Classical versus custom orbital wall reconstruction: Selected factors regarding surgery and hospitalization

Clinical outcomes of 3-dimensional printed custom porous polyethylene orbital implant for reconstruction

PurposeTo report the clinical outcomes with three-dimensional (3D)-printed custom orbital implants, designed using contralateral orbit mirroring techniques.MethodsCase series of 3D-printed custom orbital implants used for complex orbital reconstructions at University of Michigan Kellogg Eye Center is presented in this study. Data from 2020 to 2023 was collected.ResultsIn this case series of 8 patients, the surgical indications include diplopia, enophthalmos, hypoglobus either post-trauma or tumor removal. One patient had bilateral defects; others had unilateral defects. The mean follow-up time was 27.88 ± 9.66 months (Range: 7-38 months). Postoperative improvement was seen for enophthalmos in 7 of 8 cases, hypoglobus in 3 of 5 cases, and diplopia in 3 of 4 cases, and the average exophthalmometry asymmetry improved from 3.1 mm to 0.5 mm.Conclusions3D-printed orbital implants demonstrated effectiveness and safety in this diverse series of orbital reconstruction cases, yielding significant clinical improvements. Our findings support the use of these implants in a variety of complex orbital reconstructions.

Technology Guided Management of Orbital Trauma: A Systematic Review

Background

The use of technology in the surgical field has been increasing; however, the literature that studies the combination of these techniques is still scarce.

Purpose

This systematic review aims to identify the combination of the different technological tools currently available for surgical reconstruction of the orbit after trauma injury and determine the most common treatment alternatives.

Methods

A search following PRISMA criterios was carried out of articles published between January 2015 and December 2019 in PubMed, Embase, Scopus, and Ovid databases. The Mesh terms were orbit fracture, orbit trauma, computer-assisted surgery, surgical navigation system, navigation surgery, endoscopic surgical procedure, endoscopy, endoscope support, and patient-specific implants. The inclusion criteria were orbital trauma, articles that described the combination of technological tools, cases, case series, retrospective studies, and randomized clinical trials. Pediatric trauma management studies were excluded. To determine methodological quality and risk of bias the Joanna Briggs Institute Verification List (JBI) was used. The results were collected and presented in tables for easy interpretation.

Results

Of the articles found, 12 were finally chosen. Most of the articles (8) were case series, 2 were case reports, 1 was quasi-experimental, and 1 was a randomized clinical trial. A total of 418 patients were reported in all studies, and the most widely used tool was virtual planning, reported in 11 articles (91.6%). Virtual surgical planning in combination with intraoperative navigation was adopted by 9 articles (75%), being the most used combination of technologies.

Conclusions

Integration of virtual surgical planning, intraoperative navigation, patient-specific implants, and endoscopic techniques will help to improve the results significantly in the initial management of the orbital trauma. However, it is recommended in future studies that the results be evaluated in the same way to obtain more homogeneous studies.

A systematic review of implant materials for facial reconstructive and aesthetic surgery

Background

Assessing facial plastic surgery techniques is essential for improving patient safety and outcomes through evidence-based practices. Despite the extensive use of facial implants, there is a scarcity of thorough research on their long-term effects and safety profiles.

Methods

A systematic review was conducted following PRISMA guidelines, analyzing studies from 1970 to 2024 on various implant materials for facial reconstruction and augmentation. The databases searched for this review included PubMed, Web of Science, Google Scholar, and EMBASE. Inclusion criteria were full-text articles in English, focusing on alloplastic materials for craniofacial skeleton replacement or augmentation.

Results

We included 117 studies with 4,273 patients and a mean follow-up of 34 months (range: 15 days to 25 years). Of these, 56% focused on reconstruction, 33% on aesthetics, and 10% on both. Patient ages ranged from 6 months to 85 years, with most studies addressing the orbital (29%), chin (22%), and malar (19%) regions. 67% of studies evaluated potential complications and found an overall rate of 4.4%. Nerve injuries (2.1%) and infections (1.0%) were the most frequent issues, with hematoma, implant displacement, and bone resorption rates at 1.4%, 0.59%, and 0.68%, respectively. Patient-specific implants (PSIs) showed promise in reducing complications such as infections, suggesting that customization to patient anatomy may provide benefits. The highest rate of complication-free postoperative recovery was observed with polyethylene facial implants.

Conclusion

This review highlights variability in implant performance. The increased use of PSI suggests improved outcomes, warranting further investigation. Standardized outcome reporting and further research are needed to enhance comparability and guide clinical practice.

Systematic Review Registration

PROSPERO, identifier (CRD42024501754).

Does a Point-of-Care 3-Dimensional Printer Result in a Decreased Length of Surgery for Orbital Fractures?

BACKGROUND

Utilization of point-of-care 3-dimensional printing (3DP) has decreased length of surgery in facial trauma. Little is known regarding 3DP's impact on length of surgery in orbital fracture.

PURPOSE

The purpose of this study was to compare length of surgery between 3DP/preadapted (3DPPA) orbital plates and intraoperative adapted plates (IOAP) for orbital fracture reconstruction.

STUDY DESIGN, SETTING, SAMPLE

This was a prospective, non-blinded, randomized clinical study of consecutive subjects with orbital fractures presented to Grady Memorial Hospital in Atlanta, Georgia, between January 2018 and June 2021. Subjects ≥ 18 years, unilateral fracture, no previous orbital surgery, and/or congenital craniofacial anomaly were included. We excluded subjects <18 years and bilateral fractures.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

Primary predictor variable was the treatment approach. Randomization software was used, and subjects were randomized to 3DPPA or IOAP groups.

MAIN OUTCOME VARIABLE(S)

Primary outcome variable was length of surgery in minutes. Secondary outcomes were the time required for plate insertion and fixation in minutes, operating room (OR) charges, and orbital volume (OV) calculation.

