Preoperative Virtual Surgical Planning Research Articles

Alar base symmetry in orthognathic surgery: Patients with unilateral cleft.

Patients with unilateral cleft lip and palate (UCLP) could present with a notable nasal deformity with alar base retrusion, which should be considered when planning orthognathic surgery (OGS). This retrospective study included 84 patients with Class III malocclusion. Cone beam computed tomographic data were used for the investigation. 42 patients had complete UCLP, and the other 42 did not have a cleft. All the patients underwent preoperative virtual surgical planning. Preoperative and postoperative images were used to measure anteroposterior changes in the bone and soft tissue at the alar bases. In the UCLP group, varying degrees of alar base discrepancies were observed before surgery. In the piriform region of the cleft side, the bone was retruded in 32 cases, but the soft tissue was thicker in 38 cases, and the mean skin surface was anterior in 28 cases. After surgery, the bone discrepancy was not significantly changed (p = 0.288), however, the skin surface symmetry was improved (p = 0.013). Relating to the bone advancement, the ratio of soft tissue change was smaller on the cleft side than the noncleft side (0.56 ± 0.30 vs. 0.77 ± 0.33, p < 0.001). In the control group, a consistent ratio change was observed on both sides (0.76 ± 0.19 vs. 0.79 ± 0.27, p = 0.544). This study revealed improved alar base symmetry in patients with UCLP after OGS. The soft tissue change ratios were different across the cleft, which should be considered during treatment planning.

3D-assisted surgery for reconstruction in the head and neck area

Preoperative virtual surgical planning and the use of 3D-printed patient-specific models and cutting guides are increasingly being used in the reconstruction of mandibular defects with a free bone flap. This technology offers several advantages over conventional surgery, such as reduced operating time, reduced bone flap ischaemia time, and the ability to perform more complex and precise reconstructions. This review presents the evidence supporting 3D-assisted surgery for mandibular defect reconstruction and discusses the utilisation of commercial vendors versus in-house 3D-printing solutions.

Development of a virtual surgical plan for reverse shoulder arthroplasty as a treatment for complex proximal humerus fracture in an elderly patient

IntroductionFracture reduction, implant selection and tuberosity reattachment propose significant challenges in reverse shoulder arthroplasty (RSA) for proximal humerus fractures (PHFs). It is hypothesised that preoperative virtual surgical planning (VSP) can improve implant positioning and tuberosity reattachment, resulting in better functional outcomes, reduced surgery time, and decreased complication risk. Therefore, this study aims to develop, implement, and evaluate a VSP protocol for RSA in complex PHFs. MethodsThe VSP protocol is developed using 3D medical image processing software based on CT scans from four previously treated patients with RSA for complex PHF. Next, the VSP was applied prospectively in a patient with a PHF planned for RSA. Evaluation was done using an expert opinion questionnaire evaluating surgical confidence, a comparison between implant positioning on postoperative radiographs and the VSP, functional outcomes and the Oxford Shoulder Score (OSS). ResultsThe study showed that VSP is a useful preoperative tool to optimize clinical outcome by digital fracture reduction, determination of surgical cuts, calculating implant size and height, and optimising tuberosity shape and reattachment. After two and six months, the patient showed good functional outcomes (OSS: 48/48 points), healing of tuberosities, and had minimal pain complaints. ConclusionVSP for RSA in PHF might create a more thorough preoperative understanding of the fracture pattern and implant and fracture fragment placement. Further investigative study would be required to demonstrate this.

Implementation of In-house Computer-aided Design and Manufacturing for Accelerated Free Fibula Flap Reconstruction of Mandibular Defects in Cancer Patients.

