Mandibular Continuity Defects Research Articles

Erratum to "Collagen Sponge Functionalized with Chimeric Anti-BMP-2 Monoclonal Antibody Mediates Repair of Critical-Size Mandibular Continuity Defects in a Nonhuman Primate Model".

[This corrects the article DOI: 10.1155/2017/8094152.].

Collagen Sponge Functionalized with Chimeric Anti-BMP-2 Monoclonal Antibody Mediates Repair of Critical-Size Mandibular Continuity Defects in a Nonhuman Primate Model.

Antibody-mediated osseous regeneration (AMOR) has been introduced by our research group as a tissue engineering approach to capture of endogenous growth factors through the application of specific monoclonal antibodies (mAbs) immobilized on a scaffold. Specifically, anti-Bone Morphogenetic Protein- (BMP-) 2 mAbs have been demonstrated to be efficacious in mediating bone repair in a number of bone defects. The present study sought to investigate the application of AMOR for repair of mandibular continuity defect in nonhuman primates. Critical-sized mandibular continuity defects were created in Macaca fascicularis locally implanted with absorbable collagen sponges (ACS) functionalized with chimeric anti-BMP-2 mAb or isotype control mAb. 2D and 3D analysis of cone beam computed tomography (CBCT) imaging demonstrated increased bone density and volume observed within mandibular continuity defects implanted with collagen scaffolds functionalized with anti-BMP-2 mAb, compared with isotype-matched control mAb. Both CBCT imaging and histologic examination demonstrated de novo bone formation that was in direct apposition to the margins of the resected bone. It is hypothesized that bone injury may be necessary for AMOR. This is evidenced by de novo bone formation adjacent to resected bone margins, which may be the source of endogenous BMPs captured by anti-BMP-2 mAb, in turn mediating bone repair.

Computer-assisted Secondary Reconstruction of Mandibular Continuity Defects Using Non-Vascularized Iliac Crest Bone Graft Following Oral Cancer Resection

Computer-assisted Secondary Reconstruction of Mandibular Continuity Defects Using Non-Vascularized Iliac Crest Bone Graft Following Oral Cancer Resection

The Reconstruction of the Mandibular Continuity Defect by Nonvascularized Rib Graft : About two Cases

The Reconstruction of the Mandibular Continuity Defect by Nonvascularized Rib Graft : About two Cases

Secondary mandibular reconstruction for paediatric patients with long-term mandibular continuity defects: a retrospective study of six cases

Paediatric patients with long-term mandibular continuity defects following segmental resection usually present severe functional and cosmetic deformities. Secondary mandibular reconstruction for these patients is very challenging. Literature reports on how to handle these patients are scarce. The aim of this study was to describe the authors’ experience in handling those paediatric patients who have not undergone primary reconstruction, for whom the final goal of treatment is to restore a symmetrical facial appearance, masticatory function, and speech. This was a retrospective analysis of the data of six patients who underwent radical mandible resection in childhood, without immediate bone restoration, and who then underwent a secondary mandibular reconstruction procedure after reaching adulthood, during the period 2009 to 2015. The multidisciplinary treatment procedure, selection of the donor site, and reconstructive approach are discussed. Key points in relation to secondary mandibular reconstruction with the aim of achieving not only good functional and cosmetic results, but also an improvement in the paediatric patient's psychological and social outcomes, are emphasized.

Contour identical implants to bridge mandibular continuity defects--individually generated by LaserCUSING®--A feasibility study in animal cadavers.

BackgroundAblative tumor surgery often results in continuity defects of the mandible. When an immediate reconstruction using autologous bone grafts is not possible the bridging of the defects with a variety of bridging plates might be achieved. However, those bridging plates have the risk of plate fractures or exposure. Customized titanium implants manufactured using CAD/CAM and the LaserCUSING® technique might be an alternative.MethodsIn the present study, computed tomographies (CT) of porcine cadaver mandibles were generated and transferred into DICOM data. Following, different continuity defects were surgically created in the mandibles. Based on the DICOM data customized titanium implants were manufactured using CAD/CAM procedures and the LaserCUSING® technique. The implants were fixed to the remaining stumps with screws. Subsequently, the accuracy of the reconstructed mandibles was tested using plaster casts.ResultsThe workflow from the CT to the application of the customized implants was proved to be practicable. Furthermore, a stable fixation of the customized implant to the remaining stumps could be achieved. The control of the accuracy showed no frictions or obstacles.ConclusionThe customized titanium implant seems to be a promising approach to bridge continuity defects of the mandible whenever an immediate reconstruction with autologous bone is not possible.

