Does intraoperative navigation restore orbital dimensions in traumatic and post-ablative defects?

Surgical Navigation and CAD-CAM-Designed PEEK Prosthesis for the Surgical Treatment of Facial Intraosseous Vascular Anomalies

Background: Intraosseous vascular anomalies in the facial skeleton present significant diagnostic and therapeutic challenges due to complex anatomy. These anomalies represent about 0.5-1% of bony neoplastic and tumor-like lesions, usually presenting as a firm, painless mass. Most described intraosseous vascular malformations are venous malformations (VMs) and, more rarely, arteriovenous malformations. Objectives: The objectives of this work are to show our experience, protocol and the applications of computer planning, virtual surgery, CAD-CAM design, surgical navigation, and computer-assisted navigated piezoelectric surgery in the treatment of facial intraosseous vascular anomalies and to evaluate the advantages and disadvantages. Methods: Three females and one male with periorbital intraosseous vascular anomalies were treated using en-block resection and immediate reconstruction with a custom-made PEEK prosthesis. One lesion was in the supraorbital rim and orbital roof, one in the frontal bone and orbital roof, and two in the zygomatic region. We accomplished the resection and reconstruction of the lesion using virtual planning, CAD-CAM design, surgical navigation and piezoelectric device navigation. Results: There were no complications related to the surgery assisted with navigation. With an accuracy of less than 1 mm, the procedure may be carried out in accordance with the surgical plan. The surgeon's degree of uncertainty during deep osteotomies and in locations with low visibility was decreased by the use of the navigated piezoelectric device. Conclusions: Resection and reconstruction of facial intraosseous vascular anomalies benefit from this new surgical strategy using CAD-CAM technologies, computer-assisted navigated piezoelectric surgery, and surgical navigation.

Three-dimensional computer navigation in the reconstruction of complex unilateral orbital fractures: evaluation and review of applications

BACKGROUND

The eyes are the central aesthetic unit of the face. Maxillofacial trauma can alter facial proportions and affect visual function with varying degrees of severity. Conventional approaches to reconstruction have numerous limitations, making the process challenging. The primary objective of this study was to evaluate the application of three-dimensional (3D) navigation in complex unilateral orbital reconstruction.

METHODS

A prospective cohort study was conducted over 19 months (January 2020 to July 2021), with consecutive enrollment of 12 patients who met the inclusion criteria. Each patient was followed for a minimum period of 6 months. The principal investigator carried out a comparative analysis of several factors, including fracture morphology, orbital volume, globe projection, diplopia, facial morphic changes, lid retraction, and infraorbital nerve hypoesthesia.

RESULTS

Nine patients had impure orbital fractures, while the remainder had pure fractures. The median orbital volume on the normal side (30.12 cm3; interquartile range [IQR], 28.45-30.64) was comparable to that of the reconstructed orbit (29.67 cm3; IQR, 27.92-31.52). Diplopia improved significantly (T(10) = 2.667, p = 0.02), although there was no statistically significant improvement in globe projection. Gross symmetry of facial landmarks was achieved, with comparable facial width-to-height ratio and palpebral fissure lengths. Two patients reported infraorbital hypoesthesia at presentation, which persisted at the 6-month follow-up. Additionally, five patients developed lower lid retraction (1-2 mm), and one experienced implant impingement at the infraorbital border.

CONCLUSION

Our study provides level II evidence supporting the use of 3D navigation to improve surgical outcomes in complex orbital reconstruction.

Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques.

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles.

RESULTS

After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used.

CONCLUSION

Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

Surgical Treatment of Blow-out Fracture: A New Perspective

The present work aims to report 2 clinical cases of the use of current technologies for the treatment of orbital fractures. The cases are of patients who were victims of car accidents and who developed a blow-out orbital fracture. Clinically, they presented periorbital ecchymosis, blepharoedema, enophthalmos, and ophthalmoplegia and, therefore, underwent surgical reconstructive treatment. For both cases, preoperative computed tomography and biomodel impression of the orbits were performed. The modeling of the titanium mesh covering the defect in the biomodel that would be used in the surgery was performed. In the intraoperative period of reduction and fixation of the fracture with the titanium mesh, optics were used to better visualize the posterior defect, as well as computed tomography to ensure that the entire affected area was reconstructed. Both patients were followed up in the postoperative period and evolved without clinical and functional complaints.

