Virtual Surgical Planning: The Pearls and Pitfalls

Reduction Cranioplasty in Cases of Hydrocephalic Macrocephaly: Pearls and Pitfalls of Computer-Assisted Surgery

Reduction cranioplasty may be indicated to address functional or cosmetic sequelae of hydrocephalic macrocephaly. With the advent of CAD/CAM digital workflow, surgeons can design and fabricate craniotomy guides, templates, and models that allow for precise cranial reconstruction. Although there are several advantages of virtual planning, pre-determined surgical plans may limit intraoperative flexibility, requiring surgeons to troubleshoot errors in pre-operative planning or model design. The purpose of this report is to present a series of cases demonstrating our institution's technique for single-stage reduction cranioplasty using a CAD/CAM workflow. This report will highlight the benefits and challenges associated with a contemporary digital workflow for reduction cranioplasty.

Application of Computerized Surgical Planning in Craniosynostosis Surgery

Craniosynostosis, a medical condition characterized by premature fusion of one or multiple cranial sutures, has historically been treated through surgical correction. Computerized Surgical Planning (CSP) and three-dimensional (3D) modeling have gained significant popularity across craniofacial surgery. Through a collaborative effort between surgeons and engineers, it is now possible to virtually execute a surgical plan based on preoperative imaging using computed tomography scans. The CSP workflow involves several elements including virtual 3D modeling, CSP computer-aided surgical guide design, manufacturing of guides and templates, and intraoperative implementation. Through the gradual optimization of this workflow, it has been possible to achieve significant progress in the surgical process including improvements in the preoperative planning of complex craniosynostosis cases and reduction of intraoperative time. Furthermore, CSP and 3D modeling have had a positive impact on surgical simulation and residency training, along with patient education and counseling. This article summarizes the CSP workflow in the treatment of craniosynostosis and the implications of this treatment modality on medical trainee education and patient management.

Long-term outcomes in virtual surgical planning for mandibular reconstruction: A cost-effectiveness analysis

OBJECTIVE

This study is an economic evaluation comparing virtual surgical planning (VSP) utilization to free hand mandibular reconstruction (FHR) for advanced oral cavity cancer, for which the cost effectiveness remains poorly understood. The proposed clinical benefits of VSP must be weighed against the additional upfront costs.

METHODS

A Markov decision analysis model was created for VSP and FHR based on literature review and institutional data over a 35-year time horizon. Model parameters were derived and averaged from systematic review and institutional experience. VSP cost and surgical time saving was incorporated. We accounted for long-term risks including cancer recurrence and hardware failure/exposure. We calculated cost in US dollars and effectiveness in quality-adjusted-life-years (QALYs). A health care perspective was adopted, discounting costs and effectiveness at 3%/year. Deterministic and probabilistic sensitivity analyses tested model robustness.

RESULTS

In the base case scenario, total VSP strategy cost was $49,498 with 8.37 QALYs gained while FHR cost was $42,478 with 8.27 QALY gained. An incremental cost-effectiveness ratio (ICER), or the difference in cost/difference in effectiveness, for VSP was calculated at $68,382/QALY gained. VSP strategy favorability was sensitive to variations of patient age at diagnosis and institutional VSP cost with one-way sensitivity analysis. VSP was less economically favorable for patients >75.5 years of age or for institutional VSP costs >$10,745. In a probabilistic sensitivity analysis, 55% of iterations demonstrated an ICER value below a $100,000/QALY threshold.

CONCLUSIONS/RELEVANCE

VSP is economically favorable compared to FHR in patients requiring mandibular reconstruction for advanced oral cancer, but these results are sensitive to the patient's age at diagnosis and the institutional VSP cost. Our results do not suggest if one "should or should not" use VSP, rather, emphasizes the need for patient selection regarding which patients would most benefit from VSP when evaluating quality of life and long-term complications. Further studies are necessary to demonstrate improved long-term risk for hardware failure/exposure in VSP compared to FHR.

The online attention analysis on orthognathic surgery research

OBJECTIVES

Altmetrics is one of the fields of bibliometrics that seeks to assess the impact and interest of a given subject through Internet users. The aim of this study is to make an altmetric analysis of the orthognathic surgery literature.

METHODS

A literature search was conducted using Dimensions app up to December 2023. A list of the 100 most mentioned articles on the topic was compiled. A Google Trends search was performed with same strategy to visualize important data regarding internet search. Charts and tables were created using Microsoft Excel and VOSviewer software to allow bibliometric visualization.

RESULTS

There was a very poor correlation between the number of mentions and the number of citations (r = 0.0202). Most articles discussed on technical innovations associated to orthognathic surgery, majority related to virtual planning (n = 26). Other topics considered interesting to internet readers were complications (n = 18), surgical technique (n = 14), and psychological aspects/quality of life (n = 13).

CONCLUSION

Online interest in orthognathic surgery closely aligns with the level of academic interest but is also influenced by factors such as location and economic status. The internet is a powerful tool for disseminating scientific research to a broad audience, making it more accessible and engaging than traditional academic channels.

Orthognathic Surgery Trending: Retrospective Ten Years Cases Analysis in Nineveh Province, Iraq

AIMS

The study aimed at analyzing patient's case sheets in regard to the incidence of skeletal discrepancy present in cases and its relation with the demographic profile of the sample. All these are chronicled for more than 10 years periods.

METHODOLOGY

This is a retrospective study analysis of the orthognathic case sheets for more than 10 years period. The total numbers of patients are 678. Patient's case sheet was already prepared by the Multi-Disciplinary Team Orthognathic Surgery Clinic in Al-Salam Teaching Hospital, which is the only authorized committee in Nineveh Health Directorate.

RESULTS

The highest age percentage is between (18 and 27 y/76%). Angle class III cases are the uppermost cases (36%) from the total. A significant P value is clear at the level ≤0.05 and ≤0.01 between surgery type and discrepancy in anterior segmental osteotomies (upper and lower) which is performed in bi-maxillary protrusion cases and Angle class II cases (0.01**). Similarly, anterior segmental osteotomies (upper jaw only) which are indicated in both open bite and Angle Class II cases documented as a statistically significant P value (0.02*). The positive correlation is shown in all variables with the disharmony or facial discrepancies. Esthetic and beauty as causes for treatment recorded more than function in relation to time series.

CONCLUSION

This study documents that patients with skeletal class III accounted for the largest percentage (64%) in the study group. A high increase in patients number seeking treatment for their discrepancy is obvious with time from 2009 till 2022.

