Complete rehabilitation of the mandible following segmental resection

Reconstruction of Segmental Mandibular Defects with Double-Barrel Fibula Flap and Osseo-Integrated Implants: A Systematic Review

Background: Mandibular defects resulting from oncological treatment pose significant aesthetic and functional challenges due to the involvement of bone and soft tissues. Immediate reconstruction is crucial to address complications such as malocclusion, mandibular deviation, temporomandibular joint (TMJ) changes, and soft tissue retraction. These issues can lead to functional impairments, including difficulties in chewing, swallowing, and speech. The fibula flap is widely used for mandibular reconstruction due to its long bone segment and robust vascular supply, though it may not always provide adequate bone height for optimal dental rehabilitation. This systematic review aims to determine if the double-barreled fibula flap (DBFF) configuration is a viable alternative for mandibular reconstruction and to evaluate the outcomes of dental implants placed in this type of flap. Materials and Methods: This study adhered to the Cochrane Collaboration criteria and PRISMA guidelines and was registered on the International Platform of Registered Systematic Review and Meta-Analysis Protocols Database (INPLASY2023120026). We included clinical studies published in English, Spanish, or French that focused on adult patients undergoing segmental mandibulectomy followed by DBFF reconstruction and dental rehabilitation. Data sources included Medline/PubMed, the Cochrane Library, EMBASE, Scopus, and manual searches. Two reviewers independently screened and selected studies, with discrepancies resolved by a third reviewer. Data extraction captured variables such as publication year, patient demographics, number of implants, follow-up duration, flap survival, implant failure, and aesthetic outcomes. The risk of bias was assessed using the JBI appraisal tool, and the certainty of evidence was evaluated using the GRADE approach. Results: A total of 17 clinical studies were included, evaluating 245 patients and 402 dental implants. The average patient age was 43.7 years, with a mean follow-up period of 34.3 months. Flap survival was high, with a 98.3% success rate and only four flap losses. The implant failure rate was low at 1.74%. Esthetic outcomes were varied, with only three studies using standardized protocols for evaluation. The overall certainty of evidence for flap survival was moderate, low for implant failure, and very low for aesthetics due to the subjective nature of assessments and variability in reporting. Conclusions: The primary limitations of the evidence included in this review are the observational design of the studies, leading to an inherent risk of bias, inconsistency in reporting methods, and imprecision in outcome measures. Additionally, the subjective nature of aesthetic evaluations and the variability in assessment tools further limit the reliability of the findings. The DBFF technique demonstrates excellent outcomes for mandibular reconstruction, with high flap survival and low implant failure rates, making it a viable option for dental rehabilitation. However, the evidence for aesthetic outcomes is less certain, highlighting the need for more rigorous and standardized research. This review supports the DBFF as a good alternative for mandibular reconstruction with successful dental implant integration, although further studies are needed to enhance the reliability of aesthetic evaluations.

To what extent can mastication functionality be restored following mandibular reconstruction surgery? A computer modeling approach

STATEMENT OF PROBLEM

Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs.

PURPOSE

To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function.

MATERIAL AND METHODS

We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation.

RESULTS

We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%.

CONCLUSION

These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.

A preliminary analysis of patient reported outcomes following posterolateral mandible reconstruction: The role of flap type

BACKGROUND

The choice of tissue type for free flap reconstruction of posterolateral mandible resections is dependent on patient and defect characteristics. We compared clinical and patient-reported outcomes following reconstruction of these defects with a soft tissue or bony free flap.

METHODS

A retrospective review was performed on patients who underwent posterolateral segmental mandibulectomy with immediate free flap reconstruction at MSKCC from 2006 to 2021. Outcomes of interest were patient-reported outcome measures (PROMs) assessed by FACE-Q surveys and complications at the flap recipient site.

RESULTS

Ninety patients received a bony flap and 24 patients received a soft tissue flap. Patients reconstructed with soft tissue flaps had greater rates of composite soft tissue defects (p < 0.0001), condyle resection (p = 0.001), and peripheral vascular disease (p = 0.035). Complication rates were similar between the cohorts (p > 0.05). Bony flaps scored higher on multiple FACE-Q scales: Facial Appearance (p = 0.023) Eating/Drinking (p = 0.029), Smiling (p = 0.012), Speaking (p < 0.001), Swallowing (p = 0.012), Smiling Distress (p = 0.037), and Speaking Distress (p = 0.001).

CONCLUSION

Reconstruction of posterolateral mandibular defects has a similar complication profile when utilizing a bony or soft tissue free flap. Bony flaps may perform better with respect to PROMs. Reconstructive surgeons should consider using bony flap reconstruction to achieve higher patient satisfaction and quality of life.

Geometric Cuts by an Autonomous Laser Osteotome Increase Stability in Mandibular Reconstruction With Free Fibula Grafts: A Cadaver Study

BACKGROUND

Nonunion and plate exposure represent a major complication after mandibular reconstruction with free fibula flaps. These drawbacks may be resolved by geometric osteotomies increasing intersegmental bone contact area and stability.

PURPOSE

The aim of this study was to compare intersegmental bone contact and stability of geometric osteotomies to straight osteotomies in mandibular reconstructions with free fibula grafts performed by robot-guided erbium-doped yttrium aluminum garnet laser osteotomy.

STUDY DESIGN, SETTING, SAMPLE

This cadaveric in-vitro study was performed on fresh frozen human skull and fibula specimens. Computed tomography (CT) scans of all specimens were performed for virtual planning of mandibular resections and three-segment fibula reconstructions. The virtual planning was implemented in a Cold Ablation Robot-guided Laser Osteotome.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

For predictor variables, straight and geometric puzzle-shaped osteotomies were designed at resection of the mandible and corresponding fibula reconstruction.

MAIN OUTCOME VARIABLES

The primary outcome variable was the stability of the reconstructed mandible investigated by shearing tests. Moreover, secondary outcome variables were the duration of the laser osteotomies, the contact surface area, and the accuracy of the reconstruction, both evaluated on postsurgical CT scans.

COVARIATES

Covariables were not applicable.

ANALYSES

Data were reported as mean values (± standard deviation) and were statistically analyzed using an independent-sample t-test at a significance level of α = 0.05. Root mean square deviation was tested for accuracy.

RESULTS

Eight skulls and 16 fibula specimens were used for the study. One hundred twelve successful laser osteotomies (96 straight and 16 geometrical) could be performed. Geometric osteotomies increased stability (110.2 ± 36.2 N vs 37.9 ± 20.1 N, P < .001) compared to straight osteotomies. Geometric osteotomy of the fibula took longer than straight osteotomies (10.9 ± 5.1 min vs 5.9 ± 2.2 min, P = .028) but could provide larger contact surface (431.2 ± 148.5 mm2 vs 226.1 ± 50.8 mm2, P = .04). Heat map analysis revealed a mean deviation between preoperational planning and postreconstructive CT scan of -0.8 ± 2.4 mm and a root mean square deviation of 2.51 mm.

