Outcomes of Orbital Floor Reconstruction After Extensive Maxillectomy Using the Computer-Assisted Fabricated Individual Titanium Mesh Technique

Accuracy and safety of real-time navigation during insertion of temporary anchorage devices - A randomized clinical trial

Background/purpose

Temporary anchorage device (TAD) is one of the applications of dental implants that facilitate orthodontic treatment. However, there are possible complications in TAD surgery with the freehand technique. Navigation has been used in dental implantation with acceptable results. There has been no published study on the use of real-time navigation for TAD insertion.

Materials and methods

This was a split-mouth design randomized clinical trial in which the control group used a surgical guide (N = 16) for TAD insertion surgery and the experimental group used navigation for surgery (N = 16). We also performed a negative control by retrospective database survey to evaluate the freehand technique (N = 29). By comparing the platform center deviation and angular deviation of the control group, experimental group, and negative control, we can draw conclusions about the accuracy and safety of TAD insertion surgery using each method.

Results

The platform center deviation in the surgical guide group and the navigation group showed a statistical difference (P < 0.05), indicating that the surgical guide provided better position control. There was no statistical difference in terms of angular deviation.

Conclusion

The clinical use of real-time navigation in the insertion of TAD offers no more significant advantages than the freehand technique in terms of position and angular control. No immediate complications requiring implant removal occurred in this study. The combined technique has shown a trend in accuracy and safety, but a larger number of samples are still needed for statistical analysis to draw a definitive conclusion.

Intraoperative Image Guidance in Orbital and Lacrimal Surgery: A Report by the American Academy of Ophthalmology

PURPOSE

To review the efficacy and safety of the use of intraoperative image guidance (IIG) in orbital and lacrimal surgery.

METHODS

A literature search of the PubMed database was last conducted in November 2023 for English-language original research that assessed the use of any image guidance system in orbital and lacrimal surgery that included at least 5 patients. The search identified 524 articles; 94 were selected for full-text analysis by the panel. A total of 32 studies met inclusion criteria. The panel methodologist assigned a level II rating to 2 studies and a level III rating to 30 studies. No study met the criteria for level I evidence.

RESULTS

Procedures reported on were as follows: fracture repair (n = 14), neoplasm and infiltrate biopsy or excision (n = 6), orbital decompression for Graves ophthalmopathy (n = 3), dacryocystorhinostomy (n = 1), and mixed etiology and procedures (n = 8). Four studies used more than one IIG system. One study that met level II evidence criteria compared the outcomes of orbital fracture repair with IIG (n = 29) and without IIG (n = 29). Borderline better outcomes were reported in the IIG group: 2% versus 10% with diplopia (P = 0.039) and 3% versus 10% with enophthalmos (P = 0.065). The other level II study compared the repair of fractures with navigation (n = 20) and without (n = 20). The group in which navigation was used had a measured mean volume reduction of 3.82 cm3 compared with 3.33 cm3 (P = 0.02), and there was a greater measured reduction in enophthalmos in the navigation group of 0.72 mm (P = 0.001). Although the remaining 30 assessed articles failed to meet level II criteria, all alleged a benefit from IIG. No complications were reported.

CONCLUSIONS

A small number of comparative studies suggest that there are improved outcomes when IIG is used in orbital fracture repair, but each study suffers from various limitations. No high-quality comparative studies exist for the management of lacrimal surgery, neoplastic disease, or decompression. Complications attributable to the use of IIG have not been identified, and IIG has not been analyzed for cost savings.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Single-stage computer-assisted approach for tumour resection and functional restoration of Brown class III maxillary defects-titanium mesh and zygomatic implants combined with vascularized anterolateral thigh flap