Evaluating the benefit of virtual surgical planning on bony union rates in head and neck reconstructive surgery

OBJECTIVES

Virtual surgical planning (VSP) has gained acceptance because of its benefits in obtaining adequate resection, achieving cephalometric accuracy, and reducing operative time. The aim of this study is to compare the rate of union between VSP and free-hand surgery (FHS), identify predictors of non-union and evaluate the difference in operative time.

METHODS

Post-operative CT were retrospectively reviewed for 123 patients who underwent maxillary or mandibular reconstruction between 2014 and 2021 using either VSP or FHS. Each apposition was graded as complete, partial or non-union. The rate of union, risk difference and inter-rater reliability were calculated. The difference in operative time was assessed. Predictors of non-union were identified using logistic regression.

RESULTS

A total of 326 appositions were graded (VSP n = 150; FHS n = 176). The rates of complete and partial union were higher with VSP than FHS (74.7% vs. 65.3%; 18% vs. 15.9%, respectively, p = 0.01). Non-union was found at a higher rate with FHS than with VSP (18.7% vs. 7.3%). The non-union risk difference was 11.4. FHS, major complications and apposition at the native bone were predictors of non-union (OR 2.9, p = 0.02; OR 3.4, p = 0.01; OR 2.5, p = 0.05, respectively). The mean surgical time was shorter with VSP than with FHS (265.3 vs. 381.5 min, p < 0.001). The inter-rater agreement was high (k = 0.85; ICC = 0.86).

CONCLUSION

VSP demonstrated significantly higher bony union rates and shorter operative time. FHS, development of major complications and apposition with native bone correlated with non-union.

Reconstruction of Maxillary Defects Using Virtual Surgical Planning and Additive Manufacturing Technology: A Tertiary Care Centre Experience

Introduction

Maxillary reconstruction is often a challenging task for the surgeons because of the complex anatomy. However, with the advances in virtual surgical planning (VSP) and 3D printing technology there is a new avenue for the surgeons which offers a suitable alternative to conventional flap-based reconstructions.

Patients and Methods

In this article, we have described 4 case scenarios which were managed with the help of VSP and additive manufacturing technology for complex maxillary reconstruction procedures. Use of the technologies aided the clinician in achieving optimal outcomes with regards to form, function and esthetics.

Discussion

Virtual surgical planning (VSP) has gained a lot of impetus in past 1 decade. These aides the surgeon in determining the extent of disease and also carry out the treatment planning. In addition to VSP, the concept of additive manufacturing provides a viable alternative to the conventional reconstruction modalities for maxillary defect rehabilitation. Increased accuracy, rehabilitation of normal anatomical configuration, appropriate dental rehabilitation, decreased intra-operative time and post-operative complications are some of the advantages. In addition, patient-specific implants eliminate the need for a separate donor site. Apart from the treatment of pathologies, they also can be used for reconstruction of post-traumatic defect, where endosteal implant placement is not possible.

Conclusion

These modalities show promising results for reconstruction of complex maxillary defects.

The Role of Virtual Surgical Planning in Surgery for Complex Craniosynostosis

Background

Virtual surgical planning (VSP) decreases reliance on intraoperative subjective assessment of aesthetic and functional outcomes in craniofacial surgery. Here, we describe our experience of using VSP for complex craniosynostosis surgery to inform preoperative decision making and optimize postoperative outcomes.

Methods

Chart review was performed for children treated with craniosynostosis at our institution from 2015 to 2021. Eight VSP maneuvers were defined and assigned to each patient when applicable: (1) complex cranioplasty: combined autologous and synthetic; (2) autologous cranioplasty; (3) synthetic cranioplasty; (4) vector analysis and distractor placement; (5) complex osteotomies; (6) multilayered intraoperative plans; (7) volume analysis; and (8) communication with parents. Outcomes between VSP and non-VSP cohorts were compared.

Results

Of 166 total cases, 32 were considered complex, defined by multisutural craniosynostosis, syndromic craniosynostosis, or revision status. Of these complex cases, 20 underwent VSP and 12 did not. There was no difference in mean operative time between the VSP and non-VSP groups (541 versus 532 min, P = 0.82) or in unexpected return to operating room (10.5% versus 8.3%, P = 0.84). VSP was most often used to communicate the surgical plan with parents (90%) and plan complex osteotomies (85%).

Conclusions

In this cohort, VSP was most often used to communicate the surgical plan with families and plan complex osteotomies. Our results indicate that VSP may improve intraoperative efficiency and safety for complex craniosynostosis surgery. This tool can be considered a useful adjunct to plan and guide intraoperative decisions in complex cases, reducing variability and guiding parental expectations.

Management of Total Frontal Bone Loss After Surgery for Craniosynostosis: The Modified Visor Bone Flap With Brain Cage

Complications after craniosynostosis surgery occur in 11% to 36% of cases and may be precipitated by poor soft tissue coverage and concomitant exposure of non-sterile regions; sequelae may result in infection, osteomyelitis, and bone loss requiring complex reconstruction. In the pediatric population, autologous cranioplasty remains the gold standard due to growth potential and a more favorable complication profile than synthetic cranioplasty. Virtual surgery planning (VSP) and computer-assisted design (CAD)/computer-assisted manufacturing (CAM) technology can be utilized to create innovative, patient-specific autologous solutions, similar to the approach with synthetic cranioplasty. A novel surgical approach using VSP was used for an 18-month-old female with near total bifrontal bone loss. Surface area measurements were used to determine the amount of bone available to replace the infected frontal bone. VSP was utilized to determine the most efficient construct configuration possible to achieve maximal coverage via calculation of cranial bone surface area measurements. Surgical reconstruction of the defect was planned as a Modified Visor Bone Flap with Posterior Brain Cage. A construct was fashioned from available cranial bone struts to obtain widespread coverage. 3D Recon images from before and after surgery demonstrate almost complete re-ossification of the cranial vault with significant resulting clinical improvement. Reconstruction of total frontal bone loss is possible by utilizing this technique. VSP can improve the safety and efficiency of complex autologous cranial bone reconstructions. We propose a treatment algorithm to address the problem of near total frontal bone loss in young children for whom alloplastic implants are not suitable.

