Virtual planning of composite mandibular reconstruction with free fibula bone graft

The Emerging Role of Three-dimensional Technologies in Orthoplastic Surgery

Three-dimensional (3D) planning and manufacturing technologies have become integral to head and neck reconstruction following tumor resection. These technologies facilitate the prototyping of patient-specific solutions in both digital and physical form. Three-dimensional tumor models and cutting guides help conceptualize and verify the surgical approach, as well as serve as a blueprint for reconstruction. Computer-aided renderings have been shown to add precision to bony contouring to achieve functional and aesthetic goals following tumor resection, such as in mastication, oral competence, speech, and symmetric facial aesthetics. Three-dimensional technologies have also been introduced in orthopedic oncology, making limb-salvage surgery the mainstay of treatment in cases where amputation was historically required. The advent of customized 3D cutting guides and plates allows surgeons to spare surrounding healthy tissue, markedly enhancing postoperative quality of life and significantly reducing associated morbidities. Borrowing from these applications of 3D planning and modeling, our institution has recently implemented these technologies for the reconstructive planning of soft tissue defects following sarcoma resection. Here we present a series of cases that demonstrate the workflow and clinical outcomes associated with the utilization of 3D planning techniques in orthoplastic surgery.

The Implant-borne Articulation Splint in Fibula Free Flap Mandibular Reconstruction: A Technical Note

Computer-aided design and computer-aided manufacturing and digitally simulated surgeries have revolutionized maxillomandibular reconstruction. In particular, this technology has increased the accuracy and facilitated the process of dental implantation in fibula free flaps. Despite the efficacy of virtual planning, there is a minor degree of translational difference between digital and intraoperative measurements, which may affect the precision of implant and fibula orientations. This is especially concerning during the last stage of fibula insetting, where the graft segments have the potential to roll, yaw, or pitch. The objective of this study is to describe an advanced prosthodontic technique that ensures the fibula grafts and implants remain in a restorable position during final insetting. We describe the technique and workflow of the implant-borne articulation splint through a case presentation and demonstrate results at 4 months postoperative and postradiotherapy. Given the degree of investment placed in virtual planning, free flap reconstruction, and endosteal implants, a technique that ensures optimal restorability of each implant is pivotal. Larger studies are still required to fully elucidate the cost-effectiveness and long-term results of the implant-borne articulation splint.

Live Virtual Surgery and Virtual Reality in Surgery: Potential Applications in Hand Surgery Education

Accelerated in part by the coronavirus disease 2019 pandemic, medical education has increasingly moved into the virtual sphere in recent years. Virtual surgical education encompasses several domains, including live virtual surgery and virtual and augmented reality. These technologies range in complexity from streaming audio and video of surgeries in real-time to fully immersive virtual simulations of surgery. This article reviews the current use of virtual surgical education and its possible applications in hand surgery. Applications of virtual technologies for preoperative planning and intraoperative guidance, as well as care in underresourced settings, are discussed. The authors describe their experience creating a virtual surgery subinternship with live virtual surgeries. There are many roles virtual technology can have in surgery, and this review explores potential value these technologies may have in hand surgery.

Analysis of intraoral microvascular anastomosis in maxillofacial defects reconstruction

This review summarizes the research progress in the field of intraoral microvascular anastomosis techniques (IAT) and attempts to investigate the indications for procedures in which IAT can be applied, the surgical procedure and the difficulties involved, technical assessments, result evaluation and the perspective. Currently, microvascular anastomosis technique is widely used in maxillofacial defects reconstruction from various causes including cutaneous injury or congenital deformity which usually required extensive flap reconstruction and therefore a vascular free flap is routinely used. Conventional microvascular anastomosis reconstruction techniques cannot avoid new incisions, which will affect the postoperative aesthetic situation. Surgeons have therefore attempted to improve this technique to effectively eliminate scars caused by surgery: some patients can be chosen to undergo microvascular anastomosis of the free flap intraorally, thus reducing the extraoral incision caused by the anastomosis located in neck or maxillofacial improving the postoperative appearance of the patients. In addition to preserving the external appearance, intraoral anastomosis technique (IAT) can also solve some other problems of maxillofacial vascular anastomosis, such as insufficient vessel pedicle length and high risk of facial nerve injury.

Patient-Specific 3D-Printed Miniplates for Free Flap Fixation at the Mandible: A Feasibility Study

Background

This study was conducted to evaluate the feasibility, clinical outcomes, and accuracy of patient-specific 3D-printed miniplates for mandible reconstruction with fibula free flaps.

Methods

A feasibility study was conducted with 8 patients. Following virtual planning, patient-specific 1.0 mm titanium non-locking miniplates were produced via laser selective melting. 3D-printed cutting and drilling guides were used for segmental mandible resection and flap harvesting. Flap fixation was performed with two 4-hole miniplates and 2.0 mm non-locking screws (screw length 7 mm) for each intersegmental gap. Clinical follow-up was at least 6 months. Preoperative and postoperative CT/cone beam CT data were used for 3D accuracy analysis and evaluation of bone healing. Plate-related complications were monitored clinically.

Results

Patient-specific miniplate fixation of all flaps was successfully conducted (4 mono-segmental, 4 dual-segmental) with high accuracy (3.64 ± 1.18 mm) between the virtual plan and postoperative result. No technical complications were encountered intraoperatively. Osseous union occurred in all intersegmental gaps (1 partial, 18 complete) after 10 ± 2 months. No material fracture, dislocation, or plate exposure was observed.

Conclusions

Based on this pilot observational study including a limited number of patients, free flap fixation for mandibular reconstruction with patient-specific 3D-printed miniplates is feasible and associated with high accuracy, bone healing, and remote soft tissue complications.