Increased Reliability in Medial Canthal Tendon Reposition in Nasoorbitoethmoidal Fractures with Computer-assisted Surgery and Surgical Navigation

Avulsion of the medial canthal tendon secondary to nasoorbitoethmoidal fractures leads to severe aesthetic and functional impairments. The tendon should be repositioned at the posterior lacrimal crest. Owing to the complexity of nasoorbitoethmoidal fractures, accurate location of this point during surgery can be challenging. With the aid of computer-assisted planning and surgical navigation, the point at which the medial canthal tendon should be repositioned can be easily and precisely located. We have developed an innovative navigation-assisted technique that increases the reliability and safety of internal canthus repositioning. We performed a case series of three consecutive patients who underwent medial canthal tendon repositioning using computer-assisted planning and surgical navigation. We believe that this innovation provides a new and useful application of computer-assisted planning and surgical navigation in craniomaxillofacial surgery.

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.

Comparison of Postoperative Enophthalmos Between Fresh and Delayed Unilateral Orbital Fractures After Orbital Reconstruction With Titanium Mesh Using Computer-Assisted Navigation

This study compares postoperative enophthalmos between fresh and delayed unilateral orbital fractures after orbital reconstruction with titanium mesh using computer-assisted navigation. The sample was composed of 45 patients with post-traumatic unilateral enophthalmos who were divided into the fresh fracture group and the delayed fracture group. They underwent orbital reconstruction with standard preformed orbital implants and computer-assisted navigation system. The following parameters were measured with computed tomography images: the degree of enophthalmos, orbital volume, and fracture defect area. Patients were reviewed preoperatively (T0), 1 week postoperatively (T1), and 6 months postoperatively (T2). Computed tomography measurements showed that in both groups, the degree of enophthalmos decreased after surgery but increased significantly from T1 to T2 ( P <0.05). ΔE (difference in the degree of enophthalmos between T1 and T2) was similar in patients with fresh and delayed fractures. There was a significant difference in the degree of ΔE between patients with single-wall orbital fractures and those with two-wall orbital fractures. The findings indicate that postoperative enophthalmos is common in both the groups and is closely related to the degree of preoperative enophthalmos. Furthermore, the recurrence of enophthalmos is similar between the 2 groups, but it is higher in patients with orbital fractures involving 2 walls.

Primary Orbital Reconstruction with Selective Laser Melting (SLM) of Patient-Specific Implants (PSIs): An Overview of 96 Surgically Treated Patients

Contemporary advances in technology have allowed the transfer of knowledge from industrial laser melting systems to surgery; such an approach could increase the degree of accuracy in orbital restoration. The aim of this study was to examine the accuracy of selective laser melted PSIs (patient-specific implants) and navigation in primary orbital reconstruction. Ninety-six patients with orbital fractures were included in this study. Planned vs. achieved orbital volumes (a) and angles (b) were compared to the unaffected side (n = 96). The analysis included the overlay of post-treatment on planned images (iPlan 3.0.5, Brainlab®, Feldkirchen, Germany). The mean difference in orbital volume between the digitally planned orbit and the postoperative orbit was 29.16 cm3 (SD 3.54, presurgical) to 28.33 cm3 (SD 3.64, postsurgical, t = 5.00, df = 95.00; p < 0.001), resulting in a mean volume difference (planned vs. postop) of less than 1 cm3. A 3D analysis of the color mapping showed minor deviations compared to the mirrored unaffected side. The results suggested that primary reconstruction in complex orbital wall fractures can be routinely achieved with a high degree of accuracy by using selective laser melted orbital PSIs.