Computer-aided design and manufacturing (CAD/CAM) is widely adopted for optimizing microsurgical reconstruction of mandibular defects. However, commercial solutions are hampered by costs and lengthy lead times, with the latter being problematic in cancer surgery. This study aimed to investigate the efficiency of an in-house CAD/CAM service for expeditious planning and execution of free fibula mandibular reconstruction in head and neck cancer patients. This retrospective cohort study compared cancer patients undergoing segmental mandibulectomy and immediate free fibula flap reconstruction treated before and after implementation of in-house CAD/CAM. The primary endpoint was treatment delay from preoperative consultation to surgery. Cases in the two groups were matched on the number of fibula segments required for mandibular reconstruction. The control group underwent segmental mandibulectomy and fibula flap reconstruction by "freehand." The CAD/CAM group underwent preoperative virtual surgical planning and CAD/CAM of intraoperative cutting guides for the mandibulectomy and fibula osteotomies. Outcomes were compared with the unpaired t test or Wilcoxon rank-sum test. Sixteen patients were included in both groups. Treatment delay did not increase after implementation of in-house CAD/CAM with a median 6 (range 6-20) days wait in the CAD/CAM group and 8 (6-20) days wait in the control group (P = 0.48). Utilization of CAD/CAM significantly reduced fibula flap ischemia time with a mean of 18.4 [95% confidence interval 2.8; 33.9] minutes (P = 0.022). In-house CAD/CAM was implemented for free fibula flap mandibular reconstruction in head and neck cancer patients without causing treatment delay. Furthermore, CAD/CAM reduced fibula flap ischemia time.

Evaluation of the resection plane three-dimensional positional accuracy using a resection guide directional guidance slot; a randomized clinical trial

AimThe study was performed to compare the mandibular resection guide with a directional guidance slot with the conventional guide regarding three-dimensional positional accuracy.Materials and methodsTwenty-six patients with lateral segmental mandibular defects were selected, and randomly allocated into two groups. All defects were managed with preoperative virtual surgical planning. Resection in the test group was conducted using a resection guide with a directional guidance slot, while a conventional resection guide design was utilized in the control group. The linear and angular deviation of the osteotomy planes was analyzed for both groups, along with the accuracy of the insertion of the reconstruction bone block in the resected defect. Data were documented, absolute deviation was calculated, statistical analysis was performed and significance was set at the 5% level.ResultsThe cases conducted with a directional guidance templet reported a statistically significant difference when compared to the conventional edge-cutting guide regarding the linear and angular spatial osteotomy plane position (P < 0.001). The defect span analysis reported excellent levels of agreement in both groups (ICC = 1.00, ICC = 0.995), however, the difference between the groups was statistically significant (P < 0.001).ConclusionThe study demonstrated the enhanced positional accuracy of the resection plane and reconstruction block placement when a directional slot is incorporated in the computer-generated resection guide.

Modified patient-specific surgical-guide-assisted precise treatment of unilateral comminuted zygomaticomaxillary complex fractures: A 5-year retrospective study

Our study aimed to evaluate modified patient-specific surgical-guide-assisted precise treatment of unilateral comminuted zygomaticomaxillary complex (ZMC) fractures.The retrospective non-randomized study was conducted in a single hospital in China. All patients diagnosed with unilateral comminuted ZMC fractures between January 1, 2018 and December 31, 2022 were retrospectively reviewed. All patients underwent preoperative spiral computed tomography (CT). CT data were processed using software to DICOM format and transferred to Proplan CMF3.0 for preoperative virtual surgical planning and postoperative evaluation. All data were extracted from standardized electronic medical records. All statistical analyses were performed using SPSS version 20.0. The chi-square test and t-test were used for statistical analyses.The 54 included patients were divided into two comparable, equal cohorts of 27 patients, and followed up for at least 6 months. Fracture reduction was assisted using the modified patient-specific surgical guides in the guide group (23 males, four females; mean age 37.74 ± 12.07 years) and without the modified patient-specific surgical guides in the control group (20 males, seven females; mean age 37.44 ± 13.58 years).In the guide group, the mean eminence deviation between the affected and unaffected sides was 1.01 ± 0.92 mm, and the mean width deviation between the affected and unaffected sides was 1.29 ± 1.32 mm. In the control group, the mean eminence deviation between the affected and unaffected sides was 1.99 ± 1.69 mm, and the mean width deviation between the affected and unaffected sides was 2.68 ± 2.01 mm. The differences in facial protrusion (p = 0.001) and width (p = 0.003) symmetry between the affected and healthy sides of the two groups were statistically significant (p < 0.05).In conclusion, applying the modified patient-specific surgical guides to unilateral comminuted zygomaticomaxillary complex fracture reduction has the advantages of greater predictability and effectiveness, and improved bilateral ZMC symmetry. It should be noted that this approach would be especially beneficial for less-experienced surgeons.

