In-House, Open-Source 3D-Software-Based, CAD/CAM-Planned Mandibular Reconstructions in 20 Consecutive Free Fibula Flap Cases: An Explorative Cross-Sectional Study With Three-Dimensional Performance Analysis

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

Background

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.

Methods

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.

Results

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).

Conclusions

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.

In-house virtual surgical planning and guided mandibular reconstruction is less precise, but more economical and time-efficient than commercial procedures

BACKGROUND

To compare an in-house and a commercially available surgical planning solution for mandibular reconstruction in terms of postoperative reconstruction accuracy and economic benefit.

METHODS

Twenty-nine consecutive patients with advanced oral squamous cell carcinoma (OSCC) requiring segmental mandibular reconstruction were enrolled. Fifteen patients underwent in-house surgical planning and 14 patients underwent a commercially available planning solution. A morphometric comparison of preoperative and postoperative computed tomography (CT) data sets and a cost-benefit comparison were performed.

RESULTS

Volumes of planned and reconstructed bone segments differed significantly for both in-house planning (p = 0.0431) and commercial planning (p < 0.0001). Significant differences in osteotomy angles were demonstrated for in-house planning (p = 0.0391). Commercial planning was superior to in-house planning for total mandibular deviation (p = 0.0217), intersegmental space volumes (p = 0.0035), and lengths (p = 0.0007). No significant difference was found between the two planning solutions in terms of intersegmental ossification and the incidence of wound healing disorders. In-house planning took less time than commercial planning (p < 0.0001). Component manufacturing costs (p < 0.0001) and total cumulative costs (p < 0.0001) were significantly lower for in-house planning.

CONCLUSIONS

In-house surgical planning is less accurate but has a cost advantage and could be performed in less time.

Oral rehabilitation and associated quality of life following mandibular reconstruction with free fibula flap: a cross-sectional study

Introduction

Mandibular reconstruction with the free fibula flap (FFF) has become a standardized procedure. The situation is different with oral rehabilitation, so the purpose of this study was to investigate the frequency of implant placement and prosthetic restoration. Additionally, the patients' situation, motivation, and treatment course were structurally assessed.

Materials and methods

All cases between January 2013 and December 2018 that underwent mandibular reconstruction in our department with a free fibula flap and gave written informed consent to participate were interviewed with two structured questionnaires about their restoration and quality of life. Additionally, medical records, general information, status of implants and therapy, and metric analyses of the inserted implants were performed.

Results

In total 59 patients were enrolled and analyzed in this monocentric study. Overall, oral rehabilitation was achieved in 23.7% at the time of investigation. In detail, implants were inserted in 37.3% of patients and showed an 83.3% survival of dental implants. Of these implanted patients, dental implants were successfully restored with a prosthetic restoration in 63.6. Within this subgroup, satisfaction with the postoperative aesthetic and functional result was 79.9% and with the oral rehabilitation process was 68.2%. Satisfaction with the implant-borne prosthesis was 87.5%, with non-oral-squamous-cell-carcinoma patients being statistically significantly more content with the handling (p=0.046) and care (p=0.031) of the prosthesis.

Discussion

Despite the well-reconstructed bony structures, there is a need to increase the effort of achieving oral rehabilitation, especially looking at the patient's persistent motivation for the procedure.

Personalized 3D-printed cranial implants for complex cranioplasty using open-source software

Background

Cranioplasty is a routine neurosurgery treatment used to correct cranial vault abnormalities. Utilization of 3D printing technology in the field of cranioplasty involving the reconstruction of cranial defects emerged as an advanced possibility of anatomical reshaping. The transformative impact of patient-specific 3D printed implants, focuses on their remarkable accuracy, customization capabilities, and enhanced biocompatibility.

Methods

The precise adaptation of implants to patient-specific anatomies, even in complex cases we presented, result in improved aesthetic outcomes and reduced surgical complications. The ability to create highly customized implants addresses the functional aspects of cranial defects and considers the psychological impact on patients.

Results

By combining technological innovation with personalized patient care, 3D printed cranioplasty emerges as a transformative avenue in cranial reconstruction, ultimately redefining the standards of success in neurosurgery.