Three-Dimensional Printed Customized Surgical Guides for the Precise Correction of Complex Midfacial Post-Traumatic Deformities

PURPOSE

The introduction of intraoperative computed tomography and image-guided navigation have demonstrated some advantages for the correction of midfacial post-traumatic deformities. However, these methods still do not achieve satisfactory results. The authors sought to describe a novel method for the precise correction of complex midfacial post-traumatic deformities using three-dimensional printing customized surgical guides.

METHODS

Ten patients with midfacial post-traumatic deformities admitted between January 15, 2018 and August 20, 2020 were included. To design the surgical guide for each patient, preoperative planning and simulation datasets were used as a virtual template. Each surgical guide comprised three-dimensional printing cutting guides and customized titanium plates to guide the osteotomy and repositioning of the fracture fragments intraoperatively. Reduction and fixation were confirmed by intraoperative navigation. Postoperative deviation chromatography analysis and clinical examination were conducted to evaluate the surgical outcome. All operations were successfully performed.

RESULTS

The average difference between the virtual plans and postoperative results was less than 1.5 mm. The 3- to 6-month follow-up evaluation demonstrated that symptoms were alleviated, and postoperative function and esthetics improved considerably.

CONCLUSIONS

Three-dimensional-printed customized surgical guides can accurately and effectively transfer the virtual surgical plan to the patient and could be considered an ideal and valuable option for this potentially complicated procedure.

Customized and Navigated Primary Orbital Fracture Reconstruction: Computerized Operation Neuronavigated Surgery Orbital Recent Trauma (CONSORT) Protocol

ABSTRACT

Combined orbital medial wall and floor fractures and large isolated orbital floor fractures commonly require surgical treatment due to the high probability of diplopia and enophthalmos. Primary reconstruction of these orbital fractures requires a high-level surgeon with a great amount of technical surgical skill. The use of novel technology can greatly improve the accuracy of reconstruction and achieve satisfactory clinical outcomes. Hence, the authors aimed to present our findings and overall experience with respect to extensive floor and medial wall orbital fracture reconstruction according to the Computerized Operation Neuronavigated Surgery Orbital Recent Trauma (CONSORT) protocol, a workflow designed for the primary reconstruction of orbital fractures with customized mesh and intraoperative navigation. A total of 25 consecutively presenting patients presenting with unilateral extensive orbital floor fractures and orbital floor and medial wall fractures were treated following the CONSORT workflow from January 2017 to March 2020. Fractures were surgically treated with a customized implant and intraoperative navigation. Patients underwent surgery within 14 days of the trauma injury. Preoperative and postoperative functional and aesthetic outcomes are described herein. All fractures were successfully reconstructed. Postoperatively, all 19 patients with preoperative diplopia reported the resolution of diplopia. Enophthalmos resolved in 18/20 cases. No patients had major complications during follow-up. Thus, the authors conclude that the CONSORT protocol introduced by the authors is an adaptable and reliable workflow for the early treatment of orbital fractures and can clearly optimize functional and aesthetic outcomes, reduce costs and intensive time commitments, and make customized and navigated surgery more available for institutions.

Updates in Management of Craniomaxillofacial Gunshot Wounds and Reconstruction of the Mandible

This article includes updates in the management of mandibular trauma and reconstruction as they relate to maxillomandibular fixation screws, custom hardware, virtual surgical planning, and protocols for use of computer-aided surgery and navigation when managing composite defects from gunshot injuries to the face.

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.

Management of Zygomaticomaxillary Complex Fractures Utilizing Intraoperative 3-Dimensional Imaging: The ZYGOMAS Protocol

PURPOSE

Utilization of technology to aid in the assessment, planning, and management of complex craniomaxillofacial injuries is increasingly common. Limited data exist regarding the implication of intraoperative CT/3-Dimensional imaging on decision making in the management of zygomaticomaxillary complex (ZMC) fractures. This study characterizes the utilization of the intraoperative CT scanner for ZMC fracture surgery and analyzes the impact of the intraoperative CT scanner on fracture management. Using these findings, we sought to propose an algorithm to guide the appropriate utilization of intraoperative 3-Dimensional imaging in ZMC fracture surgery.