Sacroiliac joint fusion guided by intraoperatively superimposed virtual surgical planning using simulated fluoroscopic images

IntroductionSacroiliac joint fusion (SIJF) is a minimally invasive treatment for sacroiliac (SI) dysfunction. It involves placing implants through the SI joint under fluoroscopic guidance, requiring precise implant positioning to avoid nerve injury. Preoperative virtual surgical planning (VSP) aids in optimal positioning, but replicating it accurately in the operating room is challenging. Research questionThis study aims to assess the feasibility of superimposing VSP onto intraoperative fluoroscopic images to aid in optimal implant placement. Material and methodsA method for intraoperative guidance using 3D/2D registration was developed and tested during SIJF as an available and potentially efficient alternative for costly and more invasive navigation systems. Preoperatively, a VSP is performed and simulated fluoroscopic images are generated from a preoperative CT scan. During surgery, the simulated image that visually best matches the intraoperative fluoroscopic image is selected. Subsequently, the VSP is superimposed onto the intraoperative fluoroscopic image using a developed script-based workflow. The surgeon then places the implants accordingly. Postoperative implant placement accuracy was evaluated. ResultsFive interventions were performed on five patients, resulting in a total of 15 placed implants. Minor complications without clinical consequences occurred in one case, primarily attributable to the patient's anatomy and pathological manifestations. Mean deviations at implant apex and 3D angle were 4.7 ± 1.6 mm and 3.5 ± 1.3°, respectively. Discussion and conclusionsThe developed intraoperative workflow was feasible and resulted in implants placed with low deviations from the VSP. Further research is needed to automate and validate this method in a larger cohort.

Anterior Lumbar Interbody Fusion (ALIF) for Lumbar Hemivertebra in an Adult Using Three-Dimensional-Printed Patient-Specific Implants and Virtual Surgery Planning: A Technical Report

Introduction: Hemivertebrae are a common defect of vertebral formation, potentially resulting in debilitating congenital scoliosis and necessitating highly traumatic surgery. Virtual surgical planning (VSP) and 3D-printed patient-specific implants (PSIs) have increasingly been applied to complex spinal surgery, and offer a range of potential benefits. Research Question: We report the use of 3D-printed PSIs and VSP as part of a two-level anterior lumbar interbody fusion (ALIF) for the management of lateral hemivertebra and congenital scoliosis. Material and Methods: A 53-year-old male with chronic low-back pain, due to L4 hemivertebra and mild congenital scoliosis, presented with new-onset leg pain. CT revealed L4/5 and L5/S1 degeneration and foraminal stenosis. Given the complex anatomy and extensive multi-level osteophytosis, 3D-printed PSIs were designed, manufactured, and implanted as part of a two-level ALIF. Results: Excellent implant fit was achieved intraoperatively, confirmed via postoperative imaging. VSP assisted with navigating challenging bony and vascular anatomy. Three-month postoperative imaging demonstrated construct stability, early signs of bony fusion, with implant placement, spinal curvature, and disc height corrections closely matching the VSP. Clinically, the patient’s pain and functional impairment had effectively resolved by nine-month follow up, as demonstrated through subjective and objective measures. Discussion and Conclusions: Virtual surgical planning and 3D-printed PSIs can be useful surgical aids in the management of the often-complex cases involving hemivertebrae and congenital scoliosis. This case of congenital pathology adds to the growing reports of PSI application to a variety of complex spinal pathologies, with analyses showing a close match of the postoperative construct to the preoperative VSP.

Role of Temporomandibular Total Joint Replacement in Correction of Facial Deformities.

