Mirror Image Based Three-Dimensional Virtual Surgical Planning and Three-Dimensional Printing Guide System for the Reconstruction of Wide Maxilla Defect Using the Deep Circumflex Iliac Artery Free Flap

Asymmetry of the alveolar ridge in Class II maxillary defects reconstructed by an osseo-myocutaneous flap: A CBCT evaluation

STATEMENT OF PROBLEM

Alveolar ridge asymmetry remains in patients with Class II maxillary defects reconstructed by osseo-myocutaneous flaps, leading to esthetic and functional issues. Implant-supported fixed dental prostheses (IFDPs) might have the potential to improve facial appearance related to this asymmetry, but studies on this topic are lacking.

PURPOSE

The purpose of this clinical study was to determine whether IFDPs effectively improve facial appearance related to alveolar ridge asymmetry after maxillary reconstruction by using cone beam computed tomography (CBCT) based on treating the patients with IFDPs for comparable dentition defects as control.

MATERIAL AND METHODS

Sixteen patients with Class II maxillary defects who underwent reconstruction were the study group, while 16 patients with IFDPs for comparable dentition defects were the control group. CBCT images were used to obtain 3-dimensional coordinates of landmarks and the nasolabial angle. Reference planes were established and 3 anatomic landmarks related to the alveolar ridge were defined by using a constructed coordinate plane system. Asymmetry indices of the landmarks were then calculated to assess the asymmetry of reconstructed alveolar ridge. The Welch t and Mann-Whitney tests were performed to compare the differences in 3-dimensional vectors of each landmark between the groups. Additionally, both the independent samples t and chi-squared tests were used to compare the nasolabial angle between the groups (α=.05 for all tests).

RESULTS

Compared with patients with IFDPs for comparable dentition defects, the alveolar ridge asymmetry of reconstructed patients becomes increasingly pronounced from the anterior to the posterior zone. Quantitative analysis revealed this asymmetry was mainly because of vertical discrepancies at middle point (MP) (Δdy=3.72±4.44 mm, P=.003) and posterior point (ZB) (Δdz=4.05±7.20 mm, P=.010; Δdy=3.11±4.43 mm, P=.032). However, there was no significant difference in nasolabial angle between the 2 groups (P=.219).

CONCLUSIONS

Alveolar ridges reconstructed with osseo-myocutaneous flaps in Class II defects displayed acceptable asymmetry in the anterior zone. Bony reconstruction of anterior maxilla can support soft tissue lateral profile with the aid of IFDPs. Although posterior alveolar ridge showed mesial yawing, upward shifting, and less distal extension, IFDPs still could effectively improve the facial profile.

Efficiency and Applicability of Virtual Surgical Planning in Maxillofacial and Mandibular Bone Reconstruction: A Narrative Review

Background: Facial structures are critical to aesthetics and function. Deformities can cause significant problems. Advances in surgical techniques, including three-dimensional (3D) computer simulation and virtual surgical planning (VSP), have improved outcomes. VSP accurately predicts surgical outcomes, revolutionizing facial reconstruction. This article reviews VSP in facial bone reconstruction, highlighting its advantages and accuracy over traditional methods. Methods: A systematic search using Medline (PubMed), Web of Science, Scopus, and Google Scholar revealed 1645 articles that addressed the topic of this study. Results: The systematic search yielded 64 articles that were highly relevant to the study objective, underscoring the critical importance of virtual surgical planning (VSP) in enhancing surgical precision and patient satisfaction. VSP has become a key player in improving surgical interventions and reducing complications, reinforcing its role as the preferred method in modern reconstructive surgery and thus improving functional and aesthetic outcomes, significantly enhancing patient satisfaction, and ensuring accurate interpretation of treatment plans. When compared to traditional surgical planning (TSP), VSP offers increased accuracy, shorter operating times, and superior aesthetic outcomes. Conclusions: VSP has been shown to effectively manage the complex challenges of facial anatomy and has significantly enhanced the planning and execution of reconstructive surgeries. This has been achieved by leveraging advanced imaging and computer-aided design.

Complications in Deep Circumflex Iliac Artery-Related Vascularized Free Iliac Flap

BACKGROUND

Since its first application in 1978, the vascularized free iliac flap (VFIF) has gradually become a mainstay for tissue defect reconstruction. However, the complications associated with harvesting the bone flap and its corresponding reconstruction surgery cannot be overlooked.

