Reliability of Intraoperative Navigation in Restoring Normal Orbital Dimensions

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.

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.

C-Arm a Useful Tool for Surgeons in Reduction of Zygomatic Complex Fracture: A Comparative Study: Article Type-Original Research

Introduction

Reduction of zygomaticomaxillary (ZMC) fracture is often difficult to evaluate intraoperatively because of it peculiar anatomy and limited accessibility. The purpose of this study is to evaluate the efficacy of use of C-arm as a tool for intraoperative monitoring of ZMC fracture reduction.

Materials and Methods

Group I (C-Arm) and Group II (control group) comprised of patients with isolated unilateral displaced Zygomatic complex (ZMC) fractures and having orbital volume change. The efficacy of use of C-arm intra-operatively was evaluated to analyse the reduction of fracture.

Results

It was observed that mean change in ocular volume was around 1.07cm2 for Group I and 1.51cm2 in Group II. Thus post-operative eye volume was near to normal in Group I than Group II. The change in ocular volume post-operatively was observed to be statistically significant (p-value < 0.05) in both the groups. Post HOC Tukey statistical analysis determined the intergroup relation in change in eye volume between normal, pre- and post-operative and was found to be statistically significant (p-value < 0.05). The intergroup comparison between Group I and Group II was done using ANOVA statistical analysis and was found to be statistically significant (p-value < 0.05).

Discussion

Our study revealed that C-arm is definitively an effective tool in the oral and maxillofacial surgery armamentarium, giving better results with minimal surgical exposure and by eliminating operator related error.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03221-y.

Accuracy of intraoperative navigation for orbital fracture repair: A retrospective morphometric analysis

In this retrospective case series, patients undergoing surgery to treat isolated orbital floor fractures were morphometrically analyzed. Cloud Compare was used to compare mesh positioning with a virtual plan, using the distance-to-nearest-neighbor method. To assess the accuracy of mesh positioning, a mesh area percentage (MAP) parameter was introduced and three distance ranges were defined as the outcome measures: the 'high-accuracy range' included MAPs at a distance of 0-1 mm from the preoperative plan; the 'intermediate-accuracy range' included MAPs at a distance of 1.1-2 mm from the preoperative plan; the 'low-accuracy range' included MAPs at a distance of >2 mm from the preoperative plan. To complete the study, morphometric analysis of the results was combined with clinical judgment ('excellent', 'good', or 'poor') of mesh positioning by two independent blind observers. In total, 73 of 137 orbital fractures met the inclusion criteria. In the 'high-accuracy range' the mean, minimum, and maximum MAP values were 64%, 22%, and 90%, respectively. In the 'intermediate-accuracy range', the mean, minimum, and maximum values were 24%, 10%, and 42%, respectively. In the 'low-accuracy range', the values were 12%, 1%, and 48%, respectively. Both observers classified 24 cases of mesh positioning as 'excellent', 34 as 'good', and 12 as 'poor'. Within the limitations of the study, it seems that virtual surgical planning and intraoperative navigation has the potential to add quality to the repair of the orbital floor and, therefore, should be taken into consideration whenever appropriate.

Does Intraoperative Navigation Improve Implant Position Accuracy in Orbital Fracture Repair?

Purpose: Our aim was to determine if intraoperative navigation (ION) improved radiographic outcomes in patients undergoing delayed primary/secondary orbital reconstruction for inferomedial defects, as measured by volume restoration, enophthalmos correction, and positional accuracy of implants. Patients and Methods: A prospective quasiexperimental study was performed to compare two groups of patients requiring orbital reconstruction. Use of ION was the exposure evaluated. Outcome measures were (i) intraorbital volume and enophthalmos evaluated radiologically, (ii) implant position accuracy, and (iii) procedural duration. Data were analyzed statistically to compare variance between groups. Results: Forty patients (6 females and 34 males) were recruited into the study with a mean age of 27.3 years. The study group demonstrated a greater reduction of intraorbital volume (0.49 cu.cm; p = 0.02) and enophthalmos (0.72 mm; p = 0.001). Implant positioning was more accurate using ION, with less mediolateral (p = 0.006) and yaw (p = 0.04) deviations. Surgical time for implant positioning was shorter by 17 min, with navigation (p < 0.001). Conclusion: The use of ION demonstrated radiographic improvements in volume restoration, enophthalmos correction, as well as accuracy of implant positioning, in patients requiring delayed primary/secondary orbital reconstruction.