METHODS

This retrospective case series evaluates the use of the intraoperative CT scanner for orbitozygomatic trauma surgery at a level 1 trauma center from February 2011 to September 2016. We evaluated the preoperative CT images assessing for the number of displaced sutures, the presence of adjacent fractures requiring fixation, the presence of comminution of the zygomaticomaxillary buttress or body of the zygoma, as well as the number of axes displaced ≥ 5 mm. This information was evaluated to provide guidance on the appropriate utilization of the intraoperative scanner in ZMC fracture management.

RESULTS

A total of 71 patients were identified to have intraoperative facial CT scans and surgery for ZMC fractures over the study time period. There was a 23.9% (17/71) CT directed revision rate. There was a significantly increased likelihood of CT directed revision for fractures with adjacent fractures requiring fixation, and those with ≥ 2 axes displaced ≥ 5 mm. Using these findings, we proposed the ZYGOMAS algorithm outlining the indications for use of intraoperative CT in management of ZMC fractures.

CONCLUSIONS

If available, intraoperative CT/3-Dimensional imaging should be utilized in the management of ZMC fractures with the requirement for orbital floor reconstruction, where adjacent fractures require fixation and/or when ≥ 2 axes are displaced ≥ 5 mm.

Assesing Intraoperative Virtual Navigation on My Craniofacial Surgery Fellowship for Orbital Fractures Repair: Is it Useful?

ABSTRACT

Orbital fractures pose specific challenge in its surgical management. One of the greatest challenges is to obtain satisfactory restoration of normal orbital volume and globe projection following traumatic injury, due to the inability of the surgeon to gain adequate visibility and to verify proper implant position and placement during the operation. Surgical navigation is a very helpful tool when dealing with the reconstruction of such orbital fractures. During the training of the craniofacial fellowship learning to recognize the orbital floor boundaries is essential for the correct implant placement for reconstruction, their identification is a critical step, which may be assisted by intraoperative virtual navigation. Six patients were surgically treated for orbital floor fracture with intraoperative virtual navigation. The clinical evaluation showed no complications such as enophtalmos, exophtalmos or dystopia in all the patients 2 months post operatively and a correct implant/graft position.During surgery, navigation provides exact determination of transverse, cranio-caudal and postero-anterior dimensions within the orbit and precise control of the position of implants/bone grafts.This tool aids consistently on the craniofacial surgery fellow's formation, as it facilitates the identification of the bony floor boundaries and verifies the correct placement of the implants/bone grafts. It is routinely use could help to avoid implants/bone grafts misplacement not only for craniofacial surgeon's fellow, but for all the orbital surgeons.

Intraoperative Navigation and Cone Beam Computed Tomography for Restoring Orbital Dimensions: A Single-Center Experience

Background

Correction of post-traumatic orbital defects remains a challenge for the maxillofacial surgeon. We examined the added value of combined intraoperative (IO) navigation and IO cone beam computed tomography (CBCT).

Materials and Methods

A retrospective cohort study was performed in all consecutive patients requiring unilateral post-traumatic orbital surgery between January 2012 and December 2018. Patients were divided into 3 groups: IO navigation (NAV), IO-CBCT (CBCT), and IO navigation with IO-CBCT (NAV-CBCT). A detailed description of our workflow is provided. Volumetric comparison of the operated orbit to the contralateral orbit was made with Brainlab.

Results

Of the 81 cases, 22 patients were included (12 males/10 females) with a mean age of 51 years. Three patients were assigned to NAV, 6 to CBCT, and 13 to NAV-CBCT. The reconstructed orbital volume did not significantly differ from the contralateral orbital volume within the 3 groups. The mean difference between the contralateral and the operated orbit was 3.05 cm³, 3.72 cm³, and 1.47 cm³ for NAV, CBCT, and NAV-CBCT, respectively, where only NAV-CBCT showed a significant smaller volumetric difference in comparison to CBCT alone. Gender or age did not correlate with difference in orbital volume. Normal function and aesthetics was seen at 6 weeks postoperative in 0 of 3, 6of 6, and 6 of 13 patients of the NAV, CBCT, and NAV-CBCT, respectively.

