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Objectives: This study aims to introduce a novel predictive model for the post-operative facial contours of patients with mandibular defect, addressing limitations in current methodologies that fail to preserve geometric features and lack interpretability., Methods: Utilizing surface mesh theory and deep learning, our model diverges from traditional point cloud approaches by employing surface triangular mesh grids. We extract latent variables using a Mesh Convolutional Restricted Boltzmann Machines (MCRBM) model to generate a three-dimensional deformation field, aiming to enhance geometric information preservation and interpretability., Results: Experimental evaluations of our model demonstrate a prediction accuracy of 91.2 %, which represents a significant improvement over traditional machine learning-based methods., Conclusions: The proposed model offers a promising new tool for pre-operative planning in oral and maxillofacial surgery. It significantly enhances the accuracy of post-operative facial contour predictions for mandibular defect reconstructions, providing substantial advancements over previous approaches., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The Aim of the Study: To develop and implement a comprehensive algorithm for the rehabilitation of patients after partial resection of the mandible using a titanium «growing» endoprosthesis., Material and Methods: The study included 16 patients aged 2 to 7 years, with benign (6 cases) and malignant (10 cases) tumors of the mandible. The patients were divided into 2 groups depending on the time of fixation of the endoprosthesis. Group 1 included patients with simultaneous installation of a prosthesis (7 people). Group 2 included patients with delayed installation of an endoprosthesis (9 people). For the reconstruction of the mandible, «growing» titanium endoprostheses made of Ti6Al4V alloy of various designs were used. Removable orthodontic devices of mechanical and functional type of action, standard elastic mouthguards were used in the process of dental treatment., Results: A comprehensive algorithm has been developed for the rehabilitation of children after partial resection of the mandible, depending on the time of fixation of the prosthesis and the volume of surgical intervention., Conclusion: The developed algorithm of complex rehabilitation using a «growing» endoprosthesis and dental support at the pre and postoperative stages allows to reduce the volume of secondary deformation of facial structures and dentition.

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., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

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.

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., Competing Interests: Disclosure:The authors have no conflict of interest to declare., (Copyright © 2021 by the American Society of Plastic Surgeons.)

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.

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.

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.

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., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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.

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.

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 ± 3.71°) and 30° (-1.07 ± 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 ± 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., (Copyright © 2019 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

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.

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.

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.

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., (© 2019 Wiley Periodicals, Inc.)

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.

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.

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.

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., (Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The main aim of this article is to compare the complication rate associated with the use of miniplates versus reconstruction plates in vascularized osteocutaneous flap reconstruction of the mandible., Patients and Methods: The authors searched PubMed, Web of Science, EMBASE, Chinese BioMedical Literature Database (CBM), Cochrane Library, and clinicaltrials.gov up to September 2017 to identify studies that compared the complication rate of miniplates versus reconstruction plates in patients undergoing mandibular reconstruction. Two reviewers individually extracted the data and performed a quality assessment. Plate exposure, plate fracture/removal, infection, and overall complications were evaluated., Results: Five studies with 511 cases were included in our analysis. No significant difference was found between the groups. However, the reconstruction plate led to fewer overall complications and plate exposure postoperatively than did the miniplate., Conclusion: Our meta-analysis suggests that miniplates and reconstruction plates are suitable for mandibular reconstruction with a vascularized osteocutaneous flap.

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.