Impact of Periosteal Branches and Septo-Cutaneous Perforators on Free Fibula Flap Outcome: A Retrospective Analysis of Computed Tomography Angiography Scans in Virtual Surgical Planning

BACKGROUND

Virtual surgical planning (VSP) for jaw reconstruction with free fibula flap (FFF) became a routine procedure and requires computed tomography angiography (CTA) for preoperative evaluation of the lower limbs vascular system and the bone. The aim of the study was to assess whether the distribution and density of periosteal branches (PB) and septo-cutaneous perforators (SCP) of the fibular artery have an impact on flap success.

METHOD

This retrospective clinical study assessed preoperative CTA of the infra-popliteal vasculature and the small vessel system of 72 patients who underwent FFF surgery. Surgical outcome of flap transfer includes wound healing, subtotal, and total flap loss were matched with the segmental vascular supply.

RESULT

A total of 72 patients (28 females, 38.9 %; 44 males, 61.1 %) fulfilled the study inclusion criteria. The mean age was 58.5 (± 15.3 years). Stenoses of the lower limbs' vessel (n = 14) were mostly detected in the fibular artery (n = 11). Flap success was recorded in n = 59 (82.0%), partial flap failure in n = 4 (5.5%) and total flap loss in n = 9 (12.5%). The study found a mean number (± SD) of 2.53 ± 1.60 PBs and 1.39 ± 1.03 SCPs of the FA at the donor-site. The proximal FFF segment of poly-segmental jaw reconstruction showed a higher rate of PB per flap segment than in the distal segments. Based on the total number of prepared segments (n = 121), 46.7% (n = 7) of mono-, 40.4% (n = 21) of bi-, and 31.5 % (n = 17) of tri-segmental fibula flaps were at least supplied by one PB in the success group. Overall, this corresponds to 37.2% (45 out of 121) of all successful FFF. For total flap loss (n = 14), a relative number of 42.9% (n = 6) of distinct supplied segments was recorded. Wound healing disorder of the donor site was not statistically significant influenced by the detected rate of SCP.

CONCLUSION

In general, a correlation between higher rates of PB and SCP and the flap success could not be statistically proved by the study sample. We conclude, that preoperative PB and SCP mapping based on routine CTA imaging is not suitable for prediction of flap outcome.

Comparison of the Accuracy and Clinical Parameters of Patient-Specific and Conventionally Bended Plates for Mandibular Reconstruction

Objectives

This retrospective study compared two mandibular reconstruction procedures-conventional reconstruction plates (CR) and patient-specific implants (PSI)-and evaluated their accuracy of reconstruction and clinical outcome.

Methods

Overall, 94 patients had undergone mandibular reconstruction with CR (n = 48) and PSI (n = 46). Six detectable and replicable anatomical reference points, identified via computer tomography, were used for defining the mandibular dimensions. The accuracy of reconstruction was assessed using pre- and postoperative differences.

Results

In the CR group, the largest difference was at the lateral point of the condyle mandibulae (D2) -1.56 mm (SD = 3.8). In the PSI group, the largest difference between preoperative and postoperative measurement was shown at the processus coronoid (D5) with +1.86 mm (SD = 6.0). Significant differences within the groups in pre- and postoperative measurements were identified at the gonion (D6) [t(56) = -2.217; p = .031 <.05]. In the CR group, the difference was 1.5 (SD = 3.9) and in the PSI group -1.04 (SD = 4.9). CR did not demonstrate a higher risk of plate fractures and post-operative complications compared to PSI.

Conclusion

For reconstructing mandibular defects, CR and PSI are eligible. In each case, the advantages and disadvantages of these approaches must be assessed. The functional and esthetic outcome of mandibular reconstruction significantly improves with the experience of the surgeon in conducting microvascular grafts and familiarity with computer-assisted surgery. Interoperator variability can be reduced, and training of younger surgeons involved in planning can be reaching better outcomes in the future.

Advances in the Resection and Reconstruction of Midfacial Tumors Through Computer Assisted Surgery

Curatively intended oncologic surgery is based on a residual-free tumor excision. Since decades, the surgeon’s goal of R0-resection has led to radical resections in the anatomical region of the midface because of the three-dimensionally complex anatomy where aesthetically and functionally crucial structures are in close relation. In some cases, this implied aggressive overtreatment with loss of the eye globe. In contrast, undertreatment followed by repeated re-resections can also not be an option. Therefore, the evaluation of the true three-dimensional tumor extent and the intraoperative availability of this information seem critical for a precise, yet substance-sparing tumor removal. Computer assisted surgery (CAS) can provide the framework in this context. The present study evaluated the beneficial use of CAS in the treatment of midfacial tumors with special regard to tumor resection and reconstruction. Therefore, 60 patients diagnosed with a malignancy of the upper jaw has been treated, 31 with the use of CAS and 29 conventionally. Comparison of the two groups showed a higher rate of residual-free resections in cases of CAS application. Furthermore, we demonstrate the use of navigated specimen taking called tumor mapping. This procedure enables the transparent, yet precise documentation of three-dimensional tumor borders which paves the way to a more feasible interdisciplinary exchange leading e.g. to a much more focused radiation therapy. Moreover, we evaluated the possibilities of primary midface reconstructions seizing CAS, especially in cases of infiltrated orbital floors. These cases needed reduction of intra-orbital volume due to the tissue loss after resection which could be precisely achieved by CAS. These benefits of CAS in midface reconstruction found expression in positive changes in quality of life. The present work was able to demonstrate that the area of oncological surgery of the midface is a prime example of interface optimization based on the sensible use of computer assistance. The fact that the system makes the patient transparent for the surgeon and the procedure controllable facilitates a more precise and safer treatment oriented to a better outcome.