COVARIATES

Age, sex, race, etiology, laterality, location, dimension, indication for surgery, postoperative enophthalmos, and diplopia.

ANALYSES

Univariate and bivariate analyses were calculated. Statistical significance was P < .05.

RESULTS

Twenty-five subjects met the inclusion criteria. Mean ages in 3DPPA and conventional IOAP groups were 41.5 (±9) and 38.2 (±10, P = .31), respectively. The mean length of surgery was 32.6 (±13.7) in 3DPPA and 53.3 (±12.8, P < .001) in conventional IOAP. The mean time required for plate insertion and fixation was 15.8n (±14.4) in 3DPPA and 41.4 (±9.4, P < .001) in conventional IOAP. The mean OR charges were $1,072.5 (±524.6) in 3DPPA and $1,757.3 (±422.6, P ≤ 0.001) in conventional IOAP. The mean calculated OV of uninjured and reconstructed orbit for the 3DPPA was 23.5 (±3.2)cm3 and 23 (±3.5, P = .37)cm3, respectively. The mean calculated OV of uninjured and reconstructed orbit for conventional IOAP was 28.6 (±3.6)cm3 and 22.8 (±2.6, P < .001)cm3, respectively.

CONCLUSION AND RELEVANCE

Using 3DP to produce a model that enables preoperative plate bending/adaptation reduces the length of surgery, decreases OR charges, and results in predictable OV.

Does Integration of Technology and Customization of Implants Produce Better Outcomes in Post-Traumatic Orbital Reconstruction? A Systematic Review and Meta-Analysis

PURPOSE

This review aims to compare and evaluate the outcomes achieved by integrating technological aids and the influence of different implant designs in the reconstruction of post-traumatic orbital defects.

METHODS

Electronic searches of the MEDLINE, Embase, Cochrane Library, and Google Scholar databases until March 2023 were conducted. Clinical controlled trials, observational studies, cohort studies, and retrospective studies were identified and included. The predictor variables were the integration of technological aids namely, computer-assisted surgical planning, mirror image overlay, and intraoperative navigation with the utilization of different orbital implant designs (standard orbital meshes, preformed implants, prebent implants, and patient-specific implant [PSI]) during post-traumatic orbital reconstruction. The primary outcome variables were orbital volume, diplopia, and enophthalmos. Weighted or mean difference and risk ratios at 95% confidence intervals were calculated, where P ＜ .05 was considered significant and a random effects model was adopted.

RESULTS

This review included 7 studies with 560 participants. The results indicate that the difference in postoperative orbital volume between affected and nonaffected eye showed no statistically significant difference between PSI and prebent group (mean difference, -0.41 P = .28, I2 = 46%). PSI group resulted in diplopia 0.71-fold less than that of the standard orbital mesh group but was not statistically significant (P = .15). Standard orbital mesh group is 0.30 times at higher risk of developing enophthalmos as compared to PSI group (P = .010). The literature suggests PSIs are preferred for patients with large defects (Jaquiéry's III-IV), whereas prebent implants are equally effective as PSIs in patients with preserved infraorbital buttress and retrobulbar bulge.

CONCLUSION

PSIs are associated with improved outcomes, especially for correcting enophthalmos. The data suggests the potential efficacy of prebent implants and PSIs in orbital volume corrections. There is a lack of randomized studies. This review should serve as a recommendation for further studies to contribute to the existing literature.

Classical Orbital Floor Post-Traumatic Reconstruction vs. Customized Reconstruction with the Support of "In-House" 3D-Printed Models: A Retrospective Study with an Analysis of Volumetric Measurement

BACKGROUND

Orbital floor fractures (OFFs) represent an interesting chapter in maxillofacial surgery, and one of the main challenges in orbit reconstruction is shaping and cutting the precise contour of the implants due to its complex anatomy.

OBJECTIVE

The aim of the retrospective study was to demonstrate, through pre- and postoperative volumetric measurements of the orbit, how the use of a preformed titanium mesh based on the stereolithographic model produced with 3D printers ("In-House" reconstruction) provides a better reconstruction volumetric compared to the intraoperatively shaped titanium mesh.

MATERIALS AND METHODS

The patients with OFF enrolled in this study were divided into two groups according to the inclusion criteria. In Group 1 (G1), patients surgically treated for OFF were divided into two subgroups: G1a, patients undergoing orbital floor reconstruction with an intraoperatively shaped mesh, and G1b, patients undergoing orbital floor reconstruction with a preoperative mesh shaped on a 3D-printed stereolithographic model. Group 2 (G2) consisted of patients treated for other traumatic pathologies (mandible fractures and middle face fractures not involving orbit). Pre- and postoperative orbital volumetric measurements were performed on both G1 and G2. The patients of both groups were subjected to the measurement of orbital volume using Osirix software (Pixmeo SARL, CH-1233 Bernex, Switzerland) on the new CT examination. Both descriptive (using central tendency indices such as mean and range) and regressive (using the Bravais-Pearson index, calculated using the GraphPad program) statistical analyses were performed on the recorded data.

RESULTS

From 1 January 2017 to 31 December 2021, of the 176 patients treated for OFF at the "Magna Graecia" University Hospital of Catanzaro 10 fulfilled the study's inclusion criteria: 5 were assigned to G1a and 5 to G1b, with a total of 30 volumetric measurements. In G2, we included 10 patients, with a total of 20 volumetric measurements. From the volumetric measurements and statistical analysis carried out, it emerged that the average of the volumetric differences of the healthy orbits was ±0.6351 cm3, the standard deviation of the volumetric differences was ±0.3383, and the relationship between the treated orbit and the healthy orbit was linear; therefore, the treated orbital volumes tend to approach the healthy ones after surgical treatment.