Virtual surgical planning in craniomaxillofacial surgery: a structured review

Craniomaxillofacial (CMF) surgery is a challenging and very demanding field that involves the treatment of congenital and acquired conditions of the face and head. Due to the complexity of the head and facial region, various tools and techniques were developed and utilized to aid surgical procedures and optimize results. Virtual Surgical Planning (VSP) has revolutionized the way craniomaxillofacial surgeries are planned and executed. It uses 3D imaging computer software to visualize and simulate a surgical procedure. Numerous studies were published on the usage of VSP in craniomaxillofacial surgery. However, the researchers found inconsistency in the previous literature which prompted the development of this review. This paper aims to provide a comprehensive review of the findings of the studies by conducting an integrated approach to synthesize the literature related to the use of VSP in craniomaxillofacial surgery. Twenty-nine related articles were selected as a sample and synthesized thoroughly. These papers were grouped assigning to the four subdisciplines of craniomaxillofacial surgery: orthognathic surgery, reconstructive surgery, trauma surgery and implant surgery. The following variables - treatment time, the accuracy of VSP, clinical outcome, cost, and cost-effectiveness - were also examined. Results revealed that VSP offers advantages in craniomaxillofacial surgery over the traditional method in terms of duration, predictability and clinical outcomes. However, the cost aspect was not discussed in most papers. This structured literature review will thus provide current findings and trends and recommendations for future research on the usage of VSP in craniomaxillofacial surgery.

The Implant-borne Articulation Splint in Fibula Free Flap Mandibular Reconstruction: A Technical Note

Computer-aided design and computer-aided manufacturing and digitally simulated surgeries have revolutionized maxillomandibular reconstruction. In particular, this technology has increased the accuracy and facilitated the process of dental implantation in fibula free flaps. Despite the efficacy of virtual planning, there is a minor degree of translational difference between digital and intraoperative measurements, which may affect the precision of implant and fibula orientations. This is especially concerning during the last stage of fibula insetting, where the graft segments have the potential to roll, yaw, or pitch. The objective of this study is to describe an advanced prosthodontic technique that ensures the fibula grafts and implants remain in a restorable position during final insetting. We describe the technique and workflow of the implant-borne articulation splint through a case presentation and demonstrate results at 4 months postoperative and postradiotherapy. Given the degree of investment placed in virtual planning, free flap reconstruction, and endosteal implants, a technique that ensures optimal restorability of each implant is pivotal. Larger studies are still required to fully elucidate the cost-effectiveness and long-term results of the implant-borne articulation splint.

Orthognathic surgery with iliac bone grafting for an interpositional gap in a patient with type III hemifacial microsomia: A case report

Hemifacial microsomia (HFM) is characterized by uni- or bilateral microtia and hypoplasia of the mandible, orbits, facial nerve, and adjacent soft tissues. Patients with Pruzansky-Kaban type III HFM show the most severe facial deformities and often encounter difficulty obtaining treatment. In recent years, orthognathic surgery for HFM-related deformities has often been performed after the patient has stopped growing. However, few detailed reports have described the difficulties of orthognathic surgery for patients with type III HFM. This report describes the case of a patient with type III HFM who underwent three unilateral mandibular reconstructions while still growing, including autogenous reconstructions and secondary distraction osteogenesis, followed by orthognathic surgery with iliac bone grafting for an interpositional gap between the proximal and distal segments after she had stopped growing to improve facial asymmetry and malocclusion.

Gender Facial Affirmation Surgery; Techniques for Feminizing the Chin

The shape and size of the chin are very important in feminizing the lower third of the face, and osseous genioplasty is commonly used in FFS. Different variations of the osseous genioplasty can be used to feminize the chin. The 1-piece genioplasty reduces the size and rounds the chin. 2-piece genioplasty reduces or increases the projection of the chin, but retains the same shape. 3-piece genioplasty also reduces or increases the projection, but has the additional benefit of narrowing the chin. This narrowing helps to create the "V" shaped lower face that is often desired by patients seeking facial feminization. Protection of the mental nerve and resuspension of the mentalis muscle is essential to prevent permanent lower lip numbness and ptosis respectively.

V2-Net: An Attention-guided Volumetric Regression Network for Tooth Landmark Localization on CT Images with Metal Artifacts

For virtual surgical planning in orthognathic surgery, marking tooth landmarks on CT images is an important procedure. However, the manual localization procedure of tooth landmarks is time-consuming, labor-intensive, and requires expert knowledge. Also, direct and automatic tooth landmark localization on CT images is difficult because of the lower resolution and metal artifacts of dental images. The purpose of this study was to propose an attention-guided volumetric regression network (V2-Net) for accurate tooth landmark localization on CT images with metal artifacts and lower resolution. V2-Net has an attention-guided network architecture using a coarse-to-fine-attention mechanism that guided the 3D probability distribution of tooth landmark locations within anatomical structures from the coarse V-Net to the fine V-Net for more focus on tooth landmarks. In addition, we combined attention-guided learning and a 3D attention module with optimal Pseudo Huber loss to improve the localization accuracy. Our results show that the proposed method achieves state-of-the-art accuracy of 0.85 ± 0.40 mm in terms of mean radial error, outperforming previous studies. In ablation studies, we observed that the proposed attention-guided learning and a 3D attention module improved the accuracy of tooth landmark localization in CT images of lower resolution and metal artifacts. Furthermore, our method achieved 97.92% in terms of the success detection rate within the clinically accepted accuracy range of 2.0 mm.

Virtual Surgical Planning in Head and Neck Reconstruction

Virtual surgical planning is a revolutionary tool for the head and neck reconstructive surgeon. As with any tool, there are strengths and weaknesses. The strengths include shorter operative time, shorter ischemic time, streamlined dental rehabilitation, facilitation of complex reconstruction, non-inferior and possibly superior accuracy, and increased durability. The weaknesses are increased up-front costs, potential delays to operative management, limited flexibility on the day of surgery, and loss of familiarity with conventionally planned surgery.

Can Fracture Reduction be Attempted Through a 3D-Printed Guide Template Without Maxillomandibular Fixation?

BACKGROUND

Computer-aided design and manufacturing is widely used in clinical practice. This technology may change existing methods for mandibular fracture management.

PURPOSE

The purpose of this in-vitro study was to determine if the reduction for mandibular symphysis fracture is performed without maxillomandibular fixation (MMF) using 3-dimensional (3D)-printed template.

STUDY DESIGN, SETTING, AND SAMPLE

This was an in-vitro study and had the character of a proof-of-concept study. The study was planned using the existing 20 pairs of intraoral scan and computed tomography data. The mandibular model STL file was created by merging the STL file obtained for the bimaxillary dentitions with the computed tomography DICOM file, and this was set as the original model. In the original model, STL file of fracture model of mandibular symphysis was created using computer-aided design. A template similar to a wafer or an implant guide was manufactured from restoring the own occlusion, and the mandibular fracture model was reduced and fixed using the 3D-printed template and wire, and this was set as the experimental group. The 3D coordinate system error was measured at 6 landmarks and statistically compared using scan data between models of the groups.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLES

Reduction techniques with MMF or without MMF using guide template for mandibular fracture model.

MAIN OUTCOME VARIABLE(S)

The 3D coordinate system error (mm).

COVARIATES

The position of landmarks.