In Search of Excellence: From a Small Clinical Unit to an Internationally Recognized Center for Orbital Diseases Research and Surgery at the Department of Ophthalmology, Shanghai Ninth People's Hospital, China

ABSTRACT

"Where there is a will, there is a way." It is never easy to make progress and development but with full dedication and firm commitment, many aspirations can still be realized. We would like to share with the readers the story of how we develop our division of orbital diseases and surgery from scratch to strengths over a period of 2 decades at the Department of Ophthalmology of Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, China.

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.

Computer-Aided Rhinoplasty Using a Novel "navigated" Nasal Osteotomy Technique: A Pilot Study

OBJECTIVE

To describe the surgical technique of navigation-guided nasal osteotomies and assess feasibility of this technique for treating complex nasal bone deformities in reconstructive rhinoplasty.

METHODS

A retrospective chart review was performed in order to identify patients who underwent computer-aided rhinoplasty from August 2014 to February 2017. Inclusion criteria were nasal bone deformities on computed-tomography (CT) that correlated with specific nasal complaints. All patients underwent computer-aided rhinoplasty with navigation-guided nasal osteotomies using a standard navigation system. Osteotomies were performed using real-time visualization on the navigation screen. Additional soft tissue procedures were performed as needed. Medical records were reviewed for presenting symptoms, radiologic and operative findings, and postoperative course. Cosmetic outcomes were subjectively based on patients' standard 6-view photo-documentation from pre- and post-operative timepoints.

RESULTS

Twenty-one patients were included in the study; 8 were revision cases and 3 had mild-to-moderate hemifacial microsomia. Fifteen were completely closed procedures. No cases were opened because of inadequate visualization or difficulty accessing bony pathology. Mean (range) follow up was 98.6 (6-559) days. There were no intra-operative complications, unplanned admissions or re-admissions, or iatrogenic cosmetic complications (ie, "inverted V" or "saddle nose" deformities). Two patients required revision. One was after suffering nasal trauma within 4 weeks of initial rhinoplasty. The second underwent further correction of a deformity that required a costochondral graft. Both experienced good final results.

CONCLUSIONS

Computer-aided rhinoplasty is safe and feasible for treating complex nasal deformities using standard navigation systems.

A Medial Orbital Wall Fracture From Cricket Bat During Training: Surgical Approach

A 24-year-old male athlete, injured by a cricket bat during training, was transferred to the hospital with an open head bleeding trauma in the medial part of his right eye. He was conscious, with no memory loss and dizziness. A medial orbital wall fracture (MOWF) with a foreign body presence was depicted in X-ray. Head computed tomography scan confirmed initial diagnosis and revealed the complete fracture of ethmoid sinuses. Temporary sutures were placed initially to close the wound and prevent trauma's infection. The ophthalmological exam revealed strabismus of the right eye due to medial rectus muscle entrapment and consequent diplopia in the horizontal gaze. After two weeks, surgery was planned to remove the foreign body, restore eye mobility, and correct diplopia. The wooden foreign body (2.5cm x 1cm) was removed with immediate decompression of the medial rectus muscle. The fracture was repaired by an open approach, a mesh net was placed and sutured to the periosteum for bone stabilization and regeneration. Fifteen days postoperatively, visual acuity was 10/10, ocular mobility was normal, and diplopia disappeared. Imaging is essential in diagnosis' confirmation and reconstructive surgery planning, without postoperative complications and complete patient's rehabilitation. The current report highlights the value of reconstructive surgery in orbital structures' preservation in complex MOWF cases. In such cases, the foreign body that entraps medial rectus muscle should be removed in time in order to prevent the orbital content displacement towards the gap created by the fractured bone with consequences enophthalmos and diplopia, as well as consecutive intraorbital infections. Eye preservation in the correct position eliminates strabismus.

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.

Functional and Aesthetic Outcome of Extensive Orbital Floor and Medial Wall Fracture via Navigation and Endoscope-assisted Reconstruction

BACKGROUND AND PURPOSE

Extensive orbital floor and medial wall fractures compared with isolated orbital wall fractures are more likely to require surgical correction because of a higher possibility of complications like diplopia, enophthalmos, or numbness. The unique and complex contours of the orbital anatomy limit the intraoperative view of the intraorbital anatomy, and complex orbital fractures involving the buttress of the transition zone area all make orbital reconstruction surgery more challenging. The aim of this study was to describe our experience with surgical approaches using navigation- and endoscope-assisted guidance for extensive orbital floor and medial wall fracture reconstruction.