Application of Three-Dimensional Printed Customized Surgical Plates for Mandibular Reconstruction: Report of Consecutive Cases and Long-Term Postoperative Evaluation

ABSTRACT

This study aims to evaluate the use of customized surgical plates in patients with mandibular defects concerning postoperative aesthetics and functional outcomes during the 2-year follow-up. Preoperative virtual surgical plans and patient-specific three-dimensional printed plates were tailored for consecutive patients. Preoperative preparation, surgical produces, postoperative aesthetics, and functional outcomes were described in detail. The average follow-up period was over 2 years. In the presented clinical cases, aesthetic and functional outcomes were reported to be satisfactory.

Using Black Bone Magnetic Resonance Imaging for Fibula Free Flap Surgical Planning: A Means to Reduce Radiation Exposure with Accurate Surgical Outcomes

SUMMARY

Advances in virtual surgical planning and three-dimensionally-printed guides have enabled increased precision in vascularized free fibula flap reconstruction of the mandible and valuable preoperative planning. However, virtual surgical planning currently requires high-resolution computed tomographic scans, exposing patients to ionizing radiation. The aim of this study was to determine whether black bone magnetic resonance imaging can be used for accurate surgical planning and three-dimensionally-printed guide creation, thus reducing patient radiation exposure. This study included 10 cadaver heads and 10 cadaver lower extremities. A mock fibula free flap for mandible reconstruction was performed. Five operations were planned with guides created using black bone magnetic resonance imaging, whereas the other five were planned and performed using guides created with computed tomographic scan data. All specimens underwent a postoperative computed tomographic scan, and three-dimensional reconstruction of scans was performed and surgical accuracy to the planned surgery was assessed. Guides created from black bone magnetic resonance imaging demonstrated high accuracy to the surgical plan. There was no statistically significant difference in postoperative deviation from the plan when black bone magnetic resonance imaging versus computed tomographic scanning was used for virtual surgical planning and guide creation. Both modalities led to a postoperative positive or negative deviation from the virtual plan within 0.8 mm. This study demonstrates that virtual surgical planning and three-dimensionally-printed guide creation for free fibula flaps for mandible reconstruction can be performed using black bone magnetic resonance imaging with comparable accuracy to computed tomographic scanning. This could reduce radiation exposure for patients and enable a more streamlined imaging process for head and neck cancer patients.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation.

SUMMARY

Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Formulating an Easy, Affordable, and Reproducible Method for Virtual Planning and 3D Reconstruction: A State Institution's Approach for Mandibular Reconstruction

INTRODUCTION

Free fibula flap is now regarded as the criterion standard for mandibular reconstruction after oncological resection. However, the results are often confounded due to inappropriate estimate of defect or inappropriate angulation of osteotomy. Three-dimensional (3D) printing and virtual planning can be an effective tool to help in planning osteotomies, therefore simplifying the process. Unfortunately, in developing countries, it is considered to be an expensive and a time-consuming affair, refraining the surgeons to use this technology. We have devised a cheap (less than $35), rapid, and reproducible method for this process that can be performed by residents with the help of the operating surgeon using a freely available software.

MATERIALS AND METHODS

The study was conducted over a span of 5 years from 2016 to 2020. Forty patients were randomly categorized into 2 groups of 20 each, one of which underwent conventional free fibula flap and the other group consisted of those for whom 3D printing and virtual planning were used. Aesthetic outcome was measured by preoperative and postoperative CT scans with 3D reconstruction. Furthermore, the reconstruction time and total operative time were also measured in both these groups.

RESULTS

Comparative study clearly demonstrated a significantly better aesthetic outcome in the 3D printing and virtual planning group. The use of this modality significantly reduced the reconstruction time, which was 83.9 minutes in the cases group and 124 minutes in the control group.

CONCLUSIONS

Three-dimensional printing and virtual planning help to improve the quality of mandibular reconstruction giving a better aesthetic outcome. Besides, it also reduces the operative time and gives us a chance to use prebent implants used for reconstruction. Our methodology is simple, quick, and cost-effective; therefore, we believe that this tool can be incorporated often in free fibula flaps for mandibular reconstruction in developing countries such as ours.

Multicentre evaluation of the interest in planned surgery for mandibular reconstruction with fibula free flap: a retrospective cohort study

PURPOSE

The aim of this study was to determine the impact and cost-effectiveness of virtual surgical planning during fibula free flap mandibular reconstruction on peri- and postoperative data.

METHODS

We conducted a retrospective cohort study from January 2012 to December 2016 in four French university centres.

RESULTS

Three hundred fibula free flaps for mandibular reconstruction were performed in 294 patients. Surgeries were planned in 29.7% of cases (n = 89). There was no significant difference in the rate of negative-margins excision, median length of hospital stay, operative time, and early complications between planned and non-planned surgeries. Morphological analysis revealed a higher rate of centred occlusion in planned patients (satisfactory alignment of interincisal points: Planned 65.5% vs Non-Planned 33.3%, p = 0.006).

CONCLUSION

In mandibular reconstruction by fibula free flap, the additional cost generated by virtual surgical planning does not seem to be balanced by savings resulting from a shorter operative course, a reduced hospital stay, or a reduction in postoperative complications. However, virtual surgical planning may provide a higher rate of centred occlusion. Long-term benefits should be assessed by further studies.

