3D Facial Effects of a Simulated Dental Build-up.

OBJECTIVE: The purpose of this study was to evaluate the 3D-stereophotogrammetry technique to detect differences in facial appearance after a simulated rehabilitation. MATERIALS AND METHODS: Eleven volunteers without tooth wear participated. A 3D-stereophotograph was taken in five different situations: resting position, teeth in occlusion, and teeth in occlusion with a 1 mm-, 3 mm- or 5 mm resin block between the first molars. Cephalometric measurements were performed on the 3D-stereophotographs using the software program Maxilim® (Medicim NV Mechelen, Belgium). Four anatomical parameters were analyzed: (1) Subnasale-Gnathion, (2) Subnasale-Stomion, (3) Stomion-Gnathion, and (4) Masseter right-Masseter left. A paired Student's T-test was applied to detect significant differences (p < 0.05). RESULTS: Statistically significant changes in facial appearance of the lower facial height were detected in all measured positions, teeth in occlusion, 1 mm-, 3 mm-, and 5 mm block (p < 0.05). For the main distance (Subnasale-Gnathion) the mean measured differences were, respectively, 3.2 mm; 5.2 mm; and 6.7 mm. CONCLUSIONS: With 3D-stereophotograph imaging technology, it was possible to detect changes in facial appearance after an artificial increase of vertical dimension of occlusion. This finding implies that reconstruction of loss of tooth substance may cause a visible change in facial appearance of the patient. CLINICAL SIGNIFICANCE: This study reveals a new 3D imaging technique that may be used for a better and more comprehensive treatment planning in patients with severe tooth wear. (J Esthet Restor Dent 28:397-404, 2016).

Virtual Incision Pattern Planning using Three-Dimensional Images for Optimization of Syndactyly Surgery.

Syndactyly is a congenital condition characterized by fusion of the fingers. If not treated correctly during infancy, syndactyly may hinder the normal development of hand function. Many surgical techniques have been developed, with the main goal to create a functional hand with the smallest number of operative corrections. Therefore, exact preoperative planning of the reconstructive procedure is essential. An imaging method commonly used for preoperative planning is 3-dimensional (3D) surface imaging. The goal of this study was to implement the use of this technique in hand surgery, by designing a virtual planning tool for a desyndactylization procedure based on 3D hand images. A 3D image of a silicon syndactyly model was made on which the incision pattern was virtually designed. A surgical template of this pattern was printed, placed onto the silicon model and delineated. The accuracy of the transfer from the virtual delineation toward the real delineation was calculated, resulting in a mean difference of 0.82 mm. This first step indicates that by using 3D images, a virtual incision pattern can be created and transferred back onto the patient successfully in an easy and accurate way by using a template. Thereafter, 3D hand images of 3 syndactyly patients were made, and individual virtual incision patterns were created. Each pattern was transferred onto the patient by using a 3D printed template. The resulting incision pattern needed minor modifications by the surgeon before the surgery was performed. Further research and validation are necessary to develop the virtual planning of desyndactylization procedures.

Accuracy of Three Software Applications for Breast Volume Calculations from Three-Dimensional Surface Images.

BACKGROUND: Knowing breast volumes before certain surgeries helps the surgeon to obtain breast symmetry. Calculating breast volumes from three-dimensional surface images is possible with specialized software applications. However, limited data exist concerning the accuracy of such volume calculations. The purpose of this study was to investigate the accuracy of breast volume calculations performed with the 3D BreAST, 3dMD Vultus, and VECTRA software applications. METHODS: Twenty-six subjects who underwent 44 mastectomies were enrolled. Preoperative three-dimensional surface images were acquired with a VECTRA-XT stereophotogrammetry device. Breast volumes were calculated from these images with the three software applications. The mastectomy specimens were weighed to derive their actual volume and compared with the software calculations. RESULTS: For all three methods, a positive correlation between the breast volume and absolute calculation error was found (p < 0.001), but not for the errors as a percentage of the breast volume (p = 0.17, p = 0.80, and p = 0.42). The 3D BreAST, 3dMD Vultus, and VECTRA applications provided mean volume calculation errors of 21, 186, and -32 ml (p = 0.27, p < 0.001, and p = 0.14) or 2 ± 25, 48 ± 26, and -6 ± 27 percent of the breast volume (p = 0.67, p < 0.001, and p = 0.16), respectively. CONCLUSIONS: Despite that two applications calculated accurate mean breast volumes, all applications showed a high standard deviation in terms of the percentage of the breast volume. Therefore, the usefulness of absolute breast volume calculations from three-dimensional surface images seems limited. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.