ANALYSES

The Mann-Whitney U test, student's t-test, and the Kruskal-Wallis test were used to analyze the coordinate errors between the landmarks. A P value of < .05 was considered statistically significant.

RESULTS

The 3D error value of the control and experimental group were 1.06 ± 0.63 mm (range: 0.11 to 2.92 mm) and 0.96 ± 0.48 mm (range: 0.2 to 2.95 mm), respectively. There was no statistical difference between the control and experimental group. There was a statistically significant difference in the lower 2 and lower 3 landmarks compared to the upper 1 (P = .001 and .000, respectively) before and after the reduction in the experimental group.

CONCLUSION AND RELEVANCE

This study demonstrates that the reduction using a 3D-printed guide template for the mandibular symphysis fracture could be possible even without the MMF.

Synergy between artificial intelligence and precision medicine for computer-assisted oral and maxillofacial surgical planning

OBJECTIVES

The aim of this review was to investigate the application of artificial intelligence (AI) in maxillofacial computer-assisted surgical planning (CASP) workflows with the discussion of limitations and possible future directions.

MATERIALS AND METHODS

An in-depth search of the literature was undertaken to review articles concerned with the application of AI for segmentation, multimodal image registration, virtual surgical planning (VSP), and three-dimensional (3D) printing steps of the maxillofacial CASP workflows.

RESULTS

The existing AI models were trained to address individual steps of CASP, and no single intelligent workflow was found encompassing all steps of the planning process. Segmentation of dentomaxillofacial tissue from computed tomography (CT)/cone-beam CT imaging was the most commonly explored area which could be applicable in a clinical setting. Nevertheless, a lack of generalizability was the main issue, as the majority of models were trained with the data derived from a single device and imaging protocol which might not offer similar performance when considering other devices. In relation to registration, VSP and 3D printing, the presence of inadequate heterogeneous data limits the automatization of these tasks.

CONCLUSION

The synergy between AI and CASP workflows has the potential to improve the planning precision and efficacy. However, there is a need for future studies with big data before the emergent technology finds application in a real clinical setting.

CLINICAL RELEVANCE

The implementation of AI models in maxillofacial CASP workflows could minimize a surgeon's workload and increase efficiency and consistency of the planning process, meanwhile enhancing the patient-specific predictability.

Virtual reality digital surgical planning for jaw reconstruction: a usability study

BACKGROUND

Digital surgical planning (DSP) has revolutionized the preparation and execution of the management of complex head and neck pathologies. The addition of virtual reality (VR) allows the surgeon to have a three-dimensional experience with six degrees of freedom for visualizing and manipulating objects. This pilot study describes the participants experience with the first head and neck reconstructive VR-DSP platform.

METHODS

An original VR-DSP platform has been developed for planning the ablation and reconstruction of head and neck pathologies. A prospective trial utilizing this platform involving reconstructive surgeons was performed. Participants conducted a simulated VR-DSP planning session, pre- and post-questionnaire as well as audio recordings allowing for qualitative analysis.

RESULTS

Thirteen consultant reconstructive surgeons representing three surgical backgrounds with varied experience were recruited. The majority of surgeons had no previous experience with VR. Based on the system usability score, the VR-DSP platform was found to have above average usability. The qualitative analysis demonstrated the majority had a positive experience. Participants identified some perceived barriers to implementing the VR-DSP platform.

CONCLUSIONS

Virtual reality-digital surgical planning is usable and acceptable to reconstructive surgeons. Surgeons were able to perform the steps in an efficient time despite limited experience. The addition of VR offers additional benefits to current VSP platforms. Based on the results of this pilot study, it is likely that VR-DSP will be of benefit to the reconstructive surgeon.

Advantages of a Training Course for Surgical Planning in Virtual Reality for Oral and Maxillofacial Surgery: Crossover Study

BACKGROUND

As an integral part of computer-assisted surgery, virtual surgical planning (VSP) leads to significantly better surgery results, such as for oral and maxillofacial reconstruction with microvascular grafts of the fibula or iliac crest. It is performed on a 2D computer desktop screen (DS) based on preoperative medical imaging. However, in this environment, VSP is associated with shortcomings, such as a time-consuming planning process and the requirement of a learning process. Therefore, a virtual reality (VR)-based VSP application has great potential to reduce or even overcome these shortcomings due to the benefits of visuospatial vision, bimanual interaction, and full immersion. However, the efficacy of such a VR environment has not yet been investigated.

OBJECTIVE

This study aimed to demonstrate the possible advantages of a VR environment through a substep of VSP, specifically the segmentation of the fibula (calf bone) and os coxae (hip bone), by conducting a training course in both DS and VR environments and comparing the results.

METHODS

During the training course, 6 novices were taught how to use a software application in a DS environment (3D Slicer) and in a VR environment (Elucis) for the segmentation of the fibula and os coxae, and they were asked to carry out the maneuvers as accurately and quickly as possible. Overall, 13 fibula and 13 os coxae were segmented for each participant in both methods (VR and DS), resulting in 156 different models (78 fibula and 78 os coxae) per method (VR and DS) and 312 models in total. The individual learning processes in both environments were compared using objective criteria (time and segmentation performance) and self-reported questionnaires. The models resulting from the segmentation were compared mathematically (Hausdorff distance and Dice coefficient) and evaluated by 2 experienced radiologists in a blinded manner.

RESULTS

A much faster learning curve was observed for the VR environment than the DS environment (β=.86 vs β=.25). This nearly doubled the segmentation speed (cm³/min) by the end of training, leading to a shorter time (P<.001) to reach a qualitative result. However, there was no qualitative difference between the models for VR and DS (P=.99). The VR environment was perceived by participants as more intuitive and less exhausting, and was favored over the DS environment.

CONCLUSIONS

The more rapid learning process and the ability to work faster in the VR environment could save time and reduce the VSP workload, providing certain advantages over the DS environment.

Craniofacial Fibrous Dysplasia of the Skull Assisted by Virtual Surgical Planning

Craniofacial fibrous dysplasia (FD) involves thickening of the skull and facial bones, causing asymmetry and distortion of overlying soft tissues. Surgical contouring is often performed with rotary bur or osteotome, with the goal of matching contralateral unaffected anatomy. This is made technically challenging by having no direct visualization of contralateral structures, and the desire to control depth of resection to match the contour of the unaffected side. In our report, a 13-year-old male presented for surgical evaluation of craniofacial FD affecting the right parietal/temporal bones. A novel virtual surgical planning approach of premade drilling template with numerous pilot guide holes was used to assist bone debulking. The pilot holes allowed precise burring of the dysplastic bone. The patient achieved excellent calvarial contour symmetry without unintended intracranial extension. We believe that virtual surgical planning and drilling depth guides are effective tools in the reconstruction of craniofacial FD.

