Association of Plate Contouring With Hardware Complications Following Mandibular Reconstruction.

OBJECTIVES/HYPOTHESIS: Despite considerable effort being dedicated to contouring reconstruction plates, there remains limited evidence demonstrating an association between contour and reconstructive outcomes. We sought to evaluate whether optimizing mandibular reconstruction plate contouring is associated with reduced postoperative hardware complications. STUDY DESIGN: Retrospective cohort study. METHODS: A cohort study was performed with adult patients (age ≥18 years) who underwent mandibulectomy and osseous free flap reconstruction following oncologic ablation at the University Health Network in Toronto, Canada, between January 1, 2003 and December 31, 2014. Patients with computed tomography scans performed within 1 year of reconstruction were included. Computer-based three-dimensional models were generated and used to calculate the mean plate-to-bone gap (mm). The primary outcome was plate exposure. Secondary outcome included a composite of plate exposure or intraoral dehiscence. Logistic regression models were fitted for each outcome accounting for other patient and surgical characteristics associated with the primary outcome. RESULTS: Ninety-four patients met inclusion criteria, with a mean age of 60.4 (standard deviation [SD] 14.9). The mean follow-up time was 31.4 months (range 3-94). Reconstruction was performed with fibular (57%) and scapular free flaps (43%). In the multivariable model, small mean plate-to-bone gap (<1 mm) was independently associated with 86% reduced odds of plate exposure (odds ratio [OR] 0.12; 95% confidence interval [CI] 0.02-0.55). Mean plate-to-bone gap less than 1 mm was also independently associated with reduced odds of developing a composite of plate exposure or intraoral dehiscence (OR, 0.29; 95%CI, 0.11-0.75). CONCLUSION: Optimizing plate contouring during mandibular reconstruction may decrease the development of postoperative hardware complications. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:61-66, 2022.

Fibula Jaw-in-a-Day with Minimal Computer-Aided Design and Manufacturing: Maximizing Efficiency, Cost-Effectiveness, Intraoperative Flexibility, and Quality.

SUMMARY: The vascularized fibular flap has been the mainstay for mandibular reconstruction for over 30 years. Its latest evolutionary step is the jaw-in-a-day operation, during which the fibula flap and dental prosthesis restoration are performed in a single stage. Computer-aided design and manufacturing technology in mandibular reconstruction has gained popularity, as it simplifies the procedure and produces excellent outcomes. However, it is costly, time-consuming, and limited in cases that involve complex defects, including bone and soft-tissue coverage. Moreover, it does not allow for intraoperative changes in the surgical plan, including defect size and recipient vessel selection.The authors describe their approach, including a conventional technique for fibula osteoseptocutaneous flap harvest without the need for a premanufactured cutting guide, using bundled wooden tongue spatulas instead, a stereolithographic model to customize commercially ready-made reconstruction plates, and two pieces of resin to maintain occlusive alignment of the remaining jaw segments during mandibular osteotomy. Dental implants are inserted free-hand. Vector guides are then connected to the implants following insertion into the fibula to confirm acceptable alignment and subsequently replaced with scan sensors. An intraoperative digital scan is used to design and to produce a dental prosthesis by in-house milling of a polymethylmethacrylate block. From our 10-case experience over the past 3 years, we have found that our approach offers a reliable method that matches the excellent outcomes seen using full computer-assisted design and manufacturing technology. It is time- and cost-effective, not limited to relatively simple jaw defects, and can readily accommodate intraoperative changes of surgical plan.

Bacteriological and mechanical impact of the Sterrad sterilization method on personalized 3D printed guides for mandibular reconstruction.

Surgical cutting guides are increasingly used for maxillofacial reconstruction. They are usually provided by laboratories. In recent years, surgical teams have published studies on the possibility of manufacturing their own cutting guides thanks to 3D printers. The object of this study is to analyze the impact of the sterilization on the surface of those personalized models and to assess the effectiveness of sterilization. Using the data from high-resolution CT scan of patient, 3D models were generated through computerized assisted design and fabricated with a 3D printer using Acrylonitrile Butadiene Styrene (ABS). For the sterilization, a Sterrad method was used. In order to evaluate the effectiveness of sterilization, 3D models were artificially contaminated with several bacterial reference strains, sterilized and finally cultured. The surfaces and mechanical modifications were analyzed before and after sterilization with infrared spectrometry, surface contact angle, extensometer, scanning electron microscopy and atomic force microscopy. Ten models of different shapes and 24 samples were fabricated, sterilized and analyzed. The 3D models were designed in 48 h, printed in an average of 122 min and underwent a 47 min cycle of sterilization. All experimentally contaminated 3D models were negative in culture, with at least, a six log reduction of the initial inoculum. The hydrophobicity and roughness of the surface suffered few changes. The reproducibility of this procedure was proved by identical results in the three sterilization rounds. Using Sterrad process for the sterilization of ABS printed material doesn't represent a bacterial risk for the patient. It is a feasible and safe innovative reconstructive method that can save time particularly for oncological cases.