The functional restoration of Brown class III maxillary defects is a challenging endeavour in oral and maxillofacial surgery. Conventional reconstruction techniques with osseous free flaps have certain limitations, such as the need for multiple operations and greater patient morbidity. This study introduces a single-stage computer-assisted approach for tumour resection and functional restoration of these defects using titanium mesh, zygomatic implants, and a vascularized anterolateral thigh flap (ALTF). Virtual surgical planning was used to simulate tumour resection, titanium mesh placement, and zygomatic implant insertion. Surgery was performed under the guidance of mixed reality and surgical navigation. The tumour was resected by total hemimaxillectomy, and the reconstruction was performed using a pre-bent patient-specific titanium mesh for the orbital floor and two zygomatic implants placed and exposed through tunnels in an ALTF. The ALTF survived without any perioperative complications. A fixed prosthesis with built-in titanium frame was delivered 4 months postoperatively. At the 1-year follow-up, there was no tumour recurrence, the implants were osseointegrated, and aesthetics and masticatory function were satisfactory. An occlusal force of 155 N was attained on the reconstructed side, compared to 127 N on the non-surgical side.

Mixed Reality Combined with Surgical Navigation in Resection of Micro- and Mini-Tumors of the Parotid Gland: A Pilot Study

OBJECTIVE

This study aimed to evaluate the feasibility and outcomes of mixed reality combined with surgical navigation (MRSN) in the resection of parotid micro- and mini-tumors.

METHODS

Eighteen patients who underwent parotid tumor resection between December 2020 and November 2022 were included. Six patients were enrolled in MRSN group, and the surgeons performed the surgery with the help of MRSN technology. The surgical procedures include virtual planning, data transfer between mixed reality and surgical navigation, tumor localization and resection assisted by surgical navigation under mixed reality environment. Twelve patients were enrolled in control group, and intraoperative tumor localization and resection were performed according to the experience of the surgeon. Total surgery time and intraoperative bleeding were recorded. Perioperative complications were recorded during follow-up.

RESULTS

The mean surgery time of MRSN group (76.7 ± 14.0 min) and control group (65.4 ± 21.3 min) showed no significant difference (p = 0.220), so did the intraoperative bleeding of MRSN group (16.0 ± 8.0 mL) and control group (16.7 ± 6.6 mL) (p = 0.825). None of the patient in MRSN group underwent any complication, although one patient in control group suffered temporary facial paralysis. The mean deviation between the virtually marked and the intraoperative actual outermost point of tumor was 3.03 ± 0.83 mm.

CONCLUSION

MRSN technology can realize real-time three-dimensional visualization of the tumor, and it has the potential of enhancing the safety and accuracy of resection of micro- and mini-tumors of parotid gland.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1670-1678, 2024.

The Use of Patient-Specific Orbital Reconstruction Implants During Maxillectomy Reconstruction

Background: Reconstruction of the orbital floor after maxillectomy can result in significant functional and aesthetic morbidity. Study Objective: To measure eyelid position, self-reported visual outcomes, and complications in patients undergoing concurrent maxillectomy and reconstruction with a patient-specific orbital reconstruction implant (PSORI). Design Type: Case series. Materials and Methods: Case series including 12 patients who received PSORI for orbital floor reconstruction after tumor extirpation. Primary outcomes gathered were diplopia, ectropion, and wound healing complications. Results: The majority of patients were men (75%) and the mean age was 53.3 years. Ten patients underwent free flap reconstruction with the majority receiving fibula free flaps (n = 6). Median follow-up was 415.5 days. Three patients (25%) experienced long-term complications, including diplopia (n = 1) and hardware extrusion (n = 3). Each of these occurred in the context of total maxillectomy and radiation. This prompted subsequent use of a modified implant design for the final six patients and the preferential use of a midface-degloving approach. These interventions eliminated extrusions in subsequent patients. Conclusion: PSORIs can be used for orbital floor reconstruction following maxillectomy in combination with free tissue transfer. Implant design is critical to reduce complications. The use of a midface degloving approach and a modified low-profile design was associated with a low rate of complications.

