Patient-specific reconstruction plates are the missing link in computer-assisted mandibular reconstruction: A showcase for technical description

2015 ◽  
Vol 43 (5) ◽  
pp. 624-629 ◽  
Author(s):  
Carl-Peter Cornelius ◽  
Wenko Smolka ◽  
Goetz A. Giessler ◽  
Frank Wilde ◽  
Florian A. Probst
2021 ◽  
Vol 11 ◽  
Author(s):  
Henriette L. Möllmann ◽  
Laura Apeltrath ◽  
Nadia Karnatz ◽  
Max Wilkat ◽  
Erik Riedel ◽  
...  

ObjectivesThis retrospective study compared two mandibular reconstruction procedures—conventional reconstruction plates (CR) and patient-specific implants (PSI)—and evaluated their accuracy of reconstruction and clinical outcome.MethodsOverall, 94 patients had undergone mandibular reconstruction with CR (n = 48) and PSI (n = 46). Six detectable and replicable anatomical reference points, identified via computer tomography, were used for defining the mandibular dimensions. The accuracy of reconstruction was assessed using pre- and postoperative differences.ResultsIn the CR group, the largest difference was at the lateral point of the condyle mandibulae (D2) -1.56 mm (SD = 3.8). In the PSI group, the largest difference between preoperative and postoperative measurement was shown at the processus coronoid (D5) with +1.86 mm (SD = 6.0). Significant differences within the groups in pre- and postoperative measurements were identified at the gonion (D6) [t(56) = -2.217; p = .031 <.05]. In the CR group, the difference was 1.5 (SD = 3.9) and in the PSI group -1.04 (SD = 4.9). CR did not demonstrate a higher risk of plate fractures and post-operative complications compared to PSI.ConclusionFor reconstructing mandibular defects, CR and PSI are eligible. In each case, the advantages and disadvantages of these approaches must be assessed. The functional and esthetic outcome of mandibular reconstruction significantly improves with the experience of the surgeon in conducting microvascular grafts and familiarity with computer-assisted surgery. Interoperator variability can be reduced, and training of younger surgeons involved in planning can be reaching better outcomes in the future.


2014 ◽  
Vol 7 (2) ◽  
pp. 158-166 ◽  
Author(s):  
Frank Wilde ◽  
Carl-Peter Cornelius ◽  
Alexander Schramm

We investigated the workflow of computer-assisted mandibular reconstruction that was performed with a patient-specific mandibular reconstruction plate fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) techniques and a fibula flap. We assessed the feasibility of this technique from virtual planning to the completion of surgery. Computed tomography (CT) scans of a cadaveric skull and fibula were obtained for the virtual simulation of mandibular resection and reconstruction using ProPlan CMF software (Materialise®/DePuy Synthes®). The virtual model of the reconstructed mandible provided the basis for the computer-aided design of a patient-specific reconstruction plate that was milled from titanium using a five-axis milling machine and CAM techniques. CAD/CAM techniques were used for producing resection guides for mandibular resection and cutting guides for harvesting a fibula flap. Mandibular reconstruction was simulated in a cadaveric wet laboratory. No problems were encountered during the procedure. The plate was fixed accurately to the residual bone without difficulty. The fibula segments were attached to the plate rapidly and reliably. The fusion of preoperative and postoperative CT datasets demonstrated high reconstruction precision. Computer-assisted mandibular reconstruction with CAD/CAM-fabricated patient-specific reconstruction plates appears to be a promising approach for mandibular reconstruction. Clinical trials are required to determine whether these promising results can be translated into successful practice and what further developments are needed.


2017 ◽  
Vol 1 (1) ◽  
pp. s-0037-1606835 ◽  
Author(s):  
Ryo Sasaki ◽  
Michael Rasse

ProPlan CMF (Depuy Synthes, Solothurn, Switzerland, and Materialise, Leuven, Belgium) is a computer-aided surgical virtual planning service using an online meeting with professional medical engineers and transfers patient-specific surgical guide to the virtual plan. Moreover, prebent reconstruction plates or patient-specific computer-aided manufacturing-fabricated reconstruction can also be used. This service started in 2011. Currently, it is widely used in Europe. Current status of mandibular reconstruction with ProPlan CMF vertical planning service with the surgical guide was reviewed. The accuracy was excellent in terms of contact of the osteotomized parts and the contact to the remaining skeleton. The authors found that currently, a small number of reports regarding the mandibular reconstruction with virtual planning service and surgical guides are available. These reports also have a small number of cases and short-term follow-up results. In this situation, this review revealed that (1) mainly the resection guides, cutting guides, and patient-specific mandible reconstruction plates were adequately well fitted to the surgical site intraoperatively, (2) the ischemic time might be more reduced than that of the conventional surgery (3) the accuracy of computer-assisted surgery in the mandibular reconstruction was clinically acceptable, and (4) condyle positions after the computer-assisted surgery was mainly normal. The higher additional cost than that of the conventional technique is presently an issue. Large-scale clinical studies and long-term follow-up studies are demanded.


2021 ◽  
Vol 11 ◽  
Author(s):  
Gustaaf J. C. van Baar ◽  
Lars Leeuwrik ◽  
Johannes N. Lodders ◽  
Niels P. T. J. Liberton ◽  
K. Hakki Karagozoglu ◽  
...  

BackgroundOsteoradionecrosis (ORN) of the mandible is a severe complication of radiation therapy in head and neck cancer patients. Treatment of advanced stage mandibular osteoradionecrosis may consist of segmental resection and osseous reconstruction, often sacrificing the inferior alveolar nerve (IAN). New computer-assisted surgery (CAS) techniques can be used for guided IAN preservation and 3D radiotherapy isodose curve visualization for patient specific mandibular resection margins. This study introduces a novel treatment concept combining these CAS techniques for treatment of advanced stage ORN.MethodsOur advanced stage ORN treatment concept includes consecutively: 1) determination of the mandibular resection margins using a 3D 50 Gy isodose curve visualization, 2) segmental mandibular resection with preservation of the IAN with a two-step cutting guide, and 3) 3D planned mandibular reconstruction using a hand-bent patient specific reconstruction plate. Postoperative accuracy of the mandibular reconstruction was evaluated using a guideline. Objective and subjective IAN sensory function was tested for a period of 12 months postoperatively.ResultsFive patients with advanced stage ORN were treated with our ORN treatment concept using the fibula free flap. A total of seven IANs were salvaged in two men and three women. No complications occurred and all reconstructions healed properly. Neither non-union nor recurrence of ORN was observed. Sensory function of all IANs recovered after resection up to 100 percent, including the patients with a pathologic fracture due to ORN. The accuracy evaluation showed angle deviations limited to 3.78 degrees. Two deviations of 6.42° and 7.47° were found. After an average of 11,6 months all patients received dental implants to complete oral rehabilitation.ConclusionsOur novel ORN treatment concept shows promising results for implementation of 3D radiotherapy isodose curve visualization and IAN preservation. Sensory function of all IANs recovered after segmental mandibular resection.


2015 ◽  
Vol 04 (03) ◽  
pp. 85-92
Author(s):  
Seiji Kondo ◽  
Hideyuki Katsuta ◽  
Ayako Akizuki ◽  
Yuji Kurihara ◽  
Takaaki Kamatani ◽  
...  

2021 ◽  
Author(s):  
Timothy J Yee ◽  
Michael J Strong ◽  
Matthew S Willsey ◽  
Mark E Oppenlander

Abstract Nonunion of a type II odontoid fracture after the placement of an anterior odontoid screw can occur despite careful patient selection. Countervailing factors to successful fusion include the vascular watershed zone between the odontoid process and body of C2 as well as the relatively low surface area available for fusion. Patient-specific factors include osteoporosis, advanced age, and poor fracture fragment apposition. Cervical 1-2 posterior instrumented fusion is indicated for symptomatic nonunion. The technique leverages the larger posterolateral surface area for fusion and does not rely on bony growth in a watershed zone. Although loss of up to half of cervical rotation is expected after C1-2 arthrodesis, this may be better tolerated in the elderly, who may have lower physical demands than younger patients. In this video, we discuss the case of a 75-yr-old woman presenting with intractable mechanical cervicalgia 7 mo after sustaining a type II odontoid fracture and undergoing anterior odontoid screw placement at an outside institution. Cervical radiography and computed tomography exhibited haloing around the screw and nonunion across the fracture. We demonstrate C1-2 posterior instrumented fusion with Goel-Harms technique (C1 lateral mass and C2 pedicle screws), utilizing computer-assisted navigation, and modified Sonntag technique with rib strut autograft.  Posterior C1-2-instrumented fusion with rib strut autograft is an essential technique in the spine surgeon's armamentarium for the management of C1-2 instability, which can be a sequela of type II dens fracture. Detailed video demonstration has not been published to date.  Appropriate patient consent was obtained.


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