From Bone To Blood Flow: Tissue Engineering In Orthopedics - A Narrative Review

Musculoskeletal injuries and degenerative conditions necessitate advanced regenerative solutions. Tissue engineering has emerged as a pivotal field in orthopedic care, particularly in vascularized bone and cartilage regeneration. This narrative review examines the latest advancements in vascular tissue engineering, including scaffold design, cell-based techniques, and growth factor delivery. A comprehensive literature search was conducted using PubMed, ScienceDirect, and Google Scholar, focusing on innovations and challenges in the field. Vascularized bone grafts (VBGs) outperform non-vascularized counterparts in promoting healing and integration. Advances in scaffold materials, such as smart scaffolds and hybrid biomaterials, enhance osteogenesis and angiogenesis. Cellular therapies, utilizing mesenchymal stem cells and induced pluripotent stem cells, synergistically improve vascularization and bone regeneration. Growth factors like VEGF and bone morphogenic protein (BMP-2), integrated with innovative delivery systems, enable sustained angiogenic stimulation and scaffold integration. While significant strides have been made, challenges persist in achieving full vascular integration and replicating native tissue architecture. Innovations in scaffold technology and vascular surgery techniques hold promise for transforming orthopedic tissue engineering and improving patient outcomes.

Retrospective study of morphological and functional analysis of mandibular reconstructions using iliac and fibular flaps

OBJECTIVE

This retrospective study aims to evaluate and compare the morphological and functional characteristics of mandibular reconstructions performed using iliac and fibular flaps to determine their respective effectiveness and identify the technique that offers the best patient outcomes.

METHODS

Medical and imaging data were analysed from pre- and post-operative scans of 121 patients (84 with iliac flaps and 37 with fibular flaps). Mandibular reconstructions were assessed by comparing morphometric parameters (distances and angles) and symmetry between the affected and unaffected sides using Mimics software. The quality of life of patients was assessed using a modified version of the University of Washington Quality of Life Questionnaire (UW-QOL), version 4, which evaluates functional and psychosocial outcomes in head and neck cancer treatment RESULTS: The results show that the iliac group demonstrates significantly superior performance for distances D2 and D3 and for the CA angle on the unaffected side. In contrast, the fibular group shows no significant advantage in these parameters. Regarding symmetry, the iliac group achieves better results for distance D3, whereas the fibular group excels in angular measurements. Additionally, the iliac group maintains better stability for angle B. Regarding bone dimensions, the iliac flap better preserves alveolar base height (ABH) and width (ABW), providing more consistent and favorable outcomes than the fibular flap.No overall difference was observed between the two groups regarding quality of life (assessed using the UW-QOL questionnaire). However, specific variations were noted: the fibular group scores higher for pain, activity, and recreation, while the iliac group achieves better results in appearance and speech.

CONCLUSION

The iliac flaps are the preferred option for mandibular reconstruction, offering superior morphometric stability, better preservation of bone dimensions, and more robust structural consistency than fibular flaps. Although both techniques yield comparable overall quality-of-life results, iliac flaps demonstrate more pronounced clinical benefits, leading to optimal postoperative outcomes.

Vascularized iliac crest free flap in maxillofacial reconstruction: Pearls and pitfalls from 437 clinical application

OBJECTIVE

The vascularized iliac crest free (VICF) flap has been a cornerstone in maxillofacial reconstruction for decades. This study aims to provide a framework for guiding and managing maxillofacial reconstruction using the VICF flap, highlighting key techniques and potential pitfalls to optimize outcomes and reduce practice variability.

METHODS

A retrospective review was conducted on 437 patients (439 flaps) who underwent maxillofacial reconstruction with VICF flaps. The study summarized current practices, challenges, and strategies for successful flap application. Data were collected from electronic medical records and postoperative follow-ups.

RESULTS

The overall success rate of VICF flap transplantation was 98.4 %. Of the 439 VICF flaps, 37 were myo-osteocutaneous, 47 were myo-osseous, and 355 were osseous. Computer-assisted techniques (CATs) were used in 64.5 % (282/437) of cases. The average University of Washington Quality of Life score was 83.38, and the Harris Hip Score averaged 93.34. The incidence of serious complications was low, with 6 % (17/285) of patients reporting moderate-to-severe pain and 8.4 % (24/285) experiencing incisional hernia. Additionally, 11.9 % (34/285) of patients have completed implant-supported restoration.

CONCLUSION

VICF flaps offer significant morphological advantages and ample bone quantity for reconstruction; however, they are associated with some postoperative complications. With advancements in CAT and the application of chimeric perforator flaps, VICF can be successfully used to address most maxillofacial defects, including those caused by benign and malignant tumors in the neck, especially in cases with good vascular supply.

Complications in Deep Circumflex Iliac Artery-Related Vascularized Free Iliac Flap

BACKGROUND

Since its first application in 1978, the vascularized free iliac flap (VFIF) has gradually become a mainstay for tissue defect reconstruction. However, the complications associated with harvesting the bone flap and its corresponding reconstruction surgery cannot be overlooked.

METHODS

We conducted a narrative review through literature search to identify the types, incidence, influencing factors, measurement methods, and treatment approaches of complications related to DCIA-related VFIF.

RESULTS

We propose the "LIP" rule (Loss, Injury, Postoperative) for classifying donor site complications. For the four most common recipient sites, mandible, maxilla, extremities, and hip joint, we list the common and rare complications that may occur. Additionally, we provide a summary of the methods and advances in preventing these complications.

CONCLUSIONS

We comprehensively describe the complications observed in the application of DCIA-related VFIF and introduce the "LIP" principle and other strategies to minimize or avoid adverse outcomes.

Evaluation of grafts fixation techniques for temporomandibular joint reconstruction with medial femoral condyle flap: A numerical study

Reconstruction for large-scale temporomandibular joint (TMJ) defects can be challenging. Previously, we utilized the medial femoral condyle (MFC) flap for TMJ reconstruction. However, the optimal fixation method remains uncertain. In this study, finite element analysis was used to study the effects of three different fixation types of bone graft: overlap type, bevel type, and flush type. Models of different fixation types of MFC flap were reconstructed from CT images. A standard internal fixation model for extracapsular condylar fracture was also included as a control. Displacement of bone graft, deformation of plates and screws, and stress distribution of plates, screws, and cortical and cancellous of the bone graft were analyzed by finite element analysis to investigate their biomechanical features. The displacement of the bone graft and deformation of plates and screws in three different fixation types showed no significant difference. The overlap type and flush type of fixation displayed the lowest and highest stress respectively. All three fixation types could satisfy the mechanical requirement and face no risk of breakage and the major displacement of the MFC bone graft. These results provide insights into the optimal fixation approach for MFC bone grafts, offering valuable guidance and reference for clinical application.

Comparison of Patient-Specific Plates and Pre-Bent Plates for Preserving Condylar Position in Mandible Reconstruction

OBJECTIVES

To compare the efficacy of patient-specific 3-dimensional (3D)-printed plates (PSP) and pre-bent universal reconstruction plates (PBP) in preserving the 3D position of the mandibular condyle and total operation time during mandibular reconstruction with a fibula-free flap.

MATERIALS AND METHODS

This retrospective study included 18 patients who underwent mandibular reconstruction using fibular free flaps. Both groups utilized virtual surgical planning (VSP) and 3D-printed surgical guides. Nine patients received PSP, and 9 received PBP. Postoperative and computed tomography (CT) scans were analyzed to assess 3D deviations of the mandibular condyles and operation times.

RESULTS

PSP demonstrated superior accuracy in medial-lateral condylar displacement (2.5 ± 1.42 versus 4.92 ± 2.42 mm, P = 0.02) and better angular accuracy in the coronal (1.46 ± 1.16 deg versus 5.45 ± 2.75 deg, P = 0.001) and transverse planes (3.55 ± 2.82 deg versus 8.99 ± 5.56 deg, P = 0.023). There was no significant difference in total operation time between PSP and PBP groups (487.7 ± 90.1 versus 547.3 ± 110.1 min, P = 0.226), despite all PSP patients having additional immediate implant placement and prosthesis delivery.