Conclusion

3D printing allows an excellent cranioplasty cosmesis achieved at a reasonable price without sacrificing patient outcomes. Wider implementation of this strategy can lead to significant healthcare cost savings.

Comparison of three-dimensional imaging of the nose using three different 3D-photography systems: an observational study

BACKGROUND

New 3D technologies for superficial soft tissue changes, especially in plastic and reconstructive surgical procedures, can improve the planning and documentation of facial surgeries. The purpose of this study was to compare and determine the applicability and feasibility of three different 3D-photography systems in clinical practice imaging the nose.

METHODS

A total of 16 healthy non-operated noses were included in this prospective study. A plaster model of each nose was produced, digitized, and converted to a .stl mesh (= ground truth model). Three-dimensional images of each nose were then taken using Artec Space Spider (gold standard), Planmeca ProFace®, and the Bellus3D Dental Pro application. All resulting .stl files were aligned to the ground truth model using MeshLab software, and the root mean square error (RMSE), mean surface distance (MSD), and Hausdorff distance (HD) were calculated.

RESULTS

The Artec Space Spider 3D-photography system showed significantly better results compared to the two other systems in regard to RMSE, MSD, and HD (each p < 0.001). There was no significant difference between Planmeca ProFace® and Bellus3D Dental Pro in terms of RMSE, MSD, and HD. Overall, all three camera systems showed a clinically acceptable deviation to the reference model (range: -1.23-1.57 mm).

CONCLUSIONS

The three evaluated 3D-photography systems were suitable for nose imaging in the clinical routine. While Artec Space Spider showed the highest accuracy, the Bellus3D Dental Pro app may be the most feasible option for everyday clinical use due to its portability, ease of use, and low cost. This study presents three different systems, allowing readers to extrapolate to other systems when planning to introduce 3D photography in the clinical routine.

Realizing in-house algorithm-driven free fibula flap set up within 24 hours: a pilot study evaluating accuracy with open-source tools

Objective

This study aims to critically evaluate the effectiveness and accuracy of a time safing and cost-efficient open-source algorithm for in-house planning of mandibular reconstructions using the free osteocutaneous fibula graft. The evaluation focuses on quantifying anatomical accuracy and assessing the impact on ischemia time.

Methods

A pilot study was conducted, including patients who underwent in-house planned computer-aided design and manufacturing (CAD/CAM) of free fibula flaps between 2021 and 2023. Out of all patient cases, we included all with postoperative 3D imaging in the study. The study utilized open-source software tools for the planning step, and three-dimensional (3D) printing techniques. The Hausdorff distance and Dice coefficient metrics were used to evaluate the accuracy of the planning procedure.

Results

The study assessed eight patients (five males and three females, mean age 61.75 ± 3.69 years) with different diagnoses such as osteoradionecrosis and oral squamous cell carcinoma. The average ischemia time was 68.38 ± 27.95 min. For the evaluation of preoperative planning vs. the postoperative outcome, the mean Hausdorff Distance was 1.22 ± 0.40. The Dice Coefficients yielded a mean of 0.77 ± 0.07, suggesting a satisfactory concordance between the planned and postoperative states. Dice Coefficient and Hausdorff Distance revealed significant correlations with ischemia time (Spearman's rho = -0.810, p = 0.015 and Spearman's rho = 0.762, p = 0.028, respectively). Linear regression models adjusting for disease type further substantiated these findings.

Conclusions

The in-house planning algorithm not only achieved high anatomical accuracy, as reflected by the Dice Coefficients and Hausdorff Distance metrics, but this accuracy also exhibited a significant correlation with reduced ischemia time. This underlines the critical role of meticulous planning in surgical outcomes. Additionally, the algorithm's open-source nature renders it cost-efficient, easy to learn, and broadly applicable, offering promising avenues for enhancing both healthcare affordability and accessibility.