CONCLUSION AND RELEVANCE

Mandibular resection and reconstruction by fibula grafts can be accurately performed by a Cold Ablation Robot-guided Laser Osteotome without need for cutting guides. Osteotomy planning with geometric cuts offers higher stability and an increased bone contact area, which may enhance healing of the reconstructed mandible.

Is All-on-four effective in case of partial mandibular resection? A 3D finite element study

INTRODUCTION

The aim of the work is to analyze stress distribution on 3D Finite Element (FE) models at bone, implant, and framework level of different designs for fixed implant-supported prostheses in completely edentulous patients, comparing results on whole and partially resected mandibles.

MATERIALS AND METHODS

3D anisotropic FE models of a whole and of a partially resected mandible were created using a TC scan of a cadaver's totally edentulous mandible. Two types of totally implant-supported rehabilitation were simulated, with four implants: parallel fixtures on whole mandible and on resected mandible, All-on-four-configured fixtures on whole mandible and on partially resected mandible. A superstructure comprising only metal components of a prosthetic framework were added, while stress distribution and its maximum values were analyzed at bone, implant, and superstructure level.

RESULTS

The results highlight that: (1) implant stresses are greater on the whole mandible than on the resected one; (2) framework and cancellous-bone stresses are comparable in all cases; (3) on the resected mandible, maximum stress levels at the cortical-bone/implant interface are higher than in whole-mandible rehabilitation. The opposite applies for maximum stresses on external cortical bone, measured radially with respect to the implant from the point of maximum stress at the interface.

DISCUSSION

On the resected mandible, All-on-four configuration proved biomechanically superior to parallel implants considering radial stresses on implants and cortical bone. Still, maximum stresses increase at the bone/implant interface. A design with four parallel implants minimizes the stress on a resected mandible while, on the whole mandible, the All-on-four rehabilitation proves superior at all levels (bone, implant, and framework).

Comparing donor site morbidity in osteocutaneous radial forearm versus fibula free flap for mandibular reconstruction

PURPOSE

The osteocutaneous radial forearm free flap has gained popularity as a less morbid option for oromandibular reconstruction compared to the fibular free flap. However, there is a paucity of data regarding direct outcome comparison between these techniques.

METHODS

Retrospective chart review of 94 patients who underwent maxillomandibular reconstruction intervened from July 2012-October 2020 at the University of Arkansas for Medical Sciences. All other bony free flaps were excluded. Endpoints retrieved encompassed demographics, surgical outcomes, perioperative data, and donor site morbidity. Continuous data points were analyzed using independent sample t-Tests. Qualitative data was analyzed using Chi-Square tests to determine significance. Ordinal variables were tested using the Mann-Whitney U test.

RESULTS

The cohort was equally male and female, with a mean age of 62.6 years. There were 21 and 73 patients in the osteocutaneous radial forearm free flap and fibular free flap cohorts, respectively. Excluding age, the groups were otherwise comparable, including tobacco use, and ASA classification. Bony defect (OC-RFFF = 7.9 cm, FFF = 9.4 cm, p = 0.021) and skin paddle (OC-RFFF = 54.6 cm2, FFF = 72.21 cm2, p = 0.045) size were larger in the fibular free flap group. However, no significant difference was found between cohorts with respect to skin graft. There was no statistically significant difference between cohorts regarding the rate of donor site infection, tourniquet time, ischemia time, total operative time, blood transfusion, or length of hospital stay.

CONCLUSIONS

No significant difference in perioperative donor site morbidity was found between patients undergoing fibular forearm free flap and osteocutaneous radial forearm flap for maxillomandibular reconstruction. Osteocutaneous radial forearm flap performance was associated with significantly older age, which may represent a selection bias.

Towards Optimum Mandibular Reconstruction for Dental Occlusal Rehabilitation: From Preoperative Virtual Surgery to Autogenous Particulate Cancellous Bone and Marrow Graft with Custom-Made Titanium Mesh-A Retrospective Study

The purpose of this retrospective study was to evaluate computer-assisted virtual surgery and the outcomes of mandibular reconstruction using an autogenous particulate cancellous bone and marrow (PCBM) graft combined with a custom-made titanium mesh (TiMesh) using a three-dimensional (3D) printing model. Eighteen consecutive patients were included, and preoperative virtual simulation surgery was performed using digital data. Segmental bone defects showed deviation of the mandible due to displacement of the condyle and segments, unnatural length of the mandibular body, or poorer intermaxillary relationship compared to the marginal bone defect caused by previous operations. These mandibular disharmonies could be simulated, and virtual surgery was performed on a computer with adjustment of displaced mandibular segments, length of the mandibular body, and dental arch with digital bone augmentation. TiMesh was manually pre-bent using a 3D printing model, and PCBM from the iliac crest was grafted with TiMesh. The short-term clinical results were good; reconstruction of the alveolar crest was prosthetically desirable; and minor complications were observed. In conclusion, virtual reconstruction is crucial for treating complex deviated mandibles. Accurate condylar and dental arch positions with an optimum mandibular length are important for prosthetically satisfactory mandibular reconstruction.

The Amsterdam UMC protocol for computer-assisted mandibular and maxillary reconstruction; A cadaveric study

OBJECTIVES

In this cadaveric study, the accuracy of CAS guided mandibular and maxillary reconstruction including immediate dental implant placement in different Brown defect classes is assessed.

MATERIALS AND METHODS

The virtual planning and surgical procedure was conducted according to a newly proposed Amsterdam UMC reconstruction protocol. Postoperative evaluation was performed according to a previously proposed evaluation guideline.

RESULTS

Fourteen mandibular and 6 maxillary reconstructions were performed. Average mandibular angle deviations were 1.52°±1.32, 1.85°±1.58, 1.37°±1.09, 1.78°±1.37, 2.43°±1.52 and 2.83°±2.37, respectively for the left and right axial angles, left and right coronal angles and left and right sagittal angles. A total of 62 dental implants were placed in neomandibles with an average dXYZ values of 3.68 ± 2.21 mm and 16 in neomaxillas with an average dXYZ values of 3.24 ± 1.7 mm.

CONCLUSION

Promising levels of accuracy were achieved for all mandibular angles. Dental implant positions approached the preoperative preferred positions well, within the margin to manufacture prosthetic devices.

An Anatomic Analysis of Fibula Flap Mandible Reconstructions: Implications for Endosseous Implant Placement

BACKGROUND

Precise planning and evaluation of the fibula bone are necessary if immediate endosseous implant placement is considered. Limited information is available on the anatomical dimensions or density of fibula used in mandibular reconstructions. This study aimed to describe the morphology and dimensions of the fibula used to reconstruct segmental mandibular defects and contrast the findings with the native mandible.

METHODS

A retrospective analysis was performed of patients who underwent segmental mandibulectomy reconstructed with osteocutaneous fibula flaps and had at least one postoperative computed tomography scan. Fibula cross sectional dimensions and densities were evaluated with three-dimensional software. Radiographic measurements were obtained from the contralateral mandible medial to the first molar for comparison.