Skull-Base Surgery-A Narrative Review on Current Approaches and Future Developments in Surgical Navigation

Surgical navigation technology combines patient imaging studies with intraoperative real-time data to improve surgical precision and patient outcomes. The navigation workflow can also include preoperative planning, which can reliably simulate the intended resection and reconstruction. The advantage of this approach in skull-base surgery is that it guides access into a complex three-dimensional area and orients tumors intraoperatively with regard to critical structures, such as the orbit, carotid artery and brain. This enhances a surgeon's capabilities to preserve normal anatomy while resecting tumors with adequate margins. The aim of this narrative review is to outline the state of the art and the future directions of surgical navigation in the skull base, focusing on the advantages and pitfalls of this technique. We will also present our group experience in this field, within the frame of the current research trends.

Application of Augmented Reality to Maxillary Resections: A Three-Dimensional Approach to Maxillofacial Oncologic Surgery

In the relevant global context, although virtual reality, augmented reality, and mixed reality have been emerging methodologies for several years, only now have technological and scientific advances made them suitable for revolutionizing clinical care and medical settings through the provision of advanced features and improved healthcare services. Over the past fifteen years, tools and applications using augmented reality (AR) have been designed and tested in the context of various surgical and medical disciplines, including maxillofacial surgery. The purpose of this paper is to show how a marker-less AR guidance system using the Microsoft^® HoloLens 2 can be applied in mandible and maxillary demolition surgery to guide maxillary osteotomies. We describe three mandibular and maxillary oncologic resections performed during 2021 using AR support. In these three patients, we applied a marker-less tracking method based on recognition of the patient's facial profile. The surgeon, using HoloLens 2 smart glasses, could see the virtual surgical planning superimposed on the patient's anatomy. We showed that performing osteotomies under AR guidance is feasible and viable, as demonstrated by comparison with osteotomies performed using CAD-CAM cutting guides. This technology has advantages and disadvantages. However, further research is needed to improve the stability and robustness of the marker-less tracking method applied to patient face recognition.

Accurate reconstruction of bone defects in orbital-maxillary-zygomatic (OMZ) complex with polyetheretherketone (PEEK)

PURPOSE

The aim of this study was to evaluate the safety and efficacy of using patient-specific polyetheretherketone (PEEK) for the reconstruction of patients with defects in orbital-maxillary-zygomatic (OMZ) complex.

PATIENTS AND METHODS

This study included 12 patients who underwent primary/delayed reconstruction of defects in OMZ complex by using patient-specific PEEK implants. Postoperative appearance (facial and orbital symmetry) and function were assessed after 6 months. Ophthalmologic examinations including globe position, exophthalmos, and orbital volume measurement were also performed. A comparative analysis of the treatment outcomes between pre- and postoperation was performed, and a value of P < 0.05 was considered as significant.

RESULTS

All patients underwent planned surgical procedure successfully. No obvious complications occurred. Facial symmetry and globe position were improved after surgery and the postoperative esthetic assessment was rated as excellent. The postoperative evaluation revealed that exophthalmos was 15.91 ± 1.80 mm, vertical position difference of eyeball 15.91 ± 1.80 mm, and orbital volume 15.91 ± 1.80 mm, respectively. There was a statistically significant difference in the mean values of exophthalmos, vertical position difference, and orbital volume among pre- and postoperation conditions, whereas there was no statistically significant difference between the reconstructed side and the unaffected side after surgery.

CONCLUSION

With the aid of virtual surgical planning and individual custom-made surgical guides, patient-specific PEEK implantation can successfully reconstruct the complicated 3D structure of OMZ complex and shows excellent biocompatibility and clinical outcomes.