Computer assisted mandibular reconstruction using a custom-made titan mesh tray and removable denture based on the top-down treatment technique

PurposeThe purpose of this report is to propose a computer assisted mandibular reconstruction procedure, utilizing a custom-made Ti-mesh tray with particulate cancellous bone and marrow, and a removable denture. This procedure was based on the top-down treatment technique, and reviews the case of a representative patient with mandibular continuity defect. MethodsThe patient was a 74-year old female with a chief complaint of facial asymmetry and masticatory dysfunction. Due to gingival carcinoma, she underwent a segmental mandibulectomy on the left mandibule.On the VR space, using 3-D reconstructed computer tomography data, the residual right-side mandibular fragment was repositioned based on the condylar position and the occlusal relation. The mandibular fragment was then mirrored for a central sagittal plane. The position of the mirrored object was slightly arranged with the occlusal relation. Through the above operations, the landmark configuration, for the custom-made Ti-mesh tray as a virtual simulation model, was fabricated. On the physical model, we produced a custom-made Ti-mesh tray with a commercial Ti-mesh sheet. Surgical treatment was carried out using the tray.The denture pattern was designed by a dental technician on the VR space, fabricated using a 3D printer, and modified to create an impression tray with resin. Using the impression, the temporary removable denture was fabricated. ConclusionsWe propose a computer assisted design for a custom-made Ti-mesh tray and a removable denture, based on the Top-down treatment concept. We feel this technique is advantageous in reconstructing functional occlusion, and in accurately regaining dental and facial esthetics.

Complications and Risk after Mandibular Reconstruction with Fibular Free Flaps in Patients with Oral Squamous Cell Carcinoma: A Retrospective Cohort Study.

Background We retrospectively analyzed the incidence and types of postoperative complications after mandibular continuity reconstructions with fibular free flaps (FFF) in patients with oral squamous cell carcinoma (OSCC) and identified potential risk factors for postoperative complications. Methods Data were retrieved from the medical records in the Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center/Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands from April 1995 to September 2013, and were statistically analyzed. Results In this study, 85 patients were included in whom 86 FFFs were used for mandibular reconstruction. Thirty-seven patients (43%) developed ≥ 1 surgical complication and 9 patients (10.5%) developed ≥ 1 systemic complication. Three patients (3.5%) developed total flap failure and six patients (7.0%) developed partial flap failure. Surgical complications were correlated with tobacco use, partial glossectomy, type of mandibular defect, and anatomic staging. Systemic complications were associated with age > 60 years and Charlson comorbidity index > 2. Hospitalization > 30 days was associated with type of mandibular defect. Conclusions The use of the FFF for reconstructing mandibular continuity defects in OSCC patients may be associated with postoperative complications. Patients with coexisting medical conditions and anterior mandibular defects have an increased risk for developing complications. Patients who undergo segmental mandibular resection including a partial glossectomy could have a reduced risk for complications.

Production of an autologous bone tissue using cell-derived extracellular matrix as a natural biomaterial

Production of an autologous bone tissue using cell-derived extracellular matrix as a natural biomaterial

Interim reconstruction and space maintenance of mandibular continuity defects preceding definitive osseous reconstruction

Background: The use of space maintenance in mandibular defects as an interim measure prior to definitive osseous reconstruction may prevent several problems associated with delayed reconstruction including increased surgical difficulty, soft tissue contracture limiting the volume of the final reconstruct and potential for iatrogenic injury of adjacent anatomic structures.

Reconstruction of mandibular continuity defect with double-barrel vascularised free-fibula flap - A case report



Free Revascularized Fibula Graft for Reconstruction of Mandibular Continuity Defects

Mandibular reconstruction represents a challenge to the oral and maxillofacial surgeon and has been revolutionized by the modern microvascular techniques Objective: To evaluate the usefulness of the free vascularized fibula graft for reconstruction of discontinuity defects of Mandible after resections of benign aggressive odontogenic tumours. The results of 7 vascularized free fibula graft without a skin paddle that were used for mandibular reconstruction is presented. The "double barrel" technique was used in 1 case. The donor site was closed directly in all cases. All procedures were performed by the same surgical team in oral and Maxillofacial Surgery department of BSMMU and Health & Hope Hospital from January, 2006 to December 2011. A total of patients (3 males, 4 females) were treated. All flaps except 1 were viable. Success rate was 85.71% .The average length of the fibula graft was 10.96 cm, and the number of osteotomies ranged from 0 to 3. There were no long-term functional complications in the lower leg. The fibula flap provides a successful bone graft for mandibular restoration with an acceptably low complication rate. DOI: http://dx.doi.org/10.3329/bmj.v41i1.18782 Bangladesh Medical Journal 2012 Vol. 41 No. 1; 45-49