METHODS

We conducted a narrative review through literature search to identify the types, incidence, influencing factors, measurement methods, and treatment approaches of complications related to DCIA-related VFIF.

RESULTS

We propose the "LIP" rule (Loss, Injury, Postoperative) for classifying donor site complications. For the four most common recipient sites, mandible, maxilla, extremities, and hip joint, we list the common and rare complications that may occur. Additionally, we provide a summary of the methods and advances in preventing these complications.

CONCLUSIONS

We comprehensively describe the complications observed in the application of DCIA-related VFIF and introduce the "LIP" principle and other strategies to minimize or avoid adverse outcomes.

Evolution of Medical Modeling and 3D Printing in Microvascular Midface Reconstruction: Literature Review and Experience at MD Anderson Cancer Center

Reconstruction of the midface represents a challenge for reconstructive microsurgeons given the formidable task of restoring both aesthetics and functionality. In particular, preservation of proper globe positioning and maintaining normal vision are as important as restoring the proper projection of the midface and enabling a patient to speak and eat as normally as possible. The introduction of virtual surgical planning (VSP) and medical modeling has revolutionized bony reconstruction of the craniofacial skeleton; however, the overwhelming majority of studies have focused on mandibular reconstruction. Here, we introduce some novel advances in utilizing VSP for bony reconstruction of the midface. The present review aims (1) to provide a review of the literature on the use of VSP in midface reconstruction and (2) to provide some insights from the authors' early experience.

The comprehensive on-demand 3D bio-printing for composite reconstruction of mandibular defects

Background

The mandible is a functional bio-organ that supports facial structures and helps mastication and speaking. Large mandible defects, generally greater than 6-cm segment loss, may require composite tissue reconstruction such as osteocutaneous-vascularized free flap which has a limitation of additional surgery and a functional morbidity at the donor site. A 3D bio-printing technology is recently developed to overcome the limitation in the composite reconstruction of the mandible using osteocutaneous-vascularized free flap.

Review

Scaffold, cells, and bioactive molecules are essential for a 3D bio-printing. For mandibular reconstruction, materials in a 3D bio-printing require mechanical strength, resilience, and biocompatibility. Recently, an integrated tissue and organ printing system with multiple cartridges are designed and it is capable of printing polymers to reinforce the printed structure, such as hydrogel.

Conclusion

For successful composite tissue reconstruction of the mandible, biologic considerations and components should be presented with a comprehensive on-demand online platform model of customized approaches.

Interdisciplinary challenges and aims of flap or graft reconstruction surgery of sinonasal cancers: What radiologists and radiation oncologists need to know

In sinonasal cancer surgery, a fundamental challenge is to understand the postoperative imaging changes after reconstruction. Misinterpretation of post-operative imaging may lead to a misdiagnosis of tumor recurrence. Because radiotherapy planning is based on imaging, there are many gaps in knowledge to be filled in the interpretation of postoperative imaging to properly define radiotherapy tumor volumes in the presence of flaps. On the other hand, radiotherapy may be responsible for tissue fibrosis or atrophy, the anatomy of the reconstructed region and the functional outcomes may change after radiotherapy compared to surgery alone. This narrative review illustrates the interdisciplinary aims and challenges of sinonasal reconstructive surgery using flaps or grafts. It is particularly relevant to radiologists and radiation oncologists, at a time when intensity modulated radiotherapy and proton therapy have the potential to further contribute to reduction of morbidity.

Improving Left Atrial Appendage Occlusion Device Size Determination by Three-Dimensional Printing-Based Preprocedural Simulation

Background

The two-dimensional (2D)-based left atrial appendage (LAA) occluder (LAAO) size determination by using transesophageal echocardiography (TEE) is limited by the structural complexity and wide anatomical variation of the LAA.

Objective

This study aimed to assess the accuracy of the LAAO size determination by implantation simulation by using a three-dimensional (3D)-printed model compared with the conventional method based on TEE.

Methods

We retrospectively reviewed patients with anatomically and physiologically properly implanted the Amplatzer Cardiac Plug and Amulet LAAO devices between January 2014 and December 2018 by using the final size of the implanted devices as a standard for size prediction accuracy. The use of 3D-printed model simulations in device sizing was compared with the conventional TEE-based method.

