Three-Dimensional Printing of Reduction Template in the Contouring of Craniofacial Fibrous Dysplasia

A Novel Bone Contouring Technique Using Multiple Tangential Shaving for Conservative Management of Craniofacial Fibrous Dysplasia

This study aimed to propose a novel surgical technique, named multiple tangential shaving of bone contour, for the conservative management of craniofacial fibrous dysplasia. We retrospectively reviewed 17 patients who underwent conservative management of craniofacial fibrous dysplasia using multiple tangential shaving technique between July 2005 and December 2020. Demographics, tumor characteristics, and surgery-related factors were investigated. All patients underwent preoperative (T0) and postoperative computed tomography scans taken at least twice within 1 month for immediate assessment (T1) and at least 12 months postoperatively for long-term assessment (T2). Clinical outcomes, including tumor recurrence, perioperative complications, and physician measure of esthetic outcomes (Whitaker score), were investigated. This technique was applied for contouring of the zygomatic-maxillary and calvarial bone for patients aged between 16 and 60 years (mean age: 26 y). The mean±SD tumor volume reduction was 15.5±8.95 cm 3 , and the postoperative mean±SD tumor growth rate was 5.52±6.26% per year. Satisfactory outcome was obtained in terms of esthetics with a mean±SD Whitaker score of 1.41±0.62. Patients required a mean operation time of 1.67±0.43 hours and a mean number of shaving operations of 1.35±0.61 during the follow-up period. Five of 17 patients required reoperation because of the tumor recurrence (N=4) and to correct new-onset diplopia after surgery (N=1). In conclusion, the multiple tangential shaving technique allows an easy approach for conservative management of craniofacial fibrous dysplasia. An acceptable rate of tumor recurrence and esthetic outcomes can be obtained by selecting the appropriate candidate for a conservative approach.

Accuracy of the Application of 3-Dimensional Printing Models in Orbital Blowout Fractures-A Preliminary Study

BACKGROUND

Application of 3-dimensional (3D) printing technology has grown in the medical field over the past 2 decades. In managing orbital blowout fractures, 3D printed models can be used as intraoperative navigators and could shorten the operational time by facilitating prebending or shaping of the mesh preoperatively. However, a comparison of the accuracy of computed tomography (CT) images and printed 3D models is lacking.

MATERIAL AND METHODS

This is a single-center retrospective study. Patients with unilateral orbital blowout fracture and signed up for customized 3D printing model were included. Reference points for the 2D distance were defined (intersupraorbital notch distance, transverse horizontal, sagittal vertical, and anteroposterior axes for orbital cavity) and measured directly on 3D printing models and on corresponding CT images. The difference and correlation analysis were conducted.

RESULTS

In total, 9 patients were reviewed from June 2017 to December 2020. The mean difference in the intersupraorbital notch measurement between the 2 modules was -0.14 mm (P = 0.67). The mean difference in the distance measured from the modules in the horizontal, vertical, and anteroposterior axes of the traumatic orbits was 0.06 mm (P = 0.85), -0.23 mm (P = 0.47), and 0.51 mm (P = 0.32), whereas that of the unaffected orbits was 0.16 mm (P = 0.44), 0.34 mm (P = 0.24), and 0.1 mm (P = 0.88), respectively. Although 2D parameter differences (<1 mm) between 3D printing models and CT images were discovered, they were not statistically significant.

CONCLUSIONS

Three-dimensional printing models showed high identity and correlation to CT image. Therefore, personalized models might be a reliable tool of virtual surgery or as a guide in realistic surgical scenarios for orbital blowout fractures.

Augmented reality navigation method for recontouring surgery of craniofacial fibrous dysplasia

The objective of this study is to introduce the application of augmented reality (AR) navigation system developed by the authors in recontouring surgery of craniofacial fibrous dysplasia. Five consecutive patients with craniofacial fibrous dysplasia were enrolled. Through three-dimensional (3D) simulation, a virtual plan was designed to reconstruct the normal anatomical contour of the deformed region. Surgical recontouring was achieved with the assistance of the AR navigation system. The accuracy of the surgical procedure was assessed by superimposing the post-operative 3D craniomaxillofacial model onto the virtual plan. The pre-operative preparation time and operation time were also counted. In all patients, AR navigation was performed successfully, with a mean ± SD of the errors of 1.442 ± 0.234 mm. The operative time of the patients ranged from 60 to 80 min. The pre-operative preparation time was 20 min for each patient. All the patients showed uneventful healing without any complications, in addition to satisfaction with the post-operative aesthetics. Using our AR navigation system in recontouring surgery can provide surgeons with a comprehensive and intuitive view of the recontouring border, as well as the depth, in real time. This method could improve the efficiency and safety of craniofacial fibrous dysplasia recontouring procedures.