Trends in Utilization of Virtual Surgical Planning in Pediatric Craniofacial Surgery

INTRODUCTION

While the use of virtual surgical planning (VSP) has been well described in the adult craniofacial literature, there has been little written about pediatric uses or trends. The purpose of this study is to evaluate the evolving utilization of VSP for pediatric craniofacial procedures.

METHODS

The authors' prospective institutional review board-approved craniofacial registry was queried for index craniofacial procedures from January 2011 through December 2018. Data was collected regarding utilization of traditional surgical planning versus VSP, as well as the extent of VSP's influence on the operative procedure. These data were analyzed for trends over time and compared using appropriate statistics.

RESULTS

During the study period, a total of 1131 index craniofacial cases were performed, of which 160 cases (14.1%) utilized VSP. Utilization of VSP collectively increased over time, from 2.0% in 2011 to 18.6% in 2018 (P < 0.001). Utilization rates of VSP varied across procedures from 0% of craniosynostosis cases and fronto-orbital advancement cases to 67% of osteocutaneous free tissue transfers (P < 0.001). The most profound contributor to increase in VSP utilization was orthognathic surgery, utilized in 0% of orthognathic procedures in 2011 to 68.3% of orthognathic procedures in 2018 (P < 0.001).

CONCLUSIONS

Utilization of virtual surgical planning for pediatric craniofacial procedures is increasing, especially for complex orthognathic procedures and osteocutaneous free tissue transfers. Utilization patterns of individual components of the VSP system demonstrate unique footprints across the spectrum of craniofacial procedures, which reinforces the specific and variable benefits of this workflow for treating pediatric craniofacial disorders.

CAD-CAM vs conventional technique for mandibular reconstruction with free fibula flap: A comparison of outcomes

INTRODUCTION

Mandibular reconstruction always pose a challenge to the reconstructive surgeon. With the use of Computer aided designing and computer aided manufacturing (CAD-CAM) it is now possible to reconstruct mandibular defects to near normal configuration with good function and aesthetic outcomes.

AIMS/OBJECTIVES

To compare the efficacy of CAD-CAM technique vs conventional technique in mandibular reconstruction with free fibula flap.

MATERIALS AND METHODS

40 consecutive patients that required mandibular reconstruction using free fibula flap were included in the study. All patients were treated using CAD-CAM technique and then compared retrospectively with 40 patients treated with conventional technique. Comparison was done between total intraoperative time, aesthetic outcome and post-operative occlusion.

RESULTS

Total intraoperative time in the CAD-CAM group was significantly reduced (562 min) as compared to the conventional group (662 min). Patients in the CAD-CAM group also obtained a better Aesthetic score (3.6/5) when compared to the conventional group (2.5/5). Postoperative malocclusion was noted in 1 patient in the CAD-CAM group as opposed to 6 patients in the conventional group.

CONCLUSION

Use of CAD-CAM technology in mandibular reconstruction with free fibula flap offers reduced surgical time with precise and accurate reconstruction that produces better functional and aesthetic outcomes.

Evaluation of Effective Condyle Positioning Assisted by 3D Surgical Guide in Mandibular Reconstruction Using Osteocutaneous Free Flap

In the present study, the reproducibility and postoperative stability of a 3D printed surgical guide were evaluated in mandibular reconstruction with an osteocutaneous free flap (OCFF), including a fibular free flap (FFF) and deep circumflex iliac artery free flap (DCIA). Fifteen patients were enrolled, and a 3D surgical guide was fabricated by simulation surgery using preoperative (T0) Computed tomography (CT) images. Mandibular reconstruction was performed with OCFF using the 3D surgical guide. Postoperative CTs were taken immediately, 1 week (T1), and 6 months (T2) after surgery, to evaluate the reproducibility of the 3D surgical guide and condyle stability. Error of the 3D surgical guide ranged from 0.85 to 2.56 mm. There were no differences in reproducibility according to flap type. Condylar error and error at mandible midpoint were significantly different in FFF. However, there was no difference in DCIA error between the condyle and mandible midpoint. Regarding condyle stability 6 months after surgery, condyles moved more than 2 mm (up to 2.85 mm) in FFF, whereas there were no significant movement in DCIA. Careful intraoperative flap fixation and closed postoperative observation should be considered for stable clinical outcome, especially in the case of FFF.

Computer-aided Design and Syringe-aided Manufacturing for Mandibular Reconstruction Using a Vascularized Fibula Flap

Thanks to the introduction of virtual surgical planning (VSP), mandibular reconstruction using a fibula flap has become simplified, and patient-specific reconstruction is now possible. With a VSP software, surgical "cutting guides" and custom-made titanium plates can be designed to help surgeons. However, they are expensive and require extended periods of time either for prototyping or to acquire the advanced knowledge necessary for operating the VSP software. The aim of this article is to introduce a new easy and low-cost method of surgical planning for mandible reconstruction using a computer-aided design and the syringe-aided manufacturing technique. Simulations of fibula osteotomy are performed using regular and commercially available 10-ml syringes. The syringes are cut into separate segments to fit the defect of the 3-dimensional mandible model and to match the prebent titanium plate. The syringe segments are then connected together 3-dimensionally to confirm that the shape matched both the contour of the defect and the angles of the mandible. The simulated syringe segments are used as cutting guides. Then osteotomies are performed according to the cutting guide to obtain the exact lengths and angles required to achieve precise bony reconstruction. The mandibular reconstruction procedures are successful, with a good match between the preoperative planned syringe models and the final results of the surgery. Although further clinical investigation will be required to confirm its efficacy, the computer-aided design and the syringe-aided manufacturing method has the potential to be a useful technique for mandible reconstruction using a vascularized fibula flap.