Biocompatible Materials for Orbital Wall Reconstruction-An Overview

The reconstruction of an orbit after complex craniofacial fractures can be extremely demanding. For satisfactory functional and aesthetic results, it is necessary to restore the orbital walls and the craniofacial skeleton using various types of materials. The reconstruction materials can be divided into autografts (bone or cartilage tissue) or allografts (metals, ceramics, or plastic materials, and combinations of these materials). Over time, different types of materials have been used, considering characteristics such as their stability, biocompatibility, cost, safety, and intraoperative flexibility. Although the ideal material for orbital reconstruction could not be unanimously identified, much progress has been achieved in recent years. In this article, we summarise the advantages and disadvantages of each category of reconstruction materials. We also provide an update on improvements in material properties through various modern processing techniques. Good results in reconstructive surgery of the orbit require both material and technological innovations.

Accuracy of Mixed Reality Combined With Surgical Navigation Assisted Oral and Maxillofacial Tumor Resection

OBJECTIVE

To evaluate the feasibility and accuracy of mixed reality combined with surgical navigation in oral and maxillofacial tumor surgery.

METHODS

Retrospective analysis of data of seven patients with oral and maxillofacial tumors who underwent surgery between January 2019 and January 2021 using a combination of mixed reality and surgical navigation. Virtual surgical planning and navigation plan were based on preoperative CT datasets. Through IGT-Link port, mixed reality workstation was synchronized with surgical navigation, and surgical planning data were transferred to the mixed reality workstation. Osteotomy lines were marked with the aid of both surgical navigation and mixed reality images visualized through HoloLens. Frozen section examination was used to ensure negative surgical margins. Postoperative CT datasets were obtained 1 week after the surgery, and chromatographic analysis of virtual osteotomies and actual osteotomies was carried out. Patients received standard oncological postoperative follow-up.

RESULTS

Of the seven patients, four had maxillary tumors and three had mandibular tumors. There were total of 13 osteotomy planes. Mean deviation between the planned osteotomy plane and the actual osteotomy plane was 1.68 ± 0.92 mm; the maximum deviation was 3.46 mm. Chromatographic analysis showed error of ≤3 mm for 80.16% of the points. Mean deviations of maxillary and mandibular osteotomy lines were approximate (1.60 ± 0.93 mm vs. 1.86 ± 0.93 mm). While five patients had benign tumors, two had malignant tumors. Mean deviations of osteotomy lines was comparable between patients with benign and malignant tumors (1.48 ± 0.74 mm vs. 2.18 ± 0.77 mm). Intraoperative frozen pathology confirmed negative resection margins in all cases. No tumor recurrence or complications occurred during mean follow-up of 15.7 months (range, 6-26 months).

CONCLUSION

The combination of mixed reality technology and surgical navigation appears to be feasible, safe, and effective for tumor resection in the oral and maxillofacial region.

Buccal fat pad flap, an option for surgical reconstruction of orbital floor defect: A case report

Buccal fat pad (BFP) is widely used in oral and maxillofacial surgery, with paucity of literature describing its use in orbital reconstruction. We report a case of a 23year old female who had orbital floor defect surgically reconstructed with a pedicled buccal fat pad following maxillectomy.

Long-term Effect of Individualized Titanium Mesh in Orbital Floor Reconstruction After Maxillectomy

OBJECTIVE

The aim of this study was to determine the clinical outcomes and long-term stability of individualized titanium mesh combined with free flap for orbital floor reconstruction after maxillectomy and to identify the risk factors for titanium mesh exposure.

MATERIAL AND METHODS

The data of 66 patients who underwent maxillectomy and orbital floor defect reconstruction by individualized titanium mesh in Peking University School and Hospital of Stomatology between 2011 and 2019 were retrospectively reviewed. Postoperative ophthalmic function and success of aesthetic restoration were assessed. Titanium mesh exposure was recorded and the risk factors were identified.

RESULTS

Mean follow-up was for 24.8 months (range, 6-92 months). Ophthalmic function was successfully restored in 63/66 patients. Aesthetic restoration was not considered satisfactory by 10 patients. Titanium mesh exposure occurred in six patients (exposure rate, 9.1%). Preoperative radiotherapy was identified as an independent risk factor for mesh exposure (OR = 28.8, P = 0.006). Previous surgery, postoperative radiotherapy, pathological type of the primary lesion, the type of tissue flap applied, and the use of intraoperative navigation were not significant risk factors. Six patients with titanium mesh exposure underwent second surgery, but mesh exposure recurred in two patients due to insufficient soft tissue coverage.

