Mandibular Reconstruction Plate Research Articles

On effect of residual stress on fracture behavior of mandibular reconstruction plates

Titanium reconstruction plates are often used to bridge mandibulectomy defects in load bearing scenarios when bone grafts are not well integrated to the host bone. The residual stress within a standard reconstruction plate is generated when being bent and installed to adapt to a patient-specific anatomical contour and it may have a detrimental effect on the structural stability and reliability of the reconstruction system. This study aimed to evaluate the impact of residual stress on the mechanical strength of the reconstructed mandibular system by utilizing both conventional finite element method (FEM) and eXtended Finite Element Method (XFEM). The mechanical stresses introduced by plate pre-bending and screw tightening were first modeled computationally and the residual stress data induced by the surgical procedure was incorporated to the deformed reconstruction plate for the subsequent biomechanical evaluation. Static and cyclic loading conditions were then imposed on the mandibular plate models to further investigate two common failure types, namely overloading fracture and fatigue fracture. It is revealed that the residual stress could considerably increase the susceptibility of plate fracture. The simulation results demonstrate that the pre-stresses induced by screw tightening are more substantial than that from plate bending during the surgical procedure. The finding is of important clinical implications for surgeons who are commonly involved in selecting and preparing different forms of fixation plates for mandibular reconstruction. This study helps elucidate the key factors contributing on the failure of reconstruction plates and guide the development of more robust and durable mandibular reconstruction systems.

Evaluation of aesthetic outcomes of mandibular reconstruction using artificial intelligence.

Although vascularized bone graft (VBG) transfer is the current standard for mandibular reconstruction, reconstruction with a mandibular reconstruction plate (MRP) and with a soft-tissue flap (STF) alone remain crucial options for patients with poor general conditions. However, objective aesthetic outcome evaluations for these methods are limited. In a retrospective analysis of 65 patients (VBG, 33; MRP, 19; and STF, 13), mandibular asymmetry value was calculated for each patient's photograph using facial recognition AI, with a higher value indicating worse asymmetry. The MRP group had a value comparable to the VBG group regardless of mandibular defect types. The STF group had a significantly higher value than the VBG group. Regarding cosmesis, STF was inferior to VBG, whereas MRP was comparable to VBG, even for anterior defects for which rigid reconstruction is mandatory. However, MRP's risks of plate-related complications limit its use to cases where VBG is contraindicated or with poor prognosis.

Management of Exposed plate of mandibular fracture: A Case Report

Mandibular reconstruction is a trauma management to achieve good occlusal. Mandibular reconstruction plates are one of the post-ORIF reconstruction procedures that are often used at Hasan Sadikin Hospital. This article aims to determine how the management of plate exposure in mandibular fracture cases must be appropriate and according to indications for the administration. Cases of oblique area fractures that extend to the body of the mandible should be reduced and repositioned through an extra oral opening. Apart from that, modifications are needed in reconstructing cases where the mandibular bone is left thin by installing a mini plate at the champs line and mandibular margin. By modifying the attachment of the miniplate, it is hoped that the mandible will be more stable and function normally. It is hoped that the risk of plate exposure in patients can be minimized through appropriate management.

P057 A novel method to protect against plate extrusion in mandibular reconstruction by using a wrapped mandibular reconstruction plate with a customised silicone guard

P057 A novel method to protect against plate extrusion in mandibular reconstruction by using a wrapped mandibular reconstruction plate with a customised silicone guard

Biomechanical feasibility of non-locking system in patient-specific mandibular reconstruction using fibular free flaps

Mandibular reconstruction with free fibular flaps is frequently used to restore segmental defects. The osteosythesis, including locking and non-locking plate/screw systems, is essential to the mandibular reconstruction. Compared with the non-locking system that requires good adaption between plate and bone, the locking system appears to present a better performance by locking the plate to fixation screws. However, it also brings about limitations on screw options, a higher risk of screw failure, and difficulties in screw placement. Furthermore, its superiority is undermined by the advancing of patient-specific implant design and additive manufacturing. A customized plate can be designed and fabricated to accurately match the mandibular contour for patient-specific mandibular reconstruction. Consequently, the non-locking system seems more practicable with such personalized plates, and its biomechanical feasibility ought to be estimated. Finite element analyses of mandibular reconstruction assemblies were conducted for four most common segmental mandibular reconstructions regarding locking and non-locking systems under incisal biting and right molars clenching, during which the influencing factor of muscles’ capacity was introduced to simulate the practical loadings after mandibular resection and reconstruction surgeries. Much higher, somewhat lower, and similar maximum von Mises stresses are separately manifested by the patient-specific mandibular reconstruction plate (PSMRP), fixation screws, and reconstructed mandible with the non-locking system than those with the locking system. Equivalent maximum displacements are identified between PSMRPs, fixation screws, and reconstructed mandibles with the non-locking and locking system in all four reconstruction types during two masticatory tasks. Parallel maximum and minimum principal strain distributions are shared by the reconstructed mandibles with the non-locking and locking system in four mandibular reconstructions during both occlusions. Conclusively, it is feasible to use the non-locking system in case of patient-specific mandibular reconstruction with fibular free flaps based on the adequate safety, comparable stability, and analogous mechanobiology it presents compared with the locking system in a more manufacturable and economical way.