PATIENTS AND METHODS

A retrospective study was conducted on consecutive 17 patients from 2015 to 2017 presenting with unilateral extensive orbital floor and medial wall fractures at the Chang Gung Memorial Hospital, Linkou Branch. The fractures were treated surgically with a preformed mesh plate and layered Medpor (Porex Surgical Inc, Atlanta, Ga) through navigation and endoscopy. The preoperative and postoperative functional and aesthetic outcomes were described.

RESULTS

All extensive orbital floor and medial wall fractures were successfully reconstructed. Of the 17 patients, 11 experienced diplopia preoperatively, and for 2 of the 11 patients, diplopia improved immediately after surgery. In the remaining 9 patients, diplopia still persisted after surgery; however, diplopia recovered after an average of 3.44 months (range, 1-9 months). Average enophthalmos among the 10 patients, evaluated by postoperative follow-up computed tomography scan, improved from 2.99 to 0.68 mm. There were no major complications during follow-up, and all patients were satisfied with their final appearance and function.

CONCLUSIONS

On the basis of the results, our surgical approach using preformed titanium mesh plates and Medpor under the assistance of navigation and endoscopy can be a safe, accurate, and effective method for the management of extensive orbital floor and medial wall fractures and clearly optimizes functional and aesthetic outcomes.

Role of Plain Radiographs in Assessing Appropriate Placement of Orbital Implants for Repair of Floor Fractures

Intraoperative imaging is becoming increasingly common in repair of facial fractures. Many institutions do not have access to intraoperative advanced 3D imaging but have the capability of obtaining plain radiographs intraoperatively. At institutions where advanced 3D imaging is available, scout radiographs are usually obtained prior to a complete scan. These scout images can provide some information about the placement of radiopaque implants before a complete scan is performed. The aim of this study is to examine the correct anatomic positioning of an orbital floor implant using lateral plain radiographs. Titanium orbital fan implants were molded and secured to orbital floor of 14 adult dry skulls (7 males and 7 females). Lateral radiographs were obtained for both the left and the right orbits individually. The antero-posterior angle of inclination that the implant makes relative to the Frankfort horizontal plane was measured, and results were compared in the male versus female radiographs. The mean angle that the implant made with the Frankfort horizontal plane was 20.1±2.4° in the male orbits (95% CI 18.8-21.5°) and 22.6 ± 2.0° in the female orbits (95% CI, 21.4-23.7°). We found no statistically significant differences between the male and female angles (P-value 0.62). For the combined specimens (i.e., 28 sides in 14 skulls), the overall mean angle was 21.4 ± 2.5° (95% CI, 20.4-22.3°). Based on these findings, the angle that the implant makes with the Frankfort horizontal plane on lateral cross-table plain radiographs can be used intraoperatively to assist the surgeon in confirming the appropriate placement of the implant.

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.

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.

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.

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.

Use of C-Arm to Assess Reduction of Zygomatic Complex Fractures: A Comparative Study

The aim of this study was to analyze the use of C-arm and its significance in accurate reduction of zygomaticomaxillary complex (ZMC) fractures. Orbital volume is used as parameter to compared pre- and postoperative volumes of injured orbit. Differences in orbital volume calculated in cases done with intraoperative imaging and in controls treated without the use of intraoperative imaging were evaluated using Student t-test. C-arm is definitively an effective tool in the armamentarium of oral and maxillofacial surgery in assessment of reduction of ZMC fracture.

Current Management of Zygomaticomaxillary Complex Fractures: A Multidisciplinary Survey and Literature Review