CONCLUSION

This study demonstrates that if the volume is restored within the range of the standardized mean, the diplopia is completely recovered already after surgery or after one month. For orbital volumes that do not fall within this range, functional recovery could occur within 6 months or be lacking. The restoration of the orbital volume using pre-modeled networks on the patient's anatomical model, printed internally in 3D, allows for more accurate reconstructions of the orbital floor in less time, with clinical advantages also in terms of surgical timing.

Delayed Orbital Floor Reconstruction Using Mirroring Technique and Patient-Specific Implants: Proof of Concept

Enophthalmos is a severe complication of primary reconstruction following orbital floor fractures, oncological resections, or maxillo-facial syndromes. The goal of secondary orbital reconstruction is to regain a symmetrical globe position to restore function and aesthetics. In this article, we present a method of computer-assisted orbital floor reconstruction using a mirroring technique and a custom-made titanium or high-density polyethylene mesh printed using computer-aided manufacturing techniques. This reconstructive protocol involves four steps: mirroring of the healthy orbit computer tomography files at the contralateral affected site, virtual design of a customized implant, computer-assisted manufacturing (CAM) of the implant using Direct Metal Laser Sintering (DMLS) or Computer Numerical Control (CNC) methods, and surgical insertion of the device. Clinical outcomes were assessed using 3dMD photogrammetry and computed tomography measures in 13 treated patients and compared to a control group treated with stock implants. An improvement of 3.04 mm (range 0.3-6 mm) in globe protrusion was obtained for the patients treated with patient-specific implants (PSI), and no major complications have been registered. The technique described here appears to be a viable method for correcting complex orbital floor defects needing delayed reconstruction.

The Effectiveness of Three-Dimensional Osteosynthesis Plates versus Conventional Plates for the Treatment of Skeletal Fractures: A Systematic Review and Meta-Analysis

PURPOSE

To assess the difference between preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates for the treatment of skeletal fractures in terms of anatomical reduction, operation time, approach, patient outcomes, and complications.

MATERIAL AND METHODS

MEDLINE (1950 to February 2023), EMBASE (1966 to February 2023), and the Cochrane Central Register of Controlled Trials (inception to February 2023) databases were searched. Eligible studies were randomised clinical trials, prospective controlled clinical trials, and prospective and retrospective cohort studies (n ≥ 10). Inclusion criteria were studies reporting the outcomes of preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates after treating skeletal fractures. Outcome measures included anatomical reduction, stability, operation time, hospitalisation days, patients' outcomes, and complications. Two independent reviewers assessed the abstracts and analysed the complete texts and methodologies of the included studies.

RESULTS

In total, 21 out of the 5181 primarily selected articles matched the inclusion criteria. A meta-analysis revealed a significant difference in operation time in favour of the preformed anatomical plates and patient-specific implants versus conventional plates. Significant differences in operation time were found for the orbital (95% CI: -50.70-7.49, p = 0.008), upper limb (95% CI: -17.91-6.13, p < 0.0001), and lower limb extremity groups (95% CI: -20.40-15.11, p < 0.00001). The mean difference in the rate of anatomical reduction in the lower limb extremity group (95% CI: 1.04-7.62, p = 0.04) was also in favour of using preformed anatomical plates and patient-specific implants versus conventional plates.

CONCLUSIONS

This systematic review showed a significant mean difference in surgery time favouring the use of preformed anatomical plates and patient-specific implants for orbital, upper, and lower limb extremity fractures. Additionally, preformed anatomical plates and patient-specific implants in the lower limb group result in a significantly higher rate of anatomical reduction versus conventional flat plates.

Is the Pre-Shaping of an Orbital Implant on a Patient-Specific 3D-Printed Model Advantageous Compared to Conventional Free-Hand Shaping? A Systematic Review and Meta-Analysis

This study aimed to perform a systematic review and meta-analysis to compare pre-shaped implants on a patient-specific 3D-printed (3DP) model to manual free-hand shaping (MFS) for orbital wall reconstruction. The PRISMA protocol was followed in this study, and the review was registered in the PROSPERO database (CRD42021261594). A search was conducted in MEDLINE (PubMed), Embase, Cochrane Library, Clinicaltrials.gov, Google Scholar, and the grey literature. Ten articles were included, and six outcomes were analyzed. In total, 281 patients were in the 3DP group and 283 were in the MFS group. The studies had an overall high risk of bias. 3DP models resulted in a better accuracy of fit, anatomical angle reproduction, and defect area coverage. The correction of orbital volume was also superior with statistical significance. There was a higher percentage of the correction of enophthalmos and diplopia in the 3DP group. Intraoperative bleeding and hospital stay were reduced in the 3DP group. The meta-analysis of operative time showed a reduction in the average operative time by 23.58 min (95% CI: -43.98 to -3.19), which was statistically significant (t(6) = -2.8299, p = 0.0300). The 3DP models appear advantageous for an accurate orbital wall reconstruction, with fewer complications than those for conventional free-hand-shaped implants.

Primary reconstruction of combined orbital and zygomatic complex fractures with patient-specific milled titanium implants - A retrospective study

The aim of this retrospective study was to compare mid-facial symmetry and clinical outcomes between patients treated with patient-specific and standard implants in primary fracture reconstructions of combined orbital and zygomaticomaxillary complex fractures. Patients who underwent primary reconstruction of orbital and zygomaticomaxillary complex fractures during the study period were identified and background and clinical variables and computed tomography images were collected from patient records. Zygomaticomaxillary complex dislocation and orbital volume were measured from pre- and postoperative images and compared between groups. Out of 165 primary orbital reconstructions, eight patients treated with patient-specific and 12 patients treated with standard implants were identified with mean follow-up time of was 110 days and 121 days, respectively. Postoperative orbital volume difference was similar between groups (0.2 ml for patient-specific vs 0.3 ml for standard implants, p = 0.942) despite larger preoperative difference in patient-specific implant group (2.1 ml vs 1,5 ml, p = 0.428), although no statistical differences were obtained in symmetricity or accuracy between the reconstruction groups. Within the limitations of the study it seems that patient-specific implants are a viable option for primary reconstructions of combined zygomaticomaxillary complex and orbital fractures, because with patient-specific implants at least as symmetrical results as with standard implants can be obtained in a single surgery.

