Mandibular Reconstruction Research Articles

Osteosynthesis for mandibular reconstruction with fibula free flap: Which type and why? A French national survey

We explored the most suitable osteosynthesis type for mandibular reconstruction using fibula free flap (FFF) given the lack of robust data available. For this, an anonymous survey was e-mailed to 853 head-and-neck surgeons (France) asking about their practices and criteria guiding their osteosynthesis material and method choices. Questions assessed: (1) the most frequently used osteosynthesis type, (2) the explanatory variables related to surgeon career status/surgical specialty, and (3) justifications for osteosynthesis type (scientific, technical, "misuse"). Multivariate logistic regression was performed to test for associations of explanatory variables with plate type or misuse. Overall, 118 (13.8%) surgeons responded, among which flexible non-locking osteosynthesis was preferred (59%). Career status and surgical specialty were significantly associated with material choice. University professors/senior lecturers (OR 5.96 vs academic clinical associates; p = 0.02), but not ear-nose-throat/reconstructive plastic surgeons (OR 0.22 vs maxillofacial surgeons; p = 0.04), were more likely to opt for rigid locking osteosynthesis. Private practitioners preferred flexible non-locking osteosynthesis (OR = 5.03; p = 0.04). Only 18% of surgeons scientifically justified their choices. We considered misuse among 65% of surgeons and this was significantly associated with irregular practice of FFF surgery (OR 2.28 vs > 10 surgeries/year; p = 0.04). Overall, >50% of surgeons mainly rely on habits without scientific arguments assisting in decision-making.

Soft tissue movements after mandibular reconstruction using the vascularized iliac flap: patterns and predictions.

To investigate soft-to-hard tissue response following mandibular reconstruction and to develop a predictive model for projecting soft tissue movement. In this retrospective study, 18 patients receiving mandibular reconstruction using a vascularized iliac flap were enrolled. Various indicators for characterizing the movement of tissues were considered to identify the effective predictors for projecting soft tissue movements. Face-region-specific linear regression models for prediction were constructed and evaluated. The arithmetic mean of hard tissue movement in an extended area had the strongest correlation with the movement of the focal soft tissue, while the arithmetic mean in a regional area (Ram) was a more effective predictor. The linear regression model using Ram, global extrema and distances between them as the predictors performed the best in the lower margin of the face, with an average error of 1.51 ± 1.38mm. Soft tissue movement in the alveolar process was not correlated with the existence of dentition, only can be predicted by the soft tissue movement below it. The area of the masseter was strongly correlation with Ram, but no other factors. An accurate prediction of soft tissue movements in the lower margin and the alveolar process of the face can be achieved by considering hard tissue and adjacent soft tissue movements. No effective predictor in the masseter area was identified. We investigated the relationship between hard tissue movements and the soft tissue responses in the facial area. Through building predictive models for projecting postoperative soft tissue movements, we derive insights for the aesthetic outcome of face surgeries. This study was registered on the Chinese Clinical Trial Registry (registration number: ChiCTR2100054103).

Design and evaluation of mechanical strength of multi-material polymeric implants for mandibular reconstruction.

Reconstruction of mandible implants to address segmental abnormalities is still a challenging task, both in vitro and in vivo. The mechanical strength of the materials used is a critical factor that determines how well bone is regenerated. The reconstruction technique of mandibular abnormalities widely uses polymeric implants. It is critical to evaluate the mechanical resilience under different load cases, including axial, combined, and flexural loading conditions. This study developed implants for mandibular defects using a combination of four materials: polylactic acid (PLA), polyethylene terephthalate glycol (PETG), thermoplastic polyurethane (TPU), and polycaprolactone (PCL), with the aim of mimicking the inherent characteristics of cortical and cancellous bone structures and evaluating their mechanical properties to support bone Osseo integration. The eleven of these combinations of structures result below the micro strain threshold level of <3000 µε, and the five combinations of the structures result in micro strain above the threshold value. The intact bone study results show that the stress under axial, combined, and flexural loading conditions is 27.6, 38.9, and 64.9 MPa, respectively. This study's stress results are lower than those from the intact bone study. The study found that the combinations of PLA and TPU material were most preferred for the cortical and cancellous bone regions of polymeric implants. These materials are also compatible with 3D printing. The results of this study can be used to find multi-material combinations that are strong and flexible.