Conclusion

Orbital defects can be treated effectively using IO navigation. Although our data could not demonstrate a significant added value of IO-CBCT in cases where IO navigation was used based on volumetric difference alone, the combination of IO-CBCT and IO navigation seems to give the best results considering both volumetric difference and postoperative function and aesthetics. Confirmation in a prospective, randomized trial with a larger sample size is required.

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.

Implant-oriented navigation in orbital reconstruction part II: preclinical cadaver study

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and translate it to desired adjustments of the implant's position. In a previous study, a real-time implant-oriented navigation approach was introduced and the system's accuracy was evaluated. In this study, this real-time navigation approach was compared to a marker-based navigation approach in a preclinical set-up. Ten cadavers (20 orbital defects) were reconstructed twice, by two surgeons (total: 80 reconstructions). Implant positioning was significantly improved in the real-time implant-oriented approach in terms of roll (2.0° vs. 3.2°, P=0.03), yaw (2.2° vs. 3.4°, P=0.01) and translation (1.3mm vs. 1.8mm, P=0.005). Duration of the real-time navigation procedure was reduced (median 4.5 min vs. 7.5 min). Subjective appreciation of the navigation technique was higher for real-time implant-oriented navigation (mean 7.5 vs. 9.0). Real-time implant-oriented navigation feedback provides real-time, intuitive feedback to the surgeon, which leads to improved implant positioning and shortens duration of the navigation procedure.

Computer-assisted navigation in orbitofacial surgery

The purpose of this systematic review is to investigate the most common indications, treatment, and outcomes of computer-assisted surgery (CAS) in ophthalmological practice. CAS has evolved over the years from a neurosurgical tool to maxillofacial as well as an instrument to orbitofacial surgeries. A detailed and organized scrutiny in relevant electronic databases, journals, and bibliographies of the cited articles was carried out. Clinical studies with a minimum of two study cases were included. Navigation surgery, posttraumatic orbital reconstruction, computer-assisted orbital surgery, image-guided orbital decompression, and optic canal decompression (OCD) were the areas of interest. The search generated 42 articles describing the use of navigation in facial surgery: 22 on orbital reconstructions, 5 related to lacrimal sac surgery, 4 on orbital decompression, 2 articles each on intraorbital foreign body and intraorbital tumors, 2 on faciomaxillary surgeries, 3 on cranial surgery, and 2 articles on navigation-guided OCD in traumatic optic neuropathy. In general, CAS is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients were related to trauma. Treatment of complex orbital fractures was greatly improved by the use of CAS compared with empirically treated control groups. CAS seems to add a favourable potential to the surgical armamentarium. Planning details of the surgical approach in a three-dimensional virtual environment and execution with real-time guidance can help in considerable enhancement of precision. Financial investments and steep learning curve are the main hindrances to its popularity.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Precision of a Novel Craniofacial Surgical Navigation System Based on Augmented Reality Using an Occlusal Splint as a Registration Strategy

The authors have developed a novel augmented reality (AR)-based navigation system (NS) for craniofacial surgery. In this study, the authors aimed to measure the precision of the system and further analyze the primary influencing factors of the precision. The drilling of holes into the mandibles of ten beagle dogs was performed under the AR-based NS, and the precision was analyzed by comparing the deviation between the preoperational plan and the surgical outcome. The AR-based NS was successfully applied to quickly and precisely drill holes in the mandibles. The mean positional deviation between the preoperative design and intraoperative navigation was 1.29 ± 0.70 mm for the entry points and 2.47 ± 0.66 mm for the end points, and the angular deviation was 1.32° ± 1.17°. The precision linearly decreased with the distance from the marker. In conclusion, the precision of this system could satisfy clinical requirements, and this system may serve as a helpful tool for improving the precision in craniofacial surgery.