A three-dimensional printing navigational template combined with mixed reality technique for localizing pulmonary nodules

OBJECTIVES

Localizing non-palpable pulmonary nodules is challenging for thoracic surgeons. Here, we investigated the accuracy of three-dimensional (3D) printing technology combined with mixed reality (MR) for localizing ground glass opacity-dominant pulmonary nodules.

METHODS

In this single-arm study, we prospectively enrolled patients with small pulmonary nodules (<2 cm) that required accurate localization. A 3D-printing physical navigational template was designed based on the reconstruction of computed tomography images, and a 3D model was generated through the MR glasses. We set the deviation distance as the primary end point for efficacy evaluation. Clinicopathological and surgical data were obtained for further analysis.

RESULTS

Sixteen patients with 17 non-palpable pulmonary nodules were enrolled in this study. Sixteen nodules were localized successfully (16/17; 94.1%) using this novel approach with a median deviation of 9 mm. The mean time required for localization was 25 ± 5.2 min. For the nodules in the upper/middle and lower lobes, the median deviation was 6 mm (range, 0-12.0) and 16 mm (range, 15.0-20.0), respectively. The deviation difference between the groups was significant (Z = -2.957, P = 0.003). The pathological evaluation of resection margins was negative.

CONCLUSIONS

The 3D printing navigational template combined with MR can be a feasible approach for localizing pulmonary nodules.

Three-Dimensional Accuracy of Bone Contouring Surgery for Zygomaticomaxillary Fibrous Dysplasia Using Virtual Planning and Surgical Navigation

PURPOSE

Fibrous dysplasia (FD) is a benign condition in which normal cancellous bone is replaced by immature woven bone and fibrous tissue. The present study aimed to estimate and compare the 3-dimensional (3D) accuracy of bone contouring surgery for zygomaticomaxillary FD performed using virtual planning and surgical navigation versus surgeon's intraoperative assessment.

PATIENTS AND METHODS

This is a retrospective cross-sectional study. Patients with zygomaticomaxillary FD who underwent bone contouring surgery between 2012 and 2019 were reviewed. They were divided into 2 groups: group A underwent bone contouring surgery using virtual planning and surgical navigation, and group B underwent bone contouring surgery by surgeon's intraoperative assessment. The predictor variable was surgical technique. The other variables were gender, age, and operative region. The primary outcome variable was 3D accuracy, which was indicated by root mean square, calculated as a measure of the deviation of the postoperative computed tomography from the preoperative virtual plan. The other outcome variables were patient satisfaction with the outcome by self-evaluation score and operative times. Correlation analysis between the predictor variables and outcome variables was performed.

RESULTS

The sample comprised 24 patients (17 males and 7 females, mean age, 25.7 ± 10.45 years), 13 patients in group A and 11 patients in group B. The mean root mean square was significantly lower in group A than in group B (P = .007). Patient satisfaction with facial symmetry was significantly better in group A (P = .015). Mean operative time was comparable between the 2 groups (P = .918). Surgical technique (P = .011) and operative region (P = .01) were significant influence factors in 3D accuracy of surgery.

CONCLUSIONS

Virtual planning and surgical navigation can significantly improve the 3D accuracy and patient satisfaction of bone contouring surgery for zygomaticomaxillary FD, without prolonging operative time.

Intraoperative Image-Guided Navigation in Craniofacial Surgery: Review and Grading of the Current Literature

INTRODUCTION

Image-guided navigation has existed for nearly 3 decades, but its adoption to craniofacial surgery has been slow. A systematic review of the literature was performed to assess the current status of navigation in craniofacial surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) systematic review of the Medline and Web of Science databases was performed using a series of search terms related to Image-Guided Navigation and Craniofacial Surgery. Titles were then filtered for relevance and abstracts were reviewed for content. Single case reports were excluded as were animal, cadaver, and virtual data. Studies were categorized based on the type of study performed and graded using the Jadad scale and the Newcastle-Ottawa scales, when appropriate.

RESULTS

A total of 2030 titles were returned by our search criteria. Of these, 518 abstracts were reviewed, 208 full papers were evaluated, and 104 manuscripts were ultimately included in the study. A single randomized controlled trial was identified (Jadad score 3), and 12 studies were identified as being case control or case cohort studies (Average Newcastle-Ottawa score 6.8) The most common application of intraoperative surgical navigation cited was orbital surgery (n = 36), followed by maxillary surgery (n = 19). Higher quality studies more commonly pertained to the orbit (6/13), and consistently show improved results.