CONCLUSIONS

PSP offers better condylar accuracy and allows immediate implant placement without increasing surgical time compared with PBP.

Development of a universal cutting guide for raising deep circumflex iliac artery flaps

PURPOSE

The deep circumflex iliac crest flap (DCIA) is used for the reconstruction of the jaw. For fitting of the transplant by computer-aided planning (CAD), a computerized tomography (CT) of the jaw and the pelvis is necessary. Ready-made cutting guides save a pelvic CT and healthcare resources while maintaining the advantages of the CAD planning.

METHODS

A total of 2000 CTs of the pelvis were divided into groups of 500 by sex and age (≤ 45 and > 45 years). Three-dimensional (3D) pelvis models were aligned and averaged. Cutting guides were designed on the averaged pelvis for each group and an overall averaged pelvis. The cutting guides and 50 randomly selected iliac crests (10 from each group and 10 from the whole collective) were 3D printed. The appropriate cutting guide was mounted to the iliac crest and a cone beam CT was performed. The thickness of the space between the iliac crest and the cutting guide was evaluated.

RESULTS

Overall the mean thickness of the space was 2.137 mm and the mean volume of the space was 4513 mm3. The measured values were significantly different between the different groups. The overall averaged group had not the greatest volume, maximum thickness and mean thickness of the space.

CONCLUSION

Ready-made cutting guides for the DCIA flap fit to the iliac crest and make quick and accurate flap raising possible while radiation dose and resources can be saved. The cutting guides fit sufficient to the iliac crest and should keep the advantages of a standard CAD planning.

Accuracy of the surgical execution of virtually planned deep circumflex iliac artery flaps and their appropriateness for masticatory rehabilitation

BACKGROUND

Tumorous diseases of the jaw demand effective treatments, often involving continuity resection of the jaw. Reconstruction via microvascular bone flaps, like deep circumflex iliac artery flaps (DCIA), is standard. Computer aided planning (CAD) enhances accuracy in reconstruction using patient-specific CT images to create three-dimensional (3D) models. Data on the accuracy of CAD-planned DCIA flaps is scarce. Moreover, the data on accuracy should be combined with data on the exact positioning of the implants for well-fitting dental prosthetics. This study focuses on CAD-planned DCIA flaps accuracy and proper positioning for prosthetic rehabilitation.

METHODS

Patients post-mandible resection with CAD-planned DCIA flap reconstruction were evaluated. Postoperative radiograph-derived 3D models were aligned with 3D models from the CAD plans for osteotomy position, angle, and flap volume comparison. To evaluate the DCIA flap's suitability for prosthetic dental rehabilitation, a plane was created in the support zone and crestal in the middle of the DCIA flap. The lower jaw was rotated to close the mouth and the distance between the two planes was measured.

RESULTS

20 patients (12 males, 8 females) were included. Mean defect size was 73.28 ± 4.87 mm; 11 L defects, 9 LC defects. Planned vs. actual DCIA transplant volume difference was 3.814 ± 3.856 cm³ (p = 0.2223). The deviation from the planned angle was significantly larger at the dorsal osteotomy than at the ventral (p = 0.035). Linear differences between the planned DCIA transplant and the actual DCIA transplant were 1.294 ± 1.197 mm for the ventral osteotomy and 2.680 ± 3.449 mm for the dorsal (p = 0.1078). The difference between the dental axis and the middle of the DCIA transplant ranged from 0.2 mm to 14.8 mm. The mean lateral difference was 2.695 ± 3.667 mm in the region of the first premolar.

CONCLUSION

The CAD-planned DCIA flap is a solution for reconstructing the mandible. CAD planning results in an accurate reconstruction enabling dental implant placement and dental prosthetics.

Short dental implants in microvascular free flap DCIA: A case report

Placing dental implants in microvascular bone free flaps used for reconstructing the mandible or maxilla has been previously reported. However, there is scarce information available on the restorative protocol using short dental implants placed in a deep circumflex iliac artery (DCIA) microvascular free flap and the rationale behind it. This case report describes a 18-year-old patient referred to the hospital for numbness and dull pain of the left mandible, which she observed for three months. The patient underwent mandible resection and reconstruction using the DCIA free flap due to "giant cell lesion" on the left side of the mandibular angle. Short dental implants were placed and prosthetic reconstruction of the dentition involved in the resection was performed in a young patient with two integrated abutment crowns. The placement of short dental implants did not negatively affect the vascular pedicle and vitality of free flap. In our case report, two years after the healing, excellent aesthetic and function were accomplished with the DCIA flap followed by restoration with short implants.

Retrospective study of the deep circumflex iliac artery flap and the vascularized fibula free flap for maxillary defect repair

OBJECTIVES

The deep circumflex iliac artery flap (DCIA) and vascularized fibular free flap (FFF) are mainstay flaps for maxillary defect reconstruction. This study compared the functional outcomes and success rates of these flaps to provide midface reconstruction strategies.

MATERIALS AND METHODS

Maxillary defects reconstructed with DCIA or FFF at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology between May 2016 and May 2023 were retrospectively analyzed. The length, width, and height of the grafted bone segments; intermaxillary distance; buttress reconstruction rate (BRR); dental arch reconstruction rate (DAR); success rate; and dental implantation rate were compared.

RESULTS

The DCIA and FFF groups had 33 and 27 patients, respectively. Success rate in the DCIA group was 93.94 % and 100 % in the FFF group. The DCIA length was less than that of FFF; however, the width and height were significantly larger. 87.10 % of cases in the DCIA group were classified as Brown class b and c, 51.85 % of cases in the FFF group were classified as Brown class d. The average BRR in the DCIA group was 69.89 % ± 16.05 %, which was significantly higher than that in the FFF group. A total of 38.7 % and 11.1 % patients in the DCIA and FFF groups, respectively, had completed implantation.

CONCLUSION

DCIA has a greater width and height, and is more suitable for repairing Brown class b and c defects, providing sufficient bone for implantation, while the FFF is longer and more suitable for Brown class d defect reconstruction.

Donor Site Morbidity in Patients Undergoing Maxillofacial Reconstruction Using Free Fibula Flap Versus Deep Circumflex Artery Flap-A Systematic Review

Introduction

A systematic review of the literature on the donor site morbidity in patients undergoing Maxillofacial reconstruction was performed. The two widely used flaps namely free fibula flap (FFF) and DCIA flap were compared to answer the following questions: (1) Is donor site morbidity significantly different in patients undergoing maxillofacial reconstruction with FFF and DCIA flap? (2) Should donor site morbidity be considered as the criteria for choosing the flap for reconstruction.

Materials and methods

The search strategy was based on PRISMA guidelines. Various electronic databases were searched. On reviewing the seven articles included in our systematic review, we found out oral squamous cell carcinoma to be the most common pathology leading to the defects in head and neck region requiring reconstruction with free flaps.

Results

A total of 531 participants were investigated who underwent maxillofacial reconstruction using FFF and DCIA flap. The study included both the genders. The participants were assessed for short- and long-term donor site morbidity after the microvascular surgery. Mean age is 45-60 years. Three out of seven studies showed DCIA to have lesser complications at donor site than fibula group. While other two studies proved FFF to be better than DCIA. One study proved low donor site morbidity with regard to both the flap.

Conclusion

The free fibula being the flap of choice in head and neck reconstruction has a comparable donor site morbidity to DCIA. The advantages of the iliac artery flap include natural curvature, abundant vertical and horizontal bone height for bone contouring and osseointegration, hidden scar, low incidence of wound healing problems and minimal effect on function and quality of life at long-term follow-up. Thus, it makes it the free flap of choice that one cannot avoid. This systematic review was registered at PROSPERO (CRD42021268949).

The Reconstruction of Mandible Defects in War Injuries: Systematic Review and Meta-Analysis

Study Design

Systematic Review and Meta-Analysis.