RESULTS

Four hundred seventy-seven fibula cross sections from 159 segments were evaluated. Cross-sectional oval, quadrilateral, triangular, and pentagonal shapes differed significantly in proportion (p < 0.001). Thirty-eight percent of segments (95 percent CI, 30 to 46 percent) had differences in cross-section height greater than 1 mm (p < 0.001). Between segments within the same patient, the median height difference was 1.58 mm (range, 0.14 to 6 mm). The superior cortex density was significantly higher for the fibula than the native mandible; however, the medullary space density was significantly lower (p < 0.001).

CONCLUSIONS

The current study comprises the most comprehensive description of fibula morphology in mandibular reconstructions and highlights the significant variability that exists. The findings provide justification for the added time and cost of computer-aided design and computer-aided manufacturing in centers interested in performing immediate dental implant placement, as the technology provides the necessary precision and accuracy.

An anatomic study of the perforators from the peroneal artery. A new method to locate the cutaneous perforator

Background

The goal of this study was to investigate the anatomy of the perforators from the peroneal artery in Vietnamese patients.

Methods

30 cadaver's legs were dissected and investigated for the distribution, course, origin, number and types of perforators of the peroneal artery. The locations of the exit points on the skin of perforators were marked in relation to reference points and segments.

Results

The total number of cutaneous perforating branches of the peroneal artery from 30 specimens was 149, which included 63 (42.2%) musculocutaneous perforators and 86 (57.8%) septocutaneous perforators. In most cases, the perforator branches were located in the range from 4 to 7 of the total fibula length (69.8%). The average number of perforating vessels in a leg was 4.9, ranging from 1 to 8 vessels. All the perforators were positioned behind the posterior border of the peroneal bone. In all the dissected samples presented, there was always one cutaneous perforator within a distance of 18 mm from the F point, which is the junction between the 6/10 and 7/10 segments at the posterior border of the fibular bone.

Conclusion

The abundance of cutaneous perforators in Vietnamese patients can be used to plan various combined skin and bone flaps. A cutaneous perforator was consistently found near the F point, and this factor can be used in the planning of a bone flap with accompanying skin for monitoring survival of the underlying fibular bone flap.

Comparing the use of conventional and three-dimensional printing (3DP) in mandibular reconstruction

Background

There are a number of clinical disorders that require mandibular reconstruction (MR). Novel three-dimensional (3D) printing technology enables reconstructions to be more accurate and beneficial to the patient. However, there is currently no evidence identifying which techniques are better suited for MR, based on the type of clinical disorder the patient has. In this study, we aim to compare 3D techniques with conventional techniques to identify how best to reconstruct the mandible based on the clinical cause that necessitates the reconstructive procedure: cancerous or benign tumours, clinical disorders, infection or disease and trauma or injury.

Methods

PubMed, Scopus, Embase and Medline were searched to identify relevant papers that outline the clinical differences between 3D and conventional techniques in MR. Data were evaluated to provide a clear outline of suitable techniques for surgery.

Results

20 of 2749 papers met inclusion criteria. These papers were grouped based on the clinical causes that required MR into four categories: malignant or benign tumour resection; mandibular trauma/injury and other clinical disorders.

Conclusions

The majority of researchers favoured 3D techniques in MR. However, due to a lack of standardised reporting in these studies it was not possible to determine which specific techniques were better for which clinical presentations.

Double-Barrel Versus Single-Barrel Fibula Flaps for Mandibular Reconstruction: Safety and Outcomes

OBJECTIVES/HYPOTHESIS

Fibula flaps are routinely used for osseous reconstruction of head and neck defects. However, single-barrel fibula flaps may result in a height discrepancy between native mandible and grafted bone, limiting outcomes from both an aesthetic and dental standpoint. The double-barrel fibula flap aims to resolve this. We present our institution's outcomes comparing both flap designs.

STUDY DESIGN

Retrospective cohort study.

METHODS

We conducted a retrospective review of all patients undergoing free fibula flap mandibular reconstruction at our institution between October 2008 and October 2020. Patients were grouped based on whether they underwent single-barrel or double-barrel reconstruction. Postoperative outcomes data were collected and compared between groups. Differences in categorical and continuous variables were assessed using a Chi-square test or Student's t-test, respectively.

RESULTS

Out of 168 patients, 126 underwent single-barrel and 42 underwent double-barrel reconstruction. There was no significant difference in postoperative morbidity between approaches, including total complications (P = .37), flap-related complications (P = .62), takeback to the operating room (P = .75), flap salvage (P = .66), flap failure (P = .45), and mortality (P = .19). In addition, there was no significant difference in operative time (P = .86) or duration of hospital stay (P = .17). After adjusting for confounders, primary dental implantation was significantly higher in the double-barrel group (odds ratio, 3.02; 95% confidence interval, 1.2-7.6; P = .019).

CONCLUSION

Double-barrel fibula flap mandibular reconstruction can be performed safely without increased postoperative morbidity or duration of hospital stay relative to single-barrel reconstruction. Moreover, the double-barrel approach is associated with higher odds of primary dental implantation and may warrant further consideration as part of an expanded toolkit for achieving early dental rehabilitation.

LEVEL OF EVIDENCE

III Laryngoscope, 2021.

Oral rehabilitation after squamous cell carcinoma mandibular resection

Introduction: Squamous cell carcinoma of the oral cavity is the most common cause of mandibular defect. The functional and aesthetic impacts of this surgery must be considered. The number of mandibular resections depends on the TNM classification of the tumor. Mandibular reconstruction by a fibula free flap has become the gold standard. Unfortunately, not all mandibular resections are rehabilitated. The purpose of this study is to evaluate oral rehabilitation after mandibular resection in patients with squamous cell carcinoma. Materials and methods: A retrospective study was conducted to evaluate oral rehabilitations according to the type of surgical resection and reconstruction. The secondary evaluation criteria were type of rehabilitation, implant success rate, post-radiotherapy delay, rehabilitation success rate, and causes of non-rehabilitation. Results: The study included 157 patients with mandibular resection. Of the patients, 26.7 percent received oral rehabilitation. All rehabilitation with implants was functional. The main causes of non-rehabilitation were death or recurrences related to the progression of the disease, postoperative anatomical difficulties, and cost of oral rehabilitation. Conclusion: Oral rehabilitation after mandibular resection surgery is insufficient. A rehabilitation unit including a maxillofacial surgeon, oral surgeon, and dentist is essential. Implementation of the unit should be considered as soon as possible. The cost of rehabilitation should not be a limiting factor.