Postoperative facial appearance of patients with extensive oral squamous cell carcinoma can be adequately preserved with in‑house virtually planned mandibular reconstruction

The present study aimed to assess the concordance of preoperative and postoperative hard and soft tissues in patients with advanced oral squamous cell carcinoma (OSCC) following virtual surgical planning (VSP) mandibular reconstruction. In the present study, a cohort of 32 patients with OSCC underwent in-house VSP, followed by guided mandibular reconstruction utilizing vascularized free tissue grafts sourced from the fibula or scapula. A morphometric analysis was conducted comparing preoperative and postoperative three-dimensional virtual models to evaluate discrepancies and identify potential risk factors associated with poor reconstruction outcomes. The outcome variables were the differences in root mean square (RMS) and mean surface distance (MSD) resulting from the application of an iterative closest point algorithm to the virtual data. The validity of soft tissue comparison data is limited due to its susceptibility to various confounding variables. The present study conducted a comprehensive re-evaluation of these variables. High tumor stage, positive N status and the use of adjuvant therapy contributed to more noticeable differences in preoperative and postoperative facial soft tissue appearance. The accuracy of postoperative bone reconstruction results was higher in patients who underwent neomandibular formation using a fibular graft compared with those who received a scapular graft. Preoperative and postoperative soft tissue analyses were conducted for comparison. The MSD showed a deviation of 3.2 mm (± 2.0 mm SD; range 1.3-9.5 mm), whereas the RMS was 5.3 (± 2.9 SD; range 2.1-14). In conclusion, in-house VSP and guided mandibular reconstructions can yield clinically accurate results, preserving patient appearance and offering the advantage of rapid feasibility.

Virtual Surgical Planning and Three-Dimensional Models for Precision Sinonasal and Skull Base Surgery

Sinonasal and skull base malignancies represent a rare, heterogenous group of pathologies with an incidence of 0.556 per 100,000 persons in the population. Given the numerous critical anatomic structures located adjacent to the sinonasal cavity and skull base, surgery for tumors in this region requires careful pre-operative planning with the assistance of radiological imaging and intraoperative image guidance technologies to reduce the risk of complications. Virtual surgical planning (VSP) and three-dimensional models (3DMs) are adjunctive technologies which assist clinicians to better visualize patient anatomy using enhanced digital radiological images and physical stereolithographic models based on patients' personal imaging. This review summarizes our institutional experience with VSP and 3DMs in sinonasal and skull base surgical oncology. A clinical case series is used to thematically illustrate the application of VSP and 3DMs in surgical ablation, reconstruction, patient communication, medical education, and interdisciplinary teamwork in sinonasal and skull base surgery.

Activation of assembly factor for spindle microtubules triggers progression of renal cell carcinoma via Wnt3a pathway

Renal cell carcinoma, shorted as RCC is a well-known urological cancer with high level of morbidity and mortality. Although the regulatory role of the spindle microtubule assembly factor (ASPM) in tumor progression has been established, its relationship to the development of RCC remains unclear. To determine the significance of this gene in RCC, we examined its expression in RCC patients in the TCGA database and compared ASPM level between clinical samples of normal tissues and RCC tissues collected at our center. The prognostic relevance of ASPM was assessed by generating Kaplan-Meier survival curves and log-rank functions. Following alteration of ASPM expression using sh-ASPM or oe-ASPM transfection, RCC cell characteristics were evaluated through CCK-8, Transwell, and colony formation assays. Western blot analysis was conducted to measure levels of genes affected by ASPM, and rescue experiments were performed to explore the involvement of Wnt3a signaling in ASPM-mediated malignancy in RCC. Our findings indicate that ASPM is upregulated in RCC samples, and its levels are associated with the long-term survival of RCC patients. ASPM promotes the migration, proliferation, and invasiveness of RCC cells, and the Wnt3a pathway may be implicated in this process. In conclusion, these results indicate that ASPM contributes to the cancer progression of RCC by targeting the Wnt3a signaling pathway.

Mandibular reconstructions with free fibula flap using standardized partially adjustable cutting guides or CAD/CAM technique: a three- and two-dimensional comparison

Background

Mandibular reconstruction with the fibula free flap (FFF) is performed freehand, CAD/CAM-assisted, or by using partially adjustable resection/reconstruction aids. The two latter options represent the contemporary reconstructive solutions of the recent decade. The purpose of this study was to compare both auxiliary techniques with regard to feasibility, accuracy, and operative parameters.