Delayed Infection of Porous Polyethylene Implants After Oncologic Maxillectomy and Reconstruction: 2 Case Reports and Review of Literature.

Medpor porous polyethylene implants are commonly used for facial skeletal reconstruction due to reported biocompatibility, fibrovascularization, and durability. While uncommon, late implant infections are an important consideration. We report delayed infections in 2 patients after unilateral total oncologic maxillectomy and reconstruction using Medpor implants for an ossifying fibroma and squamous cell carcinoma, respectively. In the first patient, annual interval computed tomography (CT) scans showed no recurrence of tumor or inflammatory changes. The second was lost to follow-up after adjuvant chemoradiation 1 year after resection. Patients both presented with swelling, drainage, and erythema around the implant at a mean of 4.5 years following maxillectomy. Both failed several attempts at conservative treatment. Cultures of implants removed at a mean of 2.5 months after infection grew α-hemolytic Streptococcus in the first and multiple organisms in the second, showing that the potential for delayed infection should be considered years after reconstruction.

Strategic use of obturator prostheses for the rehabilitation of oral cancer patients during the COVID-19 pandemic.

During the current pandemic scenario, maxillofacial rehabilitation specialists involved with supportive care in cancer must transform its practice to cope with COVID-19 and improve protocols that could quickly return the oral function of complex cancer patients who cannot wait for surgical complex rehabilitation. This includes the role of the maxillofacial prosthodontist for the rehabilitation of surgically treated patients with maxillary cancers by the means of filling obturator prostheses that are considered an optimal scientific-based strategy to reduce hospital stay with excellent pain control, oral function (speech, swallowing, mastication, and facial esthetics), psychologic and quality of life outcomes for the patients following intraoral cancer resection. Therefore, the aim of this commentary was to bring new lights to the strategic use of obturator prostheses for the rehabilitation of oral cancer patients during the COVID-19 pandemic as well as to present a protocol for managing such cases.

Short-Term Outcomes following Virtual Surgery-Assisted Immediate Dental Implant Placement in Free Fibula Flaps for Oncologic Mandibular Reconstruction.

BACKGROUND: Despite reports demonstrating feasibility of immediate dental implant placement in mandibular reconstruction with free fibula flaps for benign disease, this practice is not routinely used in the oncologic setting. The authors aim to demonstrate the safety of immediate dental implant placement for oncologic mandible reconstruction. METHODS: In 2017, the authors' center began immediate dental implant placement in free fibula flaps for oncologic patients undergoing mandibulectomy reconstruction. Immediate dental implant placement patients were compared to a historical cohort also reconstructed with computer-aided design and manufacturing technology beginning in 2011 (n = 34) as a noninferiority study design. Primary outcomes of interest included 90-day complications, time to radiotherapy, and time to and number of patients achieving dental restoration. RESULTS: Sixty-one patients underwent free fibula flaps following mandibulectomy using computer-aided design and manufacturing. Seventy-two dental implants were placed in the immediate dental implant placement cohort (n = 27). No differences were noted in major or minor 90-day complications between groups (p > 0.05). Radiotherapy was required in 55 percent in the immediate dental implant placement cohort versus 62 percent in the historical cohort, with no significant difference in time to radiotherapy (67.6 days versus 62.2 days, respectively). One dental implant was removed for nonosseointegration noted during vestibuloplasty. Fourteen (51.8 percent) immediate dental implant patients had complete dental restoration at 90 days compared with none in the historical cohort (p < 0.05). CONCLUSIONS: Immediate dental implant placement is a safe procedure with an unchanged short-term complication profile and no delay in radiotherapy initiation. Patients undergoing immediate dental implant placement are more likely to complete full dental rehabilitation. Long-term and health-related quality-of-life outcomes remain to be determined. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

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.

Review of automatic continuous distraction osteogenesis devices for mandibular reconstruction applications.