Tissue engineered autologous cartilage-bone grafts for temporomandibular joint regeneration

Joint disorders can be detrimental to quality of life. There is an unmet need for precise functional reconstruction of native-like cartilage and bone tissues in the craniofacial space and particularly for the temporomandibular joint (TMJ). Current surgical methods suffer from lack of precision and comorbidities and frequently involve multiple operations. Studies have sought to improve craniofacial bone grafts without addressing the cartilage, which is essential to TMJ function. For the human-sized TMJ in the Yucatan minipig model, we engineered autologous, biologically, and anatomically matched cartilage-bone grafts for repairing the ramus-condyle unit (RCU), a geometrically intricate structure subjected to complex loading forces. Using image-guided micromilling, anatomically precise scaffolds were created from decellularized bone matrix and infused with autologous adipose-derived chondrogenic and osteogenic progenitor cells. The resulting constructs were cultured in a dual perfusion bioreactor for 5 weeks before implantation. Six months after implantation, the bioengineered RCUs maintained their predefined anatomical structure and regenerated full-thickness, stratified, and mechanically robust cartilage over the underlying bone, to a greater extent than either autologous bone-only engineered grafts or acellular scaffolds. Tracking of implanted cells and parallel bioreactor studies enabled additional insights into the progression of cartilage and bone regeneration. This study demonstrates the feasibility of TMJ regeneration using anatomically precise, autologous, living cartilage-bone grafts for functional, personalized total joint replacement. Inclusion of the adjacent tissues such as soft connective tissues and the TMJ disc could further extend the functional integration of engineered RCUs with the host.

Reconstruction of mandibular defects involving the central segment with fibula osteoseptocutaneous free flap following ameloblastoma resection: Patient-reported outcomes

OBJECTIVES

Mandibular defects involving the central segment are challenging. This study analyzes the impact of defect extent and reconstruction method on quality of life (QOL) and obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Twenty-nine ameloblastoma patients received segmental mandibulectomy involving the C-segment and immediate fibula free flap reconstruction were recruited. Defects: (C: 2, LC: 11, LCL: 19). Mean defect length: 8.79 cm (± 2.34). Inset: Low-single-barrel (n: 19), with secondary distraction osteogenesis (n: 8/19), high-single-barrel (n: 7), double barrel (n: 3). Patients were surveyed using University of Washington Quality of Life (UW-QOL) and Berlin risk of postoperative sleep apnea questionnaires.

RESULTS

Flap failure: None. Mean follow-up: 109.6 ± 92.8 months.

UW-QOL

Physical function 91.83 (± 14.92); social function 90.17 (± 17.19). No statistical difference between C, LC, and LCL was found, but C group which received low-single-barrel had the lowest score in appearance and chewing domains. In health-related QOL (HR-QOL) compared with 1 month before cancer, 69% reported best results. "Appearance" was the most important issue for the past 7 days, followed by "Chewing," prevailing in LC and C groups that predominately reconstructed by low-single-barrel. Berlin score: 7 patients (4 LCL, 3 LC≥8 cm) were at high risk for postoperative OSA.

CONCLUSION

"Like-with-like" reconstruction with immediate endosteal dental implants yields the best results. Inset of fibula bone could affect outcomes, favoring double-barrel or single-high-barrel inset. Appearance and chewing remain the main concerns, largely, in those with low-single-barrel inset and no dental restoration. After long/extensive LCL and LC mandibulectomies, postoperative OSA warrants further investigation, and modification of resection/reconstruction techniques.

Implant-supported fixed and removable prostheses in the fibular mandible

Background

To restore the health-related quality of life (HRQoL) of patients who underwent jaw resection and reconstruction surgery, dental rehabilitation is an essential procedure and also one of the most challenging for oral and maxillofacial surgeons. Even though recent studies have reported the possibility and reliability of dental implant rehabilitation with the fibula free flap (FFF), clinical reports of long-term follow-up cases are scarce. We herein reported seven cases of FFF reconstruction and implant rehabilitation. We also discussed implant planning strategy and surgical techniques.

Methods

From 2012 to 2019, seven patients were treated with FFF reconstructive jaw surgery combined with dental implant installation and fabrication of implant-supported prostheses at Seoul National University Dental Hospital, Seoul, Korea. Patient characteristics and FFF treatment results were collected. Records of dental implants were analyzed clinically and radiologically.

Results

Among the seven patients in this report, there were three males and four females, with an average age of 54.4 years. A total of 39 implants were placed in the fibular bone. The mean follow-up period after implant installation was 24 months. Five implants failed and were removed 3 months after installation. The implant success rate was 87.2%. Marginal bone loss at 12 months after loading was 0.23 ± 0.18 mm on the mesial side and 0.25 ± 0.26 mm on the distal side.

Conclusion

With the challenges present in FFF-reconstructed patients, an implant-supported prosthesis is a reliable option for stable and functional oral rehabilitation. The implant-supported prosthesis on the FFF has great results regarding restoration of function (mastication, swallowing, and speaking), appearance, and overall HRQoL. Collaboration between surgeons and prosthodontists is essential for a satisfying outcome.

Mandibular reconstruction using single piece zygomatic implant in conjunction with a reinforcing Fibular Graft Union: A case report

Presenting to our knowledge, for the first time in literature, a case report on the long term follow-up of an implant retained fixed prosthesis on free fibular reconstruction with a single piece zygomatic implant and single piece bicortical implant via a flapless approach and immediate functional rehabilitation. The technique involved the concept of "Remote Bone Anchorage" in conjunction with the union of grafted free fibula flap with the native mandible. It was facilitated with a single piece zygomatic implant engaged in the mandible and splinted with single piece implants on the grafted fibula as needed for prosthetic functional reconstruction. The author has reported a unique concept of immediate functional rehabilitation in the fibular graft therefore providing additional splinting of the vascularized free fibula to the mandible by splinting them with single piece zygomatic cortical implant.

Enhancement of bone marrow aspirate concentrate with local self-healing corticotomies

Bone marrow aspirate concentrate (BMAC) is a potentially useful biological product for bone regeneration. This study investigated whether BMAC can be enriched by local minor corticotomies. Five 4-month-old domestic pigs were used with each pig undergoing two minor corticotomies at one randomly-selected tibia. Two weeks after the operation, bone marrow was aspirated from both tibiae and processed into BMAC samples. The amount of mesenchymal stem cells (MSCs) and the concentration of several regenerative growth factors contained in BMAC, as well as the proliferative and osteogenic differentiation capacity of MSCs, were compared between the corticotomy and the control sides. Another four weeks later, healing of the corticotomies was evaluated by radiographic and histological methods. The results demonstrated that BMAC from the corticotomy side contained significantly more MSCs than the control side. MSCs from the corticotomy side also proliferated significantly faster and tended to have stronger osteogenic differentiation than those from the control side. In contrast, the protein concentration of TGF-β, BMP-2 and PDGF contained in BMAC was only minimally changed by the corticotomies. The corticotomies in all pigs healed uneventfully, showing complete obliteration of the corticotomy gaps on CT images. Comparison between the two sides showed that the corticotomy side had thicker and denser cortical bone and more abundant osteogenic cell differentiation than the control side. These findings suggest that the quantity and proliferative/osteogenic differentiation capacity of MSCs contained in local BMAC can be enhanced by minor corticotomies, and spontaneous healing of the corticotomy can be completed within 6 weeks of the operation.

