Grey Wolf Optimizer with Behavior Considerations and Dimensional Learning in Three-Dimensional Tooth Model Reconstruction.

Three-dimensional registration with the affine transform is one of the most important steps in 3D reconstruction. In this paper, the modified grey wolf optimizer with behavior considerations and dimensional learning (BCDL-GWO) algorithm as a registration method is introduced. To refine the 3D registration result, we incorporate the iterative closet point (ICP). The BCDL-GWO with ICP method is implemented on the scanned commercial orthodontic tooth and regular tooth models. Since this is a registration from multi-views of optical images, the hierarchical structure is implemented. According to the results for both models, the proposed algorithm produces high-quality 3D visualization images with the smallest mean squared error of about 7.2186 and 7.3999 µm2, respectively. Our results are compared with the statistical randomization-based particle swarm optimization (SR-PSO). The results show that the BCDL-GWO with ICP is better than those from the SR-PSO. However, the computational complexities of both methods are similar.

Cortical Bone Thickness and Morphology at the Infrazygomatic Crest Area in Growing Thai Patients with UCLP: A CBCT Study.

OBJECTIVES: To determine and compare buccal cortical bone thickness and morphology (in terms of shape and height) at the infrazygomatic (IZ) crest in growing Thai patients with unilateral cleft lip and palate (UCLP) using cone-beam computed tomography (CBCT) with the ultimate goal of identifying potential sites that are suitable for the placement of miniplates. DESIGN: Prospective study. SETTLING: Institutional research. PATIENTS: Twenty-four Thai patients with non-syndromic complete UCLP with Class III skeletal discrepancy aged 10-14 years. INTERVENTIONS: A total of 48 CBCT images captured the IZ crest. Five horizontal and six vertical reference planes were established in the IZ crest area. MAIN OUTCOME MEASURE: The mean buccal cortical bone thickness of the cleft and non-cleft sides were 1.13 ± 0.45 mm and 1.15 ± 0.46 mm, respectively. The most frequently observed shape for the IZ crest was the external concave contour. There were no statistically significant differences in cortical bone thickness and shape distribution between the cleft and non-cleft sides. (P > .05). RESULTS: The thickness of the buccal cortical bone increased anteriorly and superiorly from V + 0 and H + 0. The average height of IZ crest on the cleft side was 16.20 ± 1.59 mm and 16.78 ± 1.84 mm on the non-cleft side. Notably, significant differences were detected in terms of height between the cleft and non-cleft side and cortical bone thickness by gender (P < .05). CONCLUSIONS: The IZ crest was found to provide sufficient support for the insertion of a miniplate, particularly in the superior and anterior regions, ensuring primary stability in growing Thai patients with UCLP.

Correlation Between Presurgical Alveolar Cleft Volume Measured by Simulation Software Using CBCT and Actual Bone Volume Used for Grafting.

OBJECTIVE: To assess correlation between presurgical alveolar cleft volume measured by simulation software using CBCT and actual bone volume used for grafting. DESIGN: Prospective. SETTING: University hospital. PATIENTS: Patients with UCCLP who underwent alveolar bone grafting. INTERVENTIONS: 23 CBCT images of patients with UCCLP, aged 8.6-22.9 years, were taken. Alveolar cleft volume was measured using Mimics® software. Paired t-test was used to compare volume calculated from two measuring methods. Independent t-test was used to compare the volume between two age groups. Pearson's correlation coefficient was used to assess correlation between two measuring methods. MAIN OUTCOME MEASURES: Paired t-test showed statistically significant difference between two measuring methods. Independent t-test showed statistically significant difference between both measuring methods in both age groups. Differences between two variables in both age groups were not significantly different. Pearson's correlation coefficient indicated significantly positive correlation between presurgical alveolar cleft volume measured by simulation software using CBCT and actual bone volume used for grafting. RESULTS: Mean alveolar cleft volume measured by computer simulation was 1.30 ± 0.40 ml, whereas actual bone volume used for grafting was 1.10 ± 0.39 ml. Mean difference between both measuring methods was 0.20 ± 0.14 ml. Mean alveolar cleft volume measured by simulation software, as well as actual bone volume used for grafting, differ significantly between 2 age groups. CONCLUSIONS: There was significantly positive correlation between two measuring methods. CBCT method overestimated actual bone graft volume. Surgeons may harvest alveolar bone grafts ranging from 82% to 100% of CBCT volume.

Comparison of Preoperative Measurement Methods of Alveolar Cleft Volume Using Cone Beam Computed Tomography between Computer Simulation and Water Displacement Methods.

OBJECTIVE: To compare the use of a computer simulation by Mimics software and the water displacement method as means for measurement of alveolar cleft volume on cone beam computed tomography (CBCT) data. DESIGN: Prospective study. SETTLING: Institutional research. PATIENTS: Patients with unilateral complete cleft lip and palate (UCCLP) who would undergo alveolar bone grafting. INTERVENTIONS: CBCT images of twenty patients with UCCLP were included in the study. In the first method, the water displacement method was adopted to measure volume of plasticine filled in the alveolar cleft imprinted on 3D printed model of maxilla. In the second method a volumetric assessment function in Mimics software was adopted to measure volume of 3D virtual model of alveolar cleft constructed from CBCT images. A comparison on the alveolar cleft volumes derived from the two methods was assessed using the statistical paired t-test. MAIN OUTCOME MEASURE: The paired-t test showed no statistically significant difference between alveolar cleft volumes measured by the two methods (P = 0.075). RESULTS: Mean volume of the alveolar cleft measured by the water displacement method was 1.03 ± 0.31 ml whereas by the computer simulation using Mimics software the value was 1.00 ± 0.31 ml. The mean difference between the two methods was 0.03 ± 0.08 ml. CONCLUSION: The computer simulation by Mimics software as a means for measurement of alveolar cleft volume on CBCT data is as accurate as the measurement by the water displacement method.