Technical considerations of computer-aided planning in severe orbital trauma: A retrospective study.

The aim of this study was to evaluate the clinical outcomes of linear and orbital volume measurements in severe orbital trauma. Patients with severe orbital trauma that involved more than two walls and entailed a marked degree of comminution were included in this retrospective analysis. However, patients with incomplete clinical records and a simple blowout or zygmatico-orbital fractures were excluded. All the cases underwent surgical correction guided by virtual surgical planning and 3D-printed templates. The measurement protocol depended on assessing orbital dimensions, orbital volumetry, and the zygomatic bone's position in the three-dimensional planes. All patients' preoperative 3D CT scans were obtained, and DICOM files were imported into a three-dimensional image processing software. Data were then converted for 3D reconstruction in the axial, coronal, and sagittal views. A total of 18 patients with a mean age was 39.28 ± 6.28 were included in this study. The results revealed a significant difference between the pre and postoperative differences in distances in relation to the FHP (Frankfurt Horizontal Plane) (P = 0.0014) and sagittal planes (P < 0.0001). The orbital width and height of the traumatized orbit were significantly decreased from 45.26 ± 6.72 mm and 45.30 ± 2.89 mm to 39.74 ± 3.91 mm (P = 0.0022), and 40.34 ± 0.86 mm (P < 0.0001), respectively. Clinically, there was a satisfactory degree of symmetry regarding the zygomatic bones' position and orbital dimensions postoperatively. Moreover, the mean orbital volume on the traumatized side decreased significantly from 23.16 ± 1.91 cm3 preoperatively to 20.7 ± 1.96 cm3 postoperatively (P < 0.0001). These findings were associated with a low incidence of complications. Within the limitations of the study it seems that the described methodology is a relevant addition to clinical treatment options. It incorporates all the latest technology to plan virtual reconstruction surgery in the treatment of complex orbital trauma and should be adapted accordingly in cases of severe displacement and comminution.

One-Piece Fronto-orbital Distraction With Midline Splitting But Without Bandeau for Metopic Craniosynostosis: Craniometric, Volumetric, and Morphologic Evaluation.

BACKGROUND: Distraction osteogenesis has gained popularity in the treatment of different types of craniosynostosis. We aimed to present the technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau for the treatment of metopic craniosynostosis, and the protocol of outcome evaluation using craniometric, volumetric, and morphologic parameters based on 3-dimensional computer simulation. METHODS: This retrospective study included 9 patients with isolated metopic craniosynostosis who underwent surgical correction with distraction osteogenesis between December 2015 and February 2018. The osteotomy was designed in the form of 1-piece fronto-orbital distraction without separation of the orbital bandeau accompanied by midline splitting osteotomy. This was followed by the application of 2 pairs of cranial distractors to produce anterolateral expansion. The 3-dimensional files from preoperative and postdistraction computed tomographic data were used for the measurement of craniometric, volumetric, and morphologic parameters. RESULTS: The postdistraction craniometric measurement revealed a 12.52% increase in the interfrontal angle. Moreover, there were increases in the bifrontal diameter, diagonal diameters, and interorbital distance. Volumetric measurements revealed an increase in the total cranial volume by 228.1 ± 110.19 cm. The anterior compartmental volume increased by 33.24%. Morphologic evaluation in the form of curvature analysis showed shrinkage of the surface area of abnormal curvature from 29.5 ± 6.71 cm preoperatively to 3.85 ± 3.66 cm after distraction. CONCLUSIONS: The technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau is an effective surgical option for the treatment of metopic craniosynostosis. The postdistraction outcomes demonstrated the correction of various forms of dysmorphology in metopic craniosynostosis.

Evaluation of virtual surgical plan applicability in 3D simulation-guided two-jaw surgery.

BACKGROUND: Three-dimensional (3D) simulation-based orthognathic surgery is becoming a more popular technique. Therefore, standardized methods for evaluating the efficacy and reliability are required. The virtual surgical plan (VSP) applicability, which represents the degree of similarity between planned movements and actual surgical events, should be accurately measured as a separate entity. We present our method of calculating the VSP applicability and investigating the effect of some factors that are suspected to affect this applicability. METHODS: This retrospective study included 35 patients who underwent simulation-guided two-jaw surgery. The absolute differences between actual (Ta) and planned (Tp) travel distance of selected points were used as the absolute misapplication index (abMAI), whereas the ratio of this difference to the overall distance represented the relative form (rMAI). RESULTS: Mean abMAI was 1.11 mm [standard deviation (SD), 1.13] with significant differences (p < 0.001) between the maxilla (mean, 0.82; SD, 0.6 mm) and mandible (mean, 1.7; SD, 1.5). Using rMAI, calculated by ((Ta-Tp)2Ta), we found no significant difference between the mandible and maxilla (p = 0.186). The correlation test of distance revealed no significant correlation with rMAI. Analysis of the factors affecting the applicability showed that the cleft-related deformities were associated with lower applicability than noncleft-related deformities (p = 0.006). CONCLUSION: Thus, rMAI can be used to measure the VSP applicability regardless of the magnitude of the travel distance. Among all the factors studied, cleft-related deformities were found to be associated with lower applicability.