CONCLUSION

Individualized titanium mesh with free flap can effectively restore maxilla-orbital defects. Preoperative radiotherapy is an independent predictor of postoperative titanium mesh exposure. Adequate soft tissue coverage of the mesh may reduce the risk of mesh exposure.

LEVEL OF EVIDENCE

Level 4 (case-control study) Laryngoscope, 2021.

Improved procedure for Brown's Class III maxillary reconstruction with composite deep circumflex iliac artery flap using computer-assisted technique

Reconstruction of Brown's Class III maxillary defect can be challenging due to the complex geometry of maxilla. We aimed to introduce an improved method for maxillary reconstruction with a composite deep circumflex iliac artery (DCIA) flap aided by virtual surgical planning and intraoperative navigation. A 27-year-old woman diagnosed with left maxillary fibromyxoma was admitted to our institution in December 2018. Pre-operative facial and iliac computed tomography data were obtained for virtual surgical planning. Personalized cutting template, tooth-supported surgical guide, and rapid prototype model with reconstructed orbital floor were printed for pre-operative preparation. Surgery was completely guided by the intraoperative navigation system. The root mean square estimate of the reconstructed area was 3.68 mm. The average errors measured on the lateral and medial DCIA segments were 0.61 and 0.85 mm, respectively. Application of virtual surgical planning and intraoperative navigation could potentially enhance the reconstruction outcomes.

Late reconstruction of extensive orbital floor fracture with a patient-specific implant in a bombing victim

Fractures of the orbital floor and walls are among the most frequent maxillofacial fractures. Virtual three-dimensional (3D) planning and use of patient-specific implants (PSIs) could improve anatomic and functional outcomes in orbital reconstruction surgery. The presented case was a victim of a terrorist attack involving improvised explosive devices. This 58-year-old female suffered severe wounds caused by a single piece of metal from a bomb, shattering the left orbital floor and lateral orbital wall. Due to remaining hypotropia of the left eye compared to the right eye, late orbital floor reconstruction was carried out with a personalised 3D printed titanium implant. We concluded that this technique with PSI appears to be a viable method to correct complex orbital floor defects. Our research group noted good aesthetic and functional results one year after surgery. Due to the complexity of the surgery for a major bony defect of the orbital floor, it is important that the surgery be executed by experienced surgeons in the field of maxillofacial traumatology.

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.

3D titanium implant for orbital reconstruction after maxillectomy

The surgical treatment of maxillary tumours often consists of an open subtotal or total maxillectomy with a subsequent significant defect. Reconstruction is, therefore, a major challenge for head and neck surgeons. Along with 3D printing development, titanium pre-bent implants have been created for orbital wall and floor reconstruction. The aim of this study was to evaluate the post-operative tolerance of these implants in patients who had undergone this procedure in our department. Implant tolerance was the primary endpoint, evaluated by whether or not surgery was required for infection or extrusion 6 months after the procedure. The secondary endpoints were satisfactory functional and aesthetic characteristics of the reconstruction as well as the quality of life. Eleven patients underwent a maxillectomy with orbital floor resection for tumours and reconstruction using the titanium PorousiTi® (Materialise®, Leuven, Belgium) implant beginning in 2013 in Lariboisière Hospital, Paris. The mean follow-up time was 17 months (range, 6-34). During the follow-up period, two patients (n = 2/11; 18.2%) were operated again for implant extrusion and exposure through the skin 1 month later or during their radiotherapy course. During the follow-up period, no post-operative infection occurred in any of the patients. In our experience, the implant was well-tolerated with few post-operative complications and satisfactory aesthetic and functional results.