Finite element analysis of biplanar customized reconstruction plates for lateral and central segmental defects of mandible

The purpose of this study is to compare biplanar custom mandibular reconstruction plates with locking reconstruction plates in bridging central and lateral mandibular segmental defects by using the finite element method. Central and two different types of lateral segmental defects were created on mandibular model that was generated from computed tomography of a male patient. Segmental defects were fixed with conventional locking reconstruction plates and two different custom designed plates with caudobuccal and dorsobuccal cover. Stress formation on hardware and screws, strain on bone under masticatory simulation were evaluated with a finite element model. The stress values on plate and screws were higher in conventional reconstruction plate than custom plates. Simulations of central segmental defect revealed maximum von Mises stresses of 643.62 MPa and 101.83 MPa in conventional reconstruction plate and biplanar plate, respectively. Biplanar plates revealed slightly higher von Mises stresses than extended surfaced biplanar plates. The screws close to resection area were exposed to higher stress than farther screws for whole groups. In conventional reconstruction plate, the maximum von Mises stress values of fixation screws were 268.66 MPa and 95 MPa for central segmental defect and lateral segmental defect, respectively. The study reveals that the biplanar custom reconstruction plates had a favourable effect on stress distribution and can enhance function and aesthetics as supporting mandible and flaps from two different planes.

Patient-specific miniplates versus patient-specific reconstruction plate: A biomechanical comparison with 3D-printed plates in mandibular reconstruction

BackgroundPatient-specific 3D-printed miniplates for free flap fixation in mandibular reconstruction were recently associated with enhanced osseous union. Higher mechanical strains resulting from these plates are discussed as reasons, but biomechanical studies are missing. This study aims to examine, whether patient-specific 3D-printed miniplates provide an increased interosteotomy movement (IOM) and lower stiffness compared with reconstruction plates. MethodsPolyurethane (PU) mandible and fibula models (Synbone AG, Malans, Schweiz) were used to simulate mandibular reconstruction with a one segment fibula flap equivalent. Osteosynthesis was performed using either four patient-specific 3D-printed miniplates (3D-Mini) or one patient-specific 3D-printed reconstruction plate (3D-Recon). Mastication was simulated using cyclic dynamic loading with increasing loads until material failure or a maximum load of 1000 N. Continuous IOM recording was carried out using a 3D optical tracking system (ARAMIS, Carl Zeiss GOM Metrology, Braunschweig, Germany). FindingsThe averaged stiffness at a load of 100–300 N load did not differ between the groups (p = 0.296). There was a faster 1.0 mm vertical displacement in the 3D-Mini group (26 376 ± 14 190 cycles versus 44 817 ± 30 430 cycles, p = 0.018). The IOM were higher with miniplate fixation in the distal gap (p = 0.040). In the mesial gap, there was no significant difference between the groups (p = 0.160). InterpretationFixation with patient-specific 3D-printed miniplates results in higher mechanical strains. Lower rates of pseudarthrosis, as seen in clinical studies, might be caused by this phenomenon. Surgeons should evaluate the primary use of 3D-printed miniplates in mandibular reconstruction due to advantages of intraoral plate removal alongside safe osteosynthesis.