Distraction osteogenesis (DO) is an emerging method for bone tissue reconstruction. In oral and maxillofacial reconstruction applications, DO is playing an important role as a technique without the need of bone graft. In addition, in a DO treatment procedure, a superior outcome could be achieved compared to conventional reconstruction techniques. Recently, a few automatic continuous distraction osteogenesis (ACDO) devices have been designed and developed to be used in human reconstruction applications. Experiments and animal studies have validated the functionality of the developed ACDO devices. It has shown that by using such ACDO devices in a DO procedure, compared to conventional manual DO methods, superior outcomes could be obtained. However, the application of such ACDO devices is still limited. More research and investigation need to be undertaken to study all requirements of ACDO devices to be used in successful human mandibular DO treatment. It is important to determine all requirements and standards that need to be considered and applied in the design and development of ACDO devices. The purpose of this review paper is to highlight the designed and developed ACDO procedures thus far in terms of their working principles, working parameters, and technical aspects for providing a better perspective of the development progress of ACDO devices for oral and maxillofacial reconstruction applications. In this paper, design principles, device specifications, and working parameters of ACDO devices are compared and discussed. Subsequently, current limitations and gaps have been addressed, and future works for enabling an ultimate automatic DO procedure have been suggested.

Additive manufacturing of reconstruction devices for maxillofacial surgery: design and accuracy assessment of a mandibular plate prototype.

Additive manufacturing (AM) presents unique opportunities for medical applications and in particular in maxillofacial surgery for developing patient specific implants. The quality assessment of additive manufactured products is an essential aspect for the real introduction in health services. In this framework, the purpose of the present study is to investigate the possibility of developing prototypes of mandibular plates as preoperative surgical planning models, by verification of design, analysis of internal structure integrity and evaluation of the effects of variables involved in AM processes. A PolyJet three-dimensional (3D) printing system is used in the study due to its very fine resolution.The computer aided design (CAD) models of the implants were converted to stereolithography (STL) file formats in different STL conversion resolutions and then printed using commercial prototyping polymers to observe the effect of model resolution. Finite element analysis (FEA) was conducted to study the capability of the designed mandibular plate to support the involved biomechanical loads. Micro-computed tomography (micro-CT) analysis was performed to verify the dimensions and the internal defects of the printed objects, considering that the presence of defects can affect the quality and compromise the final performance. Results were analyzed to understand the effect of the 3D printing process flow conditions on the obtained prototypes. Relative error in reference to the CAD models mainly evidenced the difference in resolution due to STL files and the effect of the design. No anomalies and defects were detected inside the evaluated samples.

Lingual Application of Pre-Bent Reconstruction Plate for Segmental Mandibular Defect: Easy and Accurate Method Through the Buccal Drilling Approach Using Computer-Aided Design/Computer-Aided Manufacturing Surgical Guides.

To prevent or treat for complications of reconstruction plate, such as metal plate fracture, plate exposure, and formation of skin fistula, the use of reconstruction plates on the mandibular lingual aspect has been introduced. However, this method increases the difficulty of surgery and lengthens the surgery time. In this study, the authors aimed to present a method to apply for reconstruction plates on the lingual side of the mandible to overcome the complications associated with the use of these plates. In the proposed method, the reconstruction plate was bent and fixed by a specially designed screws on a three-dimensional model created through a pre-operative virtual surgical simulation. Next, the model, prebent reconstruction plant, and screw were 3-dimensionally scanned and then superimposed precisely onto the three-dimensional model generated through the virtual surgical simulation. After extracting the three-dimensional path of the screws on the superimposed model, a surgical guide was prepared to drill screw holes in the buccal side of the mandible by transferring the extracted paths. The proposed surgical method using virtual surgical planning and surgical guides makes mandibular lingual application of the prebent reconstruction plates convenient, fast, and precise through drilling in the buccal side of the mandible.

A simple, effective, universal, and reusable osteotomy tool for jaw reconstructions with microvascular fibula transplants.