Facial Transplantation for an Irreparable Central and Lower Face Injury: A Modernized Approach to a Classic Challenge

BACKGROUND

Facial transplantation introduced a paradigm shift in the reconstruction of extensive facial defects. Although the feasibility of the procedure is well established, new challenges face the field in its second decade.

METHODS

The authors' team has successfully treated patients with extensive thermal and ballistic facial injuries with allotransplantation. The authors further validate facial transplantation as a reconstructive solution for irreparable facial injuries. Following informed consent and institutional review board approval, a partial face and double jaw transplantation was performed in a 25-year-old man who sustained ballistic facial trauma. Extensive team preparations, thorough patient evaluation, preoperative diagnostic imaging, three-dimensional printing technology, intraoperative surgical navigation, and the use of dual induction immunosuppression contributed to the success of the procedure.

RESULTS

The procedure was performed on January 5 and 6, 2018, and lasted nearly 25 hours. The patient underwent hyoid and genioglossus advancement for floor-of-mouth dehiscence, and palate wound dehiscence repair on postoperative day 11. Open reduction and internal fixation of left mandibular nonunion were performed on postoperative day 108. Nearly 1 year postoperatively, the patient demonstrates excellent aesthetic outcomes, intelligible speech, and is tolerating an oral diet. He remains free from acute rejection.

CONCLUSIONS

The authors validate facial transplantation as the modern answer to the classic reconstructive challenge imposed by extensive facial defects resulting from ballistic injury. Relying on a multidisciplinary collaborative approach, coupled with innovative emerging technologies and immunosuppression protocols, can overcome significant challenges in facial transplantation and reinforce its position as the highest rung on the reconstructive ladder.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Orbital floor symmetry after maxillectomy and orbital floor reconstruction with individual titanium mesh using computer-assisted navigation

PURPOSE

The present study aimed to evaluate the symmetry of the orbital floor after maxillectomy and orbital floor reconstruction with individual titanium mesh using a computer-assisted navigation system.

PATIENTS AND METHODS

Nineteen patients who underwent orbital floor reconstruction with individual titanium mesh were included in this study. Postoperative computed tomography scans recorded after three-dimensional (3D) reconstruction were used to evaluate the symmetry of the orbital floor, including orbital floor height, orbital floor eminence, globe projection, orbital volume, and surface deviation.

RESULTS

The average orbital floor height of the reconstructed and the unaffected side was 37.7 ± 2.3 and 37.8 ± 2.7 mm, respectively (P = .47). The average orbital floor eminence of the reconstructed and the unaffected side was 40.1 ± 5.5 and 39.6 ± 5.3 mm, respectively (P = .17). The average globe projection of the reconstructed and the unaffected side was 15.5 ± 3.2 and 15.3 ± 3.0 mm, respectively (P = .27). The average orbital volume of the reconstructed and the unaffected side was 25.9 ± 4.4 and 26.3 ± 4.4 cm³, respectively (P = .29). Repeatability between the reconstructed and the unaffected side was 88.3% ± 2.6% at within 1 mm and 98.6% ± 0.9% at within 2 mm. The average of maximum deviation was 2.4 ± 0.2 mm.

CONCLUSION

Individual titanium mesh is one of the best techniques for orbital floor reconstruction, as it can be placed precisely and helps achieve desirable esthetic outcomes through virtual surgical planning and using a computer-assisted navigation system.

Outcomes of Zygomatic Complex Reconstruction With Patient-Specific Titanium Mesh Using Computer-Assisted Techniques

PURPOSE

Zygomatic complex defects after extensive maxillectomy can cause severe esthetic and functional deformities. Patient-specific titanium mesh fabricated using a computer-assisted technique is a promising method for such midface reconstruction. The aim of this study was to evaluate the application and clinical outcomes of this technique.

