Prosthetically Guided Maxillofacial Surgery: Evaluation of the Accuracy of a Surgical Guide and Custom-Made Bone Plate in Oncology Patients after Mandibular Reconstruction
ABSTRACT Background: The aim of the present study was to evaluate the accuracy of prosthetically guided maxillofacial surgery in reconstructing the mandible with a free vascularized flap using custom-made bone plates and a surgical guide to cut the mandible and fibula. Methods: The surgical protocol was applied in a study group of seven consecutive mandibular-reconstructed patients who were compared with a control group treated using the standard preplating technique on stereolithographic models (indirect computer-aided design/computer-aided manufacturing method). The precision of both surgical techniques (prosthetically guided maxillofacial surgery and indirect computer-aided design/computer-aided manufacturing procedure) was evaluated by comparing preoperative and postoperative computed tomographic data and assessment of specific landmarks. Results: With regard to midline deviation, no significant difference was documented between the test and control groups. With regard to mandibular angle shift, only one left angle shift on the lateral plane showed a statistically significant difference between the groups. With regard to angular deviation of the body axis, the data showed a significant difference in the arch deviation. All patients in the control group registered greater than 8 degrees of deviation, determining a facial contracture of the external profile at the lower margin of the mandible. With regard to condylar position, the postoperative condylar position was better in the test group than in the control group, although no significant difference was detected. Conclusions: The new protocol for mandibular reconstruction using computer-aided design/computer-aided manufacturing prosthetically guided maxillofacial surgery to construct custom-made guides and plates may represent a viable method of reproducing the patient's anatomical contour, giving the surgeon better procedural control and reducing procedure time.
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- "In general, computer-aided osseous reconstruction in maxillofacial surgery involves three steps: (1) virtual planning of the surgical treatment, (2) CAD/CAM and rapid prototyping procedures of the customized surgical devices, and (3) the surgery itself (Mazzoni et al., 2013). Since for every new technique a cost-benefit analysis is recommended to justify possible additional costs e even though the clinical benefits are undisputable e an evaluation is warranted to determine whether additional costs arise, especially within steps 1 and 2 of the CAD/CAM procedure. "
ABSTRACT: This study aims to evaluate the additional costs incurred by using a computer-aided design/computer-aided manufacturing (CAD/CAM) technique for reconstructing maxillofacial defects by analyzing typical cases. The medical charts of 11 consecutive patients who were subjected to the CAD/CAM technique were considered, and invoices from the companies providing the CAD/CAM devices were reviewed for every case. The number of devices used was significantly correlated with cost (r = 0.880; p < 0.001). Significant differences in mean costs were found between cases in which prebent reconstruction plates were used (€3,346.00 ± €29.00) and cases in which they were not (€2,534.22 ± €264.48; p < 0.001). Significant differences were also obtained between the costs of two, three and four devices, even when ignoring the cost of reconstruction plates. Additional fees provided by statutory health insurance covered a mean of 171.5% ± 25.6% of the cost of the CAD/CAM devices. Since the additional fees provide financial compensation, we believe that the CAD/CAM technique is suited for wide application and not restricted to complex cases. Where additional fees/funds are not available, the CAD/CAM technique might be unprofitable, so the decision whether or not to use it remains a case-to-case decision with respect to cost versus benefit.Journal of Cranio-Maxillofacial Surgery 10/2014; 42(8). DOI:10.1016/j.jcms.2014.09.014 · 2.60 Impact Factor
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ABSTRACT: At present, mandibular reconstruction with a fibular free flap is the gold standard for functional and esthetic rehabilitation after oncological surgery. The purpose of this study was to describe the computer-assisted mandibular reconstruction procedure adopting the customized solution Synthes ProPlan CMF. The study reports five consecutive patients with benign or malignant disease requiring mandibular reconstruction using a microvascular fibular free flap, pre-operative virtual planning, construction of cutting guides and customized laser pre-bent titanium plates. The surgical technique is discussed in a step-by-step fashion. The average post-operative hospital stay was 18 ± 3 days. Ischemia time was recorded in all five cases, with an average of 75 ± 8 min. No problems were encountered in any surgical step and there were no major complications. Excellent precision of cutting guides and a good fit of pre-bent plates were found on both the mandible and fibula. There was excellent precision in bone to bone contact and position between mandible and fibula graft. Measurement data from the pre-operative and post-operative CT scans were compared. The average difference (Δ) between programed segment lengths and CT control segment lengths was 0.098 ± 0.077 cm. Microsurgical mandibular reconstruction using a virtual surgical planning yields significantly shorter ischemia times and allows more precise osteotomies. The technology is becoming increasingly recognized for its ability to optimize surgical outcomes and minimize operating time. Considering that the extent of resection can be wider than predicted, this results in safer modeling of the fibula only after frozen sections have demonstrated the radicality of resection.Archives of Oto-Rhino-Laryngology 05/2014; 272(6). DOI:10.1007/s00405-014-3078-3 · 1.61 Impact Factor
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ABSTRACT: New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies form the point of view of standard-of-care implants for the mandible were looked. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury, or correction of deformity due to pathology or congenital defect. The aim of this two part paper is to review the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Also potential directions for future research was studied. To mitigate these issues the use of low-stiffness metallic alloys has been highlighted. To this end, development, processing and biocompatibility of superelastic NiTi as well as resorbable Magnesium-based alloys were discussed. Additionally, engineered porosity was reviewed as it can be an effective way of matching the stiffness with the tissue surrounding an implant. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific, and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys was also reviewed.Acta Biomaterialia 06/2014; 10(10):4058–4070. DOI:10.1016/j.actbio.2014.06.025 · 5.68 Impact Factor