BACKGROUND: Precise, expensive individual saw guides are used with increasing frequency for the reconstruction of mandibular defects with fibular grafts. In this report, an alternative is presented - the Multiuse Cutting Jig (MUC-Jig, proprietary development). It is reusable, suitable for all patients, requires simple planning based on conventional CT imaging, and is more economical. METHODS: To investigate its precision, we conducted a nonblinded experimental study, with ten participating craniomaxillofacial surgeons. Osteotomies of four different fibula segments were carried out at the same angulation, with groups defined according to the proximal and distal fixed angulation: 45°, 30°, 15°, or 0°. The sagittal cut was performed proximally, with the coronal cut performed distally. The resulting 40 segments (n = 40) were analyzed with their Tx length (primary endpoint) and osteotomy angles, and compared to the original planning. RESULTS: The mean (SD) relative deviation of all grafts from the original planning was -0.08 mm (1.12) in length and -0.71° (3.15) for the angle. Only 45° (-2.04 ±â€¯3.71°) and 30° (-1.07 ±â€¯2.52°) cuts differed significantly (p < 0.05) from smaller angle grafts. The mean (SD) absolute deviation was 0.81 mm (0.27) in length and 2.13° (0.93) in graft angles. For individual transplants, 45° cuts (1.28 ±â€¯1.03 mm) differed significantly (p < 0.005) from others. We observed no differences in relative length or absolute angle deviation. CONCLUSIONS: The MUC-Jig is precise and cost-effective for osteotomies with medium angles and smooth reconstructions of template-guided procedures.

Combined Use of Specially-Designed Digital Surgical Guides and Pre-Formed Reconstruction Plate to Treat Bilateral Mandibular Fracture.

This paper describes the application of a modified digital surgical guide, an occlusal template and a pre-formed reconstruction titanium plate in the open reduction and internal fixation of a bilateral mandibular fracture. Bilateral mandibular fracture is a commonly encountered simple type of fracture. However, even for an experience surgeon, achieving precise treatment remains a challenge due to the movable temporomandibular joint, unstable fractured segments, the difficulty in forming a reconstruction plate, and the lack of an effective stabilizing and locating device. In this case, the surgeon used a specially-designed modified guide together with a reconstruction plate and an occlusal template to treat a bilateral mandible fracture, effectively improving the accuracy and the medical outcome of the operation, saving operation time and reducing postoperative complications.

Evaluation of virtual surgical planning systems and customized devices in fibula free flap mandibular reconstruction.

PURPOSE: The purpose of this study was to evaluate the accuracy of virtual planning using customized surgical devices (VP3D) in fibula free flap mandibular reconstruction. METHODS: Fourteen patients received VP3D and 16 patients underwent conventional surgery (CS). Virtual planning was compared to postoperative scans using cephalometric and three-dimensional (3D) measurements. Operative times of both VP3D and CS groups were compared. RESULTS: Comparisons of cephalometric measurements revealed no significant difference between virtual planning and postoperative scans. 3D analysis demonstrated a high level of virtual planning accuracy. In the VP3D group, total operative time gain was 88 min (p < 0.001) and total ischemia time gain was 36 min (p = 0.04). CONCLUSION: Virtual surgical planning using customized devices enables 'tailored' surgery that is accurate and reliable and results in operative and ischemia time gain. CLINICAL TRIAL: NCT03869723.

Balsa wood for precise intra-operative bone contouring in fibula free-flap mandible reconstruction.

OBJECTIVE: To report a simple and novel method for intra-operative planning of fibula free flap reconstruction by means of a balsa wood (BW) model. STUDY DESIGN: Retrospective chart review. METHODS: Between 2010 and 2015, 29 patients underwent mandibular reconstruction by a BW osteotomy design in which a single BW beam (US$4) is cut into segments to match the plate. The segments are then assembled together in a three-dimensional (3D) fashion to conform to the contour of the defect and the angles of attachment. Osteotomies are then performed according to the BW segment lengths and angles. Outcomes were retrospectively analyzed for number of procedures, operative times, and complications between the balsa wood method and more standard techniques, e.g., conventional 3D models. RESULTS: The length of the average mandibular defect was 9.62 cm (4-19), and the mean number of fibula segments was 2.03 ± 0.92 (range 1-4). Only one case (3.4%) necessitated revision surgery. Three patients (10.3%) had minor complications. Comparison of the results of the 13 patients reconstructed solely by BW to the 16 reconstructed by both BW and a 3D-printed model revealed that the use of BW alone did not significantly alter the average number of segments [2.31 (BW) vs 1.69 (combined); P = 0.07] or ischemia time (173 min vs 171 min, respectively, P = 0.938). CONCLUSION: The use of balsa wood as a model for intra-operative planning of fibula free flap osteotomies is an effective, inexpensive, and safe technique.

Improved accuracy of hemimandibular reconstructions involving the condyle by utilizing hydroformed reconstruction plates rather than hand-bent stock plates.