Biomaterials-aided mandibular reconstruction using in vivo bioreactors

Large mandibular defects are clinically challenging to reconstruct due to the complex anatomy of the jaw and the limited availability of appropriate tissue for repair. We envision leveraging current advances in fabrication and biomaterials to create implantable devices that generate bone within the patients themselves suitable for their own specific anatomical pathology. The in vivo bioreactor strategy facilitates the generation of large autologous vascularized bony tissue of customized geometry without the addition of exogenous growth factors or cells. To translate this technology, we investigated its success in reconstructing a mandibular defect of physiologically relevant size in sheep. We fabricated and implanted 3D-printed in vivo bioreactors against rib periosteum and utilized biomaterial-based space maintenance to preserve the native anatomical mandibular structure in the defect site before reconstruction. Nine weeks after bioreactor implantation, the ovine mandibles were repaired with the autologous bony tissue generated from the in vivo bioreactors. We evaluated tissues generated in bioreactors by radiographic, histological, mechanical, and biomolecular assays and repaired mandibles by radiographic and histological assays. Biomaterial-aided mandibular reconstruction was successful in a large superior marginal defect in five of six (83%) sheep. Given that these studies utilized clinically available biomaterials, such as bone cement and ceramic particles, this strategy is designed for rapid human translation to improve outcomes in patients with large mandibular defects.

Novel Plate Design to Improve Mandibular and Maxillary Reconstruction with the Osteocutaneous Fibula Flap

Virtual surgical planning (VSP) has improved the accuracy and efficiency of craniofacial reconstruction using the osteocutaneous free fibula flap. Despite this, challenges remain in translating the VSP to a real-world construct due to small changes that can occur after osteotomies of the mandible or maxilla. Poor execution of the VSP can lead to malocclusion, undesirable aesthetics, or poor bony contact at the sites of osteosynthesis. We describe a novel technique using Selective LASER Melted plates to achieve maximum control and accuracy of complex, virtually planned reconstructions of the mandible and maxilla.

Free-Flap Reconstruction of the Mandible

Mandible reconstruction has evolved over the years with advances in surgical options and three-dimensional technology. Although nonvascularized bone grafting is still used, vascularized flaps show advantages with immediate reconstruction, the possibility of immediate dental implants, and the ability to reconstruct composite defects of both soft tissue and bone. This article discusses current vascularized techniques for mandible reconstruction. While each reconstructive method has advantages and disadvantages, a defect-based reconstruction focused on full rehabilitation allows surgeons to plan and counsel the patient for the best available reconstruction.

A Comparison of Immediate and Delayed Dental Implant Placement in Head and Neck Surgery Patients

PURPOSE

Implant-supported dental prostheses offer numerous benefits for patients after ablative procedures of the head and neck region, including restoration of function, improved self-esteem and body satisfaction, and overall quality of life. Increased experience is emerging with immediate placement of implants at the time of ablative surgery compared with the traditional delayed approach. The authors sought to identify variables affecting survival of osseointegrated dental implants in such patients and to assess the impact of timing of implant insertion (immediate vs delayed) on the time until final prosthesis insertion.

MATERIALS AND METHODS

Implant survival was assessed based on different factors: immediate versus delayed implants, benign versus malignant disease, postoperative radiotherapy, smoking status, alcohol status, age, 1- versus 2-stage surgery, hyperbaric oxygen therapy, and implant placement into native bone versus into osseous free flap reconstruction. Time to final prosthesis insertion was compared between immediate and delayed implant placement.

RESULTS

The study included 20 patients who received a total of 102 implants (39 immediate, 63 delayed). There were 7 failed implants (overall survival, 93.14%). There was no statistically relevant difference in implant survival between any of the groups assessed. However, there was a significant decrease in time to final prosthesis insertion for those patients receiving immediate implants compared with those who underwent delayed implant placement (321 days; standard error, 46.5 vs 726 days; standard error, 45 days; P < .0001).

CONCLUSIONS

Immediate implant placement is an effective approach to the prosthetic rehabilitation of patients undergoing ablative procedures of the jaws, which shortens time to final prosthesis placement without adversely affecting overall implant survival.

Nonsurgical Management of Medication-Related Osteonecrosis of the Jaws Using Local Wound Care

PURPOSE

Medication-related osteonecrosis of the jaws (MRONJ) is a known complication of antiresorptive medications with surgical and nonsurgical treatment options. The aim of this study was to evaluate the effectiveness of nonsurgical therapy using local wound care on management of MRONJ lesions.

MATERIALS AND METHODS

The authors conducted a retrospective cohort study of patients who presented to the University of California-Los Angeles School of Dentistry Oral and Maxillofacial Surgery Clinic for evaluation and treatment of MRONJ. The primary predictor variable was wound care score; secondary predictors were demographics (age, gender), anatomic location, primary condition, and type and time of antiresorptive treatment. Outcomes assessed were disease resolution and time to disease resolution. Statistical analysis was carried out using the Spearman correlation for continuous and ordinal variables or the χ2 test for categorical variables. Time-to-event statistics and Cox proportional hazards models were calculated; a Kaplan-Meier plot was generated to assess time to healing.

RESULTS

One hundred six patients with 117 MRONJ lesions were treated using local wound care; complete disease resolution was observed 71% of lesions, with an additional 22% of lesions undergoing disease improvement. Wound care score was statistically associated with disease resolution and time to resolution, whereas demographics, anatomic site, condition, and type and time of antiresorptive treatment had no effect on resolution.

CONCLUSION

Local wound care increased the likelihood of MRONJ resolution and decreased the time to disease resolution. This strategy can be used in patients who cannot undergo surgery and should be implemented in all patients with MRONJ lesions who are managed nonsurgically.

Factors Affecting Dental Rehabilitation Following Jaw Reconstruction With Free-Fibular Graft In Patients With Head and Neck Cancer

Existing anatomic factors play a significant role in affecting the possibility of dental rehabilitation in head and neck cancer patients undergoing free-fibular graft reconstruction. An observational, cross-sectional study was initiated to evaluate factors affecting dental rehabilitation following free-fibular graft jaw reconstruction in head and neck cancer patients.Patients who had undergone jaw reconstruction with free-fibular graft, requiring dental rehabilitation were recruited. Irradiated, reconstructed patients who had completed at least 1 year since the last dose of radiotherapy and nonradiated patients who had completed 6 months since reconstruction were recruited. Patients who had undergone soft-tissue reconstruction or free-fibular graft in non-condyle sparing resections were excluded. Patient's demographic data, disease and treatment-related data were obtained. An intra-oral examination was carried out to evaluate anatomic variables affecting dental rehabilitation. Descriptive statistical analyses were carried out to study demographic data. Logistic regression analysis was carried out using Pearson χ test and Fisher exact test. Estimates of regression coefficient and their standard errors with 95% confidence interval were calculated.Total of 138 patients were enrolled and considered for prosthetic rehabilitation. A review of the frequency-based data revealed that 30% (n = 41) patients were considered suitable for prosthetic rehabilitation. On multivariate logistic regression analysis, morbidity of radiotherapy (P = 0.01), interference to placement of implants by reconstruction plates and screws (P = 0.023), unfavorable diagnostic maxilla-mandibular relationship (P = 0.011), and obliterated vestibule (P = 0.001) were statistically established (P < 0.05) as the most significant reasons for not carrying out dental rehabilitation in patients who had undergone free-fibular graft reconstruction.