A comparison of preoperative soft tissue contour versus bone accuracy as a predictor of quality of life outcomes in osseous free flap jaw reconstruction using occlusal-based virtual surgical planning

ObjectivesOcclusal based virtual surgical planning (VSP) prioritises placement of endosseous dental implants, over replicating native bone contour. This may compromise facial aesthetics. This study aims to compare function and health-related quality of life (HRQOL) following maxillomandibular reconstruction according to ability to replicate preoperative soft-tissue contour and virtual plan. Materials and methodsPatients who had undergone occlusal based VSP osseous free flap reconstruction of the maxilla or mandible, with high-resolution pre- and postoperative facial computerised tomography imaging, and completion of FACE-Q questionnaire were retrospectively identified. Accuracy of reconstruction compared to preoperative soft tissue contour and virtual plan, was measured using 3DSlicer® and CloudCompare® in three dimensions. Random effects modelling determined associations between bony and soft tissue accuracy and HRQOL/functional domains. ResultsTwenty-two patients met the inclusion criteria. For mandibular and maxillary reconstructions, better soft tissue accuracy was associated with improved appearance (p = 0.048) and appearance distress (p = 0.034). For mandibular reconstructions, better soft tissue accuracy was associated with improved smile (p=0.039) and smile distress (p=0.031). For maxillary reconstructions, better bony accuracy was associated with improved appearance (p=0.023) and drooling distress (p=0.001). Unexpectedly, better bony accuracy was associated with worse eating and drinking (p=0.015), oral competence (p=0.005) and eating distress (p=0.013) in mandibular reconstructions. ConclusionWhilst soft tissue accuracy was associated with better functional and HRQOL outcomes, bone accuracy was associated with worse oral function/distress in mandibular reconstruction. These results need validation but should be considered when performing occlusal-based VSP, which prioritises dental rehabilitation over replicating facial bony contour.

Segmental mandibulectomy and microvascular reconstruction with fibula free flap: Comparison between intraoral and extraoral approaches

BackgroundSegmental mandibulectomy and reconstruction of resulting defect can be performed via intraoral approach (IOA) or extraoral approach (EOA). Both approaches have advantages, disadvantages, indications, contra-indications to consider during their selection. ObjectiveTo compare IOA vs EOA of segmental mandibulectomy and microvascular reconstruction with fibula free flap (FFF). MethodsWe conducted a retrospective cohort study in which 51 patients who underwent segmental mandibulectomy and microvascular reconstruction with FFF from 2020 to 2024 were included, especially 17 patients by IOA and 34 patients by EOA, representing both groups of this study. Clinical characteristics, surgery parameters, and patients’ prognosis were evaluated. Patients’ satisfaction and DAS59 were assessed during follow-up. ResultsAmeloblastoma was the most frequent diagnosis (52.9% by IOA vs 70.6% by EOA); FFF was frequently positioned as double barrel (94.1% by IOA vs 88.2% by EOA). Compared to EOA group, IOA group had fewer intraoperative blood loss (MD = -112.2, 95% CI (-178.9 to -45.5), p = 0.001), higher satisfaction score (MD =1.3, 95% CI (0.9 to 1.7), p ˂ 0.001), and lower DAS59 score (MD = -0.5, 95% CI (-0.7 to -0.2), p ˂ 0.001). ConclusionBoth IOA and EOA were found safe and feasible, presenting similar perioperative features and postoperative outcomes. IOA patients were very satisfied with esthetic outcome than EOA patients. In absence of simultaneous immediate implant during mandibular FFF reconstruction, after stability of FFF on the defect site patients should always be referred to implantologist and/or prosthodontist for teeth restoration to improve functional and esthetic outcomes.

Investigation of the Mechanical Strength of Artificial Metallic Mandibles with Lattice Structure for Mandibular Reconstruction.

Mandibular reconstructive surgery is necessary for large bone defects. Although various reconstruction methods have been performed clinically, there is no mandibular reconstruction method that meets both sufficient strength criteria and the patient's specific morphology. In this study, the material strength of the cylindrical lattice structures formed by electron-beam melting additive manufacturing using titanium alloy powder was investigated for mandibular reconstruction. The virtual strengths of 28 lattice structures were compared using numerical material tests with finite element method software. Subsequently, to compare the material properties of the selected structures from the preliminary tests, compression test, static bending test and fatigue test were conducted. The results showed that there were correlations with relative density and significant differences among the various structures when comparing internal stress with deformation, although there was a possibility of localized stress concentration and non-uniform stress distribution based on the lattice structure characteristics. These results suggest that the lattice structure of body diagonals with nodes and a cell size of 3.0 mm is a potential candidate for metallic artificial mandibles in mandibular reconstruction surgery.