Assessing the Role of Virtual Surgical Planning in Mandibular Reconstruction With Free Fibula Osteocutaneous Graft

BACKGROUND

The role of virtual surgical planning and three-dimensional printing in improving the accuracy, precision, functional and aesthetic outcomes have been demonstrated in the literature; however, there is a dearth of studies evaluating these parameters.

OBJECTIVE

This study was carried out at a tertiary care center in North India to assess the accuracy of virtual surgical planning in mandibular reconstruction.

METHOD

All the included patients were preoperatively assessed with a contrast enhanced computed tomography (CECT) of head and neck. Based on the dimensions a patient-specific fibula cutting guide was fabricated by three-dimensional printing. All patients were evaluated with a postoperative CECT at 6 months of follow-up. The precision outcomes were measured by comparing surgical results with the images of the preoperative virtual planning based on several measurements on the reconstructed mandible such as anteroposterior measurement, transverse measurement, height of the mandible, angle of the mandible, and lateral tilt.The secondary outcomes analyzed were the mean total operative time, mean ischemia time, and morbidity parameters.

RESULT

Twelve consecutive patients (6 male, 6 female) with mean age of 33.1 ± 11 years who underwent free fibula graft mandibular reconstruction were included in the study. The mean difference in the anteroposterior, transverse, and height dimensions were 0.87 ± 0.43 mm (P = 0.24), 2.43 ± 3.72 mm (P = 0.64), and 1.08 ± 0.67 (P = 0.88), respectively. The difference in the angles of the reconstructed mandible was 2.37 ± 3.92 degrees (P = 0.51) and of lateral tilt was 1.57 ± 1.5 degrees (P = 0.54). The mean total operative time was 639 ± 27.2 minutes and mean ischemia time was 88.4 ± 8.6 minutes.

CONCLUSION

All the patients had satisfactory aesthetic results and good oral function at 6 months postoperative period.

The New Frontier: A Review of Augmented Reality and Virtual Reality in Plastic Surgery

Mixed reality, a blending of the physical and digital worlds, can enhance the surgical experience, leading to greater precision, efficiency, and improved outcomes. Various studies across different disciplines have reported encouraging results using mixed reality technologies, such as augmented and virtual reality. To provide a better understanding of the applications and limitations of this technology in plastic surgery, we performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The initial query of the National Center for Biotechnology Information database yielded 2544 results, and only 46 articles met our inclusion criteria. The majority of studies were in the field of craniofacial surgery, and uses of mixed reality included preoperative planning, intraoperative guides, and education of surgical trainees. A deeper understanding of mixed reality technologies may promote its integration and also help inspire new and creative applications in healthcare.

Navigation-guided fibula free flap for mandibular reconstruction: A proof of concept study

OBJECTIVE

To analyze a novel technique of supporting fibula free flap harvest and fabrication with intraoperative navigation technology.

MATERIALS AND METHODS

In the first phase of the study, navigation accuracy achieved with two registration methods, namely, point-pair and hybrid technique utilizing point-pair with surface matching, were evaluated in the form of the fiducial (FRE) and target registration error (TRE). Next, a series of 42 simulated navigated fibular osteotomies were conducted on specially manufactured lower leg phantom. Postoperative results were analyzed in the form of the angular and position deviations between the virtually planned and the obtained osteotomies.

RESULTS

Mean FRE values obtained with point-pair and hybrid registration methods were 1.82 ± 0.96 mm and 1.41 ± 0.44 mm, respectively. Mean TRE value in the fibula region was 2.00 ± 0.67 mm for the first method and 1.51 ± 0.72 mm for the second. For all performed surgeries, the total mean angular deviation between the planned and actual osteotomy trajectory equaled 3.66° ± 3.60°. The total mean position disparity of osteotomy control points was 1.85 ± 0.99 mm.

CONCLUSIONS

Navigation-guided free fibula flap harvest and fabrication, due to encouraging study results and its superiority over currently popular cutting guides in many clinical aspects, may become a routine operative procedure for the reconstruction of complex mandibular defects. The presented method is especially well suited for plastic and maxillofacial surgery.

The use of vascularized fibula flap in mandibular reconstruction; A comprehensive systematic review and meta-analysis of the observational studies

BACKGROUND

Vascularized fibular flaps are considered the gold standard for the reconstruction of segmental defects in the mandible. This review compares the complication and success rates of these techniques between primary and secondary reconstruction, as well as between lateral and antero-lateral defects.

TYPE OF STUDIES REVIEWED

A systematic review and meta-analysis were conducted according to PRISMA protocol and the Cochrane Handbook for Systematic Reviews of Interventions. The authors performed an independent comprehensive search using PubMed, Ovid MEDLINE, Web of Science, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and COS Conference Papers Index according to established inclusion and exclusion criteria. The methodological index for nonrandomized studies (MINORS) was used to assess the quality of the included studies. Meta-analysis was conducted to compare the type of reconstruction and location of the defect.

RESULTS

Seventy-eight studies, involving 2461 patients, were eligible. 83.7% of the included patient received primary reconstruction with vascularized fibular flap. The overall flap success rate was 93%. There was improvement in MINORS quality score over time with positive correlation with the publication year (r = 0.5549, P < 0.0001, CI 0.3693 to 0.6979). Meta-analysis indicated no significant association in flap success between primary and secondary reconstruction, or lateral and antero-lateral defects.

CONCLUSION

Based on the available studies, this review found no evidence of difference in success or complication rates between primary and secondary reconstruction or between lateral and anterolateral defects. High-quality clinical studies are required to analyze the outcome of these techniques, especially regarding the impact of chemotherapy, radiation therapy, implant-supported dental prostheses, and preoperative planning, on the outcome of reconstruction.