CONCLUSION

Image guided surgical navigation improves outcomes in orbital reconstruction. Although image guided navigation has promise in many aspects of craniofacial surgery, current literature is lacking and future studies addressing this paucity of data are needed before universal adoption can be recommended.

Three-dimensional printing of facial contour based on preoperative computer simulation and its clinical application

Facial contouring is a complex procedure performed to alter tissue contents and restore facial appearance. However, it is difficult to measure the amount of the tissue volume that is needed. This study demonstrated the use of preoperative computer simulation (PCS) and 3-dimensional (3D) printing in contouring procedure to maximize outcomes.Three-dimensional surface imaging (3DSI) or computed tomography imaging (CTI) data were reconstructed into a 3D model by Mimics software. PCS was performed by simulating the changes in bone and soft tissue. The stimulating volume change was calculated by Boolean operations. Finally, the virtual model was exported into 3D printer to produce physical templates to guide surgical plan. PCS and actual postoperative results were compared using objective rating scales and by cephalometrical measurements.With the direct guidance of PCS and 3D templates, contouring procedure was performed accurately. Satisfactory facial contouring was achieved with less operative time. As the plastic surgery panel rated, 45.8% of the 3DSI results and 41.7% of the CTI results were identical with the actual outcome, and 0% of them was poor. There were no significant differences in patient satisfaction between the PCS of 3DSI and CTI.Preoperative computer simulation is an accurate method for designing contour adjustment plans, and can be an efficient and reliable predictor of outcomes with customized templates.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

HDAC8, A Potential Therapeutic Target, Regulates Proliferation and Differentiation of Bone Marrow Stromal Cells in Fibrous Dysplasia

Fibrous dysplasia (FD) is a disease of postnatal skeletal stem cells caused by activating mutations of guanine nucleotide-binding protein alpha-stimulating activity polypeptide (GNAS). FD is characterized by high proliferation and osteogenesis disorder of bone marrow stromal cells (BMSCs), resulting in bone pain, deformities, and fractures. The cAMP-CREB pathway, which is activated by GNAS mutations, is known to be closely associated with the occurrence of FD. However, so far there is no available targeted therapeutic strategy for FD, as a critical issue that remains largely unknown is how this pathway is involved in FD. Our previous study revealed that histone deacetylase 8 (HDAC8) inhibited the osteogenic differentiation of BMSCs via epigenetic regulation. Here, compared with normal BMSCs, FD BMSCs exhibited significantly high proliferation and weak osteogenic capacity in response to HDAC8 upregulation and tumor protein 53 (TP53) downregulation. Moreover, inhibition of cAMP reduced HDAC8 expression, increased TP53 expression and resulted in the improvement of FD phenotype. Importantly, HDAC8 inhibition prevented cAMP-induced cell phenotype and promoted osteogenesis in nude mice that were implanted with FD BMSCs. Mechanistically, HDAC8 was identified as a transcriptional target gene of CREB1 and its transcription was directly activated by CREB1 in FD BMSCs. In summary, our study reveals that HDAC8 associates with FD phenotype and demonstrates the mechanisms regulated by cAMP-CREB1-HDAC8 pathway. These results provide insights into the molecular regulation of FD pathogenesis, and offer novel clues that small molecule inhibitors targeting HDAC8 are promising clinical treatment for FD. Stem Cells Translational Medicine 2019;8:148&14.

Three-dimensional printing of navigational template in localization of pulmonary nodule: A pilot study

BACKGROUND

Small pulmonary nodules are a common problem, especially with the wide implementation of lung cancer-screening program. This poses a great challenge to thoracic surgeons because of the difficulty of nodule localization. We recently built an efficient, customized navigational template using 3-dimensional (3D) printing technology to facilitate the procedure of lung nodule localization. This study aims to investigate its feasibility in clinical application.

METHODS

Patients with peripheral lung nodules (<2 cm) were enrolled. Preadmission computed tomography images were downloaded and reconstructed into a 3D model. A digital model of the navigational template was designed via computer-aided design software and then exported into 3D printer to produce physical template. The precision of the template-guided nodule localization and associated complications were evaluated.

RESULTS

A total of 16 patients were enrolled, and 18 nodules were localized through template-guided localization. The success rate of lung nodule localization was 100%, and the median time of localization was 13 minutes (range 10-16 minutes). In our series, no significant complication occurred, except for 2 asymptomatic pneumothoraxes. The median deviation between the localizer and the center of the nodule was 10.0 mm, ranging from 5 to 20 mm.

CONCLUSIONS

This novel navigational template created by 3D printing technology is feasible, and it has acceptable accuracy for the application in lung nodule localization. The use of this navigational template could facilitate the procedure of lung nodule localization and may potentially break the dependence of percutaneous localization on computed tomography scanning.