The role of computer aided design/computer assisted manufacturing (CAD/CAM) and 3- dimensional printing in head and neck oncologic surgery: A review and future directions

Microvascular free flap reconstruction has remained the standard of care in reconstruction of large tissue defects following ablative head and neck oncologic surgery, especially for bony structures. Computer aided design/computer assisted manufacturing (CAD/CAM) and 3-dimensionally (3D) printed models and devices offer novel solutions for reconstruction of bony defects. Conventional free hand techniques have been enhanced using 3D printed anatomic models for reference and pre-bending of titanium reconstructive plates, which has dramatically improved intraoperative and microvascular ischemia times. Improvements led to current state of the art uses which include full virtual planning (VP), 3D printed osteotomy guides, and patient specific reconstructive plates, with advanced options incorporating dental rehabilitation and titanium bone replacements into the primary surgical plan through use of these tools. Limitations such as high costs and delays in device manufacturing may be mitigated with in house software and workflows. Future innovations still in development include printing custom prosthetics, 'bioprinting' of tissue engineered scaffolds, integration of therapeutic implants, and other possibilities as this technology continues to rapidly advance. This review summarizes the literature and serves as a summary guide to the historic, current, advanced, and future possibilities of 3D printing within head and neck oncologic surgery and bony reconstruction. This review serves as a summary guide to the historic, current, advanced, and future roles of CAD/CAM and 3D printing within the field of head and neck oncologic surgery and bony reconstruction.

Personalized Medicine Workflow in Post-Traumatic Orbital Reconstruction

Restoration of the orbit is the first and most predictable step in the surgical treatment of orbital fractures. Orbital reconstruction is keyhole surgery performed in a confined space. A technology-supported workflow called computer-assisted surgery (CAS) has become the standard for complex orbital traumatology in many hospitals. CAS technology has catalyzed the incorporation of personalized medicine in orbital reconstruction. The complete workflow consists of diagnostics, planning, surgery and evaluation. Advanced diagnostics and virtual surgical planning are techniques utilized in the preoperative phase to optimally prepare for surgery and adapt the treatment to the patient. Further personalization of the treatment is possible if reconstruction is performed with a patient-specific implant and several design options are available to tailor the implant to individual needs. Intraoperatively, visual appraisal is used to assess the obtained implant position. Surgical navigation, intraoperative imaging, and specific PSI design options are able to enhance feedback in the CAS workflow. Evaluation of the surgical result can be performed both qualitatively and quantitatively. Throughout the entire workflow, the concepts of CAS and personalized medicine are intertwined. A combination of the techniques may be applied in order to achieve the most optimal clinical outcome. The goal of this article is to provide a complete overview of the workflow for post-traumatic orbital reconstruction, with an in-depth description of the available personalization and CAS options.

Customised products for orbital wall reconstruction: a systematic review

The purpose of this systematic review was to critically analyse the recent literature and present the state of the art in customised reconstruction of orbital fractures. Three electronic databases and manual search approaches were used to identify relevant articles. Only controlled clinical studies were included. Primary outcome was defined as the status of recovery (complete/partial functional, and aesthetic disturbances). The benefit of intrasurgical navigation should be described. The secondary outcome was defined as the time of surgery, post-surgical events, and hospitalisation. Of the 552 records identified, eight met the inclusion criteria. Post-surgical results regarding recovery were superior in the customised group, and were comparable to the control group in five studies. The time of surgery was shorter in the customised groups, and liquid infusion and time of hospitalisation were reduced. Four studies documented more accurate reconstruction with the use of navigation. All the studies presented at least one bias, and considerable heterogeneity was evaluated. This review found that the use of customised meshes in combination with surgical navigation resulted in more accurate reconstruction. A significant reduction in surgical time was revealed.

Orbital reconstruction: a systematic review and meta-analysis evaluating the role of patient-specific implants

The purpose of this study is to execute an evidence-based review answering the following question (PICO): "Do patient-specific implants (PSI), manufactured or designed using computer-assisted technology, improve outcomes (orbital volume change, enophthalmos, diplopia, and operative duration) compared to conventional methods in orbital reconstruction following traumatic orbital injury in the adult patient population?" We performed a systematic review and meta-analysis in accordance with PRISMA guidelines. Inclusion criteria included any comparative paper whereby computer-assisted technology was used in the prefabrication or design process of implants for use in post-traumatic orbital reconstruction. Paediatric patient populations were excluded. Eight databases were systematically searched for relevant studies. Risk of bias was assessed through the NOS and RoB2 tools. Random-effects models were used to identify differences in outcomes between groups where possible. Analysis was performed using R 4.0.0. Eleven of 4784 identified studies were included, comprising 628 adult patients, with 302 and 326 patients in the patient-specific and conventional groups, respectively. Weighted mean difference between unaffected and post-operative orbital volume was 0.32 ml (SD 0.75) and 0.95 ml (SD 1.03) for patient-specific and conventional groups, respectively. Significant improvement was identified in post-operative orbital volume reconstitution with the use of PSI, compared to conventional implants, in 3 of the 5 reporting studies. Equally, post-operative enophthalmos trended towards lower severity in the patient-specific group, with 11.2% of patients affected in the patient-specific group and 19.2% in the conventional group, and operative duration was significantly reduced with the use of PSI in 3 of the 6 reporting studies. Despite a tendency to favour PSI, no statistically significant differences in key outcomes were identified on meta-analysis. Although there is some encouraging data to support improved outcomes with the use of patient-specific orbital implants in post-traumatic reconstruction, there is, at present, no statistically significant evidence to objectively support their use over conventional implants based on the currently available comparative studies. Based on the results of this study, the choice of implant used should, thus, be left to the discretion of the surgeon.

