Iterations of computer- and template assisted mandibular or maxillary reconstruction with free flaps containing the lateral scapular border – Evolution of a biplanar plug-on cutting guide

Virtual Surgical Guidance Improves Quality of Life Following Scapular Free-Flap Reconstruction of Maxillary Defects

BACKGROUND

The best approach to maxillary reconstruction with negative impact on the patient's quality of life (QOL) remains the subject of debate.

PURPOSE

This study was designed to evaluate the QOL outcomes following maxillary reconstruction using a scapular-free flap, with and without the computer-aided design and computer-aided manufacturing (CAD/CAM) technique.

STUDY DESIGN, SETTING, SAMPLE

A prospective randomized controlled clinical trial was performed following the CONSORT checklist. To be included, patients suffering from maxillary defects without previous surgery or lymph node involvement were selected. Patients with poor oncological prognosis, deficient performance status, preoperative chemotherapy, or radiotherapy, besides vascular contraindications, were excluded.

PREDICTOR VARIABLE

The predictor variable was the reconstruction technique, grouped into two equal categories. Patients were randomly assigned to reconstruction with a scapular-free flap, with the control group not utilizing a guide and the study group utilizing a CAD/CAM-customized guide.

MAIN OUTCOME VARIABLE

The primary outcome variable was the various domains of QOL, measured using the University of Washington Quality of Life score, 12 months after reconstruction.

COVARIATES

Age; sex; scapular flap side; and maxillary defect tumour type, histopathology, side, length, class, sagittal, and axial differential areas were considered.

ANALYSES

Shapiro-Wilk and Kolmogorov-Smirnov tests were performed for normality. For comparisons between the two groups, Student's t-test and Mann-Whitney test were used. The category variables were compared using the χ2 test. P ≤ .05 was considered statistically significant.

RESULTS

The sample was composed of twenty-two eligible patients, eleven in each group. The mean age of the control group was (50.09 ± 17.14) years, and 45.45% were male, while in the study group, the mean age was (48.36 ± 14.14) years, with 36.36% male. All the patients were evaluated, showing statistically significant differences between control and study groups in terms of pain, appearance, chewing, swallowing, speech, and shoulder (P ≤ .05), indicating that the scapular-free flap with a CAD/CAM osteotomy guide had improved the patient's QOL.

CONCLUSION AND RELEVANCE

The findings of this study indicate that virtual surgical planning with a CAD/CAM customized osteotomy guide using a scapular-free flap can improve QOL in maxillary reconstruction in terms of pain, appearance, chewing and swallowing food, pronouncing words, and shoulder QOL outcomes.

Deep Circumflex Iliac Artery Flap Reconstruction in Brown Class I Defect of the Mandible Using a Three-Component Surgical Template System

BACKGROUND

Computer-assisted surgery is widely used in mandibular reconstruction, but the process is not well described for cases using the deep circumflex iliac artery flap (DCIA) as the donor site. This study aimed to present a DCIA-based three-component surgical template system (3-STS) in patients with a mandibular Brown class I defect.

METHODS

This retrospective cohort study compared clinical outcomes of mandibular reconstruction with DCIA flap using 3-STS or conventional surgical templates. The primary outcome of the study was the accuracy of reconstruction, and the secondary outcomes included surgical time and bone flap ischemia time. Surgery-related parameters and functional outcomes were also recorded and compared.

RESULTS

Forty-four patients (23 in the 3-STS group and 21 in the control group) between 2015 and 2021 were included. Compared with the control group, the 3-STS group had higher accuracy of reconstruction, indicated by lower deviation in absolute distance (1.45 ± 0.76 mm versus 2.02 ± 0.89 mm; P = 0.034), and less deviation in coronal and sagittal angles (0.86 ± 0.53 degree versus 1.27 ± 0.59 degrees, P = 0.039; and 2.52 ± 1.00 degrees versus 3.25 ± 1.25 versus, P = 0.047) between preoperative and postoperative computed tomographic imaging. Surgical time and bone flap ischemia time were significantly reduced in the 3-STS group compared with the control group (median time, 385 minutes versus 445 minutes and 32 minutes versus 53 minutes, respectively; P < 0.001). In addition, masseter attachment was preserved in the 3-STS group but not in the control group. No differences were found in adverse events or other clinical variables.