Objective

There has been an increasing trend in maxillofacial injuries associated with combat trauma. Within the maxillofacial complex, the mandible is the most likely structure to be damaged during combat. The structural deficits as a result can be reconstructed with many options. These include vascularised bone grafts (VBGs), non-vascularised bone grafts (NVBGs), alloplastic implants, reconstruction bars and distraction osteogenesis. This study aimed to determine the common modality and efficacy of mandibular reconstruction in combat trauma-related defects.

Methods

A literature search was conducted on Pubmed, Prospero, Dynamed, DARE, EMBASE, COCHRANE and BMJ databases.

Results

A total of six articles met the inclusion criteria identifying 165 patients requiring mandibular reconstruction. Non-vascularised iliac bone graft (n = 137) was the most common method followed by ileac crest bone chips harvest using Dacron urethran osteomesh tray (n = 24) and frontoparietal grafts (n = 4). Meta-analysis of five out of six trials demonstrated an overall success rate of 85% (95% CI 79-90; I2 = 59%). A total of 13% (n = 22) of reconstructions failed either completely or partially and 21% (n = 34) of patients suffered postoperative complications.

Conclusions

NVBGs are a practical, cost-effective and favourable method of war zone management of mandibular defects with success rates comparable to those reported in the civilian literature. However, general trauma principles take precedence to rule out life-threatening injuries. Due consideration of patient factors, surgical factors, and available resources are required in the first-line management of combat-related mandibular defects.

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques

OBJECTIVES

To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images.

METHODS

Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender.

RESULTS

In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively.

CONCLUSIONS

This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

Reconstructive flap surgery in head and neck cancer patients: an interdisciplinary view of the challenges encountered by radiation oncologists in postoperative radiotherapy

Background

Major advances have been made in reconstructive surgery in the last decades to reduce morbidity in head and neck cancer. Flaps are now present in 80% of patients with oral cavity cancer to cover anatomic, functional, and cosmetic needs. However, gaps in interdisciplinary innovation transfer from surgery to postoperative radiotherapy (poRT) remain challenging. We aimed to provide an interdisciplinary view of the challenges encountered by radiation oncologists in planning head and neck postoperative radiotherapy.

Methods

A systematic and critical review was conducted to address areas of optimization in surgery and radiology that may be relevant to poRT.

Results

Despite extensive surgical literature on flap techniques and salvage surgery, 13 retrospective series were identified, where flap outcomes were indirectly compared between surgery alone or poRT. These low-evidence studies suggest that radiotherapy accelerates flap atrophy, fibrosis, and osteoradionecrosis and deteriorates functional outcomes. Preliminary evidence suggests that tumor spread occurs at the flap-tissue junction rather than in the flaps. One prospective 15-patient study showed 31.3% vs. 39.2% flap volume reduction without or with poRT. In an international consensus, experts recognized the needs for optimized flap-sparing poRT against flap-related functional deterioration and bone damage. CT, MRI, and PET-CT modalities show potential for the delineation of the junction area between native tissues and flap for flap segmentation and to characterize flap-specific changes quantitatively and correlate them with patterns of relapse or complications.

Conclusion

Flap management in poRT is insufficiently documented, but poRT seems to damage flaps. Current gaps in knowledge underscore the need for prospective flap assessment and interdisciplinary trials investigating flap morbidity minimization by flap-sparing poRT planning.

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.

Survival of Dental Implants Placed in Iliac, Fibula, and Radial Forearm Flaps: A Comprehensive Review

Various donor sites have been extensively documented in the literature for bone free flaps in head and neck reconstruction. These include the radius, scapula, rib, ilium, femur, fibula, and metatarsal bone. Among them, the fibula, ilium, and scapula are the most commonly used and studied for placing endosseous implants and for rehabilitation purposes. Each donor site has its own advantages and disadvantages, which depend on factors such as whether the reconstruction is for the maxilla or mandible, the required volume and length of the bone and soft tissue, and the location, extent, and type of defect that needs to be reconstructed. The aim of this current review is to comprehensively assess the existing literature on the survival of implants in fibula, radial, and iliac flaps.

Changes in condylar position and morphology after mandibular reconstruction by vascularized fibular free flap with condyle preservation

OBJECTS

Changes in condylar position and morphology after mandibular reconstruction are important to aesthetic and functional rehabilitation. We evaluated changes in condylar position and morphology at different stages after mandibular reconstruction using vascularized fibular free flap with condyle preservation.

MATERIALS AND METHODS

A total of 23 patients who underwent mandibular reconstruction with fibular flap were included in this retrospective study. CT data of all patients were recorded before surgery (T0), 7 to 14 days after surgery (T1), and at least 6 months after surgery (T2). Five parameters describing the condylar position and 4 parameters describing the morphology were measured in sagittal and coronal views of CT images. The association between clinical characteristics and changes in condylar position and morphology was analyzed. A finite element model was established to investigate the stress distribution and to predict the spatial movement tendency of the condyle after reconstruction surgery.

RESULTS

The condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved inferiorly after surgery (T0 to T1) and continually move anteriorly, inferiorly, and laterally during long-term follow-up (T1 to T2). Contrary changes were noted in the contralateral condyles with no statistical significance. No morphological changes were detected. The relationship between clinical characteristics and changes in condylar position and morphology was not statistically significant. A consistent result was observed in the finite element analysis.

CONCLUSION

Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, further studies should be conducted to evaluate the clinical function outcomes and condylar position.

CLINICAL RELEVANCE

These findings can form the basis for the evaluation of short-term and long-term changes in condylar position and morphology among patients who have previously undergone mandibular reconstruction by FFF with condyle preservation.

Vestibuloplasty and its impact on the long-term survival and success of dental implants in irradiated and non-irradiated patients after head and neck tumor therapy: a retrospective study

OBJECTIVES

This study aimed to evaluate the influence of vestibuloplasty on the clinical success and survival of dental implants in head and neck tumor patients.

MATERIALS AND METHODS

A retrospective single-center study was conducted. All patients received surgical therapy of a tumor in the head or neck and underwent surgical therapy and, if necessary, radiotherapy/radiochemotherapy. Patients with compromised soft tissue conditions received vestibuloplasty using a split thickness skin graft and an implant-retained splint. Implant survival and success and the influence of vestibuloplasty, gender, radiotherapy, and localizations were evaluated.

RESULTS

A total of 247 dental implants in 49 patients (18 women and 31 men; mean age of 63.6 years) were evaluated. During the observation period, 6 implants were lost. The cumulative survival rate was 99.1% after 1 year and 3 years and 93.1% after 5 years for patients without vestibuloplasty, compared to a survival and success rate of 100% after 5 years in patients with vestibuloplasty. Additionally, patients with vestibuloplasty showed significantly lower peri-implant bone resorption rates after 5 years (mesial: p = 0.003; distal: p = 0.001).

CONCLUSION

This study demonstrates a high cumulative survival and success rate of dental implants after 5 years in head and neck tumor patients, irrespective of irradiation. Patients with vestibuloplasty showed a significantly higher rate of implant survival and significantly lower peri-implant bone resorption after 5 years.

CLINICAL RELEVANCE

Vestibuloplasty should always be considered and applied if required by the anatomical situations to achieve high implant survival/success rates in head and neck tumor patients.