Critical appraisal of patient-specific implants for secondary post-traumatic orbital reconstruction

In orbital reconstruction, a patient-specific implant (PSI) may provide accurate reconstruction in complex cases, since the design can be tailored to the anatomy. Several design options may be embedded, for ease of positioning and precision of reconstruction. This study describes a cohort of 22 patients treated for secondary orbital reconstruction with a PSI; one patient received two PSI. The preoperative clinical characteristics and implant design options used are presented. When compared to preoperative characteristics, the postoperative clinical outcomes showed significant improvements in terms of enophthalmos (P < 0.001), diplopia (P < 0.001), and hypoglobus (P = 0.002). The implant position in all previous reconstructions was considered inadequate. Quantitative analysis after PSI reconstruction showed accurate positioning of the implant, with small median and 90th percentile deviations (roll: median 1.3°, 90th percentile 4.6°; pitch: median 1.4°, 90th percentile 3.9°; yaw: median 1.0°, 90th percentile 4.4°; translation: median 1.4 mm, 90th percentile 2.7 mm). Rim support proved to be a significant predictor of roll and rim extension for yaw. No significant relationship between design options or PSI position and clinical outcomes could be established. The results of this study show the benefits of PSI for the clinical outcomes in a large cohort of secondary post-traumatic orbital reconstructions.

Functional and Cosmetic Outcome after Reconstruction of Isolated, Unilateral Orbital Floor Fractures (Blow-Out Fractures) with and without the Support of 3D-Printed Orbital Anatomical Models

The present study aimed to analyze if a preformed "hybrid" patient-specific orbital mesh provides a more accurate reconstruction of the orbital floor and a better functional outcome than a standardized, intraoperatively adapted titanium implant. Thirty patients who had undergone surgical reconstruction for isolated, unilateral orbital floor fractures between May 2016 and November 2018 were included in this study. Of these patients, 13 were treated conventionally by intraoperative adjustment of a standardized titanium mesh based on assessing the fracture's shape and extent. For the other 17 patients, an individual three-dimensional (3D) anatomical model of the orbit was fabricated with an in-house 3D-printer. This model was used as a template to create a so-called "hybrid" patient-specific titanium implant by preforming the titanium mesh before surgery. The functional and cosmetic outcome in terms of diplopia, enophthalmos, ocular motility, and sensory disturbance trended better when "hybrid" patient-specific titanium meshes were used but with statistically non-significant differences. The 3D-printed anatomical models mirroring the unaffected orbit did not delay the surgery's timepoint. Nonetheless, it significantly reduced the surgery duration compared to the traditional method (58.9 (SD: 20.1) min versus 94.8 (SD: 33.0) min, p-value = 0.003). This study shows that using 3D-printed anatomical models as a supporting tool allows precise and less time-consuming orbital reconstructions with clinical benefits.

Accuracy of Patient-Specific Meshes as a Reconstruction of Orbital Floor Blow-Out Fractures

ABSTRACT

Computer-aided design and manufacturing (CAD-CAM)-based techniques are developing fast in facial reconstruction and osteosynthesis. Patient-specific implant (PSI) production is already sufficiently fast for everyday use and can be utilized even for primary trauma surgery such as orbital floor reconstruction after blowout fracture. Purpose of our study is to retrospectively analyze the 3-dimensional (3D) success of PSI reconstructions of orbital floor fractures in our unit. The authors analyzed retrospectively a 1-year cohort (n = 8) of orbital floor blow-out fractures that have been reconstructed using virtual surgical plan and CAD-CAM PSI. Postoperative computed topographies of patients were compared to their original virtual surgical plans. The 3D outcome and fitting of the PSI was good in all patients. Mean error for 3D position of the PSI was 1.3 to 1.8 mm (range 0.4 to 4.8 mm) and postoperative orbital volume was successfully restored in all of the patients. Use of CAD-CAM PSI for reconstruction of orbital floor blow out fracture is reliable method and thus recommended.

Patient-Specific Implants in Oculofacial Plastic Surgery

PURPOSE

To investigate how patient-specific implants (PSIs) are being utilized for periocular facial skeletal reconstruction. Specifically, to characterize indications for custom implants, areas of reconstruction, intraoperative variables impacting implant placement, as well as to report on postoperative outcomes.

MATERIALS AND METHODS

A retrospective chart review was performed for patients who received a PSI for periocular skeletal reconstruction between 2015 and 2019. Three independent academic centers were included in this study, which encompassed 4 different primary surgeons. Medical records, radiographic imaging, and operative reports were reviewed.

RESULTS

Eleven patients, 8 females and 3 males, ages ranging from 15 to 63 years old received PSIs. The average duration of follow up was 16 months ± 6.6 months (range: 9-30 months). The most common underlying etiology for reconstruction was prior trauma (54.5%) followed by benign tumor resection (18.2%). The most frequent area of reconstruction involved the inferior orbital rim and adjacent maxilla (63.6%). Implant materials included porous polyethylene, polyetheretherketone, and titanium. Six implants required intraoperative modification, most commonly accommodate critical neurovascular structures (66.6%) or improve contour (33.3%). Two postoperative complications were noted, both in the form of infection with 1 implant requiring removal.