The Biaxial Double-Barrel Fibula Flap-A Simplified Technique for Fibula Maxillary Reconstruction

PURPOSE

Previously described techniques for microvascular fibula reconstruction of Brown Class II to IV maxillectomy defects are complex, require multiple osteotomies, result in a short pedicle, and inadequately reconstruct the dental alveolus in preparation for endosseous implants. This report describes a simplified technique for Brown Class II to IV defects that re-creates facial support, allows for dental reconstruction with appropriately positioned implants, and maintains adequate pedicle length.

MATERIALS AND METHODS

A retrospective chart review was performed of all patients with Brown Class II to IV maxillectomy defects immediately reconstructed with a biaxial double-barrel fibula flap technique. The reconstructive surgeon evaluated each patient at least 1 month after reconstruction for enophthalmos, facial symmetry, nasal patency, satisfactory jaw position, deglutition, intelligible speech, and intraoperative need for vein grafting.

RESULTS

The sample was composed of 6 patients (mean age, 54 yr; range, 33 to 78 yr; 67% women) who underwent reconstruction with the biaxial double-barrel fibula flap technique for Brown Class II to IV defects. None of these patients required vein grafting. None of these patients had flap failure. Diagnoses for these patients were a hybrid odontogenic tumor (n = 1), squamous cell carcinoma (n = 3), adenoid cystic carcinoma (n = 1), and sinonasal melanoma (n = 1). All 6 patients had excellent facial contour and malar projection, regular oral intake, 100% intelligible speech, and a new maxillary skeletal Class I relation without need for intraoperative vein grafting. One patient developed enophthalmos related to inferior rectus sacrifice and removal of orbital fat. Complications included development of nasal synechia and occlusion of the maxillary sinus ostium (n = 1).

CONCLUSIONS

The biaxial double-barrel fibula flap technique achieves the goals of providing adequate facial support and an alveolar segment amenable to implant dentistry. It allows for intelligible speech, deglutition, orbital support, and separation of the oronasal, orbital, and sinus cavities. In addition, it minimizes the need for vein grafting.

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.

Updates in Management of Craniomaxillofacial Gunshot Wounds and Reconstruction of the Mandible

This article includes updates in the management of mandibular trauma and reconstruction as they relate to maxillomandibular fixation screws, custom hardware, virtual surgical planning, and protocols for use of computer-aided surgery and navigation when managing composite defects from gunshot injuries to the face.

Clinical outcomes for minimally invasive primary and secondary orbital reconstruction using an advanced synergistic combination of navigation and endoscopy

BACKGROUND

Sequelae of inadequate orbital reconstruction include enophthalmos, hypoglobus, and diplopia. Accuracy of orbital reconstruction is largely subjective and especially difficult to achieve because of anatomic distortion in secondary or late reconstruction and in extensive injury. We combined computer navigation and endoscopy to perform accurate, aesthetic, and safe minimal-access primary and secondary orbital reconstruction.

METHODS

From 2013 to 2014, 24 patients underwent unilateral primary and secondary or late minimally invasive orbital reconstruction with mainly Medpor and/or titanium mesh by navigation and endoscopic assistance through transantral, transconjunctival, or upper blepharoplasty approaches. Mean follow-up was 13.8 months (range, 6.2 months to 2.8 years).

RESULTS

All orbital fractures were successfully reduced. Average enophthalmos among patients who underwent early reconstruction, late reconstruction, and multiorbital wall repair improved (p < .001) to 0.2 mm from 1.6, 2.6, and 2.6 mm, respectively. Hypoglobus and diplopia resolved in all. In early reconstruction patients, mean interorbital volume difference improved from 1.72 ± 0.87 to 0.53 ± 0.83 ml (P = .03). For late reconstruction patients, this difference improved from 3.41 ± 1.23 to 0.56 ± 0.96 ml (p < .001). There were no major complications during follow-up, and all were satisfied with their final appearance and function.

CONCLUSION

Navigation sharpens reconstructive accuracy and avoids injury to vital structures. Combined with endoscopic assistance for minimal-access reconstruction of wide-ranging orbital defects from primary to secondary or late cases and to extensive multiwall fractures, navigation facilitates minimal cosmetic incision and synergistic endoscope use and clearly optimizes aesthetic and functional outcomes, all with enhanced safety and unparalleled intraoperative visualization.

