Objective This prospective controlled study evaluated the effect of bone-anchored maxillary protraction therapy in cleft children with Class III malocclusion using CBCT-derived 3D surface models. Materials and subjects Eighteen cleft patients between 10 and 12 years old were included. Intermaxillary elastics were worn after the placement of four zygoma bone plates for 18 months. Uniquely, three age-matched untreated groups including both cleft subjects and non-cleft subjects with Class III malocclusion served as controls. Profile photos and CBCT scans for each patient were taken before (T0) and 18 months after the protraction (T1). 3D measurements were made on CBCT surface models from the treatment group using tomographic color mapping method. Cephalometric measurements were made on lateral cephalogram reconstructed from the CBCT scans and were compared with those obtained from the control groups. Results Two thirds of the treatment subjects showed improved lip projection towards more convex facial profile. The most significant skeletal changes on 3D surface models were observed at the zygomatic regions (mean 1.5-mm forward, downward, and outward displacement) and at the maxillary complex (mean 1.5-mm forward displacement). Compared with the control groups, the treatment subjects showed significant increase in the SNA and ANB angles, increased Wits appraisal, a more forward movement of point A and overjet improvement (p < 0.05). Conclusions BAMP in cleft patients gives a significant forward displacement of the zygomaxillairy complex in favor of the Class III treatment. Clinical relevance This treatment method shows clearly favorable outcome in cleft patients after 1.5 years of BAMP.

Objectives To analyze differences in variation of orthodontic diagnostic measurements on lateral cephalograms reconstructed from ultra low dose-low dose (ULD-LD) cone beam computed tomography (CBCT) scans (RLC) as compared to variation of measurements on standard lateral cephalograms (SLC), and to determine if it is justifiable to replace a traditional orthodontic image set for an ULD-LD CBCT with a reconstructed lateral cephalogram. Material and methods ULD-LD CBCT images and SLCs were made of forty-three dry human skulls. From the ULD-LD CBCT dataset, a lateral cephalogram was reconstructed (RLC). Cephalometric landmarks (13 skeletal and 7 dental) were identified on both SLC and RLC twice in two sessions by two calibrated observers. Thirteen cephalometric variables were calculated. Variations of measurements, expressed as standard deviations of the 4 measurements on SLC and RLC, were analyzed using a paired sample t-test. Differences in the number of observations deviating ≥ 2.0 mm or degrees from the grand mean between SLC and RLC were analyzed using a McNemar test. Results Mean SDs for 7 out of 13 variables were significantly smaller for SLCs than those for RLCs, but differences were small. For 9 out of 13 variables, there was no significant difference between SLC and RLC for the number of measurements outside the range of 2 mm or degrees. Conclusions Based on the lower radiation dose and the small differences in variation in cephalometric measurements on reconstructed LC compared to standard dose LC, ULD-LD CBCT with reconstructed LC should be considered for orthodontic diagnostic purposes. Clinical relevance ULD-LD CBCT with reconstructed LC should be considered for orthodontic purposes.

Objectives This study aims to assess whether different voxel sizes in cone-beam computed tomography (CBCT) affected surface area measurements of dehiscences and fenestrations in the mandibular anterior buccal region. Materials and methods Nineteen dry human mandibles were scanned with a surface scanner (SS). Wax was attached to the mandibles as a soft tissue equivalent. Three-dimensional digital models were generated with a CBCT unit, with voxel sizes of 0.200 mm (VS200), 0.400 mm (VS400), and 0.600 mm (VS600). The buccal surface areas of the six anterior teeth were measured (in mm2) to evaluate areas of dehiscences and fenestrations. Differences between the CBCT and SS measurements were determined in a linear mixed model analysis. Results The mean surface area per tooth was 88.3 ± 24.0 mm2, with the SS, and 94.6 ± 26.5 (VS200), 95.1 ± 27.3 (VS400), and 96.0 ± 26.5 (VS600), with CBCT scans. Larger surface areas resulted in larger differences between CBCT and SS measurements (− 0.1 β, SE = 0.02, p < 0.001). Deviations from SS measurements were larger with VS600, compared to VS200 (1.3 β, SE = 0.05, P = 0.009). Fenestrations were undetectable with CBCT. Conclusions CBCT imaging magnified the surface area of dehiscences in the anterior buccal region of the mandible by 7 to 9%. The larger the voxel size, the larger the deviation from SS measurements. Fenestrations were not detectable with CBCT. Clinical relevance CBCT is an acceptable tool for measuring dehiscences but not fenestrations. However, CBCT overestimates the size of dehiscences, and the degree of overestimation depends on the actual dehiscence size and CBCT voxel size employed.