Despite the prevalence of zygomaticomaxillary complex (ZMC) fractures, there is no consensus regarding the best approach to management. The aim of this study is to determine differences in ZMC fracture treatment among various surgical specialties. A survey was conducted regarding treatment of patients with different ZMC fractures that included a minimally displaced fracture (Case 1), a displaced fracture without diplopia (Case 2), a displaced fracture with diplopia (Case 3), and a complex comminuted fracture (Case 4). The survey was distributed to members of plastic surgery, oral maxillofacial surgery, and otolaryngology societies. The rates of surgical treatment, exploration of the orbital floor, and plating three or more buttresses were analyzed among the specialties. A total of 173 surgeons participated (46 plastic and reconstructive surgeons, 25 oral and maxillofacial surgeons, and 102 otolaryngologists). In Case 1, a significantly higher percentage of plastic surgeons recommend an operation (p < 0.01) compared with other specialties. More than 90% of surgeons would perform an operation on Case 2. Plastic surgeons explored the orbital floor (p < 0.01) and also fixated three or more buttresses more frequently (p < 0.01). More than 93% of surgeons would operate on Case 3, with plastic surgeons having the greatest proportion who fixed three or more buttresses (p < 0.01). In Case 4, there was no difference in treatment patterns between specialties. Across the specialties, more fixation was placed by surgeons with fewer years in practice (<10 years). Conclusion There is no consensus on standard treatment of ZMC fractures, as made evident by the survey. Significant variability in fracture type warrants an individualized approach to management. A thorough review on ZMC fracture management is provided.

Pediatric Orbital Depth and Growth: A Radiographic Analysis

BACKGROUND

Orbital reconstruction requires knowledge of orbital depth in order to prevent optic nerve injury. Numerous analyses of adult orbital dimensions have been undertaken previously in order to characterize this measurement, including skull specimen and computerized tomography studies. However, there is a paucity of information regarding the pediatric orbit.

METHODS

The authors used pediatric magnetic resonance imaging (MRI) studies in order to quantify the change in orbital depth in relationship to patient age, and to develop methods to estimate and calculate orbital depth for individual pediatric patients. MRIs of the head in normal pediatric patients were reviewed retrospectively. Orbital depths were measured and correlated with age and cephalometric dimensions. In a randomly selected subgroup of patients, measurements were repeated by an independent investigator to determine interobserver reliability.

RESULTS

Measurements were obtained in 72 patients ranging from 3 months to 18 years of age (mean=7.8 years). There was a significant exponential relationship between orbital depth and patient age (r=0.81, F(2,69)=143.97, P<0.001). Depth increased more rapidly in the first 6 years of life, but leveled off in the early teen years toward a horizontal asymptote of approximately 45 mm. There was also a significant relationship between orbital depth and the sum of the biparietal width plus the anterior-posterior length (r=0.72, F(2,69)=87.44, P<0.0001). There was high interobserver reliability in measurements between 2 independent investigators (r=0.79, P<0.0001).

CONCLUSION

In children, orbital depth increases predictably with rising age and increasing head size. Knowledge of this growth curve and the relationship between head size and orbital depth can complement careful surgical dissection to improve safety and efficacy in pediatric orbital reconstructions.

Virtual Surgical Planning for Orbital Reconstruction

The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology.

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 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.

Treatment of Orbital Medial Wall Fractures with Titanium Mesh Plates Using Retrocaruncular Approach: Outcomes with Different Techniques

Surgical management of medial wall orbital fractures should be considered to avoid diplopia and posttraumatic enophthalmos. Treatment of these fractures remains a challenge for the maxillofacial surgeon because of complex anatomy and limited vision. This article aims to retrospectively evaluate the outcomes in the repair of medial orbital wall fractures using a retrocaruncular approach and titanium meshes, comparing the placement of the titanium mesh with three different techniques: (1) conventional free hand under direct vision, (2) with the assistance of an endoscope, and (c) with the assistance of a navigation system. Eighteen patients who underwent surgery for orbital medial wall fracture were enrolled in the study. On the basis of the implant placement technique, three groups were identified: group 1 (CONV), conventional free hand under direct vision; group 2 (ENDO), endoscopically assisted; group 3 (NAVI), a navigational system assisted (BrainLab, Feldkirchen, Germany). The postoperative quality of orbital reconstruction was assessed as satisfactory in 12 cases, good in 4 cases, and unsatisfactory in 2 cases. Particularly in group 1 (CONV) in four patients out of eight, the posterior ledge of the fracture was not reached by the implant and in one patient the mesh hinged toward the ethmoid. In group 3 (NAVI), in one patient out of five, the posterior ledge of the fracture was not reached. In conclusion, titanium orbital mesh plates and retrocaruncular approach are a reliable method to obtain an accurate orbital medial wall reconstruction. The use of endoscopic assistance through the surgical incisions improves accuracy of treatment allowing better visualization of the surgical field. Navigation aided surgery is a feasible technique especially for complex orbital reconstruction to improve predictability and outcomes in orbital repair.