Accurate Reconstruction of Mandibular Defects With Vascularized Bone Flaps Through Utilization of Mandible Space-Retention Guides

PURPOSE

Comprehensive evaluation of the effects of using computer-aided design and space retention guide technology to reconstruct mandibular defects using vascularized autogenous bone flaps.

METHOD

This study included 8 patients who received autogenous bone flaps (2 cases of vascularized fibula flaps and 6 cases of vascularized iliac flaps) for mandibular defect reconstruction at Peking University School and Hospital of Stomatology, from July 2018 to May 2021. All patients received digital surgery planning, CAD/CAM, surgical guide technique for the removal of diseased bone segments, as well as vascularized fibular flap/iliac flap reconstruction. Three-dimensional deviations were analyzed after the operation.

RESULT

The mandibular defects of all 8 patients were successfully reconstructed using the vascularized fibular flap/iliac bone flap. There were no serious complications at either the donor site or recipient site during our follow-up. The average three-dimensional deviation of all 8 patients was 1.92 mm, based on comparisons of preoperative design and actual postoperative computed tomography.

CONCLUSION

Utilizing CAD/CAM, we designed a new mandibular space-retention guide, which can accurately translate the preoperative digital design plan to real-time surgery with satisfactory accuracy and efficacy.

Applications of three-dimensional surgical planning in facial feminization surgery: A systematic review

BACKGROUND

Despite some reports that have shown an increase in safety, efficiency, and accuracy during feminizing craniofacial procedures utilizing three-dimensional (3D) technology, there are no reports summarizing the available evidence on this matter for facial feminization surgery (FFS). Here, we aimed to systematically review the application of 3D technology on FFS.

METHODS

We conducted a comprehensive search across PubMed, SCOPUS, Ovid MEDLINE®, Web of Science, and ScienceDirect looking for studies reporting the use of 3D surgical planning in the setting of FFS following the PRISMA guidelines. We extracted data on photographic assessment, imaging, surgical application, and surgical technique and outcomes.

RESULTS

This review included 10 studies comprising 1473 transgender female patients and 50 cadaveric cranial specimens. Four studies employed virtual surgical planning (VSP) and the concomitant use of prefabricated cutting guides. One study reported the implementation of 3D VSP using a female skull as a reference. One study used computer-aided design cutting guides and custom plates for FFS. Standardized incorporation of 3D printed models allowed for preoperative planning in three studies. Three studies reported VSP using 3D reconstruction of CT images, but without the use of 3D printing. Three studies used 3D photography with specialized camera technology to enrich clinical documentation and provide a comprehensive facial analysis of soft tissue. Accuracy ranged from 85.7% to 97%. Morbidity ranged from 0% to 12.5%.

CONCLUSION

Based on this data, we believe 3D VSP has promising outcomes in terms of accuracy and low morbidity, encouraging its implementation in FFS. However, further prospective double-arm cohort studies are required.

Custom Plates in Orthognathic Surgery: A Single Surgeon's Experience and Learning Curve

BACKGROUND

Virtual surgical planning (VSP) now allows for the fabrication of custom plates in orthognathic surgery. The senior author was an early adopter, using VSP and stereolithographic splints for over a decade, before transitioning to custom plates in 2019. The authors present our experience and learning curve with this new technology and compare results to a prior cohort of orthognathic patients.

METHODS

A retrospective chart review identified patients undergoing orthognathic surgery with the senior author between 2016 and 2021. All underwent VSP and stereolithographic splint formation, and then either traditional or custom-plate fixation. Demographics, perioperative variables, and postoperative outcomes were analyzed. Traditional fixation consisted of craniomaxillofacial plates, bent intraoperatively by the surgeon to adapt to the facial skeleton. Custom plates were prefabricated and prebent to fit drill holes outlined by customized cutting guides.

RESULTS

Forty-three patients underwent surgery in the study period, 25 (58.1%) with traditional fixation hardware and 18 (41.9%) with custom plates. The surgical technique evolved throughout the custom-plate cohort, with the most recent technique involving custom maxillary plate fixation and traditional mandibular plate fixation. When comparing this group of patients to the prior cohort of traditional fixation patients, operative time significantly decreased (mean 233 minutes versus 283 minutes, P = 0.044), without significant difference in complications.

CONCLUSIONS

Patient-specific cutting guides and custom plates allow for precise spatial positioning of the osteotomized jaw in the orthognathic surgery. Unsurprisingly, obstacles must be overcome in adopting this new technology; here, we outline our experience and technical modifications that have resulted in increased surgical efficiency with comparable outcomes.

Unexpected Change of Surgical Plans and Contingency Strategies in Computer-Assisted Free Flap Jaw Reconstruction: Lessons Learned From 98 Consecutive Cases

Background

Computer-assisted surgeries (CAS) are increasingly being adopted as the treatment of choice for jaw reconstructions with osseous free flaps. Although unexpected change of surgical plans remains a major concern of CAS, there are few studies focusing on this unfavorable clinical scenario. The aim of the present study was to investigate the rate of unexpected change of surgical plans and potential influential parameters, and to discuss the contingency strategies.

Methods

A retrospective study was performed to evaluate all the patients who underwent computer-assisted jaw resections and osseous free flap reconstructions. The postoperative radiographs were reviewed and compared with the preoperative surgical plans. Operating records were examined to analyze the reasons for unexpected change of surgical plans and the management. The potential influential parameters for the change of surgical plans were analyzed using Fisher-exact test. The difference was regarded as statistically significant for a p-value less than 5%.

Results

From Nov 2014 to Oct 2021, a total of 98 consecutive computer-assisted free flap jaw reconstruction cases with osseous free flaps were included in this study. Our experience showed that 5.1% of the patients (five cases) needed intra-operative change of the surgical plans. We summarized the unexpected change of surgical plans and the contingency strategies as four clinical scenarios, including extended resection and reconstruction, shortened resection and reconstruction, modified resection without changing reconstruction, and modified reconstruction without changed resection. None of the potential influential parameters was identified as significant in relation to unexpected change of surgical plans intraoperatively.

Conclusion

Our experience shows that with the comprehensive methodology for computer-assisted free flap jaw reconstruction surgery planning, we can minimize the possibility of unexpected change of surgical plans during surgery. The lessons learned from our 98 consecutive cases can help beginners prevent unexpected change of surgical plans and rationalize contingency strategies in computer-assisted free flap jaw reconstruction.

