IADR Abstract Archives
The Use of CBCT Derived Printed Models in Orthodontic Diagnosis
Objectives: Cephalometric and panoramic radiographs are required for skeletal analysis and models are required for morphological analysis in clinical orthodontics. Recently, cone beam computed tomography (CBCT) has been used for diagnostic tool. If the occlusal images from CBCT is accurate enough to use as model analysis and to fabricate appliances, there is no need to take 2-dimensional radiographs and intra-oral scanner. In this study, we analyzed the accuracy and reliability of the use of CBCT derived printed model for orthodontic diagnosis using human cadavers.
Methods: Human maxillary and mandibular cadavers were used in this study. Maxilla and mandible were scanned (TRIOUS, 3shape) and had CBCT (Planmeca, ProMax 3D Mid) taken and printed as a digital model (Form2, Formlabs). Model analysis and occlusal index analysis by peer assessment rating (PAR) was performed between the cadavers, CBCT, and scanner digital models. In addition, individual tooth size analysis (including the root) was performed. Intraclass correlation coefficients (ICC) were calculated to determine the inter-examiner reliability and paired t-tests were used for intergroup comparisons.
Results: All ICC values for the 3 measurements exceeded 0.90. There was no significant difference between groups in model analysis and total PAR analysis (p>0.05). CBCT digital model tended to result in larger over jet than the actual measurement. Less than 1.0mm of difference in individual tooth length was observed between CBCT model and actual cadaver measurements.
Conclusions: Scanner derived digital model resulted as accurate as the actual human cadaver measurement, however, CBCT digital model may have some limitation in measuring in some PAR variables. From the results of individual tooth size analysis, CBCT digital model indicated to be useful in determining the actual size of tooth such as in impacted teeth.
Methods: Human maxillary and mandibular cadavers were used in this study. Maxilla and mandible were scanned (TRIOUS, 3shape) and had CBCT (Planmeca, ProMax 3D Mid) taken and printed as a digital model (Form2, Formlabs). Model analysis and occlusal index analysis by peer assessment rating (PAR) was performed between the cadavers, CBCT, and scanner digital models. In addition, individual tooth size analysis (including the root) was performed. Intraclass correlation coefficients (ICC) were calculated to determine the inter-examiner reliability and paired t-tests were used for intergroup comparisons.
Results: All ICC values for the 3 measurements exceeded 0.90. There was no significant difference between groups in model analysis and total PAR analysis (p>0.05). CBCT digital model tended to result in larger over jet than the actual measurement. Less than 1.0mm of difference in individual tooth length was observed between CBCT model and actual cadaver measurements.
Conclusions: Scanner derived digital model resulted as accurate as the actual human cadaver measurement, however, CBCT digital model may have some limitation in measuring in some PAR variables. From the results of individual tooth size analysis, CBCT digital model indicated to be useful in determining the actual size of tooth such as in impacted teeth.