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.

Predictability in orbital reconstruction. A human cadaver study, part III: Implant-oriented navigation for optimized reconstruction

Navigation-assisted orbital reconstruction remains a challenge, because the surgeon focuses on a two-dimensional multiplanar view in relation to the preoperative planning. This study explored the addition of navigation markers in the implant design for three-dimensional (3D) orientation of the actual implant position relative to the preoperative planning for more fail-safe and consistent results. Pre-injury computed tomography (CT) was performed for 10 orbits in human cadavers, and complex orbital fractures (Class III/IV) were created. The orbits were reconstructed using preformed orbital mesh through a transconjunctival approach under image-guided navigation and navigation by referencing orientating markers in the implant design. Ideal implant positions were planned using preoperative CT scans. Implant placement accuracy was evaluated by comparing the planned and realized implant positions. Significantly better translation (3.53 mm vs. 1.44 mm, p = 0.001) and rotation (pitch: -1.7° vs. -2.2°, P = 0.52; yaw: 10.9° vs. 5.9°, P = 0.02; roll: -2.2° vs. -0.5°, P = 0.16) of the placed implant relative to the planned position were obtained by implant-oriented navigation. Navigation-assisted surgery can be improved by using navigational markers on the orbital implant for orientation, resulting in fail-safe reconstruction of complex orbital defects and consistent implant positioning.

Predictability in orbital reconstruction: A human cadaver study. Part I: Endoscopic-assisted orbital reconstruction

In the treatment of orbital defects, surgeon errors may lead to incorrect positioning of orbital implants and, consequently, poor clinical outcomes. Endoscopy can provide additional visualization of the orbit through the transantral approach. We aimed to evaluate whether endoscopic guidance during orbital reconstruction facilitates optimal implant placement and can serve as a convenient alternative for navigation and intra-operative imaging. Ten human cadaveric heads were subjected to thin-slice computed tomography (CT). Complex orbital fractures (Class III/IV) were created in all eligible orbits (n = 19), which were then reconstructed using the conventional transconjunctival approach with or without endoscopic guidance. The ideal implant location was digitally determined using pre-operative CT images, and the accuracy of implant placement was evaluated by comparing the planned implant location with the postoperative location. There were no statistically significant differences (p > 0.05) in the degree of implant dislocation (translation and rotation) between the transconjunctival orbital reconstruction and the endoscopic-assisted orbital reconstruction groups. Endoscopic-assisted orbital reconstruction may facilitate the visualization of orbital defects and is particularly useful for training purposes; however, it offers no additional benefits in terms of accurate implant positioning during the anatomical reconstruction of complex orbital defects.

Predictability in orbital reconstruction: A human cadaver study. Part II: Navigation-assisted orbital reconstruction

Preformed orbital reconstruction plates are useful for treating orbital defects. However, intraoperative errors can lead to misplaced implants and poor outcomes. Navigation-assisted surgery may help optimize orbital reconstruction. We aimed to explore whether navigation-assisted surgery is more predictable than traditional orbital reconstruction for optimal implant placement. Pre-injury computed tomography scans were obtained for 10 cadaver heads (20 orbits). Complex orbital fractures (Class III-IV) were created in all orbits, which were reconstructed using a transconjunctival approach with and without navigation. The best possible fit of the stereolithographic file of a preformed orbital mesh plate was used as the optimal position for reconstruction. The accuracy of the implant positions was evaluated using iPlan software. The consistency of orbital reconstruction was lower in the traditional reconstructions than in the navigation group in the parameters of translation and rotation. Implant position also differed significantly in the parameters of translation (p = 0.002) and rotation (pitch: p = 0.77; yaw: p < 0.001; roll: p = 0.001). Compared with traditional orbital reconstruction, navigation-assisted reconstruction provides more predictable anatomical reconstruction of complex orbital defects and significantly improves orbital implant position.