A tissue engineered 3D printed calcium alkali phosphate bioceramic bone graft enables vascularization and regeneration of critical-size discontinuity bony defects in vivo

Introduction: Recently, efforts towards the development of patient-specific 3D printed scaffolds for bone tissue engineering from bioactive ceramics have continuously intensified. For reconstruction of segmental defects after subtotal mandibulectomy a suitable tissue engineered bioceramic bone graft needs to be endowed with homogenously distributed osteoblasts in order to mimic the advantageous features of vascularized autologous fibula grafts, which represent the standard of care, contain osteogenic cells and are transplanted with the respective blood vessel. Consequently, inducing vascularization early on is pivotal for bone tissue engineering. The current study explored an advanced bone tissue engineering approach combining an advanced 3D printing technique for bioactive resorbable ceramic scaffolds with a perfusion cell culture technique for pre-colonization with mesenchymal stem cells, and with an intrinsic angiogenesis technique for regenerating critical size, segmental discontinuity defects in vivo applying a rat model. To this end, the effect of differing Si-CAOP (silica containing calcium alkali orthophosphate) scaffold microarchitecture arising from 3D powder bed printing (RP) or the Schwarzwalder Somers (SSM) replica fabrication technique on vascularization and bone regeneration was analyzed in vivo. In 80 rats 6-mm segmental discontinuity defects were created in the left femur. Methods: Embryonic mesenchymal stem cells were cultured on RP and SSM scaffolds for 7d under perfusion to create Si-CAOP grafts with terminally differentiated osteoblasts and mineralizing bone matrix. These scaffolds were implanted into the segmental defects in combination with an arteriovenous bundle (AVB). Native scaffolds without cells or AVB served as controls. After 3 and 6 months, femurs were processed for angio-µCT or hard tissue histology, histomorphometric and immunohistochemical analysis of angiogenic and osteogenic marker expression. Results: At 3 and 6 months, defects reconstructed with RP scaffolds, cells and AVB displayed a statistically significant higher bone area fraction, blood vessel volume%, blood vessel surface/volume, blood vessel thickness, density and linear density than defects treated with the other scaffold configurations. Discussion: Taken together, this study demonstrated that the AVB technique is well suited for inducing adequate vascularization of the tissue engineered scaffold graft in segmental defects after 3 and 6 months, and that our tissue engineering approach employing 3D powder bed printed scaffolds facilitated segmental defect repair.

Tenants of Mandibular Reconstruction in Segmental Defects

The premises of mandibular reconstruction are the restoration of occlusion and mandibular contour for the purpose of preserving the facial identity, oral airway, and effective speech and mastication. Establishing functional occlusion is the primary tenant in all mandibular reconstruction. In cases of segmental defects, particularly in dentate regions of the mandible, there has been a paradigm shift over the past two decades in how surgeons are approaching the restoration of load-bearing mandibular continuity with capacity for dental implantation. Here we discuss considerations for deciding the most effective method of reconstruction in segmental defects.

The Progress in Reconstruction of Mandibular Defect Caused by Osteoradionecrosis

Osteoradionecrosis (ORN) is described as a disease with exposed, nonviable bone that fails to heal spontaneously or by means of conservative treatment after radiotherapy in at least 3 months. Though traditional theories in the early stage including hypoxic-hypocellular-hypovascular and fibro-atrophic in addition to new findings such as ferroptosis were put forward to explain the mechanisms of the osteoradionecrosis, the etiology of ORN is still unclear. With the high rate of occurrence in the head and neck area, especially in the mandible, this disease can disrupt the shape and function of the irradiated area, leading to a clinical presentation ranging from stable small areas of asymptomatic exposed bone to severe progressive necrosis. In severe cases, patients may experience pain, xerostomia, dysphagia, facial fistulas, and even a jaw defect. Consequently, sequence therapy and sometimes extensive surgery and reconstructions are needed to manage these sequelae. Treatment options may include pain medication, antibiotics, the removal of sequesters, hyperbaric oxygen therapy, segmental resection of the mandible, and free flap reconstruction. Microanastomosed free-flaps are considered to be promising choice for ORN reconstruction in recent researches, and new methods including three-dimensional (3-D) printing, pentoxifylline, and amifostine are used nowadays in trying increase the success rates and improve quality of the reconstruction. This review summarizes the main research progress in osteoradionecrosis and reconstruction treatment of osteoradionecrosis with mandibular defect.

Rehabilitation of long-term mandibular defects by whole-process digital fibula flap combining with implants: A case report

Currently, the gold standard and workhorse in mandibular reconstruction is the free vascularized fibula flap. Particularly for patients who have had mandibulectomy for a long time, it is still difficult to precisely reconstruct the mandibular contour and successfully restore the patient's chewing function and esthetics. For the restoration and rehabilitation of long-term mandibular abnormalities, three-dimensional (3D) virtual surgical planning (VSP) and 3D-printed surgical guides are essential. Digital design and manufacturing were used to improve the accuracy of prostheses and facilitate occlusal reconstruction. Therefore, equipped with the methods of 3D VSP, 3D-printed surgical guides, free vascularized fibular flap, and immediate dental implants, this clinical report provides a feasible solution for mandibular reconstruction.

Three dimensional condylar positional and morphological changes following mandibular reconstruction based on CBCT analysis: a prospective study

OBJECTIVE

This study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status.

METHODOLOGY

This prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student's t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant.

RESULTS

Thirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1-62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions. In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively.

CONCLUSION

After mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.

Application of a vascularized bone free flap and survival rate of dental implants after transplantation: A systematic review and meta-analysis

PURPOSE

As maxillofacial surgical techniques have advanced, vascularized bone free flap transplantation has become the standard treatment for repairing maxillofacial defects. In this meta-analysis, we summarize the survival rates of implants after VBFF surgery for maxillary and mandibular reconstructions and investigate the factors affecting patient outcomes.

METHODS

The PubMed, Embase, and Wanfang databases were searched up to May 31, 2022. The results of the treatment effect are presented as the risk ratio or odds ratio, using 95% confidence intervals. Statistical significance was calculated at α = 0.05 (two-tailed z tests).

RESULTS

35 studies were included in our analysis. The results revealed a 3-year and 5-year implant survival rate of 95.2% and 85.4% in VBFFs, respectively. The location of jaw defects (maxilla or mandible) or timing of implantation was not found to have a statistically significant influence on the survival rate. However, statistically significant differences were observed in the failure of implants placed in irradiated bone tissue.

CONCLUSIONS

Statistically significant differences were not found in the implant survival rate between simultaneous and delayed implantation, or between maxillary and mandibular defects. However, dental implants placed in irradiated flaps tended to have a lower survival rate than those surgically placed in non-irradiated flaps.

Total mandible and bilateral TMJ reconstruction combining a customized jaw implant with a free fibular flap: a case report and literature review

BACKGROUND

The need for whole mandibular bone reconstruction and bilateral joint replacement is fortunately rare, but it is an extremely challenging topic in maxillofacial surgery, due to its functional implications. CAD-CAM techniques development has opened new broad horizons in the surgical planning of complex maxillofacial reconstructions, in terms of accuracy, predictability, and functional cosmetic results. The review of the literature has revealed a small number of scientific reports on total mandibulectomy including the condyles, with only eleven cases from 1980. Most of the works describe reconstructions secondary to dysplastic or inflammatory diseases affecting the lower jaw. The aim of this work, reporting a rare case of massive fibrous dysplasia of the whole mandible, is to share our experience in the management of extended mandibular and bilateral joint reconstruction, using porous titanium patient-specific implants.

CASE PRESENTATION

The authors present a 20-year-old male patient suffering from massive bone fibrous dysplasia of the mandible. The mandibular body and both the rami and the condylar processes had been involved, causing severe functional impairment, tooth loss, and facial deformation. The young patient, after repeated ineffective conservative surgical treatments, has required a biarticular mandibular replacement. Using virtual surgical planning (VSP) software, the authors, in collaboration with medical engineers, have created a custom-made original titanium porous mandibular implant, suspended from a bilateral artificial temporomandibular joint. The mandibular titanium implant body has been specifically designed to support soft tissues and to fix, in the alveolar region, a free fibular bone graft, for delayed dental implant prosthetic rehabilitation.

CONCLUSION

The surgical and technical details, as well as the new trends in mandibular reconstructions using porous titanium implants, are reported, and discussed, reviewing literature reports on this topic. Satisfactory functional and cosmetic restorative results have been obtained, and no major complications have occurred. The patient, currently in the 18^th month clinical and radiological follow-up, has recently completed the functional restoration program by an implant-supported full-arch dental prosthesis.

Advantages of a Training Course for Surgical Planning in Virtual Reality for Oral and Maxillofacial Surgery: Crossover Study

BACKGROUND

As an integral part of computer-assisted surgery, virtual surgical planning (VSP) leads to significantly better surgery results, such as for oral and maxillofacial reconstruction with microvascular grafts of the fibula or iliac crest. It is performed on a 2D computer desktop screen (DS) based on preoperative medical imaging. However, in this environment, VSP is associated with shortcomings, such as a time-consuming planning process and the requirement of a learning process. Therefore, a virtual reality (VR)-based VSP application has great potential to reduce or even overcome these shortcomings due to the benefits of visuospatial vision, bimanual interaction, and full immersion. However, the efficacy of such a VR environment has not yet been investigated.