Virtual Surgical Planning and 3D Printing in Veterinary Dentistry and Oromaxillofacial Surgery

Virtual surgical planning and three-dimensional (3D) printing are preoperative processes requiring the acquisition of high-quality imaging data. A surgical treatment plan is created and rehearsed virtually as the operator manipulates the 3D images of the patient within the software. When the operator is satisfied with the plan, including anticipated osteotomies, tumor excision margins, and reconstruction options, physical 3D prints can be produced. This article introduces the reader to the basic concepts involved in virtual surgical planning and 3D printing as well as their implementation in veterinary oromaxillofacial surgery.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

Adherence to Computer-Assisted Surgical Planning in 136 Maxillofacial Reconstructions

Objective

To investigate the adherence to initially planned maxillofacial reconstructions using computer-assisted surgery (CAS) and to identify the influential factors affecting its compliance for maxillofacial reconstruction.

Patients and Methods

A retrospective analysis of 136 computer-assisted maxillofacial reconstructive surgeries was conducted from January 2014 to June 2020. The categorical parameters involved age, gender, disease etiology, disease site, defect size, bone flap segments, and flap type. Apart from descriptive data reporting, categorical data were related by applying the Fisher-exact test, and a p-value below 5% was considered statistically significant (P < 0.05).

Results

The main reasons for partial or non-adherence included unfitness, patient health condition, and other subjective reasons. Out of the total patient population, 118 patients who underwent mandibular reconstruction showed higher CAS compliance (83.9%) compared to the 18 midface reconstruction (72.2%) without any statistically significant difference (p = 0.361). Based on the size of the defect, a significantly higher CAS compliance (p = 0.031) was observed with a minor defect (80.6%) compared to the large-sized ones (74.1%). The bone flaps with two or more segments were significantly (p = 0.003) prone to observe a partial (15.4%) or complete (12.8%) discard of the planned CAS compared to the bone flaps with less than two segments. The malignant tumors showed the lowest CAS compliance when compared to other disorders without any significant difference (p = 0.1).

Conclusion

The maxillofacial reconstructive surgical procedures offered optimal compliance to the initially planned CAS. However, large-sized defects and multiple bone flap segments demonstrated a higher risk of partial or complete abandonment of the CAS.

Current Trends in Orthognathic Surgery in Poland—A Retrospective Analysis of 124 Cases

The analysis aims at assessing the current trends in orthognathic surgery. The retrospective study covered a group of 124 patients with skeletal malocclusion treated by one team of maxillofacial surgeons at the University Hospital in Zielona Góra, Poland. Various variables were analysed, including demographic characteristics of the group, type of deformity, type of osteotomy used, order in which osteotomy was performed and duration of types of surgery. The mean age of the patients was 28 (ranging from 17 to 48, SD = 7). The group included a slightly bigger number of females (59.7%), with the dominant skeletal Class III (64.5%), and asymmetries were found in 21.8% of cases. Types of osteotomy performed during surgeries were divided as follows: LeFort I, segmental LeFort I, BSSO, BSSO with genioplasty, LeFort I with BSSO, LeFort I with BSSO and genioplasty, segmental LeFort I with BSSO, isolated genioplasty. Bimaxillary surgeries with and without genioplasty constituted the largest group of orthognathic surgeries (49.1%), and a slightly smaller percentage were one jaw surgeries (46.7%). A statistically significant correlation was found between the type of surgery and the skeletal class. In patients with skeletal Class III, bimaxillary surgeries were performed significantly more often than in patients with skeletal Class II (57.5% vs. 20.0%; p = 0.0002). The most common type of osteotomy in all surgeries was bilateral osteotomy of the mandible modo Obwegeser–Epker in combination with Le Fort I maxillary osteotomy (42.7%). The order of osteotomies in bimaxillary surgeries was mandible first in 61.3% of cases. The longest surgery was bimaxillary osteotomy with genioplasty (mean = 265 min), and the shortest surgery was isolated genioplasty (mean = 96 min). The results of the analysis show a significant differentiation between the needs of orthognathic surgery and the types of corrective osteotomy applied to the facial skeleton.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation.

SUMMARY

Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Point of care virtual surgical planning and 3D printing in facial gender confirmation surgery: a narrative review

Facial gender confirmation surgery (FGCS) is a powerful set of procedures in the armamentarium of plastic surgeons that can transform the male face into a gender-congruent female face and provide the transgender individual with improved quality of life, positive body image and help in social integration. The goals of the FGCS procedures are to address the individual patients' concerns and expectations about their facial appearance, offer safely executed surgery, minimize complications, and optimize surgical outcomes. Pre-operative computed tomography (CT) scanning and three-dimensional (3D) reconstruction before facial feminization or masculinization delineates important skeletal and sinus anatomy and can also be a useful tool in patient consultation. Virtual surgical planning (VSP) is a valuable tool in facial surgery. From free flap bony reconstruction after tumor resection and orthognathic surgery to craniosynostosis planning, VSP has become widely utilized in modern day cranio-maxillofacial surgery. The use of patient-specific cutting guides and implants helps in improving symmetry and safety of these procedures. Furthermore, 3D printed models are valuable tools in patient education and counseling prior to surgery. In this article we describe our approach to FGCS through the integration of point of care (POC) VSP and 3D printing (3DP) to help deliver safer and accurate FGCS outcomes.

The value of surgical articulator MT in orthognathic model surgery: Technical note and case report

The utilize of surgical articulator MT may lead to a major reduction in time and effort that usually consuming in conventional model surgery and promoted for precise planning and surgery. It can be useful in the management of several cases of dentofacial deformities when virtual surgical planning is either unaffordable or unavailable.

A Comprehensive Analysis of Complications of Free Flaps for Oromandibular Reconstruction

OBJECTIVES/HYPOTHESIS

To determine the frequency and management of short- and long-term complications related to oromandibular free flap reconstruction and identify potentially predictive factors of hardware complications.

STUDY DESIGN

Retrospective chart review.

METHODS

A retrospective database from chart review was formed consisting of 266 oromandibular free flap reconstructions performed at a single institution over a 15-year period. Data were collected on demographics, surgical treatment, complications, and management of complications. Subgroup univariate and multivariate analyses were performed to compare patients with hardware complications and those without.

RESULTS

Eighty-one of 266 patients (30.5%) that underwent oromandibular reconstruction had an early complication (<4 weeks after surgery), and the most common complications were cervical wound dehiscence (11.3%) and fistulas (9.40%). Eighty of 266 patients (30.1%) had a long-term complication (>4 weeks after surgery) and the most common complication was plate exposure (26.7%). Univariate and multivariate analyses showed no association between whether there was hardware extrusion and fibula versus scapula, smoking history, virtual surgical planning (VSP), and dental implantation (P > .05). Only early complications (OR, 3.59, 95% CI, 1.83-7.05, P < .01) and patients undergoing oromandibular reconstruction for osteoradionecrosis (OR, 2.26, 95% CI, 1.10-4.64, P = .03) were strongly and independently associated with subsequent hardware extrusion on univariate analysis.

CONCLUSIONS

Both short- and long-term complications are common after oromandibular reconstruction. The most important predictive factor for a late complication is an early complication and prior radiation. There was no difference of plate complications among the various free flap types. Dental implantation and use of VSP were not associated with hardware complications.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1997-2005, 2021.

Precision Medicine in Ossiculoplasty

INTRODUCTION

Long term results of ossiculoplasty surgery are considered poor with displacement and extrusion amongst the common reasons for failure. Application of 3Dimensional (3D) printing may help overcome some of these barriers, however digital methods to attain accurate 3D morphological studies of ossicular anatomy are lacking, exacerbated by the limitation of resolution of clinical imaging.

METHODS

20 human cadaveric temporal bones were assessed using micro computed tomography (CT) imaging to demonstrate the lowest resolution required for accurate 3D reconstruction. The bones were then scanned using conebeam CT (125 μm) and helical CT (0.6 mm). 3D reconstruction using clinical imaging techniques with microCT imaging (40 μm resolution) as a reference was assessed. The incus was chosen as the focus of study. Two different methods of 3D printing techniques were assessed.

RESULTS

A minimum resolution of 100 μm was needed for adequate 3D reconstruction of the ossicular chain. Conebeam CT gave the most accurate data on 3D analysis, producing the smallest mean variation in surface topography data relative to microCT (mean difference 0.037 mm, p < 0.001). Though the incus varied in shape in between people, paired matches were identical. Thus, the contralateral side can be used for 3D printing source data if the ipsilateral incus is missing. Laser based 3D printing was superior to extrusion based printing to achieve the resolution demands for 3D printed ossicles.

CONCLUSION

Resolution of modern imaging allows 3D reconstructions and 3D printing of human ossicles with good accuracy, though it is important to pay attention to thresholding during this process.

Accuracy of virtually planned mandibular distraction in a pediatric case series

The aim of this study was to describe the utility of 3D technology in mandibular distraction (MD) for patients with mandibular hypoplasia (MH), using 3D-printed cutting guides (CGs), and to assess the differences between virtual surgical planning (VSP) and the final result. A descriptive retrospective study of five patients diagnosed with MH, who required unilateral or bilateral MD, was carried out between January 2018 and January 2020. All patients underwent preoperative craniofacial CT scan and a 3D VSP was executed. MD was performed with the help of the 3D-printed CG. Before removal of the distractor, another CT scan was performed to compare the actual final result with the VSP. A mean difference of <4° was found for the osteotomy direction, < 7° for distractor position, and <2 mm for posterior screw placement. VSP and 3D-printed CGs have revolutionized surgical planning, facilitating surgical treatment and improving the final result. In our sample, the variations in osteotomy line, distractor position, and posterior screw placement have been minor, making the outcome more predictable.

Velopharyngeal Space Assessment in Patients Undergoing Le Fort 1 Maxillary Advancement

Background:

The effects of maxillary advancement on velopharyngeal anatomy have primarily been studied using lateral cephalometric radiographs. However, with recent advances in orthognathic surgery, there is an increased need for more detailed and precise imaging such as computerized tomographic (CT) scan reconstructions, to help in surgical planning and to measure outcomes. The purpose of this study was to compare the pre- and post-operative velopharyngeal anatomic configuration modifications as measured on CT scans.

Methods:

This is a retrospective cohort study of 44 patients with and without cleft palate who were treated with maxillary advancement. The pre- and post-operative CT scans were compared with respect to pre-established landmarks. Linear distances, cross-sectional areas, and volumes were measured using 3-dimensional CT scan reconstructions.

Results:

For the linear distances measured, a statistically significant difference was found when comparing the pre- and post-operative measures of the narrowest part of the nasopharynx and the narrowest part of the retropalatal airway space (P = 0.001 and 0.026, respectively). Retropalatal cross-sectional areas, nasopharyngeal cross-sectional areas, and the volumetric assessment of the nasopharyngeal space showed no statistically significant differences when comparing pre- and post-operative scans (P < 0.05). Mean changes in the measures did not differ over time (pre- and post-operative) depending on whether there was a prior history of cleft palate repair.

Conclusions:

Although structural modifications of the pharyngeal space are inherent to maxillary advancement, its surface area and volume do not significantly change. The use of 3-dimensional reconstruction using CT scans should be the first choice for evaluation of the upper airway.

Computational technology for nasal cartilage-related clinical research and application

Surgeons need to understand the effects of the nasal cartilage on facial morphology, the function of both soft tissues and hard tissues and nasal function when performing nasal surgery. In nasal cartilage-related surgery, the main goals for clinical research should include clarification of surgical goals, rationalization of surgical methods, precision and personalization of surgical design and preparation and improved convenience of doctor-patient communication. Computational technology has become an effective way to achieve these goals. Advances in three-dimensional (3D) imaging technology will promote nasal cartilage-related applications, including research on computational modelling technology, computational simulation technology, virtual surgery planning and 3D printing technology. These technologies are destined to revolutionize nasal surgery further. In this review, we summarize the advantages, latest findings and application progress of various computational technologies used in clinical nasal cartilage-related work and research. The application prospects of each technique are also discussed.

Assessment of the Learning Curve for Virtual Surgical Planning in Orbital Fractures

Virtual surgical planning (VSP) is becoming more widely used in maxillofacial reconstruction and can be surgeon-based or industry-based. Surgeon-based models require software training but allow surgeon autonomy. We evaluate the learning curve for VSP through a prospective cohort study in which planning times and accuracy of 7 otolaryngology residents with no prior VSP experience were compared to that of a proficient user after a single training protocol and 6 planning sessions for orbital fractures. The average planning time for the first session was 21 minutes 41 seconds ± 6 minutes 11 seconds with an average maximum deviation of 2.5 ± 0.8 mm in the lateral orbit and 2.3 ± 0.6 mm in the superior orbit. The average planning time for the last session was 13 minutes 5 seconds ± 10 minutes and 7 seconds with an average maximum deviation of 1.4 ± 0.5 mm in the lateral orbit and 1.3 ± 0.4 mm in the superior orbit. Novice users reduced planning time by 40% and decreased maximum deviation of plans by 44% and 43% in the lateral and superior orbits, respectively, approaching that of the proficient user. Virtual surgical planning has a quick learning curve and may be incorporated into surgical training.