Computer-guided orbital reconstruction to improve outcomes

OBJECTIVES

(1) To describe repair of complex orbital fractures using computer planning with preoperative virtual reconstruction, mirror image overlay, endoscopy, and surgical navigation. (2) To test the hypothesis that this technique improves outcomes in complex orbital fractures.

METHODS

A series of 113 consecutive severe orbital fracture cases was analyzed, 56 of which were performed with mirror image overlay guidance, and 57 of which were repaired without. Data were collected on patient characteristics, fracture severity, diplopia and globe position outcomes, complications, and need for revision surgery.

RESULTS

The mirror image overlay group showed decreased postoperative diplopia in all fracture types (P = .003); the effectiveness was maximal for fractures that involved 3 or 4 walls or the posterior one-third of the orbital floor (P < .001). The need for revision surgery was greatly reduced in this cohort (4% vs 20%; P = .03).

CONCLUSIONS

The efficacy of mirror image overlay navigation and orbital endoscopy was studied in one of the largest series of complex orbital fractures in the literature. Based on statistically significant improved outcomes in postoperative diplopia and orbital volume, as well as the decreased need for revision surgery, we accept the hypothesis that mirror image overlay guidance improves outcomes in complex orbital reconstruction and recommend its use for complex orbital fracture repair.

Digital surgical templates for managing high-energy zygomaticomaxillary complex injuries associated with orbital volume change: a quantitative assessment

PURPOSE

This study sought to introduce 3-dimensional (3D) virtual surgical planning and digital rapid-prototyping templates for zygomaticomaxillary complex (ZMC) injuries associated with orbital volume change and to evaluate the surgical outcomes quantitatively.

PATIENTS AND METHODS

Eight patients who underwent open reduction and fixation for a ZMC injury with orbital volume change were studied. Computed tomographic (CT) scan of the zygomaticomaxillary area was performed before the operation in each case. Scanned data were converted into 3D models using Mimics software (Materialise, Brussels, Belgium) for surgical designs. Virtual surgical reductions and correlated guiding templates were designed using Mimics and Magics software (Materialise). The operations were performed with the help of prefabricated templates to reduce the fractures. A postoperative CT scan of each patient was obtained within 2 weeks after surgery, and quantitative measurements were made to assess the surgical outcomes. Preoperative volumes of the bilateral orbits were compared, and concordance with postoperative volumes of the bilateral orbits was assessed. Twenty-one pairs of distances from 7 marker points to 3 reference planes were measured to assess postoperative facial symmetry.

RESULTS

Volumes of the injured orbits were significantly different from volumes of the uninjured orbits preoperatively (P < .05), whereas bilateral orbital volumes showed no statistically significant difference postoperatively (P > .05). In addition, 19 of the 21 pairs of bilateral distances showed no significant difference postoperatively (P > .05).

CONCLUSIONS

Quantitative assessment showed that digitally designed, rapid-prototyping templates for ZMC fractures have a positive impact on restoring facial symmetry and concordance of bilateral orbital volumes.

Traditional and contemporary surgical approaches to the orbit

Traditional orbital approaches are nearly a century old and still comprise the foundation of techniques used today. Computer-assisted planning and intraoperative navigation have recently been reported with more prevalence in the literature. The purpose of this article was to review commonly used approaches to the orbit: old and new.

Latest trends in craniomaxillofacial surgical instrumentation

PURPOSE OF REVIEW

To review the past year's literature regarding recent innovations in surgical instrumentation for craniomaxillofacial surgery.

RECENT FINDINGS

Current advances in surgical instrumentation have led to many improvements in the field, allowing greater visualization and precision both before and during procedures. One of the common goals is to achieve excellent outcomes with minimal complications, while at the same time minimizing invasiveness of surgery. Highlighted innovations include greater capacities for acquisition of data, leading to improved imaging modalities and expansion of computer-assisted surgical techniques; continued developments in biomaterials used in various reconstructions; and novel uses of bone cutting and bone fixation instrumentation.

SUMMARY

Technology in the field of craniomaxillofacial surgery is developing rapidly, leading to novel instrumentation being utilized across a broad spectrum of areas. Published data have been encouraging to date, indicating an ever increasing adaptation of these innovations in clinical practice. Future efforts need to focus on cost-benefit analysis and constructing larger-scale studies to better understand effectiveness and patient outcomes.