OBJECTIVE

This study aimed to demonstrate the possible advantages of a VR environment through a substep of VSP, specifically the segmentation of the fibula (calf bone) and os coxae (hip bone), by conducting a training course in both DS and VR environments and comparing the results.

METHODS

During the training course, 6 novices were taught how to use a software application in a DS environment (3D Slicer) and in a VR environment (Elucis) for the segmentation of the fibula and os coxae, and they were asked to carry out the maneuvers as accurately and quickly as possible. Overall, 13 fibula and 13 os coxae were segmented for each participant in both methods (VR and DS), resulting in 156 different models (78 fibula and 78 os coxae) per method (VR and DS) and 312 models in total. The individual learning processes in both environments were compared using objective criteria (time and segmentation performance) and self-reported questionnaires. The models resulting from the segmentation were compared mathematically (Hausdorff distance and Dice coefficient) and evaluated by 2 experienced radiologists in a blinded manner.

RESULTS

A much faster learning curve was observed for the VR environment than the DS environment (β=.86 vs β=.25). This nearly doubled the segmentation speed (cm³/min) by the end of training, leading to a shorter time (P<.001) to reach a qualitative result. However, there was no qualitative difference between the models for VR and DS (P=.99). The VR environment was perceived by participants as more intuitive and less exhausting, and was favored over the DS environment.

CONCLUSIONS

The more rapid learning process and the ability to work faster in the VR environment could save time and reduce the VSP workload, providing certain advantages over the DS environment.

Donor site morbidity after computer assisted surgical reconstruction of the mandible using deep circumflex iliac artery grafts: a cross sectional study

BACKGROUND

Computer Assisted Design and Computer Assisted Manufacturing (CAD/CAM) have revolutionized oncologic surgery of the head and neck. A multitude of benefits of this technique has been described, but there are only few reports of donor site comorbidity following CAD/CAM surgery.

METHODS

This study investigated comorbidity of the hip following deep circumflex iliac artery (DCIA) graft raising using CAD/CAM techniques. A cross-sectional examination was performed to determine range of motion, muscle strength and nerve disturbances. Furthermore, correlations between graft volume and skin incision length with postoperative donor site morbidity were assessed using Spearman's rank correlation, linear regression and analysis of variance (ANOVA).

RESULTS

Fifteen patients with a mean graft volume of 21.2 ± 5.7 cm³ and a mean incision length of 228.0 ± 30.0 mm were included. Patients reported of noticeable physical limitations in daily life activities (12.3 ± 11.9 weeks) and athletic activities (38.4 ± 40.0 weeks in mean) following surgery. Graft volume significantly correlated with the duration of the use of walking aids (R = 0.57; p = 0.033) and impairment in daily life activities (R = 0.65; p = 0.012). The length of the scar of the donor-site showed a statistically significant association with postoperative iliohypogastric nerve deficits (F = 4.4, p = 0.037). Patients with anaesthaesia of a peripheral cutaneous nerve had a larger mean scar length (280 ± 30.0 mm) than subjects with hypaesthesia (245 ± 10.1 mm) or no complaints (216 ± 27.7 mm).

CONCLUSIONS

Despite sophisticated planning options in modern CAD/CAM surgery, comorbidity of the donor site following  iliac graft harvesting is still a problem. This study is the first to investigate comorbidity after DCIA graft raising in a patient group treated exclusively with CAD/CAM techniques. The results indicate that a minimal invasive approach in terms of small graft volumes and small skin incisions could help to reduce postoperative symptomatology. Trial registration Retrospectively registered at the German Clinical Trials Register (DRKS-ID: DRKS00029066); registration date: 23/05/2022.

Aesthetic Reconstruction of Onco-surgical Mandibular Defects Using Free Fibular Flap with and without CAD/CAM Customized Osteotomy Guide: A Randomized Controlled Clinical Trial

BACKGROUND

Reconstruction of mandibular defects following ablative surgery remains a challenge even for experienced surgeons. Virtual planning and guided surgery, including computer-aided design/computer-aided manufacturing (CAD/CAM), afford optimized ways by which to plan complex surgery. This study aimed to evaluate and compare aesthetic outcome and surgical efficiency of free fibular flap (FFF) with and without CAD/CAM customized osteotomy guide (COG) for reconstruction of onco-surgical mandibular defects.

METHODS

Twenty-two patients indicated for segmental mandibulectomy were randomly assigned to either CAD/CAM with COG group or that without COG- Model based reconstruction (MB group) at a 1:1 ratio. Aesthetic outcomes were evaluated by means of morphometric assessment and comparison for each differential area (DAr) and angle (DAn) in the affected side to the contralateral side of the mandible using computerized digital imaging analysis (CDIA) based on the post-operative 3D CT-scan. Subjective evaluation was performed using the Visual Analogue Scale (VAS) and Patient's Satisfaction Score (PSS). Surgical efficiency was a secondary outcome and evaluated as total operative time and ischemia time.

RESULTS

The mean sagittal DAr was significantly lower in the COG group (277.28 ± 127.05 vs. 398.67 ± 139.10 mm², P = 0.045). Although there was an improvement in the axial DAr (147.61 ± 55.42 vs. 183.68 ± 72.85 mm²), the difference was not statistically significant (P = 0.206). The mean differences (Δ) in both sagittal and coronal DAn were significantly lower in the COG group than in the MB group (6.11 ± 3.46 and 1.77 ± 1.12° vs. 9.53 ± 4.17 and 3.44 ± 2.34°), respectively. There were no statistically significant differences in the axial DAn between the two groups (P = 0.386). The PSS was significantly higher in the COG group, reflecting better aesthetic satisfaction than in the MB group (P = 0.041). The total operation and ischemia time were significantly shorter in favor of the COG group with a mean of (562.91 ± 51.22, 97.55 ± 16.80 min vs. 663.55 ± 53.43, 172.45 ± 21.87 min), respectively.

CONCLUSION

The CAD/CAM with COG is more reliable and highly valuable in enhancing aesthetic outcomes and surgical efficiency of mandibular reconstruction by FFF compared to that without COG (MB reconstruction).

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov .

REGISTRATION NUMBER

NCT03757273. Registration date: 28/11/2018.

Management of Massive Mandibular Fibrous Dysplasia with Radical Excision and Different Immediate Reconstructive Modalities: Case Series Report

Purpose

To review and represent three different mandibular reconstruction modalities following surgical treatment of massive mandibular fibrous Dysplasia (MMFD).

Methods

The present retrospective case series study was conducted on 24 patients who had MMFD and treated via resection and immediate reconstruction at Al-Azhar University Hospitals, Egypt. Patients were divided into three groups according to the grafting procedure. Group I patients were grafted with iliac bone graft (IBG), group II patients were grafted with IBG and bone marrow aspirate concentrate (BMAC), while group III patients were grafted with free vascularized fibula graft (FVFG). Postoperative clinical and radiographic assessments were performed immediately, at 6 months, 12 months and 2 years to evaluate lesion recurrence and bone graft resorption. Other study variables included assessment of postoperative wound dehiscence, infection rate, amount of edema, and facial bone contour.

Results

The parameters of the clinical analysis showed non-statistically significant differences among all groups. Postoperative wound healing was clinically uneventful in all groups, except for two cases of wound dehiscence in group I (8.3%) and one case in group III (4.2%). Most patients had appropriate postoperative facial contour, and adequate facial symmetry. The radiographic measurements revealed a highly statistically significant difference between group I and II at 12 months, and two years, without any statistically significant difference between group II and III.

Conclusion

MMFD surgical defect should be repaired for function and cosmetics aims especially in young adult patients. The findings of the present study have shown that when compared to traditional IBG alone or FVFG, the use of autogenous IBG with BMAC injection produces a favorable outcome with few difficulties.

