Patient-Specific 3D-Printed Miniplates for Free Flap Fixation at the Mandible: A Feasibility Study

Abstract

BackgroundThis study was conducted to evaluate the feasibility, clinical outcomes, and accuracy of patient-specific 3D-printed miniplates for mandible reconstruction with fibula free flaps.MethodsA feasibility study was conducted with 8 patients. Following virtual planning, patient-specific 1.0 mm titanium non-locking miniplates were produced via laser selective melting. 3D-printed cutting and drilling guides were used for segmental mandible resection and flap harvesting. Flap fixation was performed with two 4-hole miniplates and 2.0 mm non-locking screws (screw length 7 mm) for each intersegmental gap. Clinical follow-up was at least 6 months. Preoperative and postoperative CT/cone beam CT data were used for 3D accuracy analysis and evaluation of bone healing. Plate-related complications were monitored clinically.ResultsPatient-specific miniplate fixation of all flaps was successfully conducted (4 mono-segmental, 4 dual-segmental) with high accuracy (3.64 ± 1.18 mm) between the virtual plan and postoperative result. No technical complications were encountered intraoperatively. Osseous union occurred in all intersegmental gaps (1 partial, 18 complete) after 10 ± 2 months. No material fracture, dislocation, or plate exposure was observed.ConclusionsBased on this pilot observational study including a limited number of patients, free flap fixation for mandibular reconstruction with patient-specific 3D-printed miniplates is feasible and associated with high accuracy, bone healing, and remote soft tissue complications.

Towards mechanobiologically optimized mandible reconstruction: CAD/CAM miniplates vs. reconstruction plates for fibula free flap fixation: A finite element study

“…Due to their application advantages in comparison to conventional fixation systems, CAD/CAM reconstruction plates are increasingly used in mandibular reconstruction ( Tarsitano et al, 2014 ; Bouchet et al, 2018 ; Rendenbach et al, 2018 ; Knitschke et al, 2022 ). Moreover, CAD/CAM miniplates have been recently proposed as an easily applicable fixation system with potential advantages over reconstruction plates in the postoperative management ( Kreutzer et al, 2022a ; Kreutzer et al, 2022b ). While CAD/CAM reconstruction plates have been found to be more rigid in comparison to conventional fixation systems, biomechanical conditions induced by CAD/CAM miniplates remain unknown ( Rendenbach et al, 2017 ; Steffen et al, 2020 ; Kreutzer et al, 2022a ).…”

“…Moreover, CAD/CAM miniplates have been recently proposed as an easily applicable fixation system with potential advantages over reconstruction plates in the postoperative management ( Kreutzer et al, 2022a ; Kreutzer et al, 2022b ). While CAD/CAM reconstruction plates have been found to be more rigid in comparison to conventional fixation systems, biomechanical conditions induced by CAD/CAM miniplates remain unknown ( Rendenbach et al, 2017 ; Steffen et al, 2020 ; Kreutzer et al, 2022a ).…”

“…These findings clinically support our assumption that reconstruction plates might be biomechanically beneficial for bone healing in the distal healing site whereas miniplates could improve the bone healing outcome in the mesial healing site. Furthermore, recent studies stated CAD/CAM miniplates as possible solutions to intraoperative and dental rehabilitation problems, especially in the mesial areas ( Kreutzer et al, 2022a ; Kreutzer et al, 2022b ). Therefore, in the mesial healing site, the use of miniplates could be beneficial from a surgical and biomechanical point of view.…”

“…However, CAD/CAM reconstruction plates provide an even higher stiffness than conventional plates, therefore could decrease the intersegmental strains and negatively influence bone healing ( Rendenbach et al, 2017 ; Rendenbach et al, 2019 ). To prevent this effect and to improve soft tissue management and dental rehabilitation, while using the advantages of CAD/CAM systems, the use of CAD/CAM miniplates has recently been proposed ( Kreutzer et al, 2022a ; Kreutzer et al, 2022b ). However, to our knowledge, it remains unknown whether the biomechanical conditions provided by CAD/CAM miniplates are more favorable compared to the ones provided by CAD/CAM reconstruction plates.…”

Advanced Hydrogel systems for mandibular reconstruction

“…Plate loss occurred in large lateral defects, and pre- or postoperative radiotherapy [ 41 ] 2000 Titanium mesh wrapping cancellous bone grafts Exposure of the titanium mesh is 7/16 in maxillary and 16/29 in mandible. The success of the bone grafting procedure was 97.72% [ 42 ] 2010s Magnesium (Mg)-based Materials [ 43 ] Mg screw was able to distribute the stress to the condyle and ramus region compared to polylactic acid polymer group [ 44 ] 2016 Finite element simulation and 3D printing technology prefabricated titanium meshes [ 45 ] 21 patients, insufficient bone formation (5 cases), postoperative infection (2 patients), Ti-mesh tray fracture in 2 patients 2022 Patient-specific 3D-printed miniplates for free flap fixation High accuracy of reconstruction (3.64 ± 1.18 mm), Osseous union occurred in all intersegmental gaps [ 46 ] Distraction osteogenesis 1992 First applied distraction osteogenesis to the mandibular deformities' reconstruction Mandibular bone lengthening ranged from 18 to 24 mm [ 47 ] 1996 A report of 5 cases of distraction osteogenesis in maxillofacial surgery 5 patients, premature consolidation (2 cases), significant relapse (1 case) [ 48 ] 1997 Case report on a patient received trifocal distraction osteogenesis in oral floor cancer underwent surgery Infection developed; Free bone transplants were needed for complete continuity [ 49 ] 2000 Combination of mandibular distraction osteogenesis with electrical stimulation (10 μA) Significant increase in bone mineral density [ 50 ] 2011 Electrical stimulation on mandibular distraction osteogenesis conducted in clinical trials 10 patients, 16 distraction sites, and direct current electrical stimulation promoted bone healing [ 51 ] …”