Individuals suffering from facial deformities experience esthetic, functional and social setback in their lives every day. These patients benefit greatly with single-stage temporomandibular joint replacement along with orthognathic surgical procedures to correct functional as well as esthetic components. Five individuals with facial deformities due to hemifacial macrosomia, fibrous dysplasia, idiopathic condylar resorption, ankylosis, etc., were treated with total joint replacement along with orthognathic surgical procedures for functional and esthetic correction. The customized temporomandibular joint was digitally custom designed, and the orthognathic procedures were virtually planned on NemoFAB software before performing the surgical procedure. Intraoperatively, the overall time was reduced considerably with minimal unpredictable complications. One-week postoperative computed tomographs were obtained and superimposed on preoperative virtual surgical planning which showed minimal discrepancy. Follow-up period of 18-30months was maintained for all the patients with stable results, minimal relapse and satisfactory functional abilities. Total joint replacement along with orthognathic procedure provides single-stage functional and esthetic corrections for the patients, considerably improving their quality of life. Precise preoperative surgical planning proves to be an indispensable step for achieving desired results with minimal margin of error and avoid any unseen complications during the surgical procedure.

Efficiency of virtual surgical planning in management of maxillofacial trauma

Background: Craniomaxillofacial (CMF) injuries has different patterns from simple to complicated ones. Surgeons usually spend time and effort planning the optimal surgical approach to avoid damage to vital structures that could otherwise lead to functional deficits. It is also imperative to optimize the skin incisions to avoid unfavourable scarring. The aim of this work is to assess the effectiveness and efficiency of virtual surgical planning (VSP) application in management of different types of CMF traumas, the advantages, and disadvantages of VSP, and the accuracy of three dimensional (3D) measures as a preoperative planning tool.Methods: This prospective consecutive series study enrolled 30 patients presented with different types of CMF trauma. All patients were subjected to CT scans. The obtained Digital imaging and communications in Medicine (DICOM) files were imported into the software for virtual planning.Results: The actual operative time (OT) after VSP was significantly lower than the expected time by traditional methods (p=0.008). There was no significant difference between the actual and expected number of incisions. The accuracy measures of preoperative VSP were very close postoperatively. The functional, anatomic reduction and patient satisfaction outcomes were very satisfying to the surgeon and the patient respectively. Conclusions: VSP can be a valuable tool for optimizing functional and aesthetic outcomes of the CMF trauma surgery. The accurate measurements obtained pre-operatively helped in reducing surgical time and minimizing the need for subsequent revision surgeries.

The Feasibility of Robot-Assisted Chin Osteotomy on Skull Models: Comparison with Surgical Guides Technique.

Surgical robotic technology is characterized by its high accuracy, good stability, and repeatability. The accuracy of mandibular osteotomy is important in tumor resection, function reconstruction, and abnormality correction. This study is designed to compare the operative accuracy between robot-assisted osteotomy and surgical guide technique in the skull model trials which simulated the genioplasty. In an experimental group, robot-assisted chin osteotomy was automatically performed in 12 models of 12 patients according to the preoperative virtual surgical planning (VSP). In a control group, with the assistance of a surgical guide, a surgeon performed the chin osteotomy in another 12 models of the same patients. All the mandibular osteotomies were successfully completed, and then the distance error and direction error of the osteotomy plane were measured and analyzed. The overall distance errors of the osteotomy plane were 1.57 ± 0.26 mm in the experimental group and 1.55 ± 0.23 mm in the control group, and the direction errors were 7.99 ± 1.10° in the experimental group and 8.61 ± 1.05° in the control group. The Bland-Altman analysis results revealed that the distance error of 91.7% (11/12) and the direction error of 100% (12/12) of the osteotomy plane were within the 95% limits of agreement, suggesting the consistency of differences in the osteotomy planes between the two groups. Robot-assisted chin osteotomy is a feasible auxiliary technology and achieves the accuracy level of surgical guide-assisted manual operation.