Results

A total of 28 cases with the percutaneous LAA occlusion were reviewed. There was a minimal difference [−0.11 mm; 95% CI (−0.93, 0.72 mm); P = 0.359] between CT-based reconstructed 3D images and 3D-printed left atrium (LA) models. Device size prediction based on TEE measurements showed poor agreement (32.1%), with a mean difference of 2.3 ± 3.2 mm [95% CI (−4.4, 9.0)]. The LAAO sizing by implantation simulation with 3D-printed models showed excellent correlation with the actually implanted LAAO size (r = 0.927; bias = 0.7 ± 2.5). The agreement between the 3D-printed and the implanted size was 67.9%, with a mean difference of 0.6 mm [95% CI (−1.9, 3.2)].

Conclusion

The use of 3D-printed LA models in the LAAO size determination showed improvement in comparison with conventional 2D TEE method.

Individualized 3D printing-assisted repair and reconstruction of neoplastic bone defects at irregular bone sites: exploration and practice in the treatment of scapular aneurysmal bone cysts

BACKGROUND

The irregular anatomical shape and complex structures of irregular bones make it more difficult to repair and reconstruct bone defects in irregular bones than in the long bones of the extremities. Three-dimensional (3D) printing technology can help to overcome the technical limitations of irregular bone repair by generating simulations that enable structural integration of the lesion area and bone structure of the donor site in all directions and at multiple angles. Thus, personalized and accurate treatment plans for restoring anatomical structure, muscle attachment points, and maximal function can be made. The present study aimed to investigate the ability of 3D printing technology to assist in the repair and reconstruction of scapular aneurysmal ABC defects.

METHODS

The study included seven patients with ABCs of the scapula. Based on computed tomography (CT) data for the patient, the scapula (including the defect) and pelvis were reconstructed using Mimics Medical software. The reconstructed scapula model was printed using a 3D printer. Before the operation, the model was used to design the surgical approach and simulate the operation process, to determine the length and radius of the plate and the number and direction of screws, and to determine the bone mass of the ilium and develop reasonable strategies for segmentation and distribution. The operation time, amount of bleeding, length and radius of the plate, and direction and number of screws were recorded.

RESULTS

The average duration of follow-up was 25.6 months, and none of the seven patients experienced recurrence during the follow-up period. The surgical approach, the length and radius of internal fixation, and the number and direction of screws were consistent with the designed operation plan. Patients gradually recovered the anatomical structure of the scapula and function of the shoulder joint.

CONCLUSIONS

In the treatment of bone defects caused by irregular bone tumors, 3D printing technology combined with surgery has the advantages of less trauma, short operation time, less bleeding and reducing the difficulty of operation, which can reduce the waste of bone graft, and more complete reconstruction of the anatomical structure of the defective bone.

Midface Reconstruction: Planning and Outcome

Reconstruction of the complex anatomy and aesthetics of the midface is often a challenge. A careful understanding of this three-dimensional (3D) structure is necessary. Anticipating the extent of excision and its planning following oncological resections is critical.

In the past over two decades, with the advances in microsurgical procedures, contributions toward the reconstruction of this area have generated interest. Planning using digital imaging, 3D printed models, osseointegrated implants, and low-profile plates, has favorably impacted the outcome. However, there are still controversies in the management: to use single composite tissues versus multiple tissues; implants versus autografts; vascularized versus nonvascularized bone; prosthesis versus reconstruction.

This article explores the present available options in maxillary reconstruction and outlines the approach in the management garnered from past publications and experiences.

Virtual Reality Simulation and Augmented Reality-Guided Surgery for Total Maxillectomy: A Case Report

With the improvement in computer graphics and sensors, technologies like virtual reality (VR) and augmented reality (AR) have created new possibilities for developing diagnostic and surgical techniques in the field of surgery. VR and AR are the latest technological modalities that have been integrated into clinical practice and medical education, and are rapidly emerging as powerful tools in the field of maxillofacial surgery. In this report, we describe a case of total maxillectomy and orbital floor reconstruction in a patient with malignant fibrous histiocytoma of the maxilla, with preoperative planning via VR simulation and AR-guided surgery. Future developments in VR and AR technologies will increase their utility and effectiveness in the field of surgery.