CONCLUSION

The 3-STS can improve accuracy, simplify intraoperative procedures to increase surgical efficiency, and preserve functionality in mandibular reconstruction for Brown class I defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Virtual Surgical Planning and 3D-Printed Surgical Guides in Facial Allotransplantation

The complex three-dimensional (3D) anatomy in facial allotransplantation creates a unique challenge for surgical reconstruction. Evolution of virtual surgical planning (VSP) through computer-aided design and computer-aided manufacturing has advanced reconstructive outcomes for many craniomaxillofacial indications. Surgeons use VSP, 3D models, and surgical guides to analyze and to trial surgical approaches even prior to entering the operating room. This workflow allows the surgeon to plan osteotomies and to anticipate challenges, which improves surgical precision and accuracy, optimizes outcomes, and should reduce operating room time. We present the development, evolution, and utilization of VSP and 3D-printed guides in facial allotransplantation at our institution, from guide conception to first clinical case.

Reconstruction of the mandibular symphysis: pilot study compares three different flaps

BACKGROUND

Restoration of mandibular continuity, functionality and attempting to return patients to their premorbid state is the ultimate goal of reconstruction. Some studies compare different flaps but the reconstructed portions vary and there is little consensus on the best option for a particular defect.

METHODS

This pilot study compares three different reconstructive options with free flap. We will analyze the accuracy of the reconstruction, the post-operative complications related to the reconstruction, the morbidity of the donor site. This pilot study compares three different reconstructive options with free flap in the reconstruction of the mandibular symphysis: iliac crest, scapula and fibula.

RESULTS

In our sample the morbidity of the donor site was overlapping, as for all three choices free from complications. In post resection edentulous patients, the fibula seems to guarantee better positioning, while in patients with residual occlusion the iliac crest (figure n.4 and n.5) seems to allow a more congruous repositioning. The fibula seems to have a superiority over the other flaps in terms of accuracy in all types of patient.

CONCLUSIONS

Contrary to the most recent work on the accuracy of CAD / CAM, we have analyzed the error in the reconstruction of a specific segment and in the repositioning of the residual mandibular component without the use of guided computer programming.

Registration of magnetic resonance and computed tomography images in patients with oral squamous cell carcinoma for three-dimensional virtual planning of mandibular resection and reconstruction

The aim of this study was to evaluate and present an automated method for registration of magnetic resonance imaging (MRI) and computed tomography (CT) or cone beam CT (CBCT) images of the mandibular region for patients with oral squamous cell carcinoma (OSCC). Registered MRI and (CB)CT could facilitate the three-dimensional virtual planning of surgical guides employed for resection and reconstruction in patients with OSCC with mandibular invasion. MRI and (CB)CT images were collected retrospectively from 19 patients. MRI images were aligned with (CB)CT images employing a rigid registration approach (stage 1), a rigid registration approach using a mandibular mask (stage 2), and two non-rigid registration approaches (stage 3). Registration accuracy was quantified by the mean target registration error (mTRE), calculated over a set of landmarks annotated by two observers. Stage 2 achieved the best registration result, with an mTRE of 2.5±0.7mm, which was comparable to the inter- and intra-observer variabilities of landmark placement in MRI. Stage 2 was significantly better aligned compared to all approaches in stage 3. In conclusion, this study demonstrated that rigid registration with the use of a mask is an appropriate image registration method for aligning MRI and (CB)CT images of the mandibular region in patients with OSCC.

Advances in Oromandibular Reconstruction with Three-Dimensional Printing

The mandibular structures are a complex anatomical structure that is fundamental to many physiological and homeostatic functions. It may be involved in many pathological processes that require partial or complete removal. When this happens, reconstruction is mandatory to improve cosmetic outcome with its effect on social interaction as well as to provide an opportunity for complete dental rehabilitation with restoration of all physiological functions. This article will review the different reconstructive options available for complex defects of the mandibular complex. It will highlight the surgical options available to maximize functional restoration. Finally, it will discuss computer modeling to optimize reconstructive planning.

Sequential application of novel guiding plate system for accurate transoral mandibular reconstruction

OBJECTIVES

The aim of this article is to introduce and share our experience in the sequential use of a novel guiding plate system for accurate mandibular reconstruction via transoral approach and evaluate its clinical effects.