Accuracy of computer-assisted surgery in mandibular reconstruction: A systematic review

Computer-assisted surgery (CAS) for mandibular reconstruction was developed to improve conventional treatment methods. In the past years, many different software programs have entered the market, offering numerous approaches for preoperative planning and postoperative evaluation of the CAS process of mandibular reconstruction. In this systematic review, we reviewed planning and evaluation methods in studies that quantitatively assessed accuracy of mandibular reconstruction performed with CAS. We included 42 studies describing 413 mandibular reconstructions planned and evaluated using CAS. The commonest software was Proplan/Surgicase CMF (55%). In most cases, the postoperative virtual 3-dimensional model was compared to the preoperative 3-dimensional model, revised to the virtual plan (64%). The commonest landmark for accuracy measurements was the condyle (54%). Accuracy deviations ranged between 0 mm and 12.5 mm and between 0.9° and 17.5°. Because of a lack of uniformity in planning (e.g., image acquisition, mandibular resection size) and evaluation methodologies, the ability to compare postoperative outcomes was limited; meta-analysis was not performed. A practical and simple guideline for standardizing planning and evaluation methods needs to be considered to allow valid comparisons of postoperative results and facilitate meta-analysis in the future.

Non-vascularised fibular bone graft after vascular crisis: compensation for the failure of vascularised fibular free flaps

After reconstruction of a segmental mandibular defect with a fibular free flap, a vascular crisis can be detected clinically and a "no-flow" phenomenon found during re-exploration. Traditional methods used to solve this include removal of the failed flap and delayed mandibular reconstruction, or restoration of the defect with a functional reconstruction plate or contralateral fibular free flap. Our aim therefore was to investigate under what circumstances it is feasible to use a non-vascularised fibular bone graft (NVFB) as a free bone graft after the failure of a vascularised fibular free flap. From 1 January 2010-31 December 2014, 10 patients who had NVFB after failure of a fibular free flap were included in the study. All patients were treated at the Peking University School and Hospital of Stomatology. NVFB were preserved successfully without infection in all 10 cases, and follow-up imaging showed that it had incorporated well with the residual mandible, the basic function and facial aesthetics of which were maintained. In conclusion we have identified that by precise selection of patients, detailed preoperative planning, and meticulous postoperative care, NVFB can be used as a "rescue" technique after failure of a fibular free flap, and can successfully restore the segmental mandibular defect and facial contour.

Three-dimensional accuracy of mandibular reconstruction by patient-specific pre-bent reconstruction plates using an "in-house" 3D-printer

PURPOSE

The purpose of this study was to compare the three-dimensional accuracy of mandibular reconstruction following mandible continuity resection in patients treated with patient-specific, pre-bent reconstruction plates, using an 'in-house' 3D printer, with that in patients treated with conventional, intraoperatively bent plates.

PATIENTS AND METHODS

We retrospectively analyzed 42 alloplastic mandibular reconstructions following continuity resection. 21 patients received patient-specific, pre-bent reconstruction plates using an in-house 3D printer. The control group consisted of 21 patients provided with intraoperatively bent reconstruction plates. Distances between corresponding anatomical landmarks on the mandibular angle and condyle (A-A', BB', CC', BC'), as well as the intercondylar angle (ICA), were measured and compared on the pre- and postoperative CT scans.

RESULTS

Multivariate analysis of variance (MANOVA) showed significant multivariate main effect of group (F_{(5, 36)} = 5.58, p = 0.001; Wilks lambda 0.564; partial η² = 0.436), indicating more accurate postoperative results for the pre-bent group. Post-hoc comparison revealed significantly larger postoperative deviation in the distances between the mandibular angle and the intercondylar angle (ICA) for the intraoperatively bent group in comparison with the pre-bent group. However, there was no significant effect on the distance between the condyles.

CONCLUSIONS

Mandibular reconstructions employing patient-specific, pre-bent reconstruction plates made using an in-house 3D printer show significantly better three-dimensional accuracy compared with intraoperatively bent plates. The described method prevents rotational error of the mandibular angle and improves restoration of the physiological intercondylar angle in mandible reconstruction after continuity resection.

Implant rehabilitation in fibula-free flap reconstruction: A retrospective study of cases at 1-18 years following surgery

PURPOSE

To determine the dental implant and prostheses success rate in a cohort of patients who underwent a vascularized fibula-free flap (FFF) for maxillary or mandibular reconstruction.

METHODS

The investigators implemented a retrospective cohort study composed of patients who had undergone primary or secondary FFF reconstruction jaw surgery plus placement of 2-6 implants in the reconstructed arch, which were restored with an implant-supported prosthesis. The sample was composed of all patients who underwent FFF surgery between 1998 and 2012 and had either simultaneous or secondary dental implant placement. A total of 28 patients met inclusion criteria. Of these, 22 patients participated in the retrospective review. Patients were examined by an independent observer between January-December 2015. In addition, all patients completed a questionnaire to access satisfaction with the implant-supported prosthesis.

RESULTS

The patient cohort consisted of 12 males and 10 females, age 12-70 years. A total of 100 implants were placed, 92 implants in fibular bone and 8 implants in native bone. In the maxilla, 35 implants were placed into fibular bone and 4 into native bone (11 in irradiated patients and 28 in non-irradiated patients). In the mandible, 57 implants were placed into fibular bone and 4 into native bone (15 in irradiated patients and 46 in non-irradiated patients). The mean follow-up after implant loading was 7.8 years (range 1.3-17.5 years). The implant survival rate was 98% (95% CI: 92.2%-99.5%). No statistically significant difference was found in implant success between maxillary and mandibular implants, or between radiated and non-radiated bone. The prostheses success rate, determined by clinical exam and patient satisfaction, was 100%.

CONCLUSION

The results of this study suggest that implant survival is high and implant-supported prostheses are a reliable rehabilitation option in patients whose jaws have been reconstruction with a FFF.

Mandibular Rami Implant: A New Approach in Mandibular Reconstruction

PURPOSE

The mandible is an essential esthetic and functional component of the lower third of the face and its reconstruction has always been a challenge, especially after severe post-traumatic injuries. The purpose of the present report was to introduce a new approach of mandibular reconstruction in a patient who had lost the entire mandible except for the rami after being severely injured in a blast.