PATIENTS AND METHODS

This was a retrospective study that included 9 patients with zygomatic complex defects after extensive maxillectomy from 2015 through 2017 at the authors' institution. A 3-dimensional stereo model was obtained based on mirror images of the unaffected side to fabricate a patient-specific titanium mesh using computer-assisted design and manufacturing. Titanium mesh was used to restore the contour of the zygomatic complex with free flap reconstruction after tumor resection. Anterolateral thigh flaps were used in 8 cases and a myocutaneous fibula flap was used in 1 case. Symmetry of the zygomatic complex was evaluated by measuring the zygomatic eminence on the postoperative computed tomogram, and complications were recorded during follow-up visits. Facial symmetry was self-evaluated and scored.

RESULTS

Mean duration for follow-up was 27.3 months (range, 15 to 39 months). Mean deviation of the zygomatic eminence between the reconstructed and unaffected sides was 1.4 ± 0.5 mm. No significant difference was noted in the zygomatic eminence between the reconstructed and unaffected sides (P = .591). Titanium mesh exposure occurred in only 1 patient after radiotherapy. There were no other remarkable complications. All patients were satisfied with their postoperative facial symmetry.

CONCLUSION

Patient-specific titanium mesh fabricated using a computer-assisted technique was an alternative option for extensive zygomatic complex reconstruction, resulting in acceptable clinical outcomes. A study with a larger sample and long-term follow-up is needed for the observation of long-term outcomes and risk of titanium mesh-related complications.

A novel approach to skull-base and orbital osteotomies through virtual planning and navigation

OBJECTIVE

Computer-assisted planning of osteotomy lines, coupled with navigation-guided performance of planned osteotomies, is a highly innovative approach to skull-base and orbital surgery. The aim of this pilot study is to provide an assessment of the accuracy of this novel approach in guiding the correct positioning of osteotomy lines in frontal, temporal, and orbital regions, defining the agreement between the spatial position of the planned and performed osteotomies.

METHODS

Fifteen patients with orbital, frontal sinus, and lateral skull-base diseases underwent virtual surgical planning. Osteotomies to access the orbit, frontal sinus, and lateral skull base were planned on computer tomography-based three-dimensional models. The planned osteotomies were reproduced on the operating field using a navigation system. The positions of the performed and planned osteotomies were compared. The results were described as the mean positional difference between planned and performed osteotomies and as Lin's concordance coefficient, and Bland-Altman limits of agreement were also defined.

RESULTS

The overall mean difference was 0.719 mm (95% confidence interval [CI]: 0.472 to 0.965 mm). Overall, Lin's concordance coefficient was 0.997 (95% CI: 0.996 to 0.998), and overall Bland-Altman limits of agreement ranged from -1.407 to 2.844 mm. The smallest mean difference (0.587 mm, 95% CI: 0.244 to 0.931 mm) was calculated in the orbit group, whereas the highest mean difference (0.904 mm, 95% CI: 0.428 to 1.379 mm) was described in the lateral skull-base group.

CONCLUSION

This study's results support the use of this novel planning and navigation protocol for guiding osteotomy in anterior and lateral skull-base surgery, providing a clinical validation of this technique.

LEVEL OF EVIDENCE

4 Laryngoscope, 00:1-9, 2018 Laryngoscope, 129:823-831, 2019.

Functional Reconstruction in Mandibular Avulsion Injuries

The present report describes the planning and surgery as well as pitfalls and management of a patient with a near total mandibular avulsion injury that was rehabilitated using three-dimensional (3D) laser printing of a titanium lower jaw. Laser-sintering involves zapping layers of powdered metal to recreate a 3D implantable skeletal defect. The process involves using either mirror imaging of the unaffected side or using archival image database of healthy individuals. A 25-year-old man presented with a gunshot injury that left him with a near total avulsed mandible. The patient received state-of-the-art treatment using a laser 3D printed mandible which was connected to the muscles of mastication for functionality. The inner side of the titanium jaw was filled with the patient's comminuted fractured bones in addition to harvested iliac crest bone graft that was covered with the patient's remaining periosteal tissue. The implantation of a near total mandible using 3D laser printing is a fast and predictable process that in selected patients can result in aesthetically as well as functionally excellent results. The authors believe that the future of craniofacial reconstruction will employ these methods for facial bony reconstruction.