BACKGROUND: Computer-aided design/computer-aided manufacturing (CAD/CAM) surgical templates allow precise mandibular reconstructive surgery. However, their clinical accuracy is limited by manual plate bending. Digitally hydroformed plates maintain a digital workstream in virtual planning. METHODS: Twelve patients with Brown's class IIc mandibular defects were randomized into two groups: group I (experimental), the reconstruction plate was digitally hydroformed, and group II (control), surgeries were performed CAD/CAM guided with the reconstruction plate manually prebent. The linear and angular deviations of reconstruction outcomes were compared to surgical simulation in both groups. RESULTS: The mean linear and angular deviations of middle and posterior segments were 2.14 ± 0.79 mm, 3.71 ± 0.95 mm, 8.73° ± 1.91°, and 9.06° ± 0.96° in group I and 4.31 ± 0.78 mm, 6.74 ± 1.40 mm, 16.35° ± 0.72°, and 31.48° ± 3.38° in group II, respectively. Measurements in group I were significantly lower than group II (P < .005). CONCLUSION: Digital hydroforming for plate prebent is a reliable method that helps improving the clinical accuracy of CAD/CAM-guided mandibular reconstruction surgery.

Continuous distraction osteogenesis device with MAAC controller for mandibular reconstruction applications.

BACKGROUND: Distraction osteogenesis (DO) is a novel technique widely used in human body reconstruction. DO has got a significant role in maxillofacial reconstruction applications (MRA); through this method, bone defects and skeletal deformities in various cranio-maxillofacial areas could be reconstructed with superior results in comparison to conventional methods. Recent studies revealed in a DO solution, using an automatic continuous distractor could significantly improve the results while decreasing the existing issues. This study is aimed at designing and developing a novel automatic continuous distraction osteogenesis (ACDO) device to be used in the MRA. METHODS: The design is comprised of a lead screw translation mechanism and a stepper motor, placed outside of the mouth to generate the desired continuous linear force. This externally generated and controlled distraction force (DF) is transferred into the moving bone segment via a flexible miniature transition system. The system is also equipped with an extra-oral ACDO controller, to generate an accurate, reliable, and stable continuous DF. RESULTS: Simulation and experimental results have justified the controller outputs and the desired accuracy of the device. Experiments have been conducted on a sheep jaw bone and results have showed that the developed device could offer a continuous DF of 38 N with distraction accuracy of 7.6 nm on the bone segment, while reducing the distraction time span. CONCLUSION: Continuous DF with high resolution positioning control, along with the smaller size of the distractor placed in the oral cavity will help in improving the result of the reconstruction operation and leading to a successful DO procedure in a shorter time period. The developed ACDO device has less than 1% positioning error while generating sufficient DF. These features make this device a suitable distractor for an enhanced DO treatment in MRA.

Arteriovenous Fistula Occurring After Alveolar Arch Repair With Free Medial Femoral Condyle Flap.

The occurrence of an arteriovenous fistula (AVF) after microvascular tissue transfer is extremely rare. This paper presents the development of an AVF in a patient who underwent a free-flap procedure for alveolar arch reconstruction and discusses the mechanisms of AVF formation and its current treatments.

Single-Unit 3D-Printed Titanium Reconstruction Plate for Maxillary Reconstruction: The Evolution of Surgical Reconstruction for Maxillary Defects-A Case Report and Review of Current Techniques.

The complex 3-dimensional anatomy of the facial skeleton creates a unique challenge for surgical reconstruction. Even more difficult is the precise reconstruction of the maxilla owing to its lack of solid bony support after large resections. Virtual surgical planning (VSP) technology has many applications in head and neck surgery, such as preoperative planning, fabrication of cutting guides and stereolithographic models, and fabrication of custom implants. We present the case of a patient who had undergone surgical resection of a mucoepidermoid carcinoma of the maxilla and immediate reconstruction with a vascularized free fibula flap using VSP. Using a custom 3-dimensional, titanium printed plate, which corresponded precisely with the surgical defect, the maxilla and midface were reconstructed to ideal dimensions with no unplanned surgical manipulation and a shorter overall operating time. We have described the technique and reviewed the pertinent reported data.

The Fate of the Mandibular Reconstruction Plate.

To preserve the continuity of the mandible after resection or traumatic bone loss, the defect is usually reconstructed with a bone graft fixed by a reconstruction plate. The fate of these plates is the objective of this study. Twenty-three patients (4 females and 19 males) required a reconstructive procedure to restore the discontinuity defect in the mandible by a mandibular reconstruction plate. Postoperative follow-up was performed to assess the outcomes of these plates. The mean age of the patients was 28.22 years. The most common cause of the discontinuity defect was bullet injury. The mean follow-up period was 3.65 years. The most common postoperative complication was the surgical site infection. The reconstruction plate of the mandible is associated with long-term success and body acceptance in the hands of an experienced surgeon.