The comprehensive on-demand 3D bio-printing for composite reconstruction of mandibular defects

Background

The mandible is a functional bio-organ that supports facial structures and helps mastication and speaking. Large mandible defects, generally greater than 6-cm segment loss, may require composite tissue reconstruction such as osteocutaneous-vascularized free flap which has a limitation of additional surgery and a functional morbidity at the donor site. A 3D bio-printing technology is recently developed to overcome the limitation in the composite reconstruction of the mandible using osteocutaneous-vascularized free flap.

Review

Scaffold, cells, and bioactive molecules are essential for a 3D bio-printing. For mandibular reconstruction, materials in a 3D bio-printing require mechanical strength, resilience, and biocompatibility. Recently, an integrated tissue and organ printing system with multiple cartridges are designed and it is capable of printing polymers to reinforce the printed structure, such as hydrogel.

Conclusion

For successful composite tissue reconstruction of the mandible, biologic considerations and components should be presented with a comprehensive on-demand online platform model of customized approaches.

Approach for Mandibular Reconstruction Using Vascularized Free Fibula Flap: A Review of the Literature

Mandible reconstruction is one of the major challenges that face any maxillofacial surgeon worldwide. Different approaches and methods are used for mandible reconstruction, including pedicle flaps, titanium reconstruction plates, and bone grafts. A free fibular flap is used commonly and is considered the gold standard in mandibular reconstruction with a good success rate. Advantages of the free fibula flap include the long pedicle, flexible skin island, good length of dense cortical bone, consistent bone shape, minimal donor site morbidity, superior union rate, anti-collapse effectiveness, segmental blood supply, the potential for two skin paddles, and ease of harvest with a flap survival rate up to 95%. This current review aims to illustrate the approach for mandibular reconstruction using a vascularized free fibula flap.

A Novel Method for Lengthening Iliac Crest Grafts for Mandibular Reconstruction

The objective of this article is to propose a technique for mandibular reconstructions of up to 17 cm, in order to obtain anterior iliac crest grafts smaller than those required, and then lengthen them using corticotomies. This technique has been performed in 5 patients with an indication for reconstruction after partial mandibulectomy due to pathology. Reconstruction of the body of the mandible, including the angle in some cases, was performed using nonvascularized anterior iliac crest grafts. These were elongated using corticotomies and fixed to cover the defect using reconstruction plates and screws (2.4 system). The wedge spaces that were formed by lengthening the bone block were grafted with autologous medullary bone and platelet-rich plasma. There was no loss of any of the grafts and there was no need for second surgical times to place more grafts. All cases were able to be rehabilitated with removable prostheses or dental implants. This method optimizes the amount of graft obtained, favors revascularization of the graft, reduces hypoxia times and allows the placement of osteoconductive and/or osteoinductive grafts directly on the exposed medullary areas, with the aim of promoting integration and reducing the resorption rate in large grafts.

Bone Augmentation for Implant Placement: Recent Advances

There are various advancements in biomaterials and methods for bone augmentation. This article aims to review the recent advances in bone augmentation for dental implants. Relevant articles on bone augmentation for dental implants were searched in PubMed/Medline, Scopus, Google Scholar, and Science Direct published in English literature published between January 1996 and March 2021. Relevant studies on bone grafts for dental implants were included and critically analyzed in this review. Various biomaterials can be used to augment bone for implant placement. Each graft procedure has advantages and disadvantages in each clinical application and needs to choose the graft material with a high success rate and less morbidity.

Survival of vascularized osseous flaps in mandibular reconstruction: A network meta-analysis

Objective

An evidence regarding which bony flap for reconstruction of mandibular defects following tumour resection is associated with the highest survival rate is still lacking. This network meta-analysis (NMA) aimed to guide surgeons selecting which vascularized osseous flap is associated with the highest survival rate for mandibular reconstruction.

Methods

From inception to March 2021, PubMed, Embase, Scopus, and Cochrane library were searched to identify the eligible studies. The outcome variable was the flap survival rate. The Bayesian NMA accompanied by a random effect model and 95% credible intervals (CrI) was calculated.

Results

Twenty-two studies with a total of 1513 patients, comparing four osseous flaps namely fibula free flap (FFF), deep circumferential iliac artery flap (DCIA), scapula flap, and osteocutaneous radial forearm flap (ORFF) were included. The respective survival rates of FFF, DCIA, Scapula, and ORFF were 94.50%, 93.12%, 97%, and 95.95%. The NMA failed to show a statistically significant difference between all comparators (FFF versus DCIA (Odd ratio, 1.8; CrI, 0.58,5.0); FFF versus ORFF (Odd ratio, 0.57; CrI, 0.077; 2.9); FFF versus scapula flap (Odd ratio, 0.25; CrI, 0.026; 1.5); DCIA versus ORFF (Odd ratio, 0.32; CrI, 0.037; 2.1); DCIA versus scapula flap (Odd ratio, 0.14; CrI, 0.015; 1.1) and ORFF versus scapula flap (Odd ratio, 2.3; CrI, 0.16; 34)).

Conclusion

Within the limitations of the current NMA, FFF, DCIA, Scapula, and ORFF showed a comparable survival rate for mandibular reconstruction. Although the scapula flap reported the highest survival rate compared to other osseous flaps for mandibular reconstruction; however, the decision making when choosing an osseous flap should be based on many factors rather than simply flap survival rate.

Salvage mandibular reconstruction: multi-institutional analysis of 17 patients

Unsuccessful mandibular reconstruction occasionally occurs, leaving the patient with undesirable function and contours. In such cases, second- or third-time corrective operations are challenging. However, published studies on the complicated retreatment of such patients are scarce. A retrospective analysis covering the years 2015-2019 was conducted in three centers. All 17 patients included had undergone prior failed mandibular reconstructions in other institutions. Salvage secondary or tertiary reconstructive surgeries were attempted and the results are presented. Major factors for these failed reconstructions included exposed non-vascularized bone grafts (n = 7, 41.2%), flap loss (n = 4, 23.5%), exposed artificial joint (n = 3, 17.6%), skewed occlusion with deformity (n = 1, 5.9%), non-union (n = 1, 5.9%), and recurrence (n = 1, 5.9%). Fibula flaps were transferred in 15 patients, while iliac flaps were used in two patients for mandibular re-do reconstructions. Virtual surgical designs were conducted in nine (52.9%) patients, with navigation-guided approaches performed in three cases. Postoperative functions were relatively favorable in these complicated mandibular re-do reconstruction cases. Mandibular symmetry (mandibular length and height; P = 0.002) and condylar position (P < 0.001) were regained after these re-do attempts. Secondary or tertiary mandibular re-do reconstruction can still achieve good functional outcomes with appropriate preoperative selection and well-conceived designs, especially with the aid of virtual surgery and navigation.

Intensive Care as an Independent Risk Factor for Infection after Reconstruction and Augmentation with Autologous Bone Grafts in Craniomaxillofacial Surgery: A Retrospective Cohort Study

Autologous bone grafts for reconstruction and augmentation are routinely used for maintaining functionality and facial aesthetics. Associated complications, however, have a significant impact on patients and health care systems. This study aims to investigate the possible risk factors associated with the occurrence of complications in order to provide evidence for the outcome of autologous bone graft reconstructive procedures. Patients from 2008 to 2018 who underwent autologous (mostly mandibular) reconstruction were included in the observational study. Clinical, pathological, and therapeutic factors were examined in univariate and multivariate analysis for significance with occurring complications. A multivariate model was used to create a prognostic model predicting the occurrence of complications. Graft complications requiring revision were exhibited by 33/128 patients. Infections were most frequent, with 4/22 patients affected by multi-resistant germs. Multivariate analysis showed radiotherapy (OR = 5.714; 95% CI: 1.839–17.752; p = 0.003), obstructive pulmonary disease (OPD) (OR = 4.329; 95% CI: 1.040–18.021; p = 0.044) and length of defect (in mm) (OR = 1.016; 95% CI: 1.004–1.028; p = 0.009) as independent risk factors associated with graft complications with high accuracy of prediction (AUC = 0.815). Intensive care (OR = 4.419; 95% CI: 1.576–12.388; p = 0.005) with a coefficient between intensive care and OPD (0.214) being low was identified as the most relevant risk factor for infection. Although intensive care is not a classic risk factor, but rather a summation of factors not reaching significance in the individual case, a stay in ICU (intensive care unit) needs to be considered for graft complications. As a clinical consequence, we recommend using the best possible hygienic measures during procedures e.g., while performing dressing and drainage changes in ICU.

