Experience with the use of prebent plates for the reconstruction of mandibular defects.
ABSTRACT: Bending of large titanium plates for mandibular reconstruction is a tedious task. This is usually done by trial and error over an intraoperatively bent template. By means of rapid prototype technology, accurate three-dimensional models can be obtained. Using these models, it is possible to design, obtain, and adapt custom hardware for individual surgical cases. Reductions of operating room time when using this technology have been reported from 17% to 60%, with an average of 20%. This translates to reduction of cost and risks, improving the overall surgical outcome. The purpose of this article is to establish the indications and contraindication for the use three-dimensional models and prebent plates. We present our experience with five cases in which prebent reconstruction plates were used for mandibular reconstruction. No significant complications occurred, and satisfactory results were achieved in all cases. We found that the models required to obtain the hardware are extremely accurate, have multiple reported applications, and represent a valuable surgical tool in the planning and execution of reconstructive surgery.
Project description:The application of additive manufacturing (AM) technology has been widely used in various medical fields, including craniomaxillofacial surgery. The aim of the present study was to examine the surgical efficiency and post-operative outcomes of patient-specific titanium mandibular reconstruction using AM. Major steps in directly designing and manufacturing 3D customized titanium implants are discussed. Furthermore, pre-operative preparations, surgical procedures and post-operative treatment outcomes were compared among patients who received mandibular reconstruction using a customized 3D titanium implant, titanium reconstruction plates or vascularized autologous fibular grafting. Use of a customized titanium implant significantly improved surgical efficiency and precision. When compared with mandibular reconstruction using the two conventional approaches, patients who received the customized implant were significantly more satisfied with their facial appearance, and exhibited minimal post-operative complications in the 12-month follow-up period. Patients who underwent mandibular reconstruction using a customized titanium implant displayed improved mandibular contour symmetry, restored occlusal function, normal range of mouth opening and no temporomandibular joint related pain; all complications frequently experienced by patients who undergo conventional approaches of mandibular reconstruction.
Project description:The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques across a variety of otolaryngological sub-specialties suggests an emerging role for rapid prototyping technology in surgical education, procedure simulation, and clinical practice.
Project description:<h4>Background</h4>Surgeons are pursuing accurate head and neck reconstruction to enhance aesthetic and functional outcomes after oncologic resection. This study aimed to investigate whether accuracy of head and neck reconstruction is improved with the use of three-dimensionally (3D)-printed patient-specific surgical plates compared with conventional plates.<h4>Methods</h4>In this comparative study, patients were prospectively recruited into the study group (3DJP16) with 3D-printed patient-specific surgical plates. The patients in control group with conventional surgical plates were from a historic cohort in the same unit. The primary end point of the study was the accuracy of head and neck reconstruction. The secondary end points were accuracy of osteotomy, intraoperative blood loss, total operative time, and length of hospital stay.<h4>Results</h4>The study recruited of 33 patients, including 17 in the study group and 16 in the control group. The patients' baseline characteristics were similar between the two groups. The absolute distance deviation of the maxilla or mandible was 1.5?±?0.5 mm in the study group and 2.1?±?0.7 mm in the control group [mean difference, - 0.7 mm; 95% confidence interval (CI) - 1.1 to - 0.3; p?=?0.003], showing superior accuracy of reconstruction for the patients with 3D-printed patient-specific surgical plates. Improved accuracy of reconstruction also was detected in terms of bilateral mandibular angles and bone grafts. Concerning the secondary end points, the accuracy of the osteotomy was similar in the two groups. No difference was found regarding intraoperative blood loss, total operative time, or length of hospital stay.<h4>Conclusions</h4>This is the first study to prove that compared with conventional plates, 3D-printed patient-specific surgical plates improve the accuracy of oncologic head and neck reconstruction.
Project description:The reconstruction of acquired mandibular defects due to ablative tumor surgery or traumatic injuries is still challenging. The gold standard in such treatment is application of reconstructive titanium plates, which should be contoured and adapted to the defect as much as possible because of their influence on postoperative functional and esthetic results. Traditionally, plate bending is achieved by trial and error intraoperatively. Use of stereolitography (STL) models potentially could reduce the risk of incorrect contouring as well as operating time. On the other hand, fabrication of STL is time-consuming and costly. However, we found only one experimental study dedicating to virtual plate bending in the literature. The aim of this article was to demonstrate clinical application of a method of virtual bending of reconstructive plate for mandibular defect bridging. No significant complications occurred, and satisfactory functional and esthetic results were achieved in all cases. We found this technique precise and applicable in cases of reconstruction of mandibular defects.
Project description:INTRODUCTION:When the application of a free vascularised flap is not possible, a segmental mandibular defect is often reconstructed using a conventional reconstruction plate. Mechanical failure of such reconstructions is mostly caused by plate fracture and screw pull-out. This study aims to develop a reliable, mechanically superior, yet slender patient-specific reconstruction plate that reduces failure due to these causes. PATIENTS AND METHODS:Eight patients were included in the study. Indications were as follows: fractured reconstruction plate (2), loosened screws (1) and primary reconstruction of a mandibular continuity defect (5). Failed conventional reconstructions were studied using finite element analysis (FEA). A 3D virtual surgical plan (3D-VSP) with a novel patient-specific (PS) titanium plate was developed for each patient. Postoperative CBCT scanning was performed to validate reconstruction accuracy. RESULTS:All PS plates were placed accurately according to the 3D-VSP. Mean 3D screw entry point deviation was 1.54 mm (SD: 0.85, R: 0.10-3.19), and mean screw angular deviation was 5.76° (SD: 3.27, R: 1.26-16.62). FEA indicated decreased stress and screw pull-out inducing forces. No mechanical failures appeared (mean follow-up: 16 months, R: 7-29). CONCLUSION:Reconstructing mandibular continuity defects with bookshelf-reconstruction plates with FEA underpinning the design seems to reduce the risk of screw pull-out and plate fractures.