Reconstruction of Maxillary and Orbital Floor Defect With Free Fibula Flap and Whole Individualized Titanium Mesh Assisted by Computer Techniques

PURPOSE

We sought to investigate the clinical application of free fibula flap and individualized titanium mesh through the use of a virtual planning and guiding template to assist the reconstruction of maxilla and orbital floor defects.

PATIENTS AND METHODS

Between 2015 and 2016, a total of 6 adult patients with maxillary and orbital floor defects were enrolled in this study. Preoperative virtual planning, including virtual maxillary resection and fibular reconstruction, was performed in all cases according to 3-dimensional radiographic and clinical findings. A 3-dimensionally printed resin model and prebent templates were used to guide the harvesting and positioning of the fibula flap during surgery. Then, an individualized titanium mesh was used to support the orbital floor and restore the maxillary contour. The results were confirmed by postoperative computed tomography scans and clinical follow-up.

RESULTS

Preoperative virtual planning and prebent templates can be used to guide the harvesting and positioning of the fibula flap, as well as the forming and positioning of the individualized titanium mesh, with satisfactory results. All flaps survived, and symmetrical facial contours were achieved with normal lower jaw movement and proper vertical distance for dental implants in all patients.

CONCLUSIONS

Computer-aided techniques such as virtual planning, 3-dimensionally printed models, and prebent guide templates can be used to harvest and position a free fibula flap, form personalized titanium mesh, and ultimately improve the clinical efficacy of maxillary and orbital floor reconstruction.

The "Drawer-Like" Resection and Reconstruction With Titanium Mesh: A Novel Surgical Technique for Treatment of Giant Ossifying Fibroma in the Maxilla

PURPOSE

The aim of this article is to introduce a new surgical method for the treatment of ossifying fibroma (OF) in the maxilla with dislocation of the eyeball and to evaluate the postoperative outcomes and prognosis.

PATIENTS AND METHODS

Cases of maxillary OF treated with "drawer-like" resection from 2014 to 2015 were reviewed. The surgical procedure consisted of total removal of the orbital floor and most of the maxilla with preservation of the alveolar ridge immediately followed by reconstruction with titanium mesh. Postoperative appearance and function were assessed. In addition, the recurrence rate was statistically observed.

RESULTS

The study included 6 patients with maxillary OF who were treated with drawer-like resection. Good esthetics and decrease of the globe were successfully achieved in all patients. Long-term follow-up showed a low recurrence rate. The original occlusal relation and masticatory function were preserved.

CONCLUSIONS

With this new method, the original occlusal relation can be well preserved and bulging of the maxilla and eyeball displacement can be corrected.

Surgical Navigation: A Systematic Review of Indications, Treatments, and Outcomes in Oral and Maxillofacial Surgery

PURPOSE

This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indications are discussed.

MATERIALS AND METHODS

A systematic search in relevant electronic databases, journals, and bibliographies of the included articles was carried out. Clinical studies with 5 or more patients published between 2010 and 2015 were included. Traumatology, orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign body removal were the areas of interests.

RESULTS

The search generated 13 articles dealing with traumatology; 5, 6, 2, and 0 studies were found that dealt with the topics of orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign body removal, respectively. The average technical system accuracy and intraoperative precision reported were less than 1 mm and 1 to 2 mm, respectively. In general, SN is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients were identified in the field of traumatology. Treatment of complex orbital fractures was considerably improved by the use of SN compared with traditionally treated control groups.

CONCLUSIONS

SN seems to be a very promising addition to the surgical toolkit. Planning details of the surgical procedure in a 3-dimensional virtual environment and execution with real-time guidance can significantly improve precision. Among factors to be considered are the financial investments necessary and the learning curve.