Objective: This study investigated the biomechanical stability of 2 plate systems-mini-plates and reconstruction plates-in reconstruction with fibular free flaps., Study Design: The reconstruction models were constructed by using 2 types of plates in representative cases with segmental mandibular defect (C, L, LC1, LC2). In each model, a masticatory simulation approximating 3 clenching tasks was conducted, using the muscle forces adjusted to the mandible structure used in this study. In addition, to evaluate the sensitivity of the 2 plate systems for masticatory load changes, a sensitivity analysis was also performed by using finite element analysis., Results: The risks of plate fracture and screw loosening measured by stress concentrations were higher in the cases using mini-plates compared with those using reconstruction plates. Moreover, the mini-plate was more sensitive to varied loads compared with the reconstruction plate and was observed to have less flexibility to absorb external forces. Mini-plates also caused high strain values, indicating the risk of hypertrophy of bone around the screw holes., Conclusions: The use of a reconstruction plate should result in more stable surgical outcomes in most cases, but we noted that the risk of atrophy may increase with the use of reconstruction plates because of lack of bone stimulation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to compare the three-dimensional accuracy of mandibular reconstruction following mandible continuity resection in patients treated with patient-specific, pre-bent reconstruction plates, using an 'in-house' 3D printer, with that in patients treated with conventional, intraoperatively bent plates., Patients and Methods: We retrospectively analyzed 42 alloplastic mandibular reconstructions following continuity resection. 21 patients received patient-specific, pre-bent reconstruction plates using an in-house 3D printer. The control group consisted of 21 patients provided with intraoperatively bent reconstruction plates. Distances between corresponding anatomical landmarks on the mandibular angle and condyle (A-A', BB', CC', BC'), as well as the intercondylar angle (ICA), were measured and compared on the pre- and postoperative CT scans., Results: Multivariate analysis of variance (MANOVA) showed significant multivariate main effect of group (F (5, 36)  = 5.58, p = 0.001; Wilks lambda 0.564; partial η 2  = 0.436), indicating more accurate postoperative results for the pre-bent group. Post-hoc comparison revealed significantly larger postoperative deviation in the distances between the mandibular angle and the intercondylar angle (ICA) for the intraoperatively bent group in comparison with the pre-bent group. However, there was no significant effect on the distance between the condyles., Conclusions: Mandibular reconstructions employing patient-specific, pre-bent reconstruction plates made using an in-house 3D printer show significantly better three-dimensional accuracy compared with intraoperatively bent plates. The described method prevents rotational error of the mandibular angle and improves restoration of the physiological intercondylar angle in mandible reconstruction after continuity resection., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objectives: Plate extrusions after free tissue transfer for mandibular reconstruction can be problematic and generally require revision surgery. Our objective was to assess the predictors of plate extrusion and compare outcomes between fibular free flaps (FFF), lateral border scapular flaps (LBSF), and scapular tip free flaps (STFF)., Methods: Retrospective review of consecutive patients who underwent osseous free tissue reconstruction of the mandible (2008-2014) at Victoria Hospital, London, Ontario. Patient demographics and treatment-related information were collected., Results: We identified 134 procedures and 27 (20.2%) plate extrusions (21/61 FFF, 3/49 STFF, and 3/24 LBSF). Freedom from extrusion after 2 years was significantly associated with the use of FFF (P = .003, HR 6.09 1.82-20.44), performing 1 osteotomy (P = .03, HR 2.61 1.08-6.31), and anterior mandibular defects (P = .01, HR 2.66 1.25-5.66) in the univariate model. FFF's were employed more frequently in younger patients, with 2.4 mm plates, more anterior defects, and with a greater number of osteotomies (P < .001). However, after controlling for these variables in multivariate analyses the use of a FFF was the only significant predictor of extrusion at 2 years (P = .006, HR 3.68 1.46-9.28)., Conclusions: At our institution, use of the STFF predicts mandibular defects that are less prone to developing plate extrusion and FFF tended to be used more frequently in anterior defects with osteotomies. However, after controlling for these factors use of the FFF appeared to have higher rates of extrusion than scapular flaps. Further prospective studies controlling for defect variables are needed to elucidate the risk factors for plate extrusion., (© 2018 Wiley Periodicals, Inc.)

The innovative TriLock Bridging Plate System (Medartis AG, Switzerland) was developed to reduce common complications related to conventional mandibular reconstruction plates. The novelties regarding the plating system concern the cross-strut structure in the centerpiece, the bendable side elements and the reduction of the plate's thickness to 2.0 mm 4 different models are available, which cover lateral and central segmental mandibular defects. The plating system has only been introduced at selected maxillofacial units so far and clinical assessment is still lacking. Thus, the aim of the study was to analyze the novel Bridging Plate system in terms of its clinical applicability, rate of trimming and postoperative outcomes in a first investigation over 6 months. The study includes 25 patients with segmental mandibular resection, who underwent reconstruction with TriLock Bridging Plates. According to the assessment parameters, excellent clinical applicability was stated in 48%. The overall trimming rate was found to be 88%. Mostly adaptions to the distal bendable elements of lateral plates were performed. The occurrence of postoperative complications was 16%. Plate fracture occurred in 4%. With reference to the results, the novel plating system represents a viable method for segmental mandibular reconstruction, however, further evaluation is needed, for a more detailed analyzation., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Computer-aided design/computer-aided manufacturing (CAD/CAM) methods for mandibular reconstruction have improved both functional and morphological results. We evaluated the accuracy of the CAD/CAM method for mandibular reconstruction and assessed the quantitative and qualitative reproducibility of virtual preoperative planning., Materials and Methods: A total of 34 consecutive patients treated with mandibular reconstruction using the CAD/CAM method between January 2011 and October 2017 were included in this study. The accuracy of the reconstruction was assessed using the automated Hausdorff distance function of the simulation software, which set the postoperative mesh as the target. This made it possible to calculate the minimum error, the maximum error, and the mean error for each reconstruction in exactly the same way and with the same settings as the difference between the postoperative mesh and virtual planning. Finally, the coloured quality mapper function was applied to superimposition of the STL files, allowing us to visually render the obtained data on differences between preoperative planning and surgical outcome., Results: The average mean error obtained after performing an accuracy evaluation of our reconstructions was 1 mm (range 0.4-2.46 mm). Based on the colour map areas, the maximum error was located in the symphysis area. The body and ramus areas showed the greatest accuracy in terms of planning reproducibility., Conclusion: This is the first study to assess the three-dimensional reproducibility of virtual planning using the CAD/CAM method for mandibular reconstruction, in a homogeneous sample of 34 cases. Our data suggest that CAD/CAM microvascular reconstruction can result in a very high degree of reproducibility. This occurs in complex areas as well as the condylar region and in the case of extensive mandibular reconstructions., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: The purpose of this study was to compare the daily food intake rate and the rate of screw loosening between 2 groups of rabbits with mandibular continuity defects: custom implant (CI) group and 5-hole mini-plate group., Materials and Methods: Two types of cylindrical implants were printed, and their physical strength was compared. In this study using rabbits, 1 group (n = 5) received a CI for the reconstruction of a mandibular continuity defect (CI group) and the other group (n = 5) received a 5-hole mini-plate without a bone graft (reconstruction plate [RP] group). After reconstruction, the daily food intake rate and the rate of screw loosening were examined postoperatively. Histologic examination in the CI group was performed 3 months after the operation., Results: The design that mimicked the mandible showed greater physical strength. The amount of time required to achieve 50% recovery was shorter in the CI group than in the RP group (P = .011). The total number of loosened screws in the CI group was lower than that in the RP group at 3 months postoperatively (P = .008). New bone formation in the porous CI was evident in the CI group., Conclusions: Rabbits with mandibular continuity defects treated with CIs for reconstruction showed faster recovery of the daily food intake rate and fewer loosened screws than those treated with a 5-hole mini-plate without bone graft., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Treatment of pseudoaneurysms in the internal carotid artery (ICA) is associated with a high risk of cerebral infarction; therefore, vessel ligation for hemostasis must be avoided. A 66-year-old man had intraoral hemorrhaging. At the time of the initial examination, computed tomography angiography showed jaw plate displacement near the ICA. A more detailed image was obtained using digital-subtraction angiography. After evaluation of the image, a pseudoaneurysm was diagnosed. Six days later, there were concerns about aspiration and airway obstruction; therefore, tracheostomy was performed. Interventional vascular radiology (IVR) and surgery were planned to facilitate complete recovery, removal of the jaw plate, and repair of the pseudoaneurysm. Before surgery, it was confirmed that it would be possible to block blood flow for approximately 20 minutes. Surgery was performed with the patient under general anesthesia. Before plate removal, cardiovascular surgeons exposed the left large saphenous vein and prepared it so that it could be used to patch the vascular wall defect. A balloon type of embolic protection device was placed so that it could be inflated at any time after plate removal via oral surgery. The pseudoaneurysm was found directly under the plate; however, it had adhered to the scar tissue. As removal progressed, hemorrhaging occurred. To achieve hemostasis, the balloon embolic protection device was inflated. The pseudoaneurysm was removed, and a red thrombus was aspirated. On postoperative day 41, bleeding reoccurred. Two days later, embolization using a platinum coil and stent placement were performed through IVR monotherapy. Postoperative progress was favorable, and the patient was discharged 83 days after treatment without neurologic sequelae. ICA pseudoaneurysms located near the skull base are risky and challenging to repair. However, for traumatic aneurysms such as the one in this case, a combination of IVR therapy and surgery is useful for controlling intraoperative hemorrhage., (Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the biomechanical performance of a commercially available bridging plate (2.4) as well as screws and bone simulating the reconstruction of hemimandibular defects and to indicate alternatives of reinforcement to prevent plate fractures either by strength or fatigue., Material and Methods: Two common hemimandibular defects are investigated using computed finite element analysis (FEA) approach. Simplified and refined computational models are developed for the geometry of the screw. Conditions of non-locking and locking plate-screw interfaces are considered. Static loads of 120 N are applied. Von Mises stresses and fatigue are calculated. As reinforcement, a second complete or partial plate is placed onto the original plate., Results: Results demonstrate that reconstruction plates are often subjected to excessive stress that may lead to fracture either by strength or by fatigue. An attached complete or partial second plate is able to reduce stress in the plate, in screws and bone so that stress remains below the allowable limit of the materials., Conclusion: A simplified technique of attaching a whole or sectioned second plate onto the original plate can reduce the stress calculated and may reduce the frequency of plate fractures for the patient's comfort, security and financial savings., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Virtual surgical planning (VSP) with subsequent computer-aided design and manufacturing have proved efficacious in improving the efficiency and outcomes of a plethora of surgical modalities, including mandibular reconstruction and orthognathic surgery., Patients and Methods: Five patients underwent complex mandibular reconstruction after traumatic injury using VSP from July 2016 to August 2017 at our institution. The Johns Hopkins University Hospital institutional review board approved the present study. The patient's occlusion was restored virtually, and a milled 2.0-mm plate was created that would bridge the defect with the patient in occlusion., Results: Appropriate occlusion was confirmed using postoperative computed tomography. No patient developed any adverse outcomes, except for a minor dehiscence of the intraoral incision in 1 patient that was treated with local wound care. The average interval from the injury to custom plate availability was approximately 7 days., Conclusions: The utility of this technology in acute complex mandibular trauma can overcome the challenges of traditional treatment. Custom patient-specific prebent and milled plates permit the use of a lower profile and therefore less palpable hardware, can guide reduction, avoid the need for plate bending, and obviate the need for an extraoral incision., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Mandibular defects involving the condyle represent a complex reconstructive challenge for restoring proper function of the temporomandibular joint (TMJ) because it requires precise bone graft alignment for full restoration of joint function. The use of computer-aided design and manufacturing (CAD/CAM) technology can aid in accurate reconstruction of mandibular condyle defects with a vascularized free fibula flap without the need for additional adjuncts. The purpose of this study was to analyze clinical and functional outcomes after reconstruction of mandibular condyle defects using only a free fibula graft with the help of virtual surgery techniques., Materials and Methods: A retrospective review was performed to identify all patients who underwent mandibular reconstruction with only a free fibula flap without any TMJ adjuncts after a total condylectomy. Three-dimensional modeling software was used to plan and execute reconstruction for all patients., Results: From 2009 through 2014, 14 patients underwent reconstruction of mandibular defects involving the condyle with the aid of virtual surgery technology. The average age was 38.7 years (range, 11 to 77 yr). The average follow-up period was 2.6 years (range, 0.8 to 4.2 yr). Flap survival was 100% (N = 14). All patients reported improved facial symmetry, adequate jaw opening, and normal dental occlusion. In addition, they achieved good functional outcomes, including normal intelligible speech and the tolerance of a regular diet with solid foods. Maximal interincisal opening range for all patients was 25 to 38 mm with no lateral deviation or subjective joint pain. No patient had progressive joint hypomobility or condylar migration. One patient had ankylosis, which required release., Conclusion: TMJ reconstruction poses considerable challenges in bone graft alignment for full restoration of joint function. The use of CAD/CAM technology can aid in accurate reconstruction of mandibular condyle defects with a vascularized free fibula flap through precise planning and intraoperative manipulation with optimal functional outcomes., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

A patient had a right mandibular defect due to resection of an ameloblastoma. Previously, the defect had been reconstructed by an iliac bone graft, and subsequently, a titanium mesh with xenograft was used. However, it was not successfully reconstructed. For the recovery of mandible continuity and rehabilitation of jaw movement, we manufactured a customized 3-dimensional titanium implant by computer-aided design and manufacturing and electron beam melting technology. This implant was designed to have a porous body structure and lingual plate. The customized implant was accurately inserted in the bony defect. As a result, the patient showed a normal range of mouth opening and jaw movement. New bone migration was observed in the porous structure of the implant. Although there was a slight plate exposure and lack of alveolar bone formation, the customized 3D titanium implant successfully reconstructed the mandibular discontinuous defect and recovered jaw movement.

Background: Surgical plates have been extensively used in head and neck reconstruction and conventional plates are mass-produced with universal configurations. To overcome disadvantages of conventional surgical plates, we have been exploring patient-specific surgical plates using the three-dimensional (3D) printing technology. We hypothesized that the application of 3D-printed patient-specific surgical plates in head and neck reconstruction is feasible, safe and precise., Methods: We are conducting a prospective clinical trial to assess the feasibility, safety and accuracy of applying 3D-printed patient-specific surgical plates in head and neck reconstruction. The primary endpoint was the intraoperative success rate. Secondary endpoints included the incidence and severity of postoperative adverse events within six months postoperatively. The accuracy of surgical outcomes was also explored by comparing the planned and final positions of the maxilla, mandible and grafted bone segments., Results: From December 2016 to October 2017, ten patients were enrolled and underwent head and neck reconstruction using 3D-printed patient-specific surgical plates. The patient-specific surgical plates adapted to bone surface precisely and no plate-bending was performed. The intraoperative success rate was 100%. The average follow-up period was 6.5 months. No major adverse events were observed. The mean absolute distance deviation of integral mandible or maxilla was 1.40 ± 0.63 mm, which showed a high accuracy of reconstruction., Conclusions: The 3D printing of patient-specific surgical plates could be effective in head and neck reconstruction. Surgical procedures were simplified. The precise jaw reconstruction was achieved with high accuracy. Long-term results with a larger sample size are warranted to support a final conclusion. The study protocol has been registered in ClinicalTrials.gov with a No. of NCT03057223., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: The mandible is an essential esthetic and functional component of the lower third of the face and its reconstruction has always been a challenge, especially after severe post-traumatic injuries. The purpose of the present report was to introduce a new approach of mandibular reconstruction in a patient who had lost the entire mandible except for the rami after being severely injured in a blast., Materials and Methods: A new approach using a titanium mandibular rami implant technique was applied using computer-aided 3-dimensional virtual planning and rapid prototyping technology. A prosthetic component was supported by the mandibular implant, which achieved occlusion and dedicated function for the patient., Results: This method offered precise adaptation of the implant and prosthesis and an easier surgical procedure, providing a shortened operation time, no donor site morbidity, and more predictable outcomes., Conclusion: This new technique allows reconstruction of large-scale mandibular defects that is not possible by conventional surgical methods., (Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: We evaluated the effects of three-dimensional virtual planning and the use of a plate-embedded surgical guide in mandibular reconstruction with microvascular fibula flaps., Materials and Methods: We retrospectively reviewed 35 patients who underwent primary mandibular reconstruction with a free fibula flap. They were divided into three groups according to the therapy they received. In group A, 12 patients underwent reconstruction using the modified surgical guide system, including virtual surgeries, pre-bent titanium plates, screw-predesignated cutting guides for mandibular and fibular osteotomies, and plate-embedded shaping guides. In group B, 14 patients underwent reconstruction using the common surgical guide system, including virtual surgeries, cutting guides and pre-bent plates. In group C, 9 patients underwent reconstruction based on the surgeon's experience. All cases were reviewed for the total operative time, ischemia time of the fibula flaps, accuracy of surgery, and postoperative complications., Results: All of the fibula flaps survived. In group A, the ischemia time was shorter than that of groups B and C (P < .05). The average gonion and condyle shift was lower in group A than in groups B and C (P < .01)., Conclusions: Application of the screw-predesignated and plate-embedded surgical guide system can reduce the ischemia time and operation time in mandibular reconstruction with a fibula flap, and can increase reconstruction accuracy. This method is a precise and highly reliable technique for improving the clinical outcome of mandibular reconstruction., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: A new method in mandible reconstruction has recently been developed using patient-specific mandible reconstruction plates (PSMP) after preoperative computer planning using CAD/CAM procedures. To transfer the virtual planned position of the PSMP into the intraoperative situs resection margins and plate position is determined by using surgical guides made by CAD/CAM procedures as well (PSMP-method)., Methods: Mandibular reconstruction with the PSMP-method was performed on 18 patients. The study included sole alloplastic reconstruction cases (AP, n = 10) and microvascular osseous reconstruction cases (MV, n = 8). Pre- and postoperative CT-scans were evaluated by measuring distances between corresponding landmarks on the mandibular rami. The difference was used to evaluate reconstruction accuracy., Results: The median deviation of all distances was 1.13 mm for PSMP-method including all cases. For AP-group, the median deviation was 0,80 mm, for MV-group it was 2,47 mm. There was a high significant difference between both groups (AP and MV). Larger mandibular resections in combination with the need of positioning the surgical guides in the region of the upper condyle seemed to reduce reconstruction-accuracy. This was found more often in MV-group as in the AP-group., Conclusions: PSMP-method seems to be an effective and satisfying method for accurate mandibular reconstruction. Microvascular reconstruction seems less accurate than sole alloplastic reconstruction. Larger resections of the mandible and technical more challenging approaches up to the mandibular condyle might explain this result., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: CAD/CAM reconstruction plates have become a viable option for mandible reconstruction. The aim of this study was to determine whether CAD/CAM plates provide higher fatigue strength compared with conventional fixation systems., Material and Methods: 1.0 mm miniplates, 2.0 mm conventional locking plates (DePuy Synthes, Umkirch, Germany), and 2.0 mm CAD/CAM plates (Materialise, Leuven, Belgium/DePuy Synthes) were used to reconstruct a polyurethane mandible model (Synbone, Malans, CH) with cortical and cancellous bone equivalents. Mastication was simulated via cyclic dynamic testing using a universal testing machine (MTS, Bionix, Eden Prairie, MN, USA) until material failure reached a rate of 1 Hz with increasing loads on the left side., Results: No significant difference was found between the groups until a load of 300 N. At higher loads, vertical displacement differed increasingly, with a poorer performance of miniplates (p = 0.04). Plate breakage occurred in miniplates and conventional locking plates. Screw breakage was recorded as the primary failure mechanism in CAD/CAM plates. Stiffness was significantly higher with the CAD/CAM plates (p = 0.04)., Conclusion: CAD/CAM plates and reconstruction plates provide higher fatigue strength than miniplates, and stiffness is highest in CAD/CAM systems. All tested fixation methods seem sufficiently stable for mandible reconstruction., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: This study develops a novel hybrid (NH) reconstruction plate that can provide load-bearing strength, secure the bone transplant at the prosthesis favored position, and also maintain the facial contour in a mandibular segmental defect. A new patient-match bending technique which uses a three-dimensional printing (3DP) stamping process is developed to increase the interfacial fit between the reconstruction plate and mandibular bone., Materials and Methods: The NH reconstruction plate was designed to produce a continuous profile with non-uniform thickness and triangular cross-screw patterns with a locking-screw feature at the plate base. Two mandible segmental defect finite element models including the NH reconstruction plate to secure a bone flap for occlusal requirement and the commercial straight (CS) reconstruction plate to secure a bone flap along the lower mandible border were generated for biomechanical fatigue testing., Results: The simulated results showed that the maximum von Mises stresses of the reconstruction plate for CS secured model are about 4.5 times more than the NH secured model. The bone strains around the fixation screws showed that the CS secured model was meaningfully higher than that of the NH secured model and exceeded the bone limit value. No fracture of any component was found in any sample in the fatigue testing., Conclusion: In conclusion, the newly developed NH reconstruction plate can secure the transplant position in accordance to the individual occlusal requirements without sacrificing the maintenance of facial contour. Finite element-based biomechanical evaluation demonstrates superior mechanical strength compared to commercial standard plates., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The progress made in recent years in the field of head and neck bone reconstruction is directly related to technological advancements made in computer-aided design and manufacturing (CAD/CAM) and three-dimensional printing in particular. Today these technologies are mainly used in mandibular reconstruction to manufacture aids for harvesting and shaping bone flaps. However problems remain when addressing patients with a contraindication to microsurgery who need extensive bone reconstruction. For these patients who cannot benefit from vascularized bone grafts, surgeons have to find alternative solutions aimed at maintaining best function and aesthetics. The goal of this article is to present an original method for mandibular body replacement with custom-made porous titanium prostheses in patients ineligible for a bone free flap. This solution has been used for two patients with an intraoral approach, resulting in no visible scars, with simple postoperative care of a short duration. This innovative solution represents an additional option for the treatment of complex mandibular reconstructions., (Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Purpose: To introduce and evaluate the clinical effects of digital surgical guide plate technology in the combined osteotomy and reconstruction pre-bent plate position (CORPPP) technique during mandibular segmental resections., Materials and Methods: Seven cases of mandibular segmental resection with simultaneous vascularized free fibula flap reconstruction by oral and maxillofacial surgery were selected (Xiangya Hospital, Changsha, China; June 2015 through December 2015). Cone-beam computed tomographic (CBCT) and spiral CT scans of mandibles and fibular donor sites, respectively, were collected. Surgical simulations were conducted after data collection. Pre-bent titanium plates were placed within the predicted mandibular models. The samples were scanned by CBCT to obtain the positional relations. Then, CORPPP surgical guide plates with location holes were designed and fabricated on pre-bent titanium plates. The CORPPP surgical guide plates were applied in osteotomy and the placement of pre-bent titanium plates during surgery. CBCT scans were obtained 2 weeks after surgery to examine the reconstructed composite models composed of mandibles and titanium plates. Then, the scans were compared with the preoperatively designed models. In addition, the deviation of the integral and characteristic structure loci was analyzed., Result: The 7 cases with placed pre-bent titanium plates exhibited good recovery in occlusal relations and the contour of the reconstructed mandibles. The absolute deviations in the integral analysis were 0.89 ± 0.96 mm (mandibles) and 0.33 ± 0.36 mm (titanium plates). The absolute deviations on the diseased side were 1.78 ± 0.35 mm (condylar head), 2.43 ± 0.29 mm (gonion), 2.22 ± 0.22 mm (gnathion), and 2.66 ± 0.36 mm (mesial inferior margin of the fibula)., Conclusion: The results of this study suggest that mandibular segmental resections and the precise orientation of pre-bent titanium plates could be simultaneously assisted by CORPPP digital surgical guide plates. The use of these guide plates should be expanded., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: We invented a two-tiered structure device based on stereolithography for residual mandible repositioning in mandibular reconstruction with fibular flap, and examined its usefulness., Patients and Methods: A total of eight patients (six carcinomas and two osteomyelitis) who had undergone mandibular reconstruction with fibular flap were included. Mandibular defects according to Jewer's classification were L for five, LC for two, and H for one patient (range of bone defect size, 7.7-13.3 cm). Based on a stereolithographic mandibular model, a two-tiered structure device was made preoperatively with resin, and was applied during surgery to define the accurate position of residual mandible following segmental mandibulectomy. Postoperative aesthetic and functional outcomes, including dental status, diet, and speech were evaluated., Results: The device was applied without any problems during surgery. Follow-up period ranged from eight to twenty-two months. Good postoperative alignment of the grafts and occlusion were also achieved in all eight patients. Five patients were able to return to eating meals as they had pre-surgery, and two patients required dental rehabilitation with dentures. As for speech, four patients scored ten points, three patients scored eight points, and one patient scored four points in Hirose's scoring system, which means that seven patients was rated as excellent, and one patient was rated as poor. Aesthetic outcomes were excellent in three patients, good in three patients, and fair in two patients., Conclusion: Our device was easy to prepare, successfully maintained the precise position of the residual mandible, and facilitated bone graft cutting and insetting during reconstruction. © 2016 Wiley Periodicals, Inc. Microsurgery 37:509-515, 2017., (© 2016 Wiley Periodicals, Inc.)

Background: The reconstruction of a large mandibular defect poses a challenging issue in oral cancer ablation surgery. One popular option for mandibular continuity reconstruction after tumor resection involves the use of a reconstruction plate (R-plate), which maintains space and contour without bone harvesting. An R-plate, however, cannot provide final functional loading rehabilitation with implants or dentures., Methods: We suggest a new method of functional mandibular reconstruction using retentive posts and an upper prosthesis. The finite element method (FEM) was used to optimize the design. Surgery was needed to adapt the retentive posts. Prosthodontic procedures were required for the upper prosthesis., Results: Eight patients were treated with retentive posts and prostheses. All patients underwent wide resections of the mandible, and reconstruction with an R-plate and microvascular soft tissue transfer. We adapted the retentive posts on an R-plate and fabricated the upper prostheses with a flexible denture or a fixed resin prosthesis. Finally, the patients had functional rehabilitation, which restored proper mastication., Conclusions: The retentive posts of the R-plate and upper prosthesis allow functional dental rehabilitation without the need for a bone graft. Virtual simulation using FEM will help to design and optimize the retentive posts. Two or three regular size posts are suitable for the quadrant jaw. This first preliminary step will allow improved patient-specific retentive post designs in the near future.

Purpose: The aims of the present study were to 1) evaluate clinical outcomes between standard and three-dimensional (3D) miniplate fixation in the management of mandibular fractures and 2) determine which fixation method is the best option for the treatment of mandibular fractures., Materials and Methods: A comprehensive electronic search language without date was performed in July 2015. Inclusion criteria were studies in humans, including randomized controlled trials, controlled clinical trials, and retrospective studies, with the aim of comparing the two techniques. In addition, the incidence of complications was evaluated., Results: Seventeen publications were included: nine randomized controlled trials, three controlled clinical trials, and five retrospective studies. The meta-analyses showed statistically significant differences for the incidence of hardware failure, malocclusion, and postoperative trismus. There were no significant differences in the incidence of postoperative infection, wound dehiscence, non-union/malunion, and paresthesia. The cumulative odds ratio was 0.48, meaning that the use of 3D miniplates in the fixation of mandibular fractures decreases the risk of the event (postoperative complication) by 52%., Conclusion: The results of this meta-analysis showed that the use of 3D miniplates was superior to the two-miniplate technique in reducing the incidence of postoperative complications in the management of mandibular fractures., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Lingual positioning of mandible reconstruction plates can prevent typical complications such as plate exposure and orocutaneous fistulas. The aim of this study was to evaluate the feasibility and clinical outcomes of lingually applied patient-specific reconstruction plates., Materials and Methods: A retrospective cohort study of patients managed with reconstruction plates positioned at the lingual side of the mandible was performed. The following outcome variables were analyzed: feasibility and handling of the lingual application, fitting accuracy, and postoperative complications., Results: The study sample included 8 patients (4 women, 4 men) with a mean age of 68.8 years (range, 43 to 79 yr). The indications for plate use were defect-like zones owing to multiple fractures in the atrophic mandible (n = 2) and segmental defects attributed to squamous cell carcinoma, osteomyelitis, and bisphosphonate-related osteonecrosis (n = 6). Off-the-shelf reconstruction plates, which were intraoperatively bent (n = 2) or pre-bent to a stereolithographic model (n = 1), or fully computer-assisted designed and computer-assisted manufactured (CAD/CAM) patient-specific reconstruction plates (n = 5) were used. Lingual application of reconstruction plates was feasible in all cases and considerably facilitated by the CAD/CAM plates. The fitting accuracy was high. Within an average follow-up period of 15.3 months, no loosening of plates or screws, plate fracture, or orocutaneous fistula occurred and no dysphagia was observed with the exception of 1 case, in which plate exposure was due to extreme soft tissue thinning and tumor recurrence., Conclusions: Lingual application of CAD/CAM patient-specific reconstruction plates is technically feasible with high accuracy. It has great potential for low complication rates, especially in unfavorable soft tissue conditions., (Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: The correct