Long-Term Plate Complications in Patient-Specific Plates Utilizing Computer-Aided Design.

Assess the long-term plate complications with patient-specific plates (PSPs) created with computer-aided design (CAD) and computer-aided manufacturing (CAM) for fibula free flap reconstructions for mandibular defects. Retrospective chart review from January 2010 to July 2022 of patients who underwent mandibular reconstruction with a fibula free flap and PSP. Primary outcome was plating-related complications, defined as plate exposure, fracture, loose screws, and plate removal. A total of 221 patients underwent PSP fibula reconstruction. Average age was 59.8 + 14.3 years old with male to female ratio of 2:1. Squamous cell carcinoma of the mandible was the most common reason for resection, 47.5%, n = 105. Plate removal occurred in 11% of patients (n = 25) about 17.4 months after the initial surgery. Plates were removed due to exposure (76%, n = 19) or screw loosening (24%, n = 6). Malignancy was associated with an increased risk of plate complications when compared to benign tumor (odds ratio [OR] 9.04, confidence interval [CI] 1.36-3.85), osteonecrosis (OR 1.38, CI 0.59-3.48), and trauma (OR 1.26, CI 0.23-12.8). Postoperative radiation therapy (OR 2.27, CI 1.07-4.82, p = 0.026) and surgical site infection (OR 9.22, CI 4.11-21.88, p = 0.001) were associated with more plate complications. CAD creates PSPs that remain stable in the majority of patients over the long term. Plate removal is less compared to non-PSP reconstruction. Consideration of the soft tissue envelope over the plate and management of perioperative infection at the time of surgery should be entertained. Level 4 Laryngoscope, 2024.

Guided Mandibular Reconstruction Based on CAD/CAM Technology

Guided Mandibular Reconstruction Based on CAD/CAM Technology

Double-Flap Elevation From the Ipsilateral Lower Extremity: The Anterior Approach to Fibula Osteo-Cutaneous Flap Elevation.

The free fibular flap has been elevated by a "lateral approach" from the posterior edge of the peroneal muscle for more than 40 years. However, in this approach, the surgical view is limited because flap elevation in mandibular reconstruction is performed simultaneously with tumor resection in the supine position, even when using positioning pillows. We herein propose an "anterior approach" as a new surgical method. We retrospectively investigated free fibular flap surgeries performed using the anterior approach, which consists of three anterior approaches, over a seven-year period. First, to avoid the course of the superficial peroneal nerve, the crural fascia was incised 1-2 cm posterior to the anterior edge of the peroneal muscle. The anterior edge of the peroneus muscle is detached from the anterior intermuscular septum. After performing osteotomies distal and proximal to the fibula, the interosseous membrane was incised from the anterior view. Pulling out the fibula to the anterior space between the anterior intermuscular septum and the peroneal muscle made the surgical field shallow. No postoperative superficial or deep peroneal nerve palsies were found in the 55 patients. Only one tourniquet was used in 31 of the 55 cases (56.4%), with an average of 95 min. Twenty-four patients (43.6%) required a second tourniquet 38 min after an interval. Only one tourniquet was used in 25 of the 30 (83.3%) cases in the last 3 years. Moreover, double flaps were used in 21 cases (38.2%), all of which involved ipsilateral ALT flaps. In 18 cases, double-flap elevation and prefabrication were successfully finished before the completion of tumor resection by otorhinolaryngologists.

Progress of Ossification after Mandibular Reconstruction by Free Fibula Flap Depending on Different Timing of Radiotherapy: A Retrospective 3D Analysis by CT Scans.

Background: The aim of this study was to evaluate the difference between pre- and post-operative radiotherapy on the progress of ossification after free fibula flap reconstruction of the mandible using three-dimensional (3D) analysis. Methods: A total of 38 free fibula reconstructions of the mandible were evaluated retrospectively for ossification between bone segments by measuring Hounsfield Units (HU) in at least two postoperative computer tomography scans (average of 2.4 scans per patient; around the 5th, 12th, 16th, and 19th month postoperative). Three subgroups were created according to the time of irradiation: preoperative radiotherapy (preORT) (n = 11), postoperative radiotherapy (postORT) (n = 16), and patients without any radiation therapy (n = 11) as the control group (noRT). HU in eight regions of interest (ROI) and overlapping surfaces between segments per contact point, as well as influencing factors, were analyzed. Results: The fastest progress in gain of HU ossification with a difference of 0.30 HU/day was observed in noRT compared to preORT (p = 0.002). postORT was -0.24 HU/day slower than preORT (p = 0.005). Original and grafted bone showed a significantly slower HU uptake than between two graft segments with -84.18 HU/day (p < 0.001). Moreover, a larger initial overlapping surface between the segments in cm2 resulted in a higher rise of HU/day (p < 0.001). Conclusions: 3D analysis of post-reconstructive CT scans shows prolonged ossification of mandible reconstructions by free fibula after head and neck radiation. The effect is distinct in cases with post-operative adjuvant radiotherapy. The effects of radiotherapy on ossification may be minimized by a larger initial contact surface and improved operational techniques. Moreover, HU longitudinal measurements and 3D analysis offer new perspectives for clinical evaluation of successful bony healing.

Long-Term Follow-Up of Computer-Assisted Microvascular Mandibular Reconstruction: A Retrospective Study.

Background: Virtual surgical planning has become a well-established practice in head and neck surgery. In oncological surgery, it permits the achievement of safe margins resections and ensures functional reconstructions and optimal esthetic outcomes. This study aimed to evaluate the long-term outcomes after virtually planned mandibular microvascular reconstruction, focusing on functional and esthetic results, as well as health-related quality of life. Methods: A long-term retrospective evaluation of 17 patients with oral cavity malignancy who underwent computer-assisted mandibular resection and reconstruction was performed. Functional and esthetic outcomes were analyzed using the EORTC, QLQ-C30, H&N35, and FACE-Q questionnaires. Results: Time since reconstruction ranged from 7 to 14 years. Patients reported high functional levels on the QLQ-C30 functional scales but lower scores on H&N35. On FACE-Q, patients demonstrated higher appraisal and satisfaction with their smiles compared to their overall facial appearance. Conclusions: In this retrospective case series, patients undergoing computer-assisted mandibular reconstruction for oral malignancies achieved good long-term functional and esthetic outcomes. Although limited by the small sample size, these results support the enduring benefits of virtual planning for mandibular reconstruction. To minimize declines in function and appearance, considerations should include immediate dental implants, enhanced reconstruction of the temporomandibular joint, newer methods of radiotherapy to minimize xerostomia, and oral exercises to prevent trismus.

Custom Endoprosthesis-Assisted Pediatric Microsurgical Jaw Reconstruction.

Surgical treatment of pediatric maxillary and mandibular tumors can cause significant postresection disfigurement, mastication, and speech dysfunction. The need to restore form and function without compromising growth at the recipient and donor sites poses a particular reconstructive dilemma. This study evaluates outcomes of the custom endoprosthesis (CE) compared with noncustom reconstruction (NCR) and introduces an algorithm using CE to optimize available soft tissue reconstructive options. An Institutional Review Board-approved retrospective review of all patients undergoing maxillary or mandibular reconstruction between 2016 and 2022 was completed. The independent variable of interest was CE utilization. Primary outcomes of interest included hardware failure/removal or exposure, major complications, and revision surgeries. Covariates of interest included patient demographics, medical comorbidities, tumor size, and pathologic diagnosis. Statistical analyses including independent t test, χ2 analyses, and univariate/multivariate logistic regression were performed using RStudio version 4.2.1. Fifty-one patients (37 mandible and 14 maxilla) underwent CE or NCR. Of patients, 37% (n = 19) received CE. Of patients who underwent mandibular reconstruction, there were significantly lower rates of hardware exposure (14.3% versus 47.8%, P = 0.018), failure (7.1% versus 43.5%, P = 0.048), major complications (28.6% versus 78.2%, P = 0.008), and revisions (11.1% versus 50.0%, P = 0.002) in the CE cohort compared with the NCR cohort. The rates of hardware failure, exposure, major complications, and revisions did not significