Virtual surgical planning and three-dimensional printing for the treatment of comminuted zygomaticomaxillary complex fracture

Point-of-care additive manufacturing: state of the art and adoption in Spanish hospitals during pre to post COVID-19 era

BACKGROUND

3D technologies [Virtual and Augmented 3D planning, 3D printing (3DP), Additive Manufacturing (AM)] are rapidly being adopted in the healthcare sector, demonstrating their relevance in personalized medicine and the rapid development of medical devices. The study's purpose was to understand the state and evolution of 3DP/AM technologies at the Point-of-Care (PoC), its adoption, organization and process in Spanish hospitals and to understand and compare the evolution of the models, clinical applications, and challenges in utilizing the technology during the COVID-19 pandemic and beyond.

METHODS

This was a questionnaire-based qualitative and longitudinal study. Data on 3DP and AM activities in Spain were collected from 73 hospitals/institutions falling under the ITEMAS (Platform for Innovation in Medical and Health Technologies) and the Plataforma ISCIII Biomodelos y Biobancos from January 2019 to May 2020 for the first study, and at the end of 2022 and 2023 for the second study.

RESULTS

A total of 23 (31.5%) hospitals during the first study, while 30 (41.09%) during the second study reported having at least one 3DP/AM initiative. Post-covid, the majority of hospitals had onsite 3DP/AM services with a well-defined, structured, and centralized system. Traumatology and maxillofacial surgery services were found to be the most involved in 3DP projects for the production of custom-made surgical guides, prostheses and orthoses. Bioprinting initiatives were also noted to be expanding. Human resources, cost, and regulatory compliance were the key hurdles in introducing 3D/AM in hospitals.

CONCLUSIONS

In-house 3DP/AM units, with Mixed-Model is the most common model in Spain; The COVID-19 pandemic influenced the 3D planning activity and adoption. Further research and clinical trials, and improvements in resources, reimbursement and regulatory compliance are critical for the Point-of-care hospital growth of this breakthrough technology.

Virtual surgical planning in tripod zygomatico-maxillary complex fractures: A prospective comparison between two different strategies

Multifragmentary and displaced zygomaticomaxillary complex (ZMC) fractures are often a challenge for the maxillofacial surgeon. The aim of this study was to evaluate the improved performance in the management of patients with tripod fracture of the orbito-zygomaticomaxillary complex, using two different methods of virtual surgical planning - virtual reduction and mirroring - compared with traditional management. A cohort of 60 patients was selected and divided into three groups, each consisting of 20 individuals. Patients in the first group were managed using the virtual reduction method, those in the second group using the mirroring method, and those in the third group using a traditional surgical approach. Having achieved virtual fracture reduction, a stereolithographic model was printed, on which preplating of the plates was performed. The results showed that virtual reduction was the most accurate in absolute terms, with a mean discrepancy in juxtaposition of the preoperative and postoperative CT images of 0.175 mm (SD ± 0.147), compared with 0.403 (SD ± 0.166) for the mirror method (and traditional method (0.875, SD ± 0.112; p > 0.0001). The average surgical time for virtual reduction (89.5 min) was faster than for mirroring (94.25 min) and for the traditional approach (96.75 min). In conclusion, the use of virtual surgical planning allows greater intraoperative accuracy, reduced surgical time, and reduced postoperative complications compared with traditional surgery. Of the two methods, virtual reduction performed best for the outcomes decribed.

Advances in Three-Dimensional Printing for Craniomaxillofacial Trauma Reconstruction: A Systematic Review

Craniomaxillofacial (CMF) fractures present significant challenges for plastic surgeons due to their intricate nature. Conventional methods such as autologous bone grafts have limitations, necessitating advancements in reconstructive surgery techniques. This study reviewed the use of three-dimensional printing for CMF trauma reconstruction using human studies. A systematic search of PubMed, EMBASE, and Google Scholar was conducted in February 2024 for case reports, case series, and clinical trials related to CMF trauma reconstruction using three-dimensional printing technology. The authors' systematic review included 20 studies and a total of 170 participants with CMF bone defects. In general, the authors observed low bias risk in analyzed case reports and series, serious bias risk in nonrandomized controlled trials, and moderate bias risk in randomized controlled trials. The printed objects included CMF structure model prototypes, patient-specific implants, and other custom surgical devices. Studies reveal successful outcomes, including restored facial symmetry and function, restored orbital occlusion, resolved enophthalmos and diplopia, achieved cosmetically symmetrical lower face reconstruction, and precise fitting of surgical devices, enhancing patient and surgeon comfort. However, complications such as local infection, implant exposure, and persistent diplopia were reported. Three-dimensional printed devices reduced surgery time but increased preparation time and production costs. In-house production options could mitigate these time and cost expenditures. Three-dimensional printing holds potential in CMF trauma reconstruction, addressing both functional and esthetic restoration. Nevertheless, challenges persist in implementing this advanced technology in resource-limited environments.

Three-dimensional measurements of symmetry for the mandibular ramus

BACKGROUND

The study examines a sample of patients presenting for viscerocranial computer tomography that does not display any apparent signs of asymmetry, assesses the three-dimensional congruency of the mandibular ramus, and focuses on differences in age and gender.

METHODS

This cross-sectional cohort study screened viscerocranial CT data of patients without deformation or developmental anomalies. Segmentations were obtained from the left and right sides and superimposed according to the best-fit alignment. Comparisons were made to evaluate three-dimensional congruency and compared between subgroups according to age and gender.

RESULTS

Two hundred and sixty-eight patients were screened, and one hundred patients met the inclusion criteria. There were no statistical differences between the left and right sides of the mandibular ramus. Also, there were no differences between the subgroups. The overall root mean square was 0.75 ± 0.15 mm, and the mean absolute distance from the mean was 0.54 ± 0.10 mm.

CONCLUSION

The mean difference was less than one millimetre, far below the two-millimetre distance described in the literature that defines relative symmetry. Our study population displays a high degree of three-dimensional congruency. Our findings help to understand that there is sufficient three-dimensional congruency of the mandibular ramus, thus contributing to facilitating CAD-CAM-based procedures based on symmetry for this specific anatomic structure.

Towards Precision Ophthalmology: The Role of 3D Printing and Bioprinting in Oculoplastic Surgery, Retinal, Corneal, and Glaucoma Treatment

In the forefront of ophthalmic innovation, biomimetic 3D printing and bioprinting technologies are redefining patient-specific therapeutic strategies. This critical review systematically evaluates their application spectrum, spanning oculoplastic reconstruction, retinal tissue engineering, corneal transplantation, and targeted glaucoma treatments. It highlights the intricacies of these technologies, including the fundamental principles, advanced materials, and bioinks that facilitate the replication of ocular tissue architecture. The synthesis of primary studies from 2014 to 2023 provides a rigorous analysis of their evolution and current clinical implications. This review is unique in its holistic approach, juxtaposing the scientific underpinnings with clinical realities, thereby delineating the advantages over conventional modalities, and identifying translational barriers. It elucidates persistent knowledge deficits and outlines future research directions. It ultimately accentuates the imperative for multidisciplinary collaboration to enhance the clinical integration of these biotechnologies, culminating in a paradigm shift towards individualized ophthalmic care.

The Use of Functional Biomaterials in Aesthetic and Functional Restoration in Orbital Surgery

The integration of functional biomaterials in oculoplastic and orbital surgery is a pivotal area where material science and clinical practice converge. This review, encompassing primary research from 2015 to 2023, delves into the use of biomaterials in two key areas: the reconstruction of orbital floor fractures and the development of implants and prostheses for anophthalmic sockets post-eye removal. The discussion begins with an analysis of orbital floor injuries, including their pathophysiology and treatment modalities. It is noted that titanium mesh remains the gold standard for orbital floor repair due to its effectiveness. The review then examines the array of materials used for orbital implants and prostheses, highlighting the dependence on surgeon preference and experience, as there are currently no definitive guidelines. While recent innovations in biomaterials show promise, the review underscores the need for more clinical data before these new materials can be widely adopted in clinical settings. The review advocates for an interdisciplinary approach in orbital surgery, emphasizing patient-centered care and the potential of biomaterials to significantly enhance patient outcomes.

Applications of three-dimensional imaging techniques in craniomaxillofacial surgery: A literature review

Three-dimensional (3D) imaging technologies are increasingly used in craniomaxillofacial (CMF) surgery, especially to enable clinicians to get an effective approach and obtain better treatment results during different preoperative and postoperative phases, namely during image acquisition and diagnosis, virtual surgical planning (VSP), actual surgery, and treatment outcome assessment. The article presents an overview of 3D imaging technologies used in the aforementioned phases of the most common CMF surgery. We searched for relevant studies on 3D imaging applications in CMF surgery published over the past 10 years in the PubMed, ProQuest (Medline), Web of Science, Science Direct, Clinical Key, and Embase databases. A total of 2094 articles were found, of which 712 were relevant. An additional 26 manually searched articles were included in the analysis. The findings of the review demonstrated that 3D imaging technology is becoming increasingly popular in clinical practice and an essential tool for plastic surgeons. This review provides information that will help researchers and clinicians consider the use of 3D imaging techniques in CMF surgery to improve the quality of surgical procedures and achieve satisfactory treatment outcomes.

Printing in Time for Cranio-Maxillo-Facial Trauma Surgery: Key Parameters to Factor in

Study Design

retrospective cohort study.

Objective

3D printing is used extensively in cranio-maxillo-facial (CMF) surgery, but difficulties remain for surgeons to implement it in an acute trauma setting because critical information is often omitted from reports. Therefore, we developed an in-house printing pipeline for a variety of cranio-maxillo-facial fractures and characterized each step required to print a model in time for surgery.

Methods

All consecutive patients requiring in-house 3D printed models in a level 1 trauma center for acute trauma surgery between March and November 2019 were identified and analyzed.

Results

Sixteen patients requiring the printing of 25 in-house models were identified. Virtual Surgical Planning time ranged from 0h 08min to 4h 41min (mean = 1h 46min). The overall printing phase per model (pre-processing, printing, and post-processing) ranged from 2h 54min to 27h 24min (mean = 9h 19min). The overall success rate of prints was 84%. Filament cost was between $0.20 and $5.00 per model (mean = $1.56).

Conclusions

This study demonstrates that in-house 3D printing can be done reliably in a relatively short period of time, therefore allowing 3D printing usage for acute facial fracture treatment. When compared to outsourcing, in-house printing shortens the process by avoiding shipping delays and by having a better control over the printing process. For time-critical prints, other time-consuming steps need to be considered, such as virtual planning, pre-processing of 3D files, post-processing of prints, and print failure rate.

Modeling Methods in Craniofacial Virtual Surgical Planning

Despite the widespread use of virtual surgical planning (VSP), few papers describe the modeling methods used to generate the digital simulations that underpin VSP. This paper aims to review the modeling methods that are currently available for use in VSP and the implications of their use in clinical practice. A literature review was undertaken of the two broad categories of modeling techniques; contour-based planning-namely mirroring from the contralateral side, templating from a normative database, and extrapolation from surrounding landmarks-and occlusal-based planning (OBP). The indications for each modeling method were discussed, including mandibular/maxillary reconstruction, pediatric craniofacial surgery, and orthognathic, as well as the limitations to the accuracy of modeling types. Unilateral defects of the upper/midface, wherein contour accuracy is paramount, are best reconstructed using mirroring methods, whereas bilateral defects-or cases with asymmetry due to craniofacial dysmorphology-are most suited to normative-data-based methods. Cases involving resection of the alveolar margin, in which functional occlusion is the primary outcome are best managed with OBP. Similarly, orthognathic surgery typically uses OBP, although complex cases involving asymmetry, such as clefts, may benefit from a combination of OBP and normative data methods. The choice of modeling methods is, therefore, largely driven by the defect type and the goals of reconstruction.

Virtual Surgical Planning and 3-Dimensional Printing for the Treatment of Zygomaticomaxillary Complex and/or Orbital Fracture

BACKGROUND

Traditionally, in zygomaticomaxillary complex and orbital fractures, miniplates and titanium orbital mesh are used and adapted intraoperatively, which may cause fatigue of the metal and increase the surgical time. Recently, computer-assisted surgery and 3-dimensional printing enable the surgeon to employ 3-dimensional segmentation and mirroring tools, which mimic the pretraumatized anatomy on which the miniplates and titanium orbital mesh are preoperatively molded to precisely duplicate the orbital volume, enophthalmos, and zygomatic bone position.

AIM

To evaluate the results of computer technology using 3-dimensional printing model to prebend miniplates and titanium orbital mesh in the restoration of orbital volume, enophthalmos, and zygomatic bone position in the initial management of patients with zygomaticomaxillary complex and/or orbital fractures.

PATIENTS AND METHODS

This prospective clinical study included 10 Iraqi male patients who met the eligibility criteria and subjected to open reduction and internal fixation utilizing virtual surgical planning and a 3-dimensional model to prebend miniplates and titanium orbital mesh as a treatment modality for facial fractures. The data were analyzed according to the orbital volume, enophthalmos, zygomatic bone position, age, gender, etiology of the fracture, and complications. The patients were radiographically followed up with a computed tomography scan at 4 months postoperatively. The statistical analysis was performed using percentages, the mean±SD, Shapiro-Wilk test, Paired t test, One Way Anova, and Independent t test.

RESULTS

The age of the patients ranged from 18 to 66 years, with an average of 28.6 years and a SD of±14.5 years. Regarding gender, all patients were males. By utilizing virtual surgical planning and 3-dimentional model to prebend miniplates and titanium orbital mesh and concerning the fracture types, which include the zygomaticomaxillary complex, orbital, and combined fractures, there was no significant difference between the measurement of intact side and 4 months postoperatively in orbital volume, enophthalmos, and zygomatic bone position ( P >0.05).

CONCLUSION

This study demonstrated that computer-aided techniques, virtual planning, and the use of prebend miniplates and titanium orbital mesh enable anatomically precise reduction and fixation of the orbital, zygomaticomaxillary complex, and combined fractures regarding orbital volume, enophthalmos, and zygomatic bone position.

Haptic-Assisted Surgical Planning (HASP) in a Case of Bilateral Mandible Fracture

Restoring normal skeletal anatomy in patients with complex trauma to the mandible can be difficult, the difficulty often increasing with an edentulous mandible. This study describes a case of a displaced edentulous bilateral mandibular fracture, which was preoperatively planned with the in-house haptic-assisted surgery planning system (HASP). A model of the virtually restored mandible was 3D-printed at the hospital and a reconstruction plate was outlined beforehand with the printed mandible as a template and served as a guide during surgery. This case suggests HASP as a valuable preoperative tool in the planning phase when dealing with maxillofacial trauma cases. With the application of virtual planning, the authors could analyze the desired outcome and were further supported in surgery by the guidance of the reconstruction plate outlined on the restored model of the mandible.

Accuracy of virtual planning and intraoperative navigation in zygomaticomaxillary complex fractures: A systematic review

OBJECTIVE

This systematic review aims to investigate the effect of virtual planning on the treatment of zygomaticomaxillary complex (ZMC) traumatology followed by intraoperative navigation. Furthermore, clinical outcomes following intraoperative navigation surgery or conventional surgery will be compared.

MATERIALS AND METHODS

A systematic literature search was conducted in PubMed, Embase, Web-of-Science, and Cochrane on January 1st, 2022. Inclusion criteria were articles using preoperative three-dimensional (3D) virtual planning combined with intraoperative navigation or comparing these 3D methods with conventional methods. Furthermore, at least one of the following outcomes needed to be included in the article: technical accuracy of the procedure, preoperative planning time, operative time, number of fixation points, patient satisfaction, complications, or total costs of the intervention.

RESULTS

Following the screening of 4478 articles, 17 were included. Five articles appeared to indicate a significantly better technical linear accuracy, one article reported better accuracy for rotation and two articles showed better accuracy in restoring orbital volume when using navigation. Nine articles investigated operative time with varying results. Seven articles calculated the additional costs, of which three concluded no extra cost while the others indicated high additional costs or questionable cost-effectiveness.

CONCLUSION

Virtual planning and intraoperative navigation technologies have the potential to assist maxillofacial trauma surgeons in reducing ZMC fractures significantly more accurately and restoring the facial contour in a less invasive manner at an acceptable cost.

REGISTRATION

The protocol for this systematic review (CRD42020216717) was registered in the International Prospective Register of Systematic Reviews (PROSPERO).

Application of Computer-Aided Design and Individualized Templates for Bilateral Zygomaticomaxillary Complex Fractures

PURPOSE

Reduction of the bilateral zygomaticomaxillary complex (ZMC) fracture with individualized templates based on computer- aided surgical simulation system. To evaluate the practicality and accuracy of this approach in the treatment of bilateral ZMC fracture.

METHODS

Sixteen patients with bilateral ZMC fractures were collected to create a study model. The authors reconstruct the ZMC on one side via the three-dimensional (3D) model, and then mirrored to the opposite side. Multiple individualized templates were made based on the 3D model, and used as intraoperative guidance to reduce fractures. After surgery, the facial symmetry and the position of zygoma were observed. The mouth opening, pupil level, and sensation of infraorbital nerve were evaluated. Some mark points on zygoma were measured and the postoperative horizontal asymmetry rate (H) was calculated. Besides, orbital height and width were measured.