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.

[Virtual surgical planning and intraoperative navigation for mandibular reconstruction: from accurate to minimal invasive]

Simultaneous restoration of function and appearance should be performed in mandibular reconstruction. Option of reconstructive techniques is determined by cause, location, extent, and classification of the mandibular defects. Vascularize bone graft is one of the most popular technique in current clinical practice of mandibular reconstruction. Fibula is the most common donor site for mandibular reconstruction. The disadvantage of low height of neo-mandible reconstructed by single fibular segment can be solved by vascularized double barrel fibula graft. Using virtual surgical planning and intraoperative navigation for mandibular reconstruction leads to simplify surgical procedure, reduce operating time and injury, and decrease donor site morbidity so that accurate mandibular reconstruction could be completed. Direction of minimal invasive surgery for mandibular reconstruction will be developed by intraoral approach and intraoral anastomosis.

Immediate mandibular reconstruction via patient-specific titanium mesh tray using electron beam melting/CAD/rapid prototyping techniques: One-year follow-up

BACKGROUND

Immediate mandibular reconstruction was performed using a patient-specific titanium mesh tray fabricated by electron beam melting (EBM) /rapid prototyping techniques.

METHODS

Patient-specific titanium trays were virtually designed and fabricated using EBM technology/rapid prototyping for patients requiring mandibular resection and immediate reconstruction using an iliac crest bone graft. Dental implants were placed in the grafted sites and the patients received prosthetic rehabilitation with a follow-up of one year. Clinical data, postoperative bone formation and complications were evaluated.

RESULTS

A symmetric appearance of facial contours was achieved. The titanium tray incorporated the particulate iliac crest bone graft that provided significant bone formation (mean 18.97 ± 1.45 mm) and predictable results. Stability of the dental implants was achieved.

CONCLUSION

The patient-specific titanium meshes and immediate particulate autogenous bone graft showed satisfactory clinical and surgical results in improving patients' quality of life and decreasing the overall treatment time with adequate functional rehabilitation.

3D printed models in mandibular reconstruction with bony free flaps

The aim of the study was to compare two types of mandible reconstructive operations with scapula and fibula free flaps: procedures with 3-D models from thermoplastic materials and conventional planning surgeries. 8 patients were treated due to an advanced oral cavity squamous cell carcinoma. In four patients with a mandibular defect, a physical 3-D model consisting of the reconstructed and unaffected sites was prepared for a reconstruction protocol. The 3-D models were designed based to high resolution CT scans. Assessment of comparative functionality (stability of junction, mobility, mastication ability) and cosmetics was examined in both groups, following a 8 weeks healing period with better results in group with 3D model. 3-D models for mandible and donor bones allow to obtain better functionality of restored mandible in comparison to the traditional method also significantly decreases time of the operation and allows to achieve the desired shape and esthetic effect within the 1/3 of the lower face.

Virtual Surgical Planning: The Pearls and Pitfalls

Objective

Over the past few years, virtual surgical planning (VSP) has evolved into a useful tool for the craniofacial surgeon. Virtual planning and computer-aided design and manufacturing (CAD/CAM) may assist in orthognathic, cranio-orbital, traumatic, and microsurgery of the craniofacial skeleton. Despite its increasing popularity, little emphasis has been placed on the learning curve.

Methods

A retrospective analysis of consecutive virtual surgeries was done from July 2012 to October 2016 at the University of Montreal Teaching Hospitals. Orthognathic surgeries and free vascularized bone flap surgeries were included in the analysis.

Results

Fifty-four virtual surgeries were done in the time period analyzed. Forty-six orthognathic surgeries and 8 free bone transfers were done. An analysis of errors was done. Eighty-five percentage of the orthognathic virtual plans were adhered to completely, 4% of the plans were abandoned, and 11% were partially adhered to. Seventy-five percentage of the virtual surgeries for free tissue transfers were adhered to, whereas 25% were partially adhered to. The reasons for abandoning the plans were (1) poor communication between surgeon and engineer, (2) poor appreciation for condyle placement on preoperative scans, (3) soft-tissue impedance to bony movement, (4) rapid tumor progression, (5) poor preoperative assessment of anatomy.

Conclusion

Virtual surgical planning is a useful tool for craniofacial surgery but has inherent issues that the surgeon must be aware of. With time and experience, these surgical plans can be used as powerful adjuvants to good clinical judgement.

[Estimated error of bone digital solid 3D-model construction algorithm]

The aim of the study was an experimental estimation of precision of maxilla bone digital solid 3D-model construction algorithm. The experiment was carried out on 12 mutton mandibles used 3D-model construction based on CT data. Estimated error was calculated for each of the stages of proposed processing algorithm including 3 software: ScanIP (triangle mesh calculation, primary solid 3D-model), ArtecStudio 9 (secondary procession for artefacts elimination), ZBrush 4R6 (triangle mesh simplification, final 3D-model). The proposed algorithm provides satisfactory precision for solid 3D-model with individual maxillary bone features.

Low-cost Method for Obtaining Medical Rapid Prototyping Using Desktop 3D printing: A Novel Technique for Mandibular Reconstruction Planning

BACKGROUND

Three-dimensional (3D) printing is relatively a new technology with clinical applications, which enable us to create rapid accurate prototype of the selected anatomic region, making it possible to plan complex surgery and pre-bend hardware for individual surgical cases. This study aimed to express our experience with the use of medical rapid prototype (MRP) of the maxillofacial region created by desktop 3D printer and its application in maxillofacial reconstructive surgeries.