MATERIALS AND METHODS

A new approach using a titanium mandibular rami implant technique was applied using computer-aided 3-dimensional virtual planning and rapid prototyping technology. A prosthetic component was supported by the mandibular implant, which achieved occlusion and dedicated function for the patient.

RESULTS

This method offered precise adaptation of the implant and prosthesis and an easier surgical procedure, providing a shortened operation time, no donor site morbidity, and more predictable outcomes.

CONCLUSION

This new technique allows reconstruction of large-scale mandibular defects that is not possible by conventional surgical methods.

Reconstruction of large mandibular defects using autologous tissues generated from in vivo bioreactors

Reconstruction of large mandibular defects is clinically challenging due to the need for donor tissue of appropriate shape and volume to facilitate high fidelity repair. In order to generate large vascularized tissues of custom geometry, bioreactors were implanted against the rib periosteum of 3-4year-old sheep for nine weeks. Bioreactors were filled with either morcellized autologous bone, synthetic ceramic particles, or a combination thereof. Tissues generated within synthetic graft-filled bioreactors were transferred into a large right-sided mandibular angle defect as either avascular grafts (n=3) or vascularized free flaps (n=3). After twelve additional weeks, reconstructed mandibular angles were harvested and compared to contralateral control angles. Per histologic and radiologic evaluation, a greater amount of mineralized tissue was generated in bioreactors filled with autologous graft although the quality of viable bone was not significantly different between groups. Genetic analyses of soft tissue surrounding bioreactor-generated tissues demonstrated similar early and late stage osteogenic biomarker expression (Runx2 and Osteocalcin) between the bioreactors and rib periosteum. Although no significant differences between the height of reconstructed and control mandibular angles were observed, the reconstructed mandibles had decreased bone volume. There were no differences between mandibles reconstructed with bioreactor-generated tissues transferred as flaps or grafts. Tissues used for mandibular reconstruction demonstrated integration with native bone as well as evidence of remodeling. In this study, we have demonstrated that synthetic scaffolds are sufficient to generate large volumes of mineralized tissue in an in vivo bioreactor for mandibular reconstruction.

STATEMENT OF SIGNIFICANCE

A significant clinical challenge in craniofacial surgery is the reconstruction of large mandibular defects. In this work, we demonstrated that vascularized tissues of large volume and custom geometry can be generated from in vivo bioreactors implanted against the rib periosteum in an ovine model. The effects of different bioreactor scaffold material on tissue ingrowth were measured. To minimize donor site morbidity, tissues generated from bioreactors filled with synthetic graft were transferred as either vascularized free flaps or avascular grafts to a large mandibular defect. It was demonstrated that synthetic graft in an in vivo bioreactor is sufficient to produce free tissue bone flaps capable of integrating with native tissues when transferred to a large mandibular defect in an ovine model.

Metallic Fixation of Mandibular Segmental Defects: Graft Immobilization and Orofacial Functional Maintenance

The aim of this study is to investigate the behavior of the healthy mandible under maximum molar bite force to demonstrate the problems associated with the current standard of care procedures for mandibular segmental defect reconstruction (ie, use of Ti-6Al-4V hardware and either a single- or double-barrel fibular graft). With current Ti-6Al-4V mandibular reconstruction hardware, there is a significant stiffness mismatch among the hardware, graft, and the remaining host anatomy. How the distribution of mechanical forces through the mandible is altered after a segmental bone loss and reconstruction is incompletely understood.

METHODS

We studied a healthy adult mandible for stress, strain, and reaction force distribution during normal mastication. Stress distribution of this model was then used to study problems encountered after mandibular segmental defect reconstructive surgery. We model the use of both single- and double-barrel fibular grafts to repair the loss of the left M₁-₃ containing segment of the mandible. These simulations were done using 2 sets of plates with different thicknesses.

RESULTS

We found that the stiffness mismatching between the fixation hardware and the graft and host bone causes stress shielding of that bone and stress concentrations in the fixation hardware and screws. These effects are expected, especially during the bone healing period. However, long term, this abnormal stress-strain distribution may lead to either the hardware's failure due to stress concentration or graft failure due to bone resorption as a result of stress shielding. We found that the stress-strain distribution is more normal with a double-barrel fibular graft. Additionally, we found that thinner fixation plates can reduce stress shielding.

CONCLUSION

The proposed model can be used to evaluate the performance and optimization of the fixation device.

Resorbable Mesh as a Containment System in Mandibular Reconstruction

The recent advances seen in computer technologies and biomaterials have changed the approach to craniomaxillofacial surgery. In this report, the authors describe the technique of using a resorbable containment system for bone graft in a large mandibular reconstruction patient. The authors provide a patient report with a 1-year follow-up.

Perioperative risk factors for postoperative pulmonary complications after major oral and maxillofacial surgery with microvascular reconstruction: A retrospective analysis of 648 cases

BACKGROUND

Postoperative pulmonary complications (PPCs) are common and result in prolonged hospital stays, higher costs and increased mortality. However, data on the incidence and predictors of PPCs after major oral and maxillofacial surgery with microvascular reconstruction are rare. This retrospective analysis identifies perioperative risk factors for postoperative pulmonary complications (PPCs) after major oral and maxillofacial surgery with microvascular reconstruction.

METHODS

Perioperative data and patient records of 648 subjects were analyzed in the period of June 2007 to May 2013. PPCs were defined as pneumonia, atelectasis, pleural effusions, pulmonary embolism, pulmonary oedema, pneumothorax or respiratory failure.

RESULTS

18.8% of all patients developed PPCs. Patient-related risk factors for PPCs were male sex, advanced age, smoking, alcohol abuse, a body mass index >30, American Society of Anaesthesiologists grade higher than 2, pre-existent pulmonary diseases and preoperative antihypertensive medication. Among the investigated procedure-related variables, the length of the operation, the amount of fluid administration and blood transfusion and an impaired oxygenation index during surgery were shown to be associated with the development of PPCs. Using a multivariable logistic regression model, we identified a body mass index >30, American Society of Anaesthesiologists grade higher than 2 and alcohol abuse as independent risk factors for PPCs.

CONCLUSIONS

Several perioperative factors can be identified that are associated with the development of PPCs. Patients having one or more of these conditions should be subjected to intensified postoperative pulmonary care.

A systematic review of functional outcome and quality of life following reconstruction of maxillofacial defects using vascularized free fibula flaps and dental rehabilitation reveals poor data quality

BACKGROUND

Reconstruction and oral rehabilitation of segmental maxillofacial defects resulting from ablative surgery is commonly achieved by osteocutaneous vascularized free fibula (VFFF) transplantation combined with implant-supported dental prostheses. We systematically reviewed the literature regarding impact of oral rehabilitation with or without dental implants on functional outcome and quality of life (Qol) following reconstruction of such segmental maxillofacial defects with VFFF.

METHODS

This systematic review was performed according to the PRISMA guidelines. A literature search was conducted using the databases of Cochrane, MEDLINE and EMBASE. Relevant search terms for maxilla or mandible, reconstruction with VFFF, and oral rehabilitation were used. Two reviewers independently assessed the publications using eligibility and research quality criteria (MINORS).