Accuracy of Segmented Le Fort I Osteotomy with Virtual Planning in Orthognathic Surgery Using Patient-Specific Implants: A Case Series.

Background: When maxillary transversal expansion is needed, two protocols of treatment can be used: a maxillary orthodontic expansion followed by a classical bimaxillary osteotomy or a bimaxillary osteotomy with maxillary segmentation. The aim of this study was to assess the accuracy of segmented Le Fort I osteotomy using computer-aided orthognathic surgery and patient-specific titanium plates in patients who underwent a bimaxillary osteotomy for occlusal trouble with maxillary transversal insufficiencies. Methods: A virtual simulation of a Le Fort I osteotomy with maxillary segmentation, a sagittal split ramus osteotomy, and genioplasty (if needed) was conducted on a preoperative three-dimensional (3D) model of each patient’s skull using ProPlan CMF 3.0 software (Materialise, Leuven, Belgium). Computer-assisted osteotomy saw-and-drill guides and patient-specific implants (PSIs, titanium plates) were produced and used during the surgery. We chose to focus on the maxillary repositioning accuracy by comparing the preoperative virtual surgical planning and the postoperative 3D outcome skulls using surface superimpositions and 13 standard dental and bone landmarks. Errors between these preoperative and postoperative landmarks were calculated and compared to discover if segmental maxillary repositioning using PSIs was accurate enough to be safely used to treat transversal insufficiencies. Results: A total of 22 consecutive patients—15 females and 7 males, with a mean age of 27.4 years—who underwent bimaxillary computer-assisted orthognathic surgery with maxillary segmentation were enrolled in the study. All patients presented with occlusion trouble, 13 with Class III malocclusions (59%) and 9 (41%) with Class II malocclusions. A quantitative analysis revealed that, overall, the mean absolute discrepancies for the x-axis (transversal dimension), y-axis (anterior–posterior dimensions), and z-axis (vertical dimension) were 0.59 mm, 0.74 mm, and 0.56 mm, respectively. The total error rate of maxillary repositioning was 0.62 mm between the postoperative cone-beam computed tomography (CBCT) and the preoperatively planned 3D skull. According to the literature, precision in maxilla repositioning is defined by an error rate (clinically relevant) at each landmark of <2 mm and a total error of <2 mm for each patient. Conclusions: A high degree of accuracy between the virtual plan and the postoperative result was observed.

Technical Note on Three- and Four-Wall Orbital Reconstructions With Patient-Specific Implants.

Orbital reconstruction is one of the most complex procedures in maxillofacial surgery. It becomes even more complex when all references to the original anatomy are lost. The purpose of this article is to provide an overview of techniques for complex three- and four-wall orbital reconstructions. Preoperative virtual surgical planning is essential when considering different reconstruction possibilities. The considerations that may lead to different approaches are described, and the advantages and drawbacks of each technique are evaluated. It is recommended to reconstruct solitary three-wall or four-wall orbital defects with multiple patientspecific implants. Optimizations of this treatment protocol are suggested, and their effects on predictability are demonstrated in a case presentation of a four-wall defect reconstruction with multiple patient-specific implants.

A Novel Approach to Virtual Surgical Planning for Mandibular and Midfacial Reconstruction With a Fibula Free Flap.

The fibula free flap is a major workhorse in facial reconstruction. To decrease operative times, virtual surgical planning (VSP) has been implemented. Traditional VSP is costly and may delay operative planning. in this study, the authors present a novel algorithm using readily accessible software packages to perform VSP in a manner that is quick and cost-effective. A 6-part survey was administered to physicians with prior training in facial reconstruction. Fourteen physicians participated regarding outcomes on 10 patients who underwent mandibular or midfacial fibula free flap reconstruction. Participants were asked to match the true postoperative and VSP models and rate the similarity of the models using the Likert scale (0-10). The goal was to determine whether the VSP models accurately depicted the actual reconstruction, and whether they would use VSP in future clinical practice. The physicians surveyed were able to match the models correctly 93.6% of the time. The mean score for the similarity between virtual and actual models ranged between 7.60 and 8.80. Most participants (90.9%) who answered stated they would use our VSP algorithm if they were trained in the protocol. Virtual surgical planning models were created utilizing our novel algorithm. Participants matched the preoperative VSP plan with the postoperative model most of the time and rated the similarity well. Participants in our study are interested in learning more about physician performed VSP. The authors believe this model may be financially and clinically relevant and serve as an excellent educational tool.

