KPG index versus OPG measurements: a comparison between 3D and 2D methods in predicting treatment duration and difficulty level for patients with impacted maxillary canines.

Aim. e aim of this study was to test the agreement between orthopantomography (OPG) based 2D measurements and the KPG independently scored by three orthodontists at and a er 1 mon2th ( ), usin2g the KPG index and the following 2D methods: 01 index, a new index based on 3D Cone Beam Computed Tomography (CBCT) images, in predicting orthodontic treatment duration and di culty level of impacted maxillary canines. Materials and Methods. OPG and CBCT images of 105 impacted canines were distance from cusp tip and occlusal plane, cusp tip position in relation to the lateral incisor, and canine inclination. Pearson’s coe cientswereusedtoevaluatethedegreeofagreementandthe withYatescorrectiontestwasusedtoassesstheindependence between them. Results. Inter- and intrarater reliability were higher with KPG compared to 2D methods. Pearson’s coe cients showedastatisticallysigni cantassociationbetweenalltheindexes,whilethe withYatescorrectiontestresultedinastatistically signi cant rejection of independency only for one 2D index. Conclusions. 2D indexes for predicting impacted maxillary canines