Methods and materials

The first twenty consecutively operated patients requiring a mandibular reconstruction (within angle-to-angle) with the FFF using the partially adjustable resection aids between January 2017 and December 2019 at our department were included. Additionally, matching CAD/CAM FFF cases were used as control group in this cross-sectional study. Medical records and general information (sex, age, indication for surgery, extent of resection, number of segments, duration of surgery, and ischemia time) were analyzed. In addition, the pre- and postoperative Digital Imaging and Communications in Medicine data of the mandibles were converted to standard tessellation language (.stl) files. Conventional measurements - six horizontal distances (A-F) and temporo-mandibular joint (TMJ) spaces - and the root mean square error (RMSE) for three-dimensional analysis were measured and calculated.

Results

In total, 40 patients were enrolled (20:20). Overall operation time, ischemia time, and the interval between ischemia time start until end of operation showed no significant differences. No significant difference between the two groups were revealed in conventional measurements of distances (A-D) and TMJ spaces. The Δ differences for the distance F (between the mandibular foramina) and the right medial joint space were significantly lower in the ReconGuide group. The RMSE analysis of the two groups showed no significant difference (p=0.925), with an overall median RMSE of 3.1 mm (2.2-3.7) in the CAD/CAM and 2.9 mm (2.2-3.8) in the ReconGuide groups.

Conclusions

The reconstructive surgeon can achieve comparable postoperative results regardless of technique, which may favor the ReconGuide use in mandibular angle-to-angle reconstruction over the CAD/CAM technique because of less preoperative planning time and lower costs per case.

Accuracy of virtual surgical planning in mandibular reconstruction: application of a standard and reliable postoperative evaluation methodology

OBJECTIVE

The purpose of this study was to determine the accuracy of virtual surgical planning for mandibular reconstruction, along with the implementation of a postoperative evaluation methodology.

MATERIALS AND METHODS

The study is a prospective case series for computer-assisted mandibular reconstruction surgery. Analysis of the degree of agreement between virtual measurements and postoperative actual outcomes was performed. The reliability of the proposed evaluation methodology was assessed and analyzed using the Inter-Class Coefficient (ICC) test. Statistical significance was set at the 5% level.

RESULTS

Nine consecutive patients were selected. The analysis of all angular and linear parameters reported a highly statistically significant degree of agreement between the preoperative and postoperative measurements (P < 0.001). Furthermore, an extreme degree of reliability was reported when the evaluation methodology was scrutinized (ICC = 0.9).

CONCLUSION

The excellent degree of agreement between the virtual plan and the actual outcome reported in this study validated the surgical accuracy of virtually assisted mandibular reconstruction. This study pointed out the reliability and reproducibility of the standardized evaluation protocol in an attempt to obtain a tolerable value for the acceptable postoperative results regarding the accuracy of computer-assisted surgery.

Point-of-Care Virtual Surgical Planning and 3D Printing in Oral and Cranio-Maxillofacial Surgery: A Narrative Review

This paper provides an overview on the use of virtual surgical planning (VSP) and point-of-care 3D printing (POC 3DP) in oral and cranio-maxillofacial (CMF) surgery based on a literature review. The authors searched PubMed, Web of Science, and Embase to find papers published between January 2015 and February 2022 in English, which describe human applications of POC 3DP in CMF surgery, resulting in 63 articles being included. The main review findings were as follows: most used clinical applications were anatomical models and cutting guides; production took place in-house or as "in-house-outsourced" workflows; the surgeon alone was involved in POC 3DP in 36 papers; the use of free versus paid planning software was balanced (50.72% vs. 49.27%); average planning time was 4.44 h; overall operating time decreased and outcomes were favorable, though evidence-based studies were limited; and finally, the heterogenous cost reports made a comprehensive financial analysis difficult. Overall, the development of in-house 3D printed devices supports CMF surgery, and encouraging results indicate that the technology has matured considerably.