moiré method proved to be useful and reliable in studying tooth and palatal morphology.