Project description:BACKGROUND:Reconstruction of mandibular continuity and function after tumor resection is challenging, particularly in cases including the mandibular condyle. Various approaches for reconstruction after disarticulation resection have been reported. However, the scapula flap has received little attention as a treatment option in these cases. PATIENTS AND METHODS:Three cases of computer aided design and computer aided manufacturing (CAD/CAM) assisted reconstruction after disarticulation resection using a vascularized scapula and latissimus dorsi flap are reported. All cases required reconstruction of the mandibular ramus and condyle in combination with the reconstruction of large and complex soft tissue defects. RESULTS:The surgical procedure was deemed successful in all cases. The scapula flap could be placed as preoperatively planned and patients regained their preoperative occlusion pattern and satisfying mouth opening-ranges. The large soft tissue defects could reliably be reconstructed using a latissimus dorsi flap. CONCLUSIONS:The scapula and latissimus dorsi flap can be considered a suitable option for the reconstruction of mandibular disarticulation resection defects in combination with large soft tissue defects.
Project description:BACKGROUND: Fractures of the distal third of the leg are increasingly common and are often handled by open reduction and internal fixation. Exposure and infection of internal hardware could occur, especially after high energy traumas, requiring hardware removal and delayed soft tissue reconstruction. Nevertheless immediate soft tissue reconstruction without internal hardware removal is still possible in selected patients. In this study the effectiveness and the complications of immediate soft tissue reconstruction without internal hardware removal is analyzed. METHODS: 13 patients, affected by internal hardware exposure in the distal leg, treated with immediate soft tissue reconstruction with pedicled flaps and hardware retention, are retrospectively analyzed, with special regard to flap survival and wound infection. RESULTS: Wound infection was observed in 10 cases before surgery and in 5 cases surgical debridement was necessary before reconstruction which was performed in a separate operative session. After reconstruction, wound dehiscence and infection occurred in 5 cases, and in 3 cases removal of internal hardware was necessary in order to achieve the complete healing of dehiscence. In one case the previous flap failed but prompt reconstruction with a sural fasciocutaneous flap was performed without hardware removal and without complications. Pre-operative infection and late reconstructive surgery are predictive for higher rates of post-operative complications (respectively p 0.018 and p 0.028). CONCLUSION: Our approach achieved full recovery in 53.8% of the treated cases after one-step surgery, therefore reducing hospitalization and allowing early mobilization. Controlled trials are needed to confirm the effectiveness of this strategy, although the present case series shows encouraging results.
Project description:The aim of the study is to analyze the effectiveness of rigid internal fixation (RIF) for treating edentulous mandibular fractures. Because of the low incidence of fractures in edentulous mandible, there is no consensus of the optimal treatment for it. This study included all edentulous patients with mandibular fracture diagnosis, who were treated with internal fixation at the Hospital Italiano de Buenos Aires from November 1991 to July 2011. Data such as age, gender, etiology and location of fracture, surgical approach, type of osteosynthesis used, and postoperative complications were analyzed. A total of 18 patients, 76.2 years mean age, 12 females (66.6%), presented a total of 35 mandibular fractures. The mandibular body was the most common localization of the fractures. Twenty-five fractures received surgical treatment with RIF, mainly approached extraorally. Reconstruction plates were the most common type of fixation used. Fracture reduction was considered satisfactory in 96.5%, with 22.2% of complications and 11.1% of reoperations needed. Open reduction and RIF demonstrated to be a reliable method for treating edentulous mandibular fractures. Nevertheless, there is lack of high-level recommendation publication to support this.
Project description:Management of distal clavicle fractures remains controversial. Various treatment options have been described including open reduction and internal fixation with hook plate fixation, tension band wiring, screw fixation, and distal locking plates. Many of these techniques are associated with a high perioperative complication rate. We describe a surgical technique that allows indirect fixation of distal clavicle fractures and reconstruction of the CC ligaments without the use of prominent hardware.
Project description:Mandibular reconstruction is performed after segmental mandibulectomy, and precise repositioning of the condylar head in the temporomandibular fossa is essential for maintaining preoperative occlusion.In cases without involvement of soft tissue around the mandibular bone, the autopolymer resin in a soft state is pressed against the lower border of the mandible and buccal and lingual sides of the 3D model on the excised side. After hardening, it is shaved with a carbide bar to make the proximal and distal parts parallel to the resected surface in order to determine the direction of mandibular resection. On the other hand, in cases that require resection of soft tissue around the mandible such as cases of a malignant tumor, right and left mandibular rami of the 3D model are connected with the autopolymer resin to keep the preoperative position between proximal and distal segments before surgical simulation. The device is made to fit the lower border of the anterior mandible and the posterior border of the mandibular ramus. The device has a U-shaped handle so that adaptation of the device will not interfere with the soft tissue to be removed and has holes to be fixed on the mandible with screws.We successfully performed the planned accurate segmental mandibulectomy and the precise repositioning of the condylar head by the device.The present technique and device that we developed proved to be simple and useful for restoring the preoperative condylar head positioning in the temporomandibular fossa and the precise resection of the mandible.