Reconstructionof Human Mandibular Continuity Defects with Allogenic Scaffold and Autologousmarrow Mesenchymal Stem Cells

Reconstructionof Human Mandibular Continuity Defects with Allogenic Scaffold and Autologousmarrow Mesenchymal Stem Cells

Mandibular Reconstruction With a Prefabricated Free Vascularized Fibula and Implant-Supported Prosthesis Based on Fully Three-Dimensional Virtual Planning

Because optimal reconstruction of maxillofacial defects requires functional rehabilitation, the current study demonstrates the successful secondary reconstruction of a large mandibular continuity defect using a fully digitally planned prefabricated free vascularized fibula with immediate implant-supported prosthodontic restoration. A 56-year-old man presented with a large mandibular continuity defect after resection of an enlarged squamous cell carcinoma arising from the floor of the mouth. For secondary reconstruction, the shape of the neomandible and implant position for support of the lower prosthesis were planned virtually. The combined cutting and drilling guide was printed in 3 dimensions. In a 2-step surgical approach, first, the implants were inserted into the fibula and covered with a split-thickness skin graft to form a neogingiva. In a second operation, the fibula was harvested, osteotomized, and fixed with the denture on the preinserted implants. The fibula was placed to its final position guided by the occlusion. Using three-dimensional virtual backward planning, it was feasible to perform a mandibular reconstruction with immediate prosthetic rehabilitation.

Mandibular reconstruction with an alloplast: A case report and review of the current literature

The mandible plays a major role in definition of lower facial contour, airway protection and support for the tongue, dentition and the muscles of the floor of the mouth. Interruption of mandibular continuity, therefore, produces both cosmetic and functional derangements. The restoration of a patient, therefore, into acceptable cosmetics and satisfactory function after surgical ablation is a challenge for the oral and maxillofacial surgeon. This was a case of composite post-ablative defect which was reconstructed with a non-biological material (alloplast). The alloplast got exteriorised intraorally within a period of 1 year with resultant infection and had to be removed. It was concluded that alloplasts served only as temporary stabilisation in delayed reconstructtion of mandibular continuity defects. The reasons for delay may, however, vary. Resource development is necessary to facilitate surgical skills acquisition in free microvascular techniques of reconstruction which offers better and sustainable outcomes.

One vs. two piece customized implants to reconstruct mandibular continuity defects: A preliminary study in pig cadavers

ObjectivesThe reconstruction of mandibular continuity defects by bridging plates often leads to complications. Customized mandibular implants might be an alternative option. In the present study, the stability at the bone–implant-interface of customized two-piece implants was compared to one-piece implants. MethodsThirty pig mandibles were randomly divided into three groups. One group (A) was left untreated and served as reference. In groups B and C, a continuity defect was created in the left mandibular side. The defects were reconstructed by customized pure titanium implants, manufactured using the LaserCUSING® technology. Group B received a one-piece implant; in group C a two-piece implant was inserted to reconstruct the continuity defect. The bonding strength was examined statically and dynamically under standardized conditions. Digital Image Correlation was used for distortion measurement. Different dynamic measurements were performed for orientation purposes. ResultsThe highest bonding strength was measured for the reference group. The two-piece implant showed an increased bonding strength when compared to the one-piece design. In all pig mandibles treated with individual implants a fracture occurred on the non-operated side. This indicates a high primary stability of the bone–implant-interface. ConclusionThe two-piece individual mandibular implant manufactured by LaserCUSING® technology should be further analyzed in future studies.

Finite element analysis of customized reconstruction plates for mandibular continuity defect therapy

Large mandibular continuity defects pose a significant challenge in oral maxillofacial surgery. One solution to this problem is to use computer-guided surgical planning and additive manufacturing technology to produce patient-specific reconstruction plates. However, when designing customized plates, it is important to assess potential biomechanical responses that may vary substantially depending on the size and geometry of the defect.The aim of this study was to assess the design of two customized plates using finite element method (FEM). These plates were designed for the reconstruction of the lower left mandibles of two ameloblastoma cases (patient 1/plate 1 and patient 2/plate 2) with large bone resections differing in both geometry and size. Simulations revealed maximum von Mises stresses of 63MPa and 108MPa in plates 1 and 2, and 65MPa and 190MPa in the fixation screws of patients 1 and 2. The equivalent strain induced in the bone at the screw-bone interface reached maximum values of 2739 micro-strain for patient 1 and 19,575 micro-strain for patient 2. The results demonstrate the influence of design on the stresses induced in the plate and screw bodies. Of particular note, however, are the differences in the induced strains. Unphysiologically high strains in bone adjacent to screws can cause micro-damage leading to bone resorption. This can adversely affect the anchoring capabilities of the screws. Thus, while custom plates offer optimal anatomical fit, attention should be paid to the expected physiological forces on the plates and the induced stresses and strains in the plate–screw–bone assembly.