Single-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction: Technical Note.

OBJECTIVE: Simultaneous tumor resection and cranial reconstruction can be a challenging task. Surgical navigation is an indispensable tool in making this single-step procedure possible. In this technical note, we describe a new technique for this procedure to ensure a precise resection and optimal fit of the implant in a patient with an intraosseous meningioma. METHODS: We generated a 3-dimensional (3D) model of the patient's skull based on a computed tomography scan and created a digital "resection line" object using 3D Studio Max 2016 software. Based on this object, the patient-specific implant was generated and printed with a 3D printer. Before surgery, the digital object was transferred to the neuronavigation system to enable a navigated resection of the lesion to ensure maximum precision. During surgery, the craniotomy was performed, and the custom-made implant was fitted in a single step. RESULTS: The planned resection was achieved, and the implant could be fitted without need for further adjustments to the resection border. CONCLUSIONS: We provide a simple technique to digitally define a planned resection site and create a custom-made implant using specialized software and 3D printing to enable single-step resection of a skull lesion and cranial reconstruction, thereby reducing surgical time and costs and ensuring a good cosmetic result.

3D stereophotogrammetry in upper-extremity lymphedema: An accurate diagnostic method.

BACKGROUND: Upper-extremity lymphedema is a frequent complication in patients treated for breast cancer. Current diagnostic methods for the upper-extremity volume measurements are cumbersome or time consuming. The purpose of this study was to assess the validity and reliability of three-dimensional (3D) stereophotogrammetry for volume measurements in patients with upper-extremity lymphedema. METHOD: Patients with unilateral upper-extremity lymphedema were included. The water displacement volume measurement of both arms was performed using a standardized method. In addition, 3D stereophotogrammetry volume measurements were conducted. RESULTS: Eleven patients (22 arms) were included. The mean volumes obtained by 3D stereophotogrammetry and water displacement show a high correlation, with a Pearson's correlation coefficient of 0.99 (p = 0.01). The variance calculated by 3D stereophotogrammetry measurements (205 mL) was statistically significant less than that obtained via water displacement measurements (1540 mL) (p < 0.001). CONCLUSION: 3D stereophotogrammetry is an accurate method for measuring upper-extremity volume in patients with lymphedema and gives a lower variance value compared to that of the water displacement measurements. We recommend the use of this method in the diagnosis and follow-up of patients with lymphedema.

Accuracy of virtually 3D planned resection templates in mandibular reconstruction.

OBJECTIVE: Since reconstruction of composite defects in the head and neck region is a challenging and demanding problem for head and neck surgeons, surgical aids have been sought for decades. The purpose of this study was to evaluate the accuracy of prefabricated surgical resection templates used in mandibular segmental resections in comparison to the virtual surgical plan. MATERIALS AND METHODS: A prospective study was performed in 11 consecutive patients, with a primary T4 oral squamous cell carcinoma or osteoradionecrosis of the mandible. Preoperatively, a CBCT scan was acquired to delineate the size and extension of tumor invasion; a virtual patient-specific resection template was designed based on this information. Intraoperatively, the resection template was positioned on the mandible and secured using four fixation screws. Postoperatively, a CBCT scan was acquired. This scan was superimposed on the preoperative scan. Positioning of the resection template and inclination of the resection planes were evaluated on the virtual head model. In order to test the interobserver reliability of these new measurement methods, two different observers executed all measurements. RESULTS: The mean shift of the proximal resection templates was 3.76 mm (standard deviation [SD] 3.10 mm). For the distal resection templates, the mean shift was 3.06 mm (SD 1.57 mm) with no significant interobserver difference (ICC = 0.99). An absolute mean deviation of 8.5° (SD 5.3°) was found for the proximal resection angle and 10.4° (SD 5.0°) for the distal resection angle. Again, no significant interobserver differences were found (ICC = 0.98). CONCLUSION: The resection templates used in this study proved reasonably accurate. Although the concept of virtual surgical planning aids significantly in mandibular reconstruction with microvascular free flaps, further improvement of resection accuracy is necessary for further improvement of reconstruction accuracy.