The Use of Virtual Surgical Planning for Reduction Cranioplasty

Hydrocephalic macrocephaly may occur as a result of untreated hydrocephalus. Reduction cranioplasty is the treatment of choice for these patients when the weight of their head interferes with normal development and negatively impacts quality of life. However, this procedure has several associated risks, including prolonged anesthesia, significant blood loss, and death. Virtual surgical planning (VSP) has been shown to be a useful adjunct for orthognathic and craniofacial surgery. The following report details the application and advantages of this technology in the setting of a reduction cranioplasty. We report the case of a 2-year-old girl with severe hydrocephalic macrocephaly who underwent a reduction cranioplasty guided by VSP with computer-aided design and manufacturing (CAD/CAM). Prefabricated cutting guides and a concave assembly bowl were used for precise fixation of bony segments. Our patient underwent a successful reduction cranioplasty using VSP and CAD/CAM. This technology allowed precise remodeling of the cranial vault with minimal bony gaps in the final construct. Head circumference and intracranial volume were reduced from 70 cm and 4,575 cm³ to 62 cm and 2,645 cm³, respectively. VSP with CAD/CAM can serve as a useful adjunct in complex cases of cranioplasty allowing for an increase in the precision, the efficacy, and the esthetic result.

Current status of surgery-first approach (part III): the use of 3D technology and the implication in obstructive sleep apnea

Considering psychosocial needs of patients, it is not surprising that surgery-first approach (SFA) is becoming more popular than ever. Although the concept of SFA was introduced a few decades ago, the limitation of analysis method based on two-dimensional images makes surgeons reluctant to choose SFA. Recently, the advancement of three-dimensional technology allows us to perform SFA even without minimal pre-surgical orthodontic treatment, and the prediction of surgical outcome became more accurate, especially in obstructive sleep apnea (OSA) patients to whom the advantages of SFA should be more significant. Here, we describe the current trend of SFA and its implication in OSA patients.

Virtual Surgical Planning for Successful Second-Stage Mandibular Defect Reconstruction Using Vascularized Iliac Crest Bone Flap: A Valid and Reliable Method

PURPOSE

Second-stage reconstruction of mandibular defects faces problems of anatomic disorder and bone displacement due to tumor resection. As a newer technique, virtual surgical planning (VSP) may help to increase the accuracy and efficiency of the complicated reconstruction. This study aims to evaluate the application of VSP and splint-guided surgery in second-stage mandibular reconstruction using vascularized iliac crest bone flap.

METHODS

Between October 2016 and February 2018, 5 patients (3 men and 2 women) with mandibular defects of duration between 8 months and 8 years underwent VSP-aided secondary reconstruction in the School and Hospital of Stomatology of Wuhan University (Wuhan, China). Virtual surgical planning was performed and serial guiding splints were printed to replicate the design into the actual operation. The linear and 3-dimensional deviations after surgery were analyzed. Patient complications and feedback were recorded during follow up.

RESULTS

All 5 patients underwent successful reconstruction using vascularized iliac crest bone flap. No serious donor sites or recipient site complications were observed after 10- to 28-month follow-up. In comparison with the presurgery designs, the linear deviations in coronal plane were 2.7 ± 0.4 mm (range, -2.2 to 3.9 mm) in measurements from the condylar head to the condylar head and 0.70 ± 0.6 mm (range, -0.1 to 1.7 mm) from the gonial angle to the gonial angle, and that in sagittal plane was 2.4 ± 0.88 mm (range, -3 to 4.4 mm) from the anterior inferior mandibular border to the center point on the condylar head to the condylar head line. The whole 3-dimensional deviation was 1.2 ± 1.7 mm in all patients.

CONCLUSION

Well-designed splints can assist in precise mandibular reconstruction with high efficiency and accuracy, and thus are a reliable method for complicated second-stage mandibular reconstruction. However, to achieve a better outcome, a satisfactory design is required to adapt the complicated and varied defect.

Virtual Surgical Planning Computer-aided Design-guided Osteocutaneous Fibular Free Flap for Craniofacial Reconstruction: A Novel Surgical Approach

Advancements and increased availability of radiological services have revolutionised our approach to oncological and reconstructive surgical practice. With an increasing demand for accuracy in diagnosis and improved oncological outcome, the requirement for precise application of radiological tools and the exploration of novel software has developed. This has led to the evaluation of modern technologies such as computer-aided design to enhance reconstructive surgery. Mandibular reconstruction following oncological resection using an osteocutaneous fibular free flap is now considered to be the gold standard reconstructive surgical approach, as this approach provides more satisfactory outcomes for both patients and reconstructive surgeons. Recent years have seen Irish reconstructive surgeons introduce computer-aided design pre-operative planning to operating theatres as means of improving cosmetic, functional and oncological outcome, yet the detailed, complex planning required pre-operatively is not well described. Herein, the purpose of this article was to demonstrate the precision and accuracy of virtual surgical planning computer-aided design (VSP-CAD) as a modern surgical approach to craniofacial reconstruction following surgical resection of an American Joint Committee on Cancer stage 4 oral carcinoma.

Computer-Assisted Design and Manufacturing Assists Less Experienced Surgeons in Achieving Equivalent Outcomes in Cranial Vault Reconstruction

PURPOSE

The purpose of this study was to assess whether long-term outcomes were equivalent between computer-assisted design and manufacturing (CAD/CAM) -assisted cranial vault reconstruction performed by an inexperienced surgeon, with fewer years of surgical experience, and traditional reconstruction performed by senior surgeons with many decades of experience.

METHODS

An Institutional Review Board-approved retrospective cohort study was performed for all patients with nonsyndromic craniosynostosis between the ages of 1 month to 18 years who received primary, open calvarial vault reconstruction at the Johns Hopkins Hospital between 1990 and 2017. The primary outcome variable was the Whitaker category (I-IV) for level of required revision at the 2-year follow-up visit. Secondary outcomes included estimated blood loss, length of stay, operative time, and postoperative complications. CAD/CAM-assisted surgery was considered noninferior if the proportion of cases requiring any revision (Whitaker II, III, or IV) was no more than 10% greater than the proportion in the traditional surgery group with multivariate logistic regression analysis. t tests and fisher exact tests were used for secondary outcomes.

RESULTS

A total of 335 patients were included, with 35 CAD/CAM-assisted reconstructions. CAD/CAM-assisted reconstruction was noninferior to traditional after accounting for patient demographics, type of surgery, and experience level of the plastic surgeon. The traditional group required revision more frequently at 29.0% compared to CAD/CAM at 14.3%. Secondary outcomes were not significantly different between groups, but CAD/CAM had significantly longer average operative times (5.7 hours for CAD/CAM, 4.3 hours for traditional, P < 0.01).

CONCLUSION

CAD/CAM technology may lower the learning curve and assist less experienced plastic surgeons in achieving equivalent long-term outcomes in craniofacial reconstruction.