Computer-Assisted Orthognathic Surgery Combined With Fibular Osteomyocutaneous Flap Reconstruction to Correct Facial Asymmetry and Maxillary Defects Secondary to Maxillectomy in Childhood:

New Perspectives on Maxillofacial Reconstruction in Patients With Skeletal Malocclusion: Deep Integration of Maxillofacial Reconstruction and Orthognathic Surgery Concepts

The application of computer-assisted design and manufacturing (CAD/CAM) technology and digital guides has made maxillofacial defect reconstruction surgery faster, more convenient, precise, and highly accurate in restoration. However, in addressing maxillofacial reconstruction for patients with skeletal malocclusion, the restoration of facial contours has received less attention, and surgical planning for such cases remains challenging. In this study, we report a case where the deep integration of maxillofacial reconstruction and orthognathic surgery concepts was applied. The patient presented with an ameloblastoma of the mandible along with mandibular prognathism. By utilizing translational and rotational maneuvers of the bone flap, along with appropriate shaping, we replaced the traditional mandibular bilateral sagittal split osteotomy (BSSO), achieving both mandibular reconstruction and the treatment of mandibular prognathism. The postoperative recovery was excellent, with significant improvement in the patient's facial contour, yielding satisfactory results. We believe that incorporating orthognathic surgery principles into maxillofacial reconstruction can effectively balance functional and aesthetic requirements.

Reconstruction of Dentomaxillofacial Deformity Secondary to Mandibular Defect Using Concomitant Orthognathic Surgery and Fibula Free Flap

SUMMARY

The reconstruction of mandibular defects may be delayed or compromised for many reasons, especially in pediatric patients. With the growth of the remaining mandible and the maxilla in the malocclusion status, secondary dentomaxillofacial deformity is plausible. To treat the concomitant mandibular defect and secondary dentomaxillofacial deformity, a hierarchical algorithm using orthodontics, orthognathic surgery, and fibula free flap was developed. This retrospective case series included six patients with long-term mandibular defects caused by tumor resection without repair or with compromised costochondral reconstruction. All patients were treated using the same staged protocol, but with minor changes: (1) presurgical orthodontics, (2) virtual surgical planning, (3) fabrication of the guides and splints, (4) sequenced operations, and (5) postoperative care. The sequence of surgery included the Le Fort I osteotomy, mandibular sagittal split ramus osteotomy of the remaining ramus, final occlusion registration, repositioning of the distal segment of the mandible, segmented fibula reconstruction, and finally, the fixation of mandibular sagittal split ramus osteotomy. The operations and wound healing were uneventful in all patients, and no flap failure or severe complications were detected. Also, the patients exhibited no signs of temporomandibular joint ankylosis during the follow-up. The subspinale-nasion-supramental angle was significantly reduced after surgery. A significant improvement was detected in the facial contour symmetry measurements postoperatively. This proposed workflow of concomitant orthognathic surgery and the fibula free flap is effective and reliable for the reconstruction of dentomaxillofacial deformity secondary to the long-term mandibular defect.

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.

Simultaneous Computer-Aided Design/Computer-Aided Manufacture Bimaxillary Orthognathic Surgery and Mandibular Reconstruction Using Selective-Laser Sintered Titanium Implant

This patient report describes simultaneous bimaxillary orthognathic surgery and mandibular reconstruction by means of three-dimensional (3D) planning, 3D printed biocompatible surgical wafers, and 3D selective-laser sintered titanium implant. A 26-year-old male patient presented with a left mandibular defect secondary to trauma. The whole body of the mandible on the left hand side was deficient with a narrow connection with the remaining left condyle. He had undergone orthodontic treatment for 18 months and was ready to undergo bimaxillary orthognathic surgery. Advanced cranio-maxillofacial software was used in processing his cone beam computer tomography scan data, and e-casts of his upper and lower dental arches. Bimaxillary surgery was planned with Le Fort 1 maxillary impaction and mandibular advancement to achieve a class 1 incisor relationship. Intermediate and final surgical wafers were designed following the planned movements and printed using biocompatible resin. The deficient left side of the mandible was reconstructed by means of mirror imaging the contra-lateral right side into the deficient left side with the aim of restoring normal facial symmetry. Biomedical software was then used in designing a reconstruction plate that connected the condylar head and the mandible following the planned bimaxillary surgery and mandibular continuity symmetry reconstruction. The plate was printed in titanium following state-of the-art selective laser sintering technology. The bimaxillary surgery and mandibular reconstruction were done simultaneously as planned along with an iliac-crest bone graft. This patient confirms the advantages of 3D computer-aided design/computer-aided manufacture technologies in optimizing clinical outcomes for cranio-maxillofacial reconstruction, especially when conducting two simultaneous clinical procedures.

Ancillary procedures necessary for translational research in experimental craniomaxillofacial surgery

INTRODUCTION

Swine are often regarded as having analogous facial skeletons to humans and therefore serve as an ideal animal model for translational investigation. However, there is a dearth of literature describing the pertinent ancillary procedures required for craniomaxillofacial research. With this in mind, our objective was to evaluate all necessary procedures required for perioperative management and animal safety related to experimental craniomaxillofacial surgical procedures such as orthotopic, maxillofacial transplantation.

METHODS

Miniature swine (n = 9) were used to investigate perioperative airway management, methods for providing nutrition, and long-dwelling intravenous access. Flap perfusion using near-infrared laser angiography and facial nerve assessment with electromyoneurography were explored.

RESULTS

Bivona tracheostomy was deemed appropriate versus Shiley because soft, wire-reinforced tubing reduced the incidence of tracheal necrosis. Percutaneous endoscopic gastrostomy tube, as opposed to esophagostomy, provided a reliable route for postoperative feeding. Femoral venous access with dorsal tunneling proved to be an ideal option being far from pertinent neck vessels. Laser angiography was beneficial for real-time evaluation of graft perfusion. Facial electromyoneurography techniques for tracing capture were found most optimal using percutaneous leads near the oral commissure.Experience shows that ancillary procedures are critical, and malpositioning of devices may lead to irreversible sequelae with premature animal death.

CONCLUSIONS

Face-jaw-teeth transplantation in swine is a complicated procedure that demands special attention to airway, feeding, and intravascular access. It is critical that each ancillary procedure be performed by a dedicated team familiar with relevant anatomy and protocol. Emphasis should be placed on secure skin-level fixation for all tube/lines to minimize risk for dislodgement. A reliable veterinarian team is invaluable and critical for long-term success.

Computer simulation surgery for mandibular reconstruction using a fibular osteotomy guide

In the present study, a fibular osteotomy guide based on a computer simulation was applied to a patient who had undergone mandibular segmental ostectomy due to oncological complications. This patient was a 68-year-old woman who presented to our department with a biopsy-proven squamous cell carcinoma on her left gingival area. This lesion had destroyed the cortical bony structure, and the patient showed attenuation of her soft tissue along the inferior alveolar nerve, indicating perineural spread of the tumor. Prior to surgery, a three-dimensional computed tomography scan of the facial and fibular bones was performed. We then created a virtual computer simulation of the mandibular segmental defect through which we segmented the fibular to reconstruct the proper angulation in the original mandible. Approximately 2-cm segments were created on the basis of this simulation and applied to the virtually simulated mandibular segmental defect. Thus, we obtained a virtual model of the ideal mandibular reconstruction for this patient with a fibular free flap. We could then use this computer simulation for the subsequent surgery and minimize the bony gaps between the multiple fibular bony segments.