A case of displaced mandibular reconstruction plate and the airway

Difficult airway is a common problem encountered in oro-maxillo-facial surgeries. We describe a case where a displaced mandibular reconstruction plate obstructing the access to oral cavity. The airway was further compromised by previous tracheostomy, and limited neck extension owing to previous surgeries and radiotherapy. The inability of the patient to swallow increased the risk of pulmonary aspiration. The first line of airway management in such patient should be fibro-optic laryngoscopy. However, one must have alternative plans for securing airway if there are expected difficulties with fiberoptic laryngoscopy. Such plans were made considering her clinical presentation. We believe this case highlights the importance of pre-planning the strategies for airway management according to the presentation.
 Key words: Difficult airway; Oro-maxillary-facial surgeries; Fiberoptic intubation; Mandibular reconstruction
 Citation: Ratnayake A, Nanayakkara S, Herath M. A case of displaced mandibular reconstruction plate and the airway. Anaesth. pain intensive care 2022;27(1):139−141; DOI: 10.35975/apic.v27i1.2126
 Received: September 24, 2022; Reviewed: November 15, 2022; Accepted: November 15, 2022

Accuracy and outcomes of virtual surgical planning and 3D-printed guides for osseous free flap reconstruction of mandibular osteoradionecrosis

ObjectivesVirtual surgical planning, 3D-printed osteotomy guides and preoperatively-bent or custom-milled mandibular reconstruction plate (VSP/3Dprinted-guide/plate) have been shown to ease intraoperative decision making and reduce operative time. Few studies have examined outcomes of VSP/3Dprinted-guide/plate specifically for mandibular osteoradionecrosis (mORN) cases, which pose unique challenges. We aimed to examine reconstruction accuracy, functional outcomes, and postoperative complications following osseous-free-flap reconstruction with VSP/3Dprinted-guide/plate for mORN. Materials and methodsSingle academic medical center retrospective case series of ORN-related osseous-free-flap mandibular reconstructions with VSP/3Dprinted-guide/plate between January 2015 and March 2021. Most cases were performed by the same two-surgeon team. Outcomes include reconstruction accuracy (assessed by 3D-overlay computer models with cephalometric and donor-bone segment length measurements), complications and function. ResultsTwenty-six cases were identified with a mean follow-up of 85 weeks. Most patients were male (69 %); mean age was 64 years. 3D-model-overlay demonstrated minimal deviation between planned and actual reconstruction among 18 evaluable cases: intercondylar distance = 1.46 mm (SD 2.4); intergonial distance = 1.82 mm (SD 2.0); anterior-posterior distance = 2.14 mm (SD 1.9); gonial angle = 3.33 degrees (SD 2.4). Mean change donor-bone segment length inferiorly 4.39 mm (SD 4.3) and superiorly 3.43 mm (SD 4.0). Complications: returned to operating room (N = 2), minor primary/neck site infection/dehiscence (N = 11). Function improved postoperatively: 20/21 (95 %) cases with preoperative pain, resolved; 13/20 (65 %) with preoperative trismus, improved; 21/24 (87 %) with preoperative malocclusion/jaw malignment, improved. ConclusionsThis is the largest series of VSP/3Dprinted-guide/plate surgery for mORN to date. Mandibular reconstruction for ORN is aided by VSP/3Dprinted-guide/plate with accurate results, acceptable complications, and improved function.

Virtual planning and 3D-printed guides for mandibular reconstruction: Factors impacting accuracy.

Examine accuracy and factors impacting accuracy for mandibular reconstruction with virtual surgical planning, 3D printed osteotomy guides and preoperatively bent mandibular reconstruction plate (VSP/3Dprinted-guide/plate). Retrospective review of osseous-free-flap mandibular reconstructions with VSP/3Dprinted-guide/plate between January 2015 and July 2020 at a single academic medical center.Patient demographics, disease, and treatment variables were extracted. Accuracy was assessed by 3D-model-overlay with cephalometric and donor-bone segment length measurements. Multivariate analyses were performed to determine factors impacting cephalometric accuracy. 60 cases met criteria: 41 (68%) cancer, 14 (23%) osteoradionecrosis (ORN), 5 (8%) secondary mandibular reconstruction. Thirteen cases (22%) were Brown class III or IV. Thirty-nine cases (65%) had ≥2 flap bone segments. Average donor-bone length was 82 mm (SD: 28). 3D-model-overlay accuracy demonstrated minimal deviation between planned and actual reconstruction: intercondylar distance=2.10 mm (SD: 2.2); intergonial distance=2.23 mm (SD: 1.9); anterior-posterior distance (APD)=1.76 mm (SD: 1.5); gonial angle (GA)=3.11 degrees (SD: 2.4). Mean change in donor-bone segment length inferiorly was 2.67 mm (SD: 2.6) and superiorly 3.27 mm (SD: 3.2). Higher number of donor-bone segments was associated with decreased accuracy in GA (p= .023) and longer donor-bone length was associated with decreased accuracy in APD (p= .031). To our knowledge this is the largest series assessing surgical accuracy of VSP/3Dprinted-guide/plate for osseous-free-flap mandibular reconstruction. We demonstrate highly accurate results, with increased number of donor-bone segments and donor-bone length associated with decreased accuracy. Our findings further support VSP/3Dprinted-guide/plate as a reliable and accurate tool for mandibular reconstruction. Level 4.

Benefits of Patient-Specific Reconstruction Plates in Mandibular Reconstruction Surgical Simulation and Resident Education.

Poorly contoured mandibular reconstruction plates are associated with postoperative complications. Recently, a technique emerged whereby preoperative patient-specific reconstructive plates (PSRP) are developed in the hopes of eliminating errors in the plate-bending process. This study’s objective is to determine if reconstructions performed with PSRP are more accurate than manually contoured plates. Ten Otolaryngology residents each performed two ex vivo mandibular reconstructions, first using a PSRP followed by a manually contoured plate. Reconstruction time, CT scans, and accuracy measurements were collected. Paired Student’s t-test was performed. There was a significant difference between reconstructions with PSRP and manually contoured plates in: plate-mandible distance (0.39 ± 0.21 vs. 0.75 ± 0.31 mm, p = 0.0128), inter-fibular segment gap (0.90 ± 0.32 vs. 2.24 ± 1.03 mm, p = 0.0095), mandible-fibula gap (1.02 ± 0.39 vs. 2.87 ± 2.38 mm, p = 0.0260), average reconstruction deviation (1.11 ± 0.32 vs. 1.67 ± 0.47 mm, p = 0.0228), mandibular angle width difference (5.13 ± 4.32 vs. 11.79 ± 4.27 mm, p = 0.0221), and reconstruction time (16.67 ± 4.18 vs. 33.78 ± 8.45 min, p = 0.0006). Lower plate-mandible distance has been demonstrated to correlate with decreased plate extrusion rates. Similarly, improved bony apposition promotes bony union. PSRP appears to provide a more accurate scaffold to guide the surgeons in assembling donor bone segments, which could potentially improve patient outcome and reduce surgical time. Additionally, in-house PSRP can serve as a low-cost surgical simulation tool for resident education.

MANDIBULAR RESECTION IN A PATIENT AFFECTED BY AMELOBLASTOMA AND IMMEDIATE RECONSTRUCTION USING A CUSTOM PROSTHESIS

Ameloblastoma is a benign, locally aggressive odontogenic tumor that can cause expansion and destruction of the cortical bone of the maxillary bones. It shows a high rate of recurrence. Eighty percent of cases appear in the mandible, and 66% of cases are located in the posterior region. The objective of this report is to present a case of an 18-year-old White female patient with ameloblastoma. The patient underwent mandibulectomy and was treated immediately with a custom prosthesis. On tomographic examination, an osteolytic lesion was noted in the left mandible compatible with ameloblastoma. Incisional biopsy of the lesion was performed, with confirmation of conventional solid ameloblastoma on anatomopathologic examination. The treatment consisted of removing the entire lesion with safety margins. Then, a personalized mandibular reconstruction plate was placed. This patient is being monitored to adapt a future implant on her prosthesis to replace the missing teeth.

Biomechanical validation of structural optimized patient-specific mandibular reconstruction plate orienting additive manufacturing

Background and objectiveOwing to the unexpected in vivo fracture failure of the original design, structural optimized patient-specific mandibular reconstruction plates (PSMRPs) were created to boost the biomechanical performance of bridging segmental bony defect in the mandibular reconstruction after tumor resection. This work aimed to validate the biomechanical benefit of the structural optimized PSMRPs relative to the original design and compare the biomechanical performance between PSMRP1 with generic contour customization and PSMRP2 with a tangent arc upper margin in mandibular angle region. MethodsFinite Element Analysis (FEA) was used to evaluate the biomechanical behavior of mandibular reconstruction assemblies (MRAs) concerning these two structural optimized PSMRPs by simulating momentary left group clenching and incisal clenching tasks. Bonded contact was set between mandibular bone and fixation screws and between PSMRP and fixation screws in the MRA, while the frictionless connection was allocated between mandibular bone and PSMRP. The loads were applied on four principal muscles, including masseter, temporalis, lateral and medial pterygoid, whose magnitudes along the three orthogonal directions. The mandibular condyles were retrained in all three directions, and either the left molars or incisors area were restrained from moving vertically. ResultsThe peak von Mises stresses of structural optimized PSMRPs (264 MPa, 296 MPa) were way lower than that of the initial PSMRP design (393 MPa), with 33 and 25% reduction during left group clenching. The peak magnitude of von Mises stress, minimum principal stress, and maximum principal strain of PSMRP1 (264 MPa, 254 MPa; -297 MPa, -285 MPa; 0.0020, 0.0020) was lower than that of PSMRP2 (296 MPa, 286 MPa; -319 MPa, -306 MPa; 0.0022, 0.0020), while the peak maximum principal stress of PSMRP1 (275 MPa, 257 MPa) was higher than that of PSMRP2 (254 MPa, 235 MPa) during both left group clenching and incisal clenching tasks. ConclusionsThe structural optimized PSMRPs reveal their biomechanical advantage compared with the original design. The PSMRP1 presents better biomechanical performance to the patient-specific mandibular reconstruction than PSMRP2 as a result of its superior safety, preferable flexibility, and comparable stability. The PSMRP2 provides biomechanical benefit in reducing the maximum tension than PSMRP1, indicated by lower peak maximum principal stress, through tangent arc upper margin in mandibular angle region.

Quantification of the Bimodal Plate-Specific Complication Profile Associated With Reconstruction of Segmental Mandibular Defects With Reconstruction Plate and Soft Tissue Flap: Evidence From Systematic Review.

Reconstruction of segmental mandibular defects with a mandibular reconstruction plate and separate soft tissue flap can be indicated in certain patients. Whilst this technique can provide acceptable results, its exact longevity and timing of associated complications is poorly understood. This study was designed to quantify and plot in time the complication profile associated with this technique of mandibular reconstruction.A search of the Medline and PubMed Central databases was conducted using the terms "Mandibulectomy" and "Reconstruction Plate." Articles reporting total number of plate extrusions and fractures and their postoperative timing were included.Nine articles were included, representing 265 patients with mandibulectomy defects reconstructed using mandibular reconstruction plates. Of these, 135 were male (62%) and 82 were female (38%). The mean age was 59 years. The predominant pathology was oral cavity Squamous Cell Carcinoma (SCC) (80%). Seventy-three patients (28%) experienced complications (mean follow-up: 24 months), with median time to complication of 3 months. Forty-three plate extrusions (16%), 20 plate fractures (8%) and 10 cases of loosened screws (4%) were reported. A bimodal temporal distribution of complications was found.Overall, a plate-specific complication rate of 28% was found, confirming a higher incidence of complications in comparison to osseous free flap reconstruction. These occur over a bimodal time distribution, with extrusion occurring earlier than fracture. interference with speech, swallow and dental rehabilitation, and delay of adjuvant therapy are potential consequences. These findings indicate that patients may be better served by more complex reconstructive procedures, to minimize exposure to a frequent and prolonged complication profile.

Metal on metal - removal of an extruding mandibular titanium reconstruction plate with a high-speed electrical surgical drill.

Metal on metal - removal of an extruding mandibular titanium reconstruction plate with a high-speed electrical surgical drill.

Biomechanical comparison of locking and non-locking patient-specific mandibular reconstruction plate using finite element analysis

Patient-specific mandibular reconstruction plate (PSMRP), as one of the patient-specific implants (PSIs), offers a host of benefits to mandibular reconstruction. Due to the limitation of fabricating screw hole threads in the PSMRP, 3D printed PSMRP is applied to the non-locking system directly in the mandibular reconstruction with bone graft regardless of the locking system. Since the conventional manual-bending reconstruction plate (CMBRP) provides better fixation in the locking system, it needs to be validated whether the locking PSMRP performs better than the non-locking PSMRP in the patient-specific mandibular reconstruction. Thereupon, the purpose of this study was to compare the biomechanical behavior between the locking and non-locking PSMRP. Finite element analysis (FEA) was used to conduct the biomechanical comparison between the locking PSMRP and non-locking PSMRP by simulating the momentary incisal clenching through static structural analysis. Mandible was reconstructed through the virtual surgical planning, and subsequently a 3D model of mandibular reconstruction assembly, including reconstructed mandible, PSMRP, and fixation screws, was generated and meshed for the following FEA simulations. In the form of equivalent von Mises stress, equivalent elastic strain, and total deformation, the locking PSMRP demonstrated its higher strengths of preferable safety, desirable flexibility, and anticipated stability compared with the non-locking PSMRP, indicated by much lower maximum stress, lower maximum strain and equivalent displacement. Locking PSMRP/screw system provides a better fixation effect to the patient-specific mandibular reconstruction than the non-locking one as a result of its productive fixation nature. FEA plays a paramount role in pre-validating the design of PSMRP through the biomechanical behavior evaluation in static structural analysis.