MATERIAL AND METHODS

Three patients with benign mandible tumors were included in this study after obtaining informed consent. All patient's maxillofacial CT scan data was processed by segmentation and isolation software and mandible MRP was printed using our desktop 3D printer. These models were used for preoperative surgical planning and prebending of the reconstruction plate.

CONCLUSIONS

MRP created by desktop 3D printer is a cost-efficient, quick and easily produced appliance for the planning of reconstructive surgery. It can contribute in patient orientation and helping them in a better understanding of their condition and proposed surgical treatment. It helps surgeons for pre-operative planning in the resection or reconstruction cases and represent an excellent tool in academic setting for residents training. The pre-bended reconstruction plate based on MRP, resulted in decreased surgery time, cost and anesthesia risks on the patients. Key words:3D printing, medical modeling, rapid prototype, mandibular reconstruction, ameloblastoma.

Mandibular Rami Implant: A New Approach in Mandibular Reconstruction

PURPOSE

The mandible is an essential esthetic and functional component of the lower third of the face and its reconstruction has always been a challenge, especially after severe post-traumatic injuries. The purpose of the present report was to introduce a new approach of mandibular reconstruction in a patient who had lost the entire mandible except for the rami after being severely injured in a blast.

MATERIALS AND METHODS

A new approach using a titanium mandibular rami implant technique was applied using computer-aided 3-dimensional virtual planning and rapid prototyping technology. A prosthetic component was supported by the mandibular implant, which achieved occlusion and dedicated function for the patient.

RESULTS

This method offered precise adaptation of the implant and prosthesis and an easier surgical procedure, providing a shortened operation time, no donor site morbidity, and more predictable outcomes.

CONCLUSION

This new technique allows reconstruction of large-scale mandibular defects that is not possible by conventional surgical methods.

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.

Which Patients With Ossifying Fibroma of the Jaws Would Be Suitable for Radical Ablative Surgery?

OBJECTIVE

The aim of authors' study was to present their 10-year experience in the treatment of giant ossifying fibroma (GOF), and to prove if GOF can be totally excised preventing recurrence. The authors' secondary goal was to study the aesthetic and functional outcomes after radical resection of GOF followed by immediate reconstruction.

METHODS

Eighteen patients who underwent radical ablative surgery of GOF of the jaw followed by immediate reconstruction with vascularized fibula flap or ilium flap between May 2003 and May 2013 were taken. Recurrence rate was statistically observed and 2-year postoperative aesthetic and functional outcomes were evaluated.

RESULTS

The average length of follow-up was 4.5 years. There was no residual tumor or tumor recurrence observed in any patient during the mean follow-up of 4.5 years, and good cosmesis and functional outcome was noted after ablative surgery of GOF followed by computer-assisted reconstruction.

CONCLUSIONS

For giant OF, if it is mainly located in the jaws without invasion of the skull base and/or pterygoid process, radical surgical treatment should be performed for prevention of tumor recurrence. And good aesthetic and functional results can be achieved by immediate computer-assisted reconstruction and dental rehabilitation.

The Application of Virtual Planning and Navigation Devices for Mandible Reconstruction and Immediate Dental Implantation

Routine reconstruction of subtotal defects of the mandible and orthopedic rehabilitation supported by dental implants is achieved by means of detailed planning and lasts over a year. This article shows the outcomes of single-stage surgical treatment and immediate orthopedic rehabilitation performed with the help of preoperative virtual computer simulation. 3D investigation of pathological and donor sites, virtual simulation of tumor resection, positioning of the dental implants into fibula, virtual flap bending and transfer, virtual bending of fixing reconstruction plates, and fabrication of navigation templates and bridge prosthesis supported by dental implants were done preoperatively. The surgery included tumor resection, insertion of dental implants into fibula, elevation of fibula osteocutaneous free flap, rigid fixation within recipient site, and immediate loading by bridge orthopedic device. On 10-month follow-up, functional and esthetic results were asses as reasonable. Radiography showed dental implants to be integrated and positioned appropriately. We found that successful rehabilitation of the patients with extensive defects of the jaws could be achieved by ablative tumor resection, dental implants insertion prior to flap elevation guided by navigation templates, further osteotomy, modeling of the flap based on navigation template, flap transfer, and rigid fixation within recipient site by prebended plates, with application of prefabricated prosthesis.

Computer-aided design and manufacturing in craniosynostosis surgery

BACKGROUND

Considerable operative time is expended during the planning, shaping, and reconfiguring of the cranial vault in the pursuit of symmetry during open craniosynostosis surgery. Computer-aided design and manufacturing has recently been implemented in orthognathic surgery and complex craniomaxillofacial reconstruction as a means of optimizing operative accuracy and efficiency. In this report, we highlight our growing experience with this promising modality for the preoperative planning and intraoperative execution of cranial vault remodeling in patients with both simple and complex forms of craniosynostosis.

METHODS

Computer-assisted surgical planning begins with acquisition of high-resolution computed tomography scans of the craniofacial skeleton. An Internet-based teleconference is then held between the craniofacial and biomedical engineering teams and provides a forum for virtual manipulation of the patient's preoperative three-dimensional computed tomography with real-time changes and feedback. Through virtual surgical planning, osteotomies are designed and calvarial bones reconfigured to achieve the desired cranial vault appearance. Cutting and positioning guides are manufactured to transform the virtual plan into a reality.

RESULTS

From February to March 2012, 4 children (aged 9 months to 6 years) with craniosynostosis underwent computer-assisted simulation and surgery. Diagnoses included metopic, unicoronal (n = 2), and multisutural synostoses (sagittal and left unicoronal). Open craniofacial repairs were performed as virtually planned, including front o-orbital remodeling, fronto-orbital advancement, and anterior two-thirds calvarial remodeling, respectively. Cutting and final positioning guides demonstrated excellent fidelity and ease of use.