METHODS

Ten patients were operated with transoral mandibulectomy and simultaneous mandibular reconstruction using a novel guiding plate system. Postoperatively, aesthetic assessment and quantitative evaluation were analyzed by measuring the parameters like discrepancy in osteotomy lines, mandibular similarity and symmetry. The independent samples t-test was used and P < 0.05 was considered as significant.

RESULTS

All patients underwent planned transoral surgical procedure successfully. The postoperative aesthetic assessment was rated as excellent. The discrepancy between virtual and actual osteotomy lines, at anterior and posterior regions was 0.80 ± 0.08 and 0.98 ± 0.37 mm, respectively. The postoperative evaluation revealed that mandibular similarity was 0.85 ± 0.03, coronal mandibular angle (CMA) 0.66 ± 0.40, axial mandibular angle (AMA) 1.97 ± 1.25, and sagittal mandibular angle (SMA) 1.97 ± 1.05. There was statistically significant difference in the mean values of osteotomy line discrepancy, mandibular similarity and symmetry, among novel guiding plate and traditional plate groups.

CONCLUSIONS

The novel guiding plate system is a viable and easy-to-use technology for improving the surgical outcomes in patients requiring transoral mandibulectomy and simultaneous mandibular reconstruction by overcoming the problem of limited access due to the presence of lips and cheeks. This can highly improve the precision in osteotomy, fixation of the prebent titanium reconstruction plate, spatial relation transfer, and achieving better symmetry and similarity of mandibular contour.

Dental implant-based oral rehabilitation in patients reconstructed with free fibula flaps: Clinical study with a follow-up 3 to 6 years

BACKGROUND

Oral rehabilitation of patients after maxillofacial reconstructive surgery represents a challenge and stable prosthetic retention can be achieved with the use of dental implants.

PURPOSE

This retrospective report aimed to evaluate implant-based oral rehabilitation following maxillofacial reconstruction with free fibula flaps.

MATERIALS AND METHODS

A total of 14 patients who had reconstruction with fibula flaps either by CAD/CAM or conventional surgery were included in this study. A total of 56 implants (40 in flaps, 16 in native bone) were evaluated. Follow-up after reconstructive surgery ranged between 3.25 and 6.3 years. Follow-up after implant surgery ranged between 1.5 and 3.8 years.

RESULTS

Overall survival rate was 85.7% in free fibula flaps and 85.6% in dental implants. Eight implants were lost in three patients and all of these failures were in dental implants inserted in free flaps. According to the results on patient basis, the implant survival was not influenced by any variable.

CONCLUSIONS

The maxillofacial reconstruction with free fibula flap and oral rehabilitation with implant-supported prostheses after ablative surgery can be considered as an effective and safe procedure with successful aesthetic and functional outcomes.

Three-dimensional CAD/CAM reconstruction of the iliac bone following DCIA composite flap harvest

This article reports a new technique to restore iliac bone integrity with a customized titanium device designed by CAD/CAM, in patients undergoing deep circumflex iliac artery (DCIA) composite flap harvest. Eight consecutive patients who underwent the repair of major head and neck defects with DCIA flaps were enrolled retrospectively. Computed tomography scans of the pelvis were obtained preoperatively. Starting from DICOM data, each personalized device was designed using modelling software and was finally made by additive manufacturing using a laser sintering machine. After surgery, the patients were followed up at 3-month intervals to evaluate the incidence of complications and the long-term outcome at the donor site. A subcutaneous seroma developed in one patient and an inguinal skin burn occurred in another. At a median follow-up of 12 months, the patients did not report pain, or any gait or sensory disturbance at the donor site. There was no occurrence of bulging, herniation, or instability or inflammation near the device for the entire follow-up duration. All patients were satisfied with the aesthetic result. In conclusion, reconstruction of the iliac bone with a customized device is safe and well tolerated. We recommend use of this device in patients deemed at high risk of herniation. Further studies are needed to confirm the stability of the device in the long term.

Condyle dislocation following mandibular reconstruction using a fibula free flap: complication cases

Background

Condylar dislocation can arise as a complication in patients who required mandibular and/or condylar reconstruction and were operated on with fibula free flap (FFF) using surgical guides designed using simulation surgery. Surgeons should be aware of the complications in these present cases when planning and performing reconstructions as well as predicting prognoses.