CONCLUSIONS

Reconstruction of complex facial skeletal defects can be achieved by utilizing computer-assisted design software and 3D printing techniques to create PSIs. These implants represent the most customizable option for symmetric restoration of the facial skeleton by not only addressing structural deficits but also volumetric loss. This was particularly apparent in reconstruction of the orbital rim and midface. PSIs were found to be of most benefit in patients with prior trauma or complex skeletal defects after tumor resection.

Utilizing 3D-Printed Orbital Floor Stamps to Create Patient-Specific Implants for Orbital Floor Reconstruction

PURPOSE

This study seeks to test a novel technique of custom-printed midface contour models with orbital floor "stamps" to guide reconstruction of orbital floor blowout fractures, with or without concomitant zygomaticomaxillary complex injury.

METHODS

A series of 4 consecutive patients with orbital floor blowout fractures (including 3 with zygomatic maxillary complex fractures) were retrospectively examined for outcomes associated with orbital floor reconstruction using 3-dimensional-printed stamps and midface models. Data collected included demographics, pre- and postoperative visual globe malposition, motility, and visual field disturbances. Three-dimensional printing methodology is reported, as well as associated costs and time required to generate the models and stamps.

RESULTS

The cost of producing a midface-contour model and orbital floor stamps was $131, inclusive of labor and materials. Cases averaged 170 minutes to segment, design, and print. Patients with preoperative diplopia and motility restrictions had resolution of their symptoms. Two patients had resolution of their enophthalmos, while one patient with a concomitant zygomaticomaxillary fracture had persistent mild enophthalmos.

CONCLUSIONS

Midface contour models and orbital floor stamps may be produced in a timely and cost-effective manner. Use of these "homemade" stamps allows for patient-specific custom-contoured orbital floor reconstruction. Further studies are warranted to examine long-term visual and esthetic outcomes for these patients.

Assessment of Differences in the Dimensions of Mandible Condyle Models in Fan- versus Cone-Beam Computer Tomography Acquisition

Modern treatment in the field of head and neck surgery aims for the least invasive therapy and places great emphasis on restorative treatment, especially in the case of injury and deformation corrective surgery. More and more often, surgeons use CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) tools in their daily practice in the form of models, templates, and computer simulations of planning. These tools are based on DICOM (Digital Imaging and Communications in Medicine) files derived from computed tomography. They can be obtained from both fan-beam (FBCT) and cone-beam tomography (CBCT) acquisitions, which are subsequently segmented in order to transform them into a 1-bit 3D model, which is the basis for further CAD processes.

AIM

Evaluation of differences in the dimensions of mandible condyle models in fan- versus cone-beam computer tomography for surgical treatment purposes.

METHODS

499 healthy condyles were examined in CT-based 3D models of Caucasians aged 8-88 years old. Datasets were obtained from 66 CBCT and 184 FBCT axial image series (in each case, imaging both mandible condyles resulted in the acquisition of 132 condyles from CBCT and 368 condyles from FBCT) and were transformed into three-dimensional models by digital segmentation. Eleven different measurements were performed to obtain information whether there were any differences between FBCT and CBCT models of the same anatomical region.

RESULTS

7 of 11 dimensions were significantly higher in FBCT versus lower in CBCT (p < 0.05).

Clinical outcome of patients with orbital fractures treated with patient specific CAD/CAM ceramic implants - A retrospective study

The aim of this study was to determine whether patients benefit from a secondary reconstruction since it carries the risks of no improvement or worsening of their current situation. Patients treated with individual computer-aided-design/computer-aided-manufacturing (CAD/CAM) ceramic implants were reviewed. To ascertain changes throughout the secondary reconstruction, the study investigators reviewed ophthalmological examinations, took volumetric measurements of the orbits and asked the patients for evaluation of their situation before and after the reconstruction. Points addressed were double vision, visual acuity, field of vision, limitations in daily life and aesthetic considerations. A total of 14 patients were reviewed and 11 answered the questionnaire. Ophthalmological examinations showed that the physical integrity of the eye was maintained. Volumetric measurements preopeatively (33.94 ± 3.24 cm³) and postoperatively (30.67 ± 2.07 cm³) showed that a statistically significant overcorrection of orbital volume leads to good functional and aesthetic outcomes. Patients' subjective opinions were that they greatly benefitted, especially concerning limitations in daily life, which improved by 4.4 ± 2.8 points out of 10 possible points, and aesthetics, with an improvement of 5.9 ± 1.78 points. Based on these findings, we conclude that secondary reconstructions contribute to improvement of the patients' quality of life and therefore should be considered as an option to improve patients' condition.

Automatic evaluation of the orbital shape after application of conventional and patient-specific implants: Correlation of initial trauma patterns and outcome

Purpose

To evaluate the precision of orbital shape reconstructions using either conventional plates (CPs) or patient-specific implants (PSIs) to treat different types of orbital fractures, and to evaluate their clinical outcomes.

Methods

A total of 92 orbital-reconstruction patients were included. Forty-seven patients, treated with PSIs, formed the main group. The remainder, treated with CPs, were the control group. All patients were examined pre- and postoperatively using computerized tomography (CT) and evaluated for enophthalmos and diplopia. Evaluation of differences in orbital shape between damaged and intact orbits after surgery was performed by commercial orbital analysis software.

Results

In the main group, mean orbital shape difference between damaged and intact orbits after surgery was 0.137 ± 0.8 cm³ (range -1.7-2.3 cm³). In the control group, the mean shape difference was 1.05 ± 1.9 cm³ (range -1.8-8.3 cm³), significantly higher (p = 0.007). Diplopia occurred in seven PSI patients three months after surgery (14.9%) and in thirteen CP patients (28.9%) (p = 0.181). Enophthalmos occurred in five PSI patients (10.6%) and in sixteen CP patients (35.6%) (p = 0.001).