positioning of the microvascular-free fibula flap (MFFF) is essential for satisfactory mandibular reconstruction. However, the effect of acrylic resin-based surgical guides on prosthetic rehabilitations has not yet been properly investigated., Purpose: The purpose of this randomized clinical trial was to evaluate whether intraoral and extraoral acrylic resin-based surgical guides improve anatomic, functional, esthetic, and quality of life (QoL) results for dental prosthetic rehabilitation with MFFF., Material and Methods: Participants subjected to mandibular reconstruction with MFFF were selected and randomly distributed into 2 groups, control (Co; using conventional surgery) and acrylic resin-based surgical guides (Sg). Functional parameters related to prosthetic rehabilitation and QoL were evaluated by interviews and an oral health impact profile (OHIP)-14 questionnaire. Functional parameters and questionnaire scores were subjected to statistical analysis: the likelihood ratio and the Fisher exact and Mann-Whitney U tests (α=.05)., Results: Of 40 participants, 18 were rehabilitated, 10 with tooth-tissue-supported partial removable dentures and 8 with implant prostheses. In Sg, the study measured an enhancement in functional parameters and revealed a significant improvement in QoL (P=.020)., Conclusions: The guides proposed directly improved mandibular reconstruction. Functional aspects may be improved by allowing good intermaxillary relationships and posterior dental rehabilitation. Functional success is directly dependent on soft tissue status and the quality of its reconstruction. Soft tissue evaluation is important before dental rehabilitation., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: The free fibula is the flap of choice for reconstructing most segmental mandibular defects resulting from head and neck resections. The use of miniplates or reconstruction bars for fixation has been described in the literature. We wanted to compare outcomes between the 2 methods of fixation in head and neck cancer patients., Patients and Methods: An IRB approved retrospective review of 25 consecutive patients undergoing free fibula flap reconstruction of the mandible for head and neck cancer over a period of 5 years was performed. Patient demographics, risk factors, number of fibula osteotomies, defect length, and clinical outcomes were noted. Fourteen patients were reconstructed with miniplates and 12 with reconstruction bars. The choice of plate fixation was determined by the individual reconstructive surgeon. Wound complications requiring surgery and hardware removal rate were recorded., Results: Average follow-up was 27 months. There was no significant difference with regard to age (P = 0.67), sex (P = 0.77), smoking (P = 0.63), neoadjuvant radiation (P = 0.47), number of osteotomies (P = 0.99), or defect length (P = 0.95) between the 2 groups. Of the 4 patients requiring hardware removal for infection or persistent symptoms, all were in the miniplate group (P = 0.05). Other clinical outcomes, such as hematoma, wound dehiscence, infection, fistula formation, and osteoradionecrosis were comparable between the 2 groups without significant differences. The overall complication rate was similar as well (P = 0.25)., Discussion: Different from other reports in the literature, we show that miniplate use resulted in more hardware removal for infection or persistent symptoms, and this was statistically significant while controlling for patient demographics, risk factors, number of osteotomies, and defect length. Much like other reports in the literature, however, there is no statistically significant difference in overall complication rates, and all other specific complications, when using miniplates versus reconstruction bars. The decision to use miniplates versus reconstruction bars remains a clinical one. In our experience, for 0 to 1 osteotomy, a reconstruction bar suffices. For multiple osteotomies, however, miniplates allow for more customization.

In mandibular reconstructive surgery, straight surgical plates are predominantly used for osteotomy. In this process, a straight plate is bent to fit to the shape of the patient's defect. This potentially compromises the stability of the plate because of changes in mechanical properties resulting from plastic deformation; however, the effect of plastic deformation on stability has yet been investigated. In this study, we assess the stability of three types of commonly used bent plates for two types of mandible defect cases, using three-dimensional finite element analysis (FEA). We compare the stability of plastically deformed plates with customized plates having the same shape, but not the residual stresses from plastic deformation. The results indicate that while the bearing strength of the bent plate is sufficient, there is much higher stress in the plate due to the residual stresses from the bending process that may significantly decrease the safety of the reconstruction surgery.