RESULTS

For all patients, the position of bilateral ZMC was basically restored. The patients with restriction of mouth opening all recovered to normal. The H values were less than 3.0% at all mark points. There was almost no difference in bilateral orbital width and height. Meanwhile, there was no significant difference between the preoperative measurements of the ideal virtual 3D model and the postoperative measurements of patients.

CONCLUSIONS

The study proves that application of computer-aided design and individualized templates can accurately guide the reduction operation of ZMC fracture, restore the ideal shape of ZMC, and obtain good facial symmetry.

3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery

Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.

Application of Rapid Digital Locating Technology in Emergency Treatment of Maxillofacial Space Infection

ABSTRACT

Space infection occurs commonly in the oral and maxillofacial region, and is usually caused by odontogenic infection, resulting in acute symptoms through the maxillofacial space. If timely, correct, and effective treatment is not provided, local infection may quickly spread through the maxillofacial space and cause serious consequences such as suffocation, intracranial infection, and chest infection. A 55-year-old man visited our hospital with obvious swelling and pain in the right maxillofacial region. Maxillofacial computed tomography images showed revealed obvious low-density shadows on the inner side of the right mandibular angle and the right neck. Unlike the usual presentation of maxillofacial space infection, no obvious flushing or fluctuation was seen in the patient's maxillofacial region due to the deep location of the infection. Blind puncture examination and incision exploration may cause unnecessary pain and trauma to the patient. Therefore, to accurately position the infection focus, the operator reconstructed the infection cavity in three-dimensional with digital technology. The puncture point and incision site were quickly determined by three-dimensional measurement and the use of the compass and straightedge construction method, thereby achieving free drainage with an accurate and minimally invasive incision. Following 1 week of routine flushing and dressing changes, the patient recovered and was discharged from hospital. To our knowledge, this is the first precise minimally invasive treatment of a maxillofacial space infection conducted with the aid of digital positioning technology.

Use of modified 3D digital surgical guides in the treatment of complex mandibular fractures

The objective of this study was to evaluate the use of 3D modified digital surgical guide plates combined with preformed titanium plates in the treatment of complex mandibular fractures. Patients with complex mandibular fractures were randomized into three groups. Group A was treated with a combination of 3D modified digital surgical guide plates and preformed titanium plates, Group B was treated with preformed titanium plates only, and Group C was treated conventionally. The key design point of the guide plates is the "slot" structure, which is crucial for accurately locating the preformed titanium plate. Clinical outcomes, including facial symmetry, surgical accuracy, and maximum deviation were quantitatively assessed postoperatively. Twenty-two patients were recruited for this study, eight for Group A, six for Group B, and eight for Group C. Group A exhibited better postoperative clinical outcomes. Among three groups, significant improvements were found in Group A for facial symmetry (S1 [0.74 ± 0.17 mm, P < 0.001], S2 [0.86 ± 0.21 mm, P = 0.004], S3 [0.92 ± 0.26 mm, P < 0.001], S4 [0.32 ± 0.09 mm, P < 0.001], S5 [0.47 ± 0.16 mm, P = 0.042], S6 [0.35 ± 0.04 mm, P = 0.001], S10 [0.50 ± 0.31 mm, P = 0.048], S11 [0.97 ± 0.29 mm, P = 0.018]) and surgical accuracy (T1 [R, 0.56 ± 0.18 mm, P = 0.021], T1 [L, 0.60 ± 0.30 mm, P = 0.022], T2 [L, 0.76 ± 0.21 mm, P = 0.006], T4 [R, 0.37 ± 0.15 mm, P < 0.001], T4 [L, 0.40 ± 0.15 mm, P = 0.001], T8 [R, 0.40 ± 0.15 mm, P = 0.007], T8 [L, 0.31 ± 0.29 mm, P = 0.001], T9 [L, 0.51 ± 0.33 mm, P = 0.042], T10 [R, 0.58 ± 0.28 mm, P = 0.049], T10 [L, 0.53 ± 0.34 mm, P = 0.046], T11 [R, 0.54 ± 0.13 mm, P = 0.021], T12 [0.45 ± 0.16 mm, P = 0.003]). The ideal postoperative effect was found in Group A with maximum deviation analysis. 3D printed modified digital surgical guide plates can effectively improve treatment outcomes in complex mandibular fractures.