[Anatomy of the deep circumflex iliac artery perforators and reconstruction of complex mandibular defects with chimeric deep circumflex iliac artery perforator flap]

OBJECTIVE

To investigate the anatomy of the perforator vessels of the deep circumflex iliac artery (DCIA) and the techniques for repairing mandibular complex defect using chimeric deep circumflex iliac artery perforator flap (DCIAPF).

OBJECTIVE

We analyzed the origin, distribution, number and courses of the perforator vessels of the DCIA, and measured the outside diameters of the vessels at the origin in 6 adult cadaveric specimens (12 sides) with latex perfusion. From July, 2018 to September, 2019, based on the results of anatomical study and imaging findings and using the digital surgical guide plate, we harvested DCIAPF from 4 patients for repairing mandibular body or angle defects and oral soft tissue defects.

OBJECTIVE

The perforating vessels of the DCIA included abdominal muscular branches, osteomusculocutaneous branches and terminal musculocutaneous branches. The abdominal muscle branches originated from the DCIA inguinal segment in 4 and from both the inguinal and iliac segments in 2 of the specimens. The osteomusculocutaneous branches all originated from the internal iliac crest in 75% and from both the inguinal and internal iliac crest segments in 25% of cases; the inguinal segment gave rise to only one perforating branch. The number of the musculocutaneous perforating branches was 1 (58.3%) or 2 (41.7%). In the 4 patients undergoing mandibular reconstruction, the DCIAPF survived in all cases with good recovery of the donor site wound. Satisfactory facial appearance with good oral morphology and occlusal relationship was achieved at 1 month postoperatively in all the patients. None of the patients experienced obvious functional abnormalities at the donor site, and imaging examination confirmed successful reconstruction of the oromandibular defects in all the cases.

OBJECTIVE

A good understanding of the anatomic characteristics of the perforator vessels of the DCIA combined with imaging examinations and digital surgery technology facilitates the harvest of DCIAPF for repairing mandibular body or angle defects complicated by oral soft tissue defects.

The application of chimeric deep circumflex iliac artery perforator flap for oromandibular reconstruction: A case report

RATIONALE

The free fibular flap is considered the gold standard, particularly for a mandibular defect combined with a significant soft tissue defect. However, the fibular flap has the disadvantages of a lack of height for postoperative dental restoration and donor site skin graft if the skin paddle is wider than 5 cm. The larger bone and soft tissue defects tend to be reconstructed using either a scapula or a combination of iliac artery and radial free flap. Few cases involving reconstruction using chimeric deep circumflex iliac artery perforator flap (DCIAPF) for mandibular defect combined with more significant soft tissue defects have been reported due to perforator variations. We successfully performed oromandibular reconstruction using chimeric DCIAPF.

PATIENT CONCERNS

A 56-year-old male patient was admitted due to "constant pain in the gradually enlarged right lower gingival mass since the previous four months." The patient had no other obvious symptoms, and no history of diabetes or hypertension was reported. The patient reported long-term smoking and drinking habits.

DIAGNOSES

Computed tomography (CT) revealed a neoplasm in the right buccal space, which is primarily considered a malignancy. The pathological results of a gingival mass biopsy presented squamous cell carcinoma.

INTERVENTIONS

No operative contraindications were confirmed after regular tests and examinations were undertaken. The patient underwent a primary extent resection of a 6-cm-long mandible, including mass and suprascapulohyoid neck dissection. The oromandibular defects were then reconstructed with chimeric DCIAPF, simultaneously using the iliac crest bone flap to repair the mandibular lateral segment defect and the skin paddle to repair the intraoral soft tissue defect of 5 × 10 cm.

OUTCOMES

The total operating time was five and half hours and blood loss was approximately 500 ml. The operation was successful, with no infections or flap loss. Six months postoperatively, CT showed that the iliac crest bone had connected to the alveolar bone of the mandible. The height of the iliac crest bone was sufficient for postoperative dental restoration. The patient healed without obvious complications and no tumor recurrence.

LESSONS

Chimeric DCIAPF is an excellent option for mandibular angle or body segment defects combined with significant soft tissue defects.

An innovative tool for mandibular reconstruction in oral malignancies: A pictorial essay

Mandibular reconstruction is challenging for most head and neck surgeons. Technological advances have led to the development of a new innovative procedure based on the concepts of computer-assisted design (CAD) and virtual surgical planning (VSP). The main disadvantage of this technique is the lack of flexibility, especially in oncology. A possible solution is the development of a semi-standardized mandible and fibula resection cutting guide: the L1® mandible ReconGuide. We provided a step-by-step description of the operative technique for mandibular reconstruction with the L1® mandible ReconGuide. The L1® mandible ReconGuide is a guiding force toward mandibular reconstruction. Moreover, the tool has been designed to suit the needs of the patients, particularly those with oral cancer, thereby permitting intraoperative planning and increasing time and cost effectiveness. In this pictorial essay, we have presented the operative techniques of using the L1® mandible ReconGuide for reconstruction.

Three salvage strategies in microvascular fibula osteocutaneous flap for mandible reconstruction with vascular compromise and establishment of an algorithm

BACKGROUND

Fibula osteocutaneous flap is associated with a higher rate of reexploration in mandible reconstruction due to limited space for the fixation of various tissue components on multiple segments of the fibula flap. To maintain optimal circulation to the flap and to prevent negative outcomes because of partial or total flap loss, we shared our experiences on salvaging the free fibula flap with vascular compromise in the first reexploration and we developed an algorithm.

METHODS

From 1992 to 2018, 12 patients between the ages of 48 to 63 (mean: 52.5) who had presented with oral squamous cell carcinoma (n = 10) followed by osteoradionecrosis of the mandible (n = 2) were explored. The operative findings were; (1) occlusions of vein (3 cases); (2) occlusions of artery (4 cases); and (3) occlusions of both artery and vein (5 cases). After correcting the kinking or evacuating the hematoma, the arterial inflow was initially reestablished by anterograde flow. If this was nonfunctional, retrograde flow from the distal end of the peroneal artery was provided. For the vein, anterograde venous drainage was reestablished. If the thrombus extended deep into the peroneal vein, regular venous return was blocked on the anterograde side, and the flap remained congested therefore retrograde venous drainage was performed regardless of the valves in the vein. However, the two ends of the peroneal artery were anastomosed to prevent thrombosis of the artery.

RESULTS

The success rate of revised cases was 75% (9/12). All failed cases had presented with both artery and vein occlusion (three cases). Pectoralis major musculocutaneous flap and anterolateral thigh flap were needed for the external surface in two cases. Skin graft was required for seven cases to restore intraoral lining. Six patients underwent dental rehabilitation with prosthetic implants.

CONCLUSION

Immediate reexploration is mandatory to salvage the flap.

Maxillofacial reconstruction with prefabricated prelaminated osseous free flaps

BACKGROUND

The prefabricated fibula flap is an advanced method of occlusal-based reconstruction that combines placement of osseointegrated dental implants with prelamination, using a split skin graft on the fibula, weeks prior to the definitive reconstruction. This approach is resource intensive but has several advantages including eliminating the delay from reconstruction to dental rehabilitation.

METHODS

A retrospective cohort study of all prefabricated fibula flaps used for mandible and maxillary reconstruction from 2012 to 2020 was performed. Outcome measures were implant survival, implant utilization and functional dental rehabilitation.

RESULTS

A total of 17 prefabricated fibula flaps were performed including two analogue and 15 digital plans. There were nine maxillary and eight mandibular reconstructions, of which 11 were primary and seven were secondary. There were no free flap failures. A total of 65 implants were placed (average 3.8, median 3 implants). There was one implant failure at 6 years giving a 1.5% failure rate. There was 91% implant utilization and 94% functional dental rehabilitation.