Virtual Surgical Planning of Deep Circumflex Iliac Artery Flap for Midface Reconstruction.

ObjectiveMidface reconstruction is challenging for functional and esthetic reasons. The present study analyzed the effect of virtual surgical planning (VSP) of the deep circumflex iliac artery (DCIA) flap for midface reconstruction.Patients and MethodsThirty-four patients who underwent midface reconstruction with the DCIA flap were included in this retrospective study. Of the 34 patients, 16 underwent preoperative VSP, which used a three-dimensionally printed surgical guide, computer-assisted navigation system, and pre-bent titanium implants to transfer VSP into real-world surgery. The other 18 patients underwent traditional midface reconstruction. The following were compared between the two groups: bony contact rate in the buttress region (BCR), dental arch reconstruction rate (DAR), surgical approach, position of vascular anastomosis, and dental implantation rate. The independent-samples t-test and Fisher’s exact test were used for analysis. P < 0.05 was considered statistically significant.ResultsIn total, 12 males and 22 females were included in this study. All patients underwent midface reconstruction using the DCIA flap at the same institution. The median age of patients was 33 years (range: 16–68 years). The average BCR and DAR values in the VSP group were 59.4% ± 27.9% and 87.5% ± 18.9%, respectively, which were significantly higher compared with the non-VSP group (P = 0.049 and P = 0.004, respectively). The dental implantation rate in the VSP group (50.0%) was significantly higher compared with the non-VSP group (11.1%; P = 0.023). The intraoral approach for tumor ablation and vascular anastomosis was the most frequent choice in both groups. There was no significant difference between the two groups. All patients were satisfied with facial symmetry postoperatively.ConclusionsVSP could effectively augment the effect of midface reconstruction with the DCIA flap. Stronger bone contact in the buttress region and higher DAR provide more opportunity for dental implantation, which might be the best solution to improve masticatory function in patients with midface defects.

Prevention of Mandible Fractures in Medication-Related Osteonecrosis of the Jaws: The Role of Virtual Surgical Planning and Computer-Aided Design and Manufacturing in Two Clinical Case Reports

Background: Marginal mandible resection is required to achieve healing in some cases of medication-related osteonecrosis of the jaws (MRONJ). Despite the sparsity of the literature, computer-aided design/computer-aided manufacturing (CAD/CAM) materials may provide superior outcomes for patients with an increased risk of mandible fracture. The aim of this study was to report a digital workflow for surgical interventions to prevent mandible fracture in MRONJ patients. Methods: We present two cases in which virtual surgical planning (VSP) and CAD/CAM surgical guides and reconstruction plates were used to prevent mandible fractures in elderly MRONJ patients submitted for marginal resection. Two osteoporotic patients, aged 73 and 84 years, presented with stage 3 MRONJ of the right mandibular body with inferior alveolar nerve involvement. The unaffected bone height was 6 mm in both cases, implying a high risk of mandible fracture. After preoperative VSP, surgery was performed through a combined intraoral–transbuccal approach. CAD/CAM-customized cutting guides and reconstruction plates were used for the marginal resection of necrotic bone and internal fixation. Results: Complete healing was achieved and the patients remained asymptomatic up to 1 year post-surgery. Conclusions: VSP and CAD/CAM-customized materials facilitated the complete resection of necrotic bone and rigid fixation in MRONJ patients, allowing a simplified approach with shorter operative times, reduced morbidity, and predictable results.