RESULTS

In total, 554 unique publications were found. After scrutinization, 2 prospective studies and 8 retrospective case-series without comparison were left for ultimate analysis. Quality ranged from 44% to 88% of the maximum score. Overall survival rate of the VFFF was 99% and the survival rate of dental implants was 95%. Speech intelligibility and overall aesthetic outcome were 'good' to 'excellent'. No statistically significant changes in QoL were found. Methods to measure functional outcome varied strongly, making pooling impossible.

CONCLUSIONS

Oral rehabilitation with implant-supported dental prostheses after reconstruction of segmental maxillofacial defects with VFFF results in good to excellent speech intelligibility and aesthetics. Results are probably positively biased by the retrospective nature of the studies. In future prospective research, functional outcome measures should be addressed using standardized questionnaires and validated objective tests with adequate follow-up.

3D Finite Element Study on: Bar Splinted Implants Supporting Partial Denture in the Reconstructed Mandible

AIM:

This study aimed to estimate the stress patterns induced by the masticatory loads on a removable prosthesis supported and retained by bar splinted implants placed in the reconstructed mandible with two different clip materials and without clip, in the fibula-jaw bone and prosthesis using finite element analysis.

METHODS:

Two 3D finite element models were constructed, that models components were modeled on commercial CAD/CAM software then assembled into finite element package. Vertical loads were applied simulating the masticatory forces unilaterally in the resected site and bilaterally in the central fossa of the lower first molar as 100N (tension and compression). Analysis was based on the assumption full osseointegration between different types of bones, and between implants and fibula while fixing the top surface of the TMJ in place.

RESULTS:

The metallic bar connecting the three implants is insensitive to the clips material. Its supporting implants showed typical behavior with maximum stress values at the neck region. Fibula and jaw bone showed stresses within physiologic, while clips material effect seems to be very small due to its relatively small size.

CONCLUSION:

Switching loading force direction from tensile to compression did-not change the stresses and deformations distribution, but reversed their sign from positive to negative.

Sagittal split osteotomy on the previously reconstructed mandible with fibula free flap

The fibula free flap offers several advantages in mandibular reconstruction, including an optimal length and bone quality for dental implantation; therefore, the use of this flap has become a method of choice for mandibular reconstruction. Although the development of computer-assisted surgical planning has increased the accuracy of mandibular reconstruction, some unexpected outcomes still occur in clinical settings. The patient in this report underwent mandibular reconstruction with the fibula free flap because of mandibular resection resulting from an ameloblastoma. However, unexpected movement of the grafted fibula bone had been observed, and we could not achieve a proper occlusal relationship even with implant-supported prosthesis. To resolve this problem, we corrected the position of previously grafted fibula and implants by using orthognathic surgery: sagittal split osteotomy on body and angle area and vertical osteotomy on the mandibular symphysis. After the orthognathic surgery at the previously reconstructed mandible with fibula free flap, a favorable and stable occlusal relationship could be achieved. The result demonstrated that the sagittal split osteotomy at the previous fibula free flap site can be successfully carried out to establish the proper occlusion.

Oral Cavity Carcinoma: Current Management, Controversies, and Future Directions

Oral cavity carcinoma (OCC) remains a major cause of morbidity and mortality in patients with head and neck cancer. Although the incidence has decreased over the last decade, outcomes remain stagnant with only a 5% improvement in overall survival in the last 20 years. Although surgical resection remains the primary treatment modality, several areas of controversy exist with regard to work-up, management of the primary and neck tumors, and adjuvant therapy. As surgical techniques evolve, so has the delivery of radiotherapy and systemic treatment, which have helped to improve the outcomes for patients with advanced disease. Recently, the addition of cetuximab has shown promise as a way to improve outcomes while minimizing toxicity, and this remains an active area of study in the adjuvant setting. Advances in microvascular free-flap reconstruction have extended the limits of resection and enabled enhanced restoration of function and cosmesis. While these advances have led to limited survival benefit, evaluation of alternative modalities has gained interest on the basis of success in other head and neck subsites. Organ preservation with definitive chemoradiotherapy, though proven in the larynx and pharynx, remains controversial in OCC. Likewise, although the association of human papillomavirus is well established in oropharyngeal carcinoma, it has not been proven in the pathogenesis or survival of OCC. Future study of the molecular biology and pathogenesis of OCC should offer additional insight into screening, treatment selection, and novel therapeutic approaches.

Effect of proper oral rehabilitation on general health of mandibulectomy patients

Here, we aimed to assess whether postoperative oral rehabilitation for mandibulectomy patients is necessary to improve patients’ general health in terms of health-related quality of life.

Evaluation of swallowing function after supracricoid laryngectomy as a primary or salvage procedure

The primary functional issues following conservative therapy for advanced laryngeal cancer concern swallowing. Here, we evaluated the recovery of swallowing after supracricoid partial laryngectomy (SCL) in patients with primary or recurrent laryngeal cancer. We evaluated the swallowing recovery in 27 SCL patients through oropharyngoesophageal scintigraphy, and we evaluated their quality of life using EORTC questionnaires. Four patients underwent total laryngectomy during follow-up. Patients who retained their larynges were able to feed without nutritional support and without tracheostoma. The only significantly different parameter between the primary and salvage cases was the time elapsed to the removal of nasogastric/PEG tubes, which was longer in salvage cases. SCL has been demonstrated as a valuable option for primary and recurrent laryngeal cancer patients. The present data demonstrate good functional results, particularly in terms of swallowing after previous treatments and in primary settings. The combination of oropharyngoesophageal scintigraphy and questionnaires appears to be an adequate, standardizable approach to assessing swallowing function after SCL.

Reconstruction of the segmental mandibular defect using a retroauricular or modified face-lift incision with an intraoral approach in head and neck cancer

CONCLUSIONS

This is the first report of mandibular reconstruction using the retroauricular (RA) or the modified face-lift (MFL) approach in head and neck cancer. This approach may have advantages over the conventional approach, especially in its superior aesthetic results.

OBJECTIVE

The fibular osseous or osteocutaneous free flap is a widely accepted option for the reconstruction of mandibular defects. Recently, we devised an RA or an MFL approach for neck dissection (ND) using an endoscopic or robotic surgical system. Here, we performed the reconstruction of a segmental mandibular defect with a fibular free flap using the RA or the MFL approach.

METHODS

A total of five patients underwent mandibular reconstruction with the RA or MFL approach for mandibular discontinuity, which developed after the surgical extirpation of head and neck cancer. We performed ND, segmental mandibulectomy, and the reconstruction of the mandibular defect via RA or MFL incisions.

RESULTS

An osseous free flap was used for the reconstruction in two patients and the osteocutaneous free flap was used in three patients. The mean operation times for mandibulectomy and ND were 82 (range 45-120) min and 156 (range 140-180) min, respectively. No significant complications were noted. All flaps survived successfully.