CONCLUSION

The prefabricated fibula flap provides outstanding dental rehabilitation in well-selected patients.

Anatomic study of the femur-vastus intermedius muscle-anterolateral thigh osteomyocutaneous free flap

INTRODUCTION

Resection of head and neck malignancy usually causes facial defects and esthetic deformities. Among the wide range of free flaps available for reconstruction, a novel chimeric free flap-the femur-vastus intermedius muscle-anterolateral thigh osteomyocutaneous free flap (FVATLO flap)-has been demonstrated for clinical use. In this study, we illustrate the anatomy and harvest of the FVATLO flap.

METHODS

Eighteen fresh cadavers without damage to either thigh were recruited for dissection. Blood supply to the vastus intermedius muscle and femur were traced and recorded. The diameter, circumference of the middle part of the femur, and thickness of the femoral cortex were measured.

RESULTS

The major blood supply to the vastus intermedius muscle showed two patterns of origin. The first arising from the descending branch of the lateral circumflex femoral artery (LCFA-db) accounts for 78% of the cases (28/36), and the second arising from the transverse branch of the lateral circumflex femoral artery (LCFA-tb) accounts for 22% (8/36). Blood supply to the femur consists of two major sources: one from branches penetrating through the nutrient foramen on the posteromedial surface of the femur to the medullary cavity, and the other from the periosteum branches spreading over on the femoral surface. No visible branch from the vastus intermedius muscle to the underlying periosteum was found. The mean diameter, femoral circumference, and mean cortical thickness were 26.30 mm, 85.58 mm, and 6.85 mm, respectively.

CONCLUSION

Considering that there is only one injured donor site, the FVALTO flap is an alternative chimeric flap for cases with a large amount of soft tissue loss together with small bony defects.

Quality of life in patients with oral hard or soft tissue defects after reconstructive microsurgery

With current advances in medicine, many surgical methods have emerged for the reconstruction of soft and hard tissue defects of the head and neck. Current literature provides only a limited amount of evidence in studies addressing differences in quality of life for specific therapeutic measures in microvascular reconstruction. The validated University of Washington quality of life questionnaire version 4 (UW-QoL v4), a distress thermometer, and two questions addressing donor-site morbidity were sent to 134 patients at a tertiary care centre. All participants had undergone a type of microvascular reconstructive surgery of the head and neck. They were distributed into three groups according to the defect and type of treatment: defects reconstructed by soft-tissue microvascular tissue transfer, defects involving the hard tissue and treated by alloplastic reconstruction, and hard tissue defects receiving microvascular osseous reconstruction. A total of 82 patients completed the questionnaire in full and returned it. Patients from all the groups showed improved distress thermometer values postoperatively. Those who underwent osseous microvascular reconstruction had better functional items than those who had alloplastic reconstruction plates. Donor-site morbidity was rated low in all groups. Microvascular osseous reconstructive surgery might help to improve functional outcomes in patients with osseous defects more than alloplastic reconstruction.

Reconstruction of Oromandibular Defect After Tumor Resection by Sternomastoid-clavicular Flap

ABSTRACT

The study aims to evaluate sternocleidomastoid-clavicular osteo-myocutaneous flap (SCM-OMCF) for reconstruction of mandibular defects after tumor resection. In the period between 2010 and 2018, thirteen patients with primary mandibular tumors underwent mandibular resection and reconstruction with SCM-OMCF. Patients were followed up for 10 to 66 months. Hospital was 13 ± 4 days. All patients started fluid in the 2nd day. The mean time to start oral fluid was 7.5 ± 0.8 day. Four (30.8%) patients suffered from complications (infection and salivary leak in 1 case due to partial flap loss, donor wound dehiscence in 1 case, deep venous thrombosis in 1 case and chest infection in 1 case). None of our cases experienced motor disability. Two cases (15.9%) underwent reoperations. The overall aesthetic outcome was found excellent in 5 cases, satisfactory in 5 cases and fair in 3 cases. The functional outcomes were satisfactory. Tumor recurrences were detected in 2 (15.9%) patients. Two patients died during follow up within 2 years after 1st surgery due to local and distant recurrences. SCM-OMCF is a versatile, safe and simple technique for reconstructing mandibular defects less than 11 cm.

Use of CAD-CAM Bridging Mandibular Prosthesis in Osteonecrosis of the Jaw: The Experience of Our School

Osteonecrosis of the jaw (ONJ) is a disease that affects the jaw. It is mainly related to radiation or bisphosphonates therapy, and the symptoms and signs consist of pain, bone exposure, inflammation of the surrounding soft tissue swelling, and secondary infection or drainage. In the case of advanced disease of the mandibular area, the treatment of choice is mandibular resection and reconstruction. In the present study, we report a case series of patients affected by ONJ and treated with a customised bridging mandibular prosthesis-only technique. From 2016 to 2018, we treated five consecutive patients affected by ONJ: three patients were affected by biphosphonate-related osteonecrosis of the mandible (BRONJ) and two were affected by osteoradionecrosis of the mandible (ORNJ). Three patients needed a soft tissue free flap to permit optimal wound closure, intra- and/or extraorally. All reconstructive procedures were carried out successfully, with no major or minor microvascular complication. The average postoperative follow-up was 24.8 (range 10–41) months. Considering that microvascular bone transfer is a high-risk procedure in BRONJ patients, we can conclude that the positioning of a customised bridging mandibular prosthesis (CBMP), whether or not associated with a microvascular soft tissue transfer, is a safe technique in terms of surgical outcome and feasibility.

Temporomandibular joint reconstruction with medial femoral condyle osseocartilaginous flap: a case series

Reconstruction for large-scale temporomandibular joint (TMJ) defects can be challenging. We have used the medial femoral condyle (MFC) osseocartilaginous flap for repair of TMJ defects. The aim of this paper was to describe our technique and to present the preliminary results. The MFC osseocartilaginous flap was used as a free vascularized graft for TMJ defect in four patients who had undergone resection for benign tumor of the TMJ region (n = 2) or TMJ ankylosis (n=2). A computer-assisted technique was used in all cases. Symmetry of the mandible was objectively evaluated by postoperative computed tomography. Complications were recorded during follow-up visits. Lower extremity functional status was assessed by the Lower Extremity Functional Scale (LEFC) questionnaire. The MFC osseocartilaginous flap success rate was 100%; bony union was obtained in all four patients, and normal occlusion was achieved within 6-11 months after surgery. No flap-related complications occurred. All patients were satisfied with their postoperative facial symmetry and oral function. The LEFC score ranged from 72 to 80, indicating normal lower extremity function. Vascularized MFC osseocartilaginous flap appears to be a reliable option for reconstruction of large-scale TMJ defects.

Retrospective analysis of complications in 190 mandibular resections and simultaneous reconstructions with free fibula flap, iliac crest flap or reconstruction plate: a comparative single centre study

Objectives

The purpose of this study was to evaluate the incidence of complications following mandibular reconstruction and to analyse possible contributing factors.

Materials and methods

Clinical data and computed tomography scans of all patients who needed a mandibular reconstruction with a reconstruction plate, free fibula flap (FFF) or iliac crest (DCIA) flap between August 2010 and August 2015 were retrospectively analysed.

Results

One hundred and ninety patients were enrolled, encompassing 77 reconstructions with reconstruction plate, 89 reconstructions with FFF and 24 reconstructions with DCIA flaps. Cutaneous perforation was most frequently detected in the plate subgroup within the early interval and overall (each p = 0.004). Low body mass index (BMI) and total radiation dosage were the most relevant risk factors for the development of analysed complications.

Conclusions

Microvascular bone flaps have overall less skin perforation than reconstruction plates. BMI and expected total radiation dosage have to be respected in choice of reconstructive technique.

Clinical relevance

A treatment algorithm for mandibular reconstructions on the basis of our results is presented.

Electronic supplementary material

The online version of this article (10.1007/s00784-020-03607-8) contains supplementary material, which is available to authorized users.