CONCLUSIONS

Computer-aided design and manufacturing may offer a platform for optimizing operative efficiency, precision, and accuracy in craniosynostosis surgery, while accelerating the learning curve for future trainees.

Improved operative efficiency of free fibula flap mandible reconstruction with patient-specific, computer-guided preoperative planning

BACKGROUND

Free fibula osteocutaneous flaps are the primary option for reconstruction after segmental mandibulectomies. This study evaluates the impact of CT-guided preoperative planning on operative outcomes after free fibula mandible reconstruction.

METHODS

We conducted a retrospective review of all patients undergoing free fibula reconstruction of the mandible from 2002 to 2011.

RESULTS

Fifty-seven patients underwent free fibula osteocutaneous flap reconstruction for head and neck cancers involving the mandible. Twelve patients had shaping of the neomandible performed on the back table while 20 patients underwent shaping in situ without the use of any adjunctive technology. The remaining 25 patients underwent preoperative CT imaging, which significantly decreased operative time (707 minutes vs 534 minutes; p < .0003) as well as overall costs ($24,532.50 vs $20,950.48). There were no significant differences in outcomes or complications.

CONCLUSION

Preoperative, patient-specific CT modeling, and cutting guide fabrication outweigh the costs associated with the additional technology without jeopardizing overall outcomes or increasing complication rates.

Rapid prototyping-assisted maxillofacial reconstruction

Rapid prototyping (RP) technologies have found many uses in dentistry, and especially oral and maxillofacial surgery, due to its ability to promote product development while at the same time reducing cost and depositing a part of any degree of complexity theoretically. This paper provides an overview of RP technologies for maxillofacial reconstruction covering both fundamentals and applications of the technologies. Key fundamentals of RP technologies involving the history, characteristics, and principles are reviewed. A number of RP applications to the main fields of oral and maxillofacial surgery, including restoration of maxillofacial deformities and defects, reduction of functional bone tissues, correction of dento-maxillofacial deformities, and fabrication of maxillofacial prostheses, are discussed. The most remarkable challenges for development of RP-assisted maxillofacial surgery and promising solutions are also elaborated.

Computer-assisted surgical planning and intraoperative navigation in the treatment of condylar osteochondroma

Mandibular condylar osteochondroma (OC) results in asymmetric prognathism with facial morphology and functional disturbances. The aim of this study was to explore the feasibility of computer-assisted surgical planning combined with intraoperative navigation in the treatment of condylar OC. Five patients with mandibular condylar OC were enrolled in this study. Surgical planning and simulation was performed based on a computed tomography reconstruction model using SurgiCase software. Under the guidance of navigation, a condylar OC resection and conservative condylectomy was carried out via intraoral approach. Simultaneous orthognathic surgery was used to correct the facial asymmetry and malocclusion. All patients healed uneventfully. No facial nerve injury or salivary fistula occurred. Facial symmetry and morphology were greatly improved and stable occlusion was obtained in all cases. Good matching between preoperative planning and postoperative results was achieved. Patients showed no signs of recurrence or temporomandibular joint ankylosis during follow-up of 12-30 months. Computer-assisted surgical planning and intraoperative navigation is a valuable option in the treatment of mandibular condylar OC.

Surgical planning and microvascular reconstruction of the mandible with a fibular flap using computer-aided design, rapid prototype modelling, and precontoured titanium reconstruction plates: a prospective study

The standard of mandibular reconstruction has increased since the introduction of computer-assisted design (CAD) and rapid prototype modelling (RPM) for surgical planning. Between 2008 and 2013, a prospective pilot study of 20 patients was planned to compare the outcomes of patients treated by mandibular reconstruction who had CAD and RPM-guided operations using a precontoured titanium plate, with the outcomes of patients treated conventionally. We recorded the time taken for reconstruction, total operating time, and whether this type of planning could improve the results of mandibular reconstruction. We found significant differences in the incidence of dental malocclusion (p=0.03) and exposure of the titanium plate (p=0.009). The mean operating time for reconstruction in the preoperative planning group was 135 (37)min compared with 176 (58)min in the conventional group (p=0.04). Preoperative planning using CAD and RPM can increase the accuracy of microvascular mandibular reconstruction and reduce the operating time for reconstruction.

Virtual surgical planning for extensive fibrous dysplasia in the mandible

The reconstruction of extensive mandibular defects is a challenge for which virtual surgical planning is extremely helpful. This report describes the case of a 33-year-old woman who experienced the gradual development of a severe mandibular deformity with elongation of the chin and mandibular border because of fibrous dysplasia. Consequently, 19 cm of the mandible extending from the neck of the condyle to the contralateral body was resected together with vestibular and lingual deformities. This bone was replaced with a fibula-free flap. For planning, a virtual resection was performed via a Web conference, followed by virtual reconstruction by superimposition of the fibula on the mandibular defect after the creation of three osteotomies. A stereolithographic model of the reconstructed mandible and cutting guides for the mandibular resection and fibula osteotomies were made. The stereolithographic model of the neo-mandible allowed prebending of a reconstruction plate before the surgery because the deformity did not allow this to be performed intraoperatively. The cutting guides shortened the operating time and enabled accurate reproduction of the virtual plan with exact bone-to-bone contact in the reconstructed mandible. Surgical virtual planning, despite its upfront cost, is a time-saving procedure, which is especially important in complex reconstruction cases, and eliminates the variability of surgical expertise for flap in-setting.