Comparison of 3D Scanner Systems for Craniomaxillofacial Imaging

Two-dimensional photographs are the standard for assessing craniofacial surgery clinical outcomes despite lacking three-dimensional (3D) depth and shape. Therefore, 3D-scanners have been gaining popularity in various fields of plastic and reconstructive surgery, including craniomaxillofacial surgery. Head shapes of eight adult volunteers were acquired with four 3D scanners: 1.5T Avanto MRI, Siemens; 3dMDface System, 3dMD Inc.; M4D Scan, Rodin4D; and Structure Sensor, Occipital Inc. Accuracy was evaluated as percentage of data within a range of 2 mm from the 3DMDface System reconstruction, by surface-to-surface root mean square distances (RMS), and with facial distance maps. Precision was determined with RMS. Relative to the 3dMDface System, accuracy was highest for M4D Scan (90% within 2 mm; RMS of 0.71 mm ± 0.28 mm), then Avanto MRI (86%; 1.11 mm ± 0.33 mm), and Structure Sensor (80%; 1.33 mm ± 0.46). M4D Scan and Structure Sensor precision were 0.50 mm ± 0.04 mm and 0.51 mm ± 0.03 mm. Clinical and technical requirements govern scanner choice, however, 3dMDface System and M4D Scan provide high-quality results. It is foreseeable that compact, hand-held systems become more popular in the near future

A population-specific material model for sagittal craniosynostosis to predict surgical shape outcomes

Sagittal craniosynostosis consists of premature fusion (ossification) of the sagittal suture during infancy, resulting in head deformity and brain growth restriction. Spring-assisted cranioplasty (SAC) entails skull incisions to free the fused suture and insertion of two springs (metallic distractors) to promote cranial reshaping. Although safe and effective, SAC outcomes remain uncertain. We aimed hereby to obtain and validate a skull material model for SAC outcome prediction. Computed tomography data relative to 18 patients were processed to simulate surgical cuts and spring location. A rescaling model for age matching was created using retrospective data and validated. Design of experiments was used to assess the effect of different material property parameters on the model output. Subsequent material optimization—using retrospective clinical spring measurements—was performed for nine patients. A population-derived material model was obtained and applied to the whole population. Results showed that bone Young’s modulus and relaxation modulus had the largest effect on the model predictions: the use of the population-derived material model had a negligible effect on improving the prediction of on-table opening while significantly improved the prediction of spring kinematics at follow-up. The model was validated using on-table 3D scans for nine patients: the predicted head shape approximated within 2 mm the 3D scan model in 80% of the surface points, in 8 out of 9 patients. The accuracy and reliability of the developed computational model of SAC were increased using population data: this tool is now ready for prospective clinical application

Extracraniofacial anomalies in Treacher Collins syndrome: A multicentre study of 248 patients

Treacher Collins syndrome (TCS) is a congenital malformation of the craniofacial structures derived from the first and second pharyngeal arches. The craniofacial deformities are well described in the literature. However, little is known about whether there are associated extracraniofacial anomalies. A retrospective study was conducted using data from four craniofacial units. Medical charts were reviewed for the presence and type of extracraniofacial anomalies, as well as age at diagnosis. A possible correlation between the severity of the phenotype and the presence of e