Cases presentation

Two cases showed condylar dislocation in mandibular reconstruction using a FFF fixed with a reconstruction plate. Three cases showed condylar dislocation in mandibular reconstruction using a fibula free flap fixed with a mini-plate.

Conclusion

Despite the lack of clinical symptoms in these cases following mandibular reconstruction using an FFF, the mandibular condyle was severely displaced away from the glenoid fossa. A surgeon must have sufficient time to consider the use of a long flap with thickness similar to that of the mandible, ways to minimize span and bending, and methods of fixation. The patient, moreover, should be educated on condylar dislocation. Customized CAD/CAM-prototyped temporomandibular condyle-connected plates may be a good alternative even if virtual simulation surgery is to be performed before surgery. These considerations may help reduce the incidence of complications after mandibular reconstruction.

[Virtual surgical planning and intraoperative navigation for mandibular reconstruction: from accurate to minimal invasive]

Simultaneous restoration of function and appearance should be performed in mandibular reconstruction. Option of reconstructive techniques is determined by cause, location, extent, and classification of the mandibular defects. Vascularize bone graft is one of the most popular technique in current clinical practice of mandibular reconstruction. Fibula is the most common donor site for mandibular reconstruction. The disadvantage of low height of neo-mandible reconstructed by single fibular segment can be solved by vascularized double barrel fibula graft. Using virtual surgical planning and intraoperative navigation for mandibular reconstruction leads to simplify surgical procedure, reduce operating time and injury, and decrease donor site morbidity so that accurate mandibular reconstruction could be completed. Direction of minimal invasive surgery for mandibular reconstruction will be developed by intraoral approach and intraoral anastomosis.

All-in-one surgical guide: A new method for cranial vault resection and reconstruction

INTRODUCTION

Great precision is required for craniofacial surgery, and computer-aided design (CAD) methods may be used to plan surgery before it is performed. In this study, three-dimensional (3D)-printed cutting guides are used to match computer models with surgical procedures. We describe a novel method of computer-aided surgery for autologous cranioplasty that includes a new strategy for generating and using cutting guides. These guides may be used not only for osteotomies, but also for many other steps in the surgical procedure.

MATERIALS AND METHODS

Preoperatively, anatomical data were imported into a CAD package and used for virtual surgical planning (VSP). Cutting guides were designed after considering how to integrate all the surgical steps. Models of the microplates and micro-screws were also made. Surgical guides were exported and printed, and preoperative simulations using a replica of the patient's skull established the sequence of steps. The accuracy of the procedure was evaluated postoperatively using computed tomography (CT) scans.

RESULTS

In every patient examined, the all-in-one surgical-guide system was able to automate the many steps in the procedure and dramatically decreased the duration of surgery. The experimental guide enhanced every phase of surgery, including excising the lesion, and harvesting, positioning, and fixing the graft. In each step, precision was enhanced and the outcome corresponded with the VSP.

CONCLUSIONS

The few previous reports on cutting guides used in cranioplasty generally describe the use of separate guides for dismantling and reconstruction. The ability to perform more surgical sequences using a single tool can improve surgical accuracy. Clearly there is no single perfect surgical guide; however, effective surgical-design strategies should be used to build the best approach to each procedure.

Introduction of an algorithm for planning of autologous fibular transfer in mandibular reconstruction based on individual bone curvatures

BACKGROUND

Reconstruction of the mandible with autologous transplants is a challenging task and current computer-aided surgical planning remains cumbersome. Thus, the aim of the present study was to create an automated computational approach for this procedure.

METHODS

The developed algorithm is based on curves following characteristic anatomical features. Geometrical data from a physiological mandible and a fibula were used to generate six different defects, and geometrical accordance was investigated to demonstrate the applicability of the method with different reconstruction parameters (n = 309).

RESULTS

The method proved to be applicable, it recognized given clinical constraints and the values of accordance could be used to quantify the success of reconstructions.

CONCLUSIONS

With the present approach, the complex three-dimensional task of mandibular reconstruction was simplified, and thus it allows implementation in clinical routine. The computational planning that is proposed may be used to design cutting guides or as geometrical input data for real-time navigated surgery.