Use of computer-assisted surgery in the orbit

ABSTRACT Purpose To present the application of computer-assisted surgery (CAS) in pre-operative planning, intra-operative navigation, and post-operative assessment as an adjunct tool in orbital surgery. Methods An IRB-approved, retrospective review was performed to identify patients who had undergone orbital surgery by a single surgeon from July 2013 to December 2019 with attention to pre-operative virtual surgical planning, intra-operative navigation, and post-operative assessment. The reasons and methods of CAS use were classified. Results The use of computer-assisted technologies was identified in 91 cases out of 464 orbital surgeries (19.6%). This included 23 (25.3%) orbital decompression surgeries, 39 (42.9%) fracture repairs, and 25 (27.5%) orbital tumors. In all cases, pre-, intra-, and post-operative CAS allowed for increased operative efficiency and safety with good outcomes. Conclusions Use of CAS in orbital surgery can allow for complex radiographic analysis and in select cases is a great tool to add to the orbital surgeon’s armamentarium.

Revision of a Failed C5-7 Corpectomy Complicated by Esophageal Fistula Using a 3-Dimensional−Printed Zero-Profile Patient-Specific Implant: A Technical Case Report

Esophageal fistulae are rare, though serious, complications of anterior cervical surgery. Hardware-related issues are important etiologic factors. Patient-specific implants (PSIs) have increasingly been adapted to spinal surgery and offer a range of benefits. Zero-profile implants are a recent development primarily aimed at combating postoperative dysphagia. We report the first use of a 3-dimensional (3D)-printed zero-profile PSI in managing implant failure with migration and a secondary esophageal fistula. A 68-year-old female had a prior C5-7 corpectomy with cage and plate fixation, as well as posterior C3-T1 lateral mass fixation, complicated by anterior plate displacement, resulting in pseudoarthrosis and an esophageal fistula. A 3D-printed zero-profile PSI was designed and implanted as part of a revision procedure to assist in recovery, prevent recurrence, and facilitate bony fusion. Optimal implant placement was achieved on the basis of preoperative virtual surgical planning. By 1 month postoperatively the patient had significantly improved, with evidence of esophageal fistula resolution and radiographic evidence of optimal implant placement. Zero-profile 3D-printed PSIs may combat common and serious complications of anterior cervical surgery including postoperative dysphagia and esophageal fistulae. Further research is required to validate their widespread use for either cervical corpectomy or diskectomy and interbody fusion.

Maxillectomy Reconstruction Revision Using Virtual Surgical Planning and Intraoperative Navigation

Secondary revision of osseous flap reconstructions of the maxilla can enhance facial symmetry, but can be challenging due to the absence of normal anatomy and landmarks. We report four cases of maxillectomy reconstruction with scapula tip flap employing a novel combined approach with preoperative virtual surgical planning (VSP) and intraoperative navigation (ION) for secondary revision. VSP was employed to superimpose mirrored normal anatomy upon the reconstructed anatomy, and ION used for real-time intraoperative anatomical mapping. VSP and ION can be used to optimize maxillary bony revisions and recontouring, thereby improving anatomic symmetry and funtionality. Laryngoscope, 131:E2655-E2659, 2021.

Mandibular Reconstruction With the Iliac Flap Under the Guidance of A Series of Digital Surgical Guides.

The authors aimed to evaluate the accuracy of mandibular reconstruction with the iliac flap under the guidance of a series of digital surgical guides. Seven patients were enrolled to evaluate the accuracy of reconstruction immediately after surgery. Patients underwent mandibular reconstruction with a vascularized iliac flap guided by a series of digital surgical guides at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, from September 2017 to June 2018.All flaps survived. Chromatographic analysis showed that the area with a chromatographic difference of ≤1 mm between preoperative virtual surgical planning model and postoperative mandible accounted for 73.97% ± 3.89% of mandible surface, the area ≤2 mm accounted for 87.21% ± 2.65%, and the area ≤3 mm accounted for 94.09% ± 2.50%. In all of the 7 cases, the mean of maximum deviation was 6.25 ± 1.00 mm, and the mean of average deviation was 0.95 ± 0.13 mm. The authors conclude that mandibular reconstruction with the iliac flap under the guidance of a series of digital surgical guides is accurate and effective.