Palatal volume and area assessment on digital casts generated from cone-beam computed tomography scans

Objectives: The objective of this study was to develop a reproducible method to measure the change of palatal volume and area through superimposition using maxillary expansion digital cast models. Materials and Methods: A total of 10 pre- and 10 postexpansion dental cast models were scanned by the same cone-beam computed tomography machine. Superimposition was performed using a fully automated surface-best fit of the palatal surfaces on the digital cast models. A gingival plane, identified only once on superimposed casts, and a distal plane with the lateral closing border and the palatal surface were used to localize this selection of air. Area and volume were calculated for pre- and postexpansion records. Pre- and postexpansion palatal volume and area were measured by the main investigator and three different observers for inter- and intra-observer reproducibility assessment. Results: The level of intra- and inter-observer agreement was very strong (intraclass correlation coefficients > 0.953; P value < .0001) for all measurements. Conclusions: Palatal volume and area measurements based on the proposed superimposition are reproducible and can be used reliably.