Conclusion

Precise orbital reconstruction prevents the development of enophthalmos after trauma in patients with orbital wall fractures. In patients with preserved infraorbital buttresses and posterior orbital ledges, there were no significant clinical differences between PSIs and CPs. For cases requiring cantilevered reconstruction, including those with zigomatic or maxillary fragment repositioning, preference should be given to the PSI procedure for both effectiveness and predictability.

Overview of tools for the measurement of the orbital volume and their applications to orbital surgery

There are numerous applications in craniofacial surgery with orbital volume (OV) modification. The careful management of the OV is fundamental to obtain good esthetic and functional results in orbital surgery. With the growth of computer-aided design - computer-aided manufacturing (CAD-CAM) technologies, patient-specific implants and custom-made reconstruction are being used increasingly. The precise measurement of the OV before surgery is becoming a necessity for craniofacial surgeons. There is no consensus on orbital volume measurements (OVMs). Manual segmentation of computed tomography (CT) images is the most used method to determine the OV, but it is time-consuming and very sensitive to operator errors. Here, we describe the various methods of orbital volumetry validated in the literature that can be used by surgeons in preoperative planning of orbital surgery. We also describe the leading software employed for these methods and discuss clinical use (posttraumatic enophthalmos prediction and orbital reconstruction) in which OVMs are important.

Theoretical model of pediatric orbital trapdoor fractures and provisional personalized 3D printing-assisted surgical solution

Pediatric orbital trapdoor fractures are common in children and adolescents and usually require emergency surgical intervention. Herein, a personalized 3D printing-assisted approach to surgical treatment is proposed, serving to accurately and effectively repair pediatric orbital trapdoor fractures. We first investigated stress distribution in external force-induced orbital blowout fractures via numerical simulation, determining that maximum stresses on inferior and medial walls exceed those on superior and lateral walls and thus confer higher probability of fracture. We also examined 36 pediatric patients treated for orbital trapdoor fractures between 2014 and 2019 to verify our theoretical construct. Using 3D printing technique, we then created orbital models based on computed tomography (CT) studies of these patients. Absorbable implants were tailor-made, replicating those of 3D-printed models during surgical repairs of fractured orbital bones. As follow-up, we compared CT images and clinical parameters (extraocular movements, diplopia, enophthalmos) before and 12 months after operative procedures. There were only two patients with diplopia and six with enophthalmos >2 mm at 12 months, attesting to the efficacy of our novel 3D printing-assisted strategy.

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Numerical simulation is used to theoretically investigate the mechanism of external force-induced orbital blowout fractures.

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3D printing--assisted surgical treatment is proposed to effectively repair pediatric orbital trapdoor fractures.

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Clinical studies are performed by repairing fractured orbital bones via 3D printed customized absorbable implants.

Three-Dimensional Analysis of Isolated Orbital Floor Fractures Pre- and Post-Reconstruction with Standard Titanium Meshes and "Hybrid" Patient-Specific Implants

The aim of this study was to compare the efficacy of the intraoperative bending of titanium mesh with the efficacy of pre-contoured “hybrid” patient-specific titanium mesh for the surgical repair of isolated orbital floor fractures. In-house 3D-printed anatomical models were used as bending guides. The main outcome measures were preoperative and postoperative orbital volume and surgery time. We performed a retrospective cohort study including 22 patients who had undergone surgery between May 2016 and November 2018. The first twelve patients underwent conventional reconstruction with intraoperative free-hand bending of an orbital floor mesh plate. The subsequent ten patients received pre-contoured plates based on 3D-printed orbital models that were produced by mirroring the non-fractured orbit of the patient using a medical imaging software. We compared the preoperative and postoperative absolute volume difference (unfractured orbit, fractured orbit), the fracture area, the fracture collapse, and the effective surgery time between the two groups. In comparison to the intraoperative bending of titanium mesh, the application of preformed plates based on a 3D-printed orbital model resulted in a non-significant absolute volume difference in the intervention group (p = 0.276) and statistically significant volume difference in the conventional group (p = 0.002). Further, there was a significant reduction of the surgery time (57.3 ± 23.4 min versus 99.8 ± 28.9 min, p = 0.001). The results of this study suggest that the use of 3D-printed orbital models leads to a more accurate reconstruction and a time reduction during surgery.

Clinical efficacy of peek patient-specific implants in orbital reconstruction

Purpose

To assess the clinical efficacy of custom made PEEK patient-specific implants in treatment of orbital wall defects.

Methods

Forty-five patients with unilateral post-traumatic orbital wall defects were enrolled in the study. They underwent subsequent reconstructive procedures using PEEK patient-specific implants (PSI) or pre-bent titanium plates. All the patients were examined with the standardized algorithm, including local status examination, vision assessment and computer tomography (CT) with measurements of the orbital volume. A comparative analysis of the treatment outcomes in two groups of patients (pre-bent plates/PSI) was performed.

Results

The study findings show an absence of any postoperative infection, inflamation or decreased visual acuity in either group. In PSI group, diplopia after surgery was absent in 82.1% of patients versus 70.6% of controls. The mean duration of surgery was 54.25 ± 16.8 min with PSI application and 82.9 ± 10.8 min with pre-bent plates. The mean difference between the intact and damaged orbital volume was 1.9 ± 1.4 cm³ in the control group versus 0.74 ± 0.6 cm³ in PSI group (р<0.05).

Conclusion

PEEK PSI demonstrated higher clinical efficacy in comparison to pre-bent plates in orbital wall reconstruction especially in restoring the volume and shape of the damaged orbit.