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

PURPOSE

Orbital floor defects after extensive maxillectomy can cause severe esthetic and functional deformities. Orbital floor reconstruction using the computer-assisted fabricated individual titanium mesh technique is a promising method. This study evaluated the application and clinical outcomes of this technique.

PATIENTS AND METHODS

This retrospective study included 10 patients with orbital floor defects after maxillectomy performed from 2012 through 2014. A 3-dimensional individual stereo model based on mirror images of the unaffected orbit was obtained to fabricate an anatomically adapted titanium mesh using computer-assisted design and manufacturing. The titanium mesh was inserted into the defect using computer navigation. The postoperative globe projection and orbital volume were measured and the incidence of postoperative complications was evaluated.

RESULTS

The average postoperative globe projection was 15.91 ± 1.80 mm on the affected side and 16.24 ± 2.24 mm on the unaffected side (P = .505), and the average postoperative orbital volume was 26.01 ± 1.28 and 25.57 ± 1.89 mL, respectively (P = .312). The mean mesh depth was 25.11 ± 2.13 mm. The mean follow-up period was 23.4 ± 7.7 months (12 to 34 months). Of the 10 patients, 9 did not develop diplopia or a decrease in visual acuity and ocular motility. Titanium mesh exposure was not observed in any patient. All patients were satisfied with their postoperative facial symmetry.

CONCLUSION

Orbital floor reconstruction after extensive maxillectomy with an individual titanium mesh fabricated using computer-assisted techniques can preserve globe projection and orbital volume, resulting in successful clinical outcomes.

Image-guided bone resection as a prospective alternative to cutting templates—A preliminary study

OBJECTIVE

To evaluate the accuracy of craniomaxillofacial resections performed with an image-guided surgical sagittal saw.

MATERIAL AND METHODS

Twenty-four craniomaxillofacial resections were performed using an image-guided sagittal saw. Surgical outcomes were compared with a preoperative virtual plan in terms of the resected bone volume, control point position and osteotomy trajectory angle. Each measurement was performed twice by two independent observers.

RESULTS

The best convergence between the planned and actual bone resection was observed for the orbital region (6.33 ± 4.04%). The smallest mean difference between the preoperative and postoperative control point positions (2.00 ± 0.66 mm) and the lowest mean angular deviation between the virtual and actual osteotomy (5.49 ± 3.17 degrees) were documented for the maxillary region. When all the performed procedures were analyzed together, mean difference between the planned and actual bone resection volumes was 9.48 ± 4.91%, mean difference between the preoperative and postoperative control point positions amounted to 2.59 ± 1.41 mm, and mean angular deviation between the planned and actual osteotomy trajectory equaled 8.21 ± 5.69 degrees.

CONCLUSION

The results of this study are encouraging but not fully satisfactory. If further improved, the hereby presented navigation technique may become a valuable supporting method for craniomaxillofacial resections.

Three-dimensional computer-assisted surgical simulation and intraoperative navigation in orthognathic surgery: a literature review

By incorporating three-dimensional (3D) imaging and computer-aided design and manufacturing techniques, 3D computer-assisted technology has been applied widely to provide accurate guidance for assessment and treatment planning in clinical practice. This technology has recently been used in orthognathic surgery to improve surgical planning and outcome. The modality will gradually become popular. This study reviewed the literature concerning the use of computer-assisted techniques in orthognathic surgery including surgical planning, simulation, intraoperative translation of the virtual surgery, and postoperative evaluation. A Medline, PubMed, ProQuest, and ScienceDirect search was performed to find relevant articles with regard to 3D computer-assisted orthognathic surgery in the past 10 years. A total of 460 articles were revealed, out of which 174 were publications addressed the topic of this study. The purpose of this article is to present an overview of the state-of-art methods for 3D computer-assisted technology in orthognathic surgery. From the review we can conclude that the use of computer-assisted technique in orthognathic surgery provides the benefit of optimal functional and aesthetic results, patient satisfaction, precise translation of the treatment plan, and facilitating intraoperative manipulation.