Experimental findings on customized mandibular implants in Göttingen minipigs – A pilot study

Reconstructing continuity defects of the mandible is still challenging for surgeons. The currently applied conventional titanium bridging plates have considerable rates of complications. Now, a new technology enables an individual shape-identical creation of a mandibular implant in a form-board design by the method of LaserCUSING® using pure titanium. This technology has been successfully performed in previous examinations to individually reconstruct mandibular continuity defects. This pilot study evaluated the surgical procedure in 10 female Göttingen mini pigs. First, a computed tomography scan from a mini pig cranium was performed. A three-dimensional model of the mandible was designed by data conversion. Based on the data, a customized mandibular implant resembling the natural shape was virtually created and manufactured. Then, a continuity defect of the left mandible was created in a standardized way. The implants were inserted into the defect and the wounds were allowed to heal for 21, 35, 56 and 180 days. During the healing period, no signs of inflammation or infection were observed. After the sacrifice of the minipigs the mandibles were resected. Histological microsections using Donath's sawing and grinding technique were manufactured and stained with Masson Goldner trichrome staining. The histomorphological results showed a pronounced ossification at the outer and inner surface of the implants. This animal study describes a promising approach to optimize customized implants for the application in humans.

Accurate positioning of the mandibular proximal segments in reconstructive and orthognathic surgery. The role of the virtual planning and CAD–CAM technology

The correction of developmental and acquired facial deformities demands an accurate surgical plan. In some cases, however, traditional methods of planning may fail due to inherent limitations, as the incapability of predicting 3D movements with 2D predictive tracings. Considering this, a virtual surgical simulation technique was created and has been used successfully in complex cases requiring orthognathic surgery or mandibular reconstruction, allowing precise repositioning of the mandibular proximal segment. We present the case of a 45 years old Caucasian female with asymmetry who was treated using the described method. The patient history included shortening of the mandibular perimeter due to a body fracture. Using CAD–CAM softwares and a standardized sequence of movements, Le Fort I and bilateral sagittal split osteotomy were planned to achieve optimal symmetry. However, the best outcome was reached when a body osteotomy over the malunited fracture was performed and the mandibular advancement simulated, creating a 12.5 mm continuity defect in the mandible. In order to reproduce the same movement during the surgery, a first guide was designed to orient the drilling and cutting and a second one to assure correct positioning of both distal and proximal segments as it was screwed against the mandible using the same holes drilled with the first guide. The surgery was performed uneventfully. Superimposition of the 3D-simulation and postoperative 3D-CT scan showed high level of accuracy, assessed by a distance color map (disparity inferior to 1.5 mm). The precision of this technique is related to computer-aided manufactured guides for drilling, cutting and positioning, in addition to the occlusion-based guides designed with the current virtual planning methods. The technique is particularly useful when grafting in extensive mandibular continuity defects through the intraoral approach seems challenging due to the difficulty in positioning and fixing the proximal segments in their desired positions.

Early bone resorption of free microvascular reanastomized bone grafts for mandibular reconstruction – A comparison of iliac crest and fibula grafts

ObjectivesPatients with continuous bone defects of the mandible after ablative tumor surgery need bony reconstruction for proper function and aesthetics. Free microvascular reanastomized bone grafts provide a clinically proven option for such patients, yet the optimal source of donor tissue has not yet been established. The aim of this study was to evaluate and compare the bone volume stability of vascularized bone grafts, particularly in the early highly resorptive phase, from the iliac crest (DCIA) and the fibula and to assess the implantologic rehabilitations. Materials and methodsThirty-six patients with mandibular continuity defects due to tumor resection were reconstructed by the use of vascularized bone grafts; 21 patients received DCIA flaps and 15 patients received a composite free fibular flap, depending on the size and location of the defect. Bone resorption was assessed using digital panographs. Radiographs were taken immediately after bone reconstruction, 6 months postoperatively, prior to implant surgery, and at prosthetic loading. ResultsAfter a mean observation period of 6 months, vertical bone resorption was 6.79% for the patients of the iliac crest group (DCIA), 10.20% after 11 months, and 12.58% after 17 months. Fibular grafts showed a bone resorption of 5.30% after a mean observation time of 6 months, 8.26% after 11 months, and 16.95% after 17 months. Eighteen patients received 71 implants for implant-retained dental reconstructions. ConclusionsMicrovascular reanastomized bone grafts represent a reliable treatment option for reconstruction in cases of large defects of the mandible, with low graft resorption in the early healing phase. Additionally, the compared grafts provide sufficient bone volume to permit implant rehabilitation.