Orbit in a Box: A Simplified Technique for Patient-Specific Virtually Planned Orbital Floor Reconstruction

PURPOSE

Possibilities for the reconstruction of orbital floor fractures have been extensive for years with regard to materials, methods and differential indications and are inconsistent worldwide. With the spread of CAD/CAM techniques, new and mostly time-consuming possibilities for orbital floor reconstructions have been added.

METHODS

The simple and time-efficient CT-to-patient-specific implant workflow presented here shows that a "form-box" can be created from a patient's computer tomography data set using planning software and a 3D printer. The box is then used to form a patient-specific implant for orbital floor reconstruction: here polydioxanone foil was used, for which stable thermoplastic deformability has been demonstrated for 3D reconstructions.

RESULTS

Patient-specific thermoplastic shaping of polydioxanone is feasible in a theoretical clinical setting, though its thermoplastic shaping is not yet certified for clinical use. However, a flexible adaptation of the "form-box" design to other materials is possible by setting a single planning parameter.

CONCLUSIONS

The simple structure of the box and its straightforward planning/fabrication process with widely available low-cost materials offer the possibility that a surgeon without a 3D specialist can produce a "form-box" for next day surgery if needed.

Reconstruction of Post-Traumatic Orbital Defects and Deformities with Custom-Made Patient-Specific Implants: Evaluation of the Efficacy and Clinical Outcome

The main purpose of this article is to evaluate the efficacy of patient-specific implants (PSI) in treatment of patients with post-traumatic orbital defects and deformities. Twenty-three patients with post-traumatic orbital defects and deformities, who underwent subsequent reconstructive procedures using PSI, were included in the study. All the patients were examined according to the standard algorithm involving the local status examination, vision assessment, and computed tomography before and after surgery. The study findings show neither postoperative infectious complications nor decreased visual acuity or loss of visual fields. Functional disorders resolved in 65.2% of cases 1 month after the surgical intervention and in 86.96% of patients within a 3-month term. Positive aesthetic outcomes were seen in 95.7% of cases. Reconstruction with computer-aided design/computer-aided manufactured PSI is an effective procedure that allows accurate restoring of the complex orbital anatomy.

Extent of Inflammation and Foreign Body Reaction to Porous Polyethylene In Vitro and In Vivo

BACKGROUND/AIM

High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo.

MATERIALS AND METHODS

Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines.

RESULTS

Cells showed a significantly decreased proliferation (p<0.001) after 48 h and a significantly increased expression of TNF-α (p<0.05) at 24, 48 and 72 h. All animals showed foreign body cell reactions and signs of chronic inflammation. Expression of all but one of the investigated cytokines dropped to non-significant levels after an initial increase.

CONCLUSION

Application of porous polyethylene can cause local chronic inflammatory reactions. Although clinical application seems to be immunologically safe, indication and risks should be evaluated carefully when using PP implants.

Generation of customized orbital implant templates using 3-dimensional printing for orbital wall reconstruction

OBJECTIVES

To describe and evaluate a novel surgical approach to orbital wall reconstruction that uses three-dimensionally (3D) printed templates to mold a customized orbital implant.

METHODS

A review was conducted of 11 consecutive patients who underwent orbital wall reconstruction using 3D-printed customized orbital implant templates. In these procedures, the orbital implant was 3D pressed during surgery and inserted into the fracture site. The outcomes of this approach were analyzed quantitatively by measuring the orbital tissue volumes within the bony orbit using computed tomography.

RESULTS

All 11 orbital wall reconstructions (6 orbital floor and 5 medial wall fractures) were successful with no post operative ophthalmic complications. Statistically significant differences were found between the preoperative and post operative orbital tissue volumes for the affected orbit (24.00 ± 1.74 vs 22.31 ± 1.90 cm³; P = 0.003). There was no statistically significant difference found between the tissue volume of the contralateral unaffected orbit and the affected orbit after reconstruction (22.01 ± 1.60 cm³ vs 22.31 ± 1.90 cm³; P = 0.182).

CONCLUSION

3D-printed customized orbital implant templates can be used to press and trim conventional implantable materials with patient-specific contours and sizes for optimal orbital wall reconstruction. It is difficult to design an orbital implant that exactly matches the shape and surface of a blowout fracture site due to the unique 3D structure of the orbit. The traditional surgical method is to visually inspect the fracture site and use eye measurements to cut a two-dimensional orbital implant that corresponds to the anatomical structure of the fracture site. However, implants that do not fit the anatomical structure of a fracture site well can cause complications such as enophthalmos, diplopia and displacement of the implant.

The influence of concomitant medial wall fracture on the results of orbital floor reconstruction

INTRODUCTION

Up to 35% of orbital floor fractures extend to the medial wall. This results in restriction of both abduction and adduction, leading to horizontal diplopia. The greater the defect, the more pronounced the enophthalmos.

AIM OF THE STUDY

The aim of the study was to determine the influence of concomitant medial wall defects on enophthalmos and diplopia, and the influence of intraoperative revision on the results of surgical reconstruction in patients with orbital floor fracture.

MATERIAL AND METHODS

78 cases of orbital floor fracture, with or without concomitant medial wall defect, were retrospectively analyzed. Reconstruction surgeries were performed in a similar fashion, but with variation in the alloplastic materials used. Careful investigation of the area was performed during the surgery.

RESULTS

Patients with associated medial wall defects had significantly more pronounced enophthalmos than those with isolated floor fracture, with no such difference after the orbital reconstruction. Postoperative vertical diplopia was more common in patients with an associated medial defect.

CONCLUSIONS

Associated medial wall defect leads to more severe enophthalmos at presentation. However, if the medial aspect of the orbital wall is revised properly, postoperative outcomes are not inferior to those in cases of isolated floor fracture.