Association of Plate Contouring With Hardware Complications Following Mandibular Reconstruction

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. Retrospective cohort study. 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. 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). Optimizing plate contouring during mandibular reconstruction may decrease the development of postoperative hardware complications. 4 Laryngoscope, 132:61-66, 2022.

Treatment of medication‐related osteonecrosis of the jaw using segmental mandibulectomy and a reconstruction plate: A case report and 5‐year follow‐up

AbstractMedication‐related osteonecrosis of the jaw (MRONJ) has been commonly known as a adverse side effect of antiresorptive or antiangiogenic agents for the treatment of osteoporosis patients. Although there is considerable evidence on the occurrence of MRONJ in the literature, the number of studies focusing on Stage 3 MRONJ attributable to oral administration of bisphosphonates (BPs) in patients with osteoporosis is limited. The patient had exposed necrotic bone in the mandible and pus discharge through an extraoral fistula attributed to an oral BPs for the treatment of steroidal osteoporosis. She was diagnosed with Stage 3 MRONJ. She had no other identifiable cause of mandible necrosis. Given the severity and risk of pathological fractures of the mandibular bone, an extensive surgical therapy was performed after failure of compressive conservative therapy. Our surgical treatment satisfied the patient with regard to esthetics, leading to a dramatic improvement in her quality of life for 5 years after surgery. We report a case of Stage 3 MRONJ associated with BP administration for steroid‐induced osteoporosis and discuss esthetically successful reconstruction of the mandible using mandibular reconstruction plates following segmental mandibulectomy. To prevent such severe complications, it is important to develop appropriate medical and surgical treatment strategy for immunosuppressed patients with osteoporosis.

Managing a grossly comminuted and infected mandibular fracture using mandibular reconstruction plate system

Mandible fractures are one of the most common sites of maxillofacial injuries due to their anatomical location which makes its vulnerable to direct impacts. The main promoters of this kind of injury are assault, road traffic accidents, and gunshot injuries. The prevalence of comminuted mandibular fracture is 30%–50% when compared to other facial bones. It is often associated with the presence of multiple bones involving several lines of fracture, resulting in small fragments within the same area. This often leads to functional and esthetic problems. Management of comminuted mandibular fractures includes various modalities such as closed reduction, external pin fixation, wire osteosynthesis, and open reduction and internal fixation (ORIF) using miniplates, reconstruction plates, titanium mesh tray, and bone grafts. The objective of this case report is to highlight a 31-year-old male patient with comminuted mandibular fracture treated with ORIF using a 2.7 mm reconstruction plate, followed by a short period of maxillomandibular fixation

Mandibular Defect Reconstitution: A Contaminated Caprine Model of Bone Regeneration

Mandibular reconstitution with bioabsorbable scaffolds seems feasible with the application of 3-dimensional printing combined with bioactive proteins. As yet, previous studies have been limited in number of animals and have avoided a contaminated defect. We present a caprine model of mandibular defect bone regeneration with a 3-dimensionally printed bioabsorbable scaffold contaminated with oral secretions and explore the impact of bone morphogenic protein in mandibular bone reconstitution. A 3-cm, contaminated mandibular defect was generated in 18 goats and stabilized with 2 mandibular reconstruction plates. An uncoated scaffold was placed in 6 goats, and in the final 6 goats, the scaffold was coated with bone morphogenic protein-2. In 6 goats, the defect was left empty. After 12weeks, the operative site, scaffold, and adjacent mandible were plasticized, sectioned, and evaluated histologically to assess for bone regeneration. The specimens revealed only focal (average of 5.8% of the scaffold pores) and early bone formation in the scaffold-only group. In the scaffold+bone morphogenic protein-2 group, there was more (average of 51.4% of the pores) bone formation. In the periosteum-only group, the ratio of the bone thickness of the defect to that of the normal bone ranged from 0.16 to 0.78. No major infections occurred. This caprine model serves as an excellent method to assess reconstructive options for contaminated mandibular deficits. Bone regeneration was documented in a 3-cm contaminated caprine mandibular defect reconstructed with a 3-dimensionally printed synthetic scaffold with or without the addition of bone morphogenic protein-2. Bone morphogenic protein-2 significantly augments bone generation in the synthetic scaffold. Residual mandibular periosteum generated bone. Future studies will focus on optimizing vascularization.