Palatal bone thickness measurement in white patients considering different facial patterns : A retrospective study of agreement between lateral cephalograms and cone-beam computed tomography images.

Aim: To investigate the agreement between palatal bone thickness (PBT) measurements performed on lateral cephalograms and cone-beam computed tomography (CBCT) images in a group of white patients considering different facial patterns.

Materials and methods: Measurements performed on lateral cephalograms and CBCT images from 60 white patients (39 females and 21 males; 24.1 ± 6.4 years) were retrospectively compared. On lateral cephalograms, PBT values were measured by drawing lines perpendicular to the maxillary occlusal plane (MOP) at the point of contact between the first and second premolar (P1-P2), second premolar and first molar (P2-M1), and first and second molar (M1-M2), as well as at the buccal cusps of the second premolar (P2) and first molar (M1). On CBCT images, they were measured at the same landmarks at 2 mm, 4 mm, 6 mm and 8 mm off-centre to the midpalatal suture. Vertical facial pattern of the patients was determined using the Frankfort-mandibular plane angle (FMA). Analysis of variance (ANOVA) and Tukey post hoc tests were used to ascertain the degree of agreement between the two measurement sets (p < 0.05), subsequently quantified by intraclass correlation coefficient (ICC) tests.

Results: Good agreement was found at all investigated sites regardless of vertical facial pattern, except at sites P1-P2 and P2 (8 mm off-centre) and M1 and M1-M2 (2 mm off-centre; p < 0.05). The two measurement sets displayed excellent agreement (ICC > 0.8) at P1-P2 (4 mm off-centre), at P2 (2, 4 and 6 mm off-centre), and all P2-M1 sites.

Conclusion: The lateral cephalogram can be a viable option for digital planning of palatal miniscrews insertion, with the preferred sites being P1-P2 at 4 mm off-centre and P2 at 4 and 6 mm off-centre in selected cases for adolescents and young adults. No significant differences in the degree of agreement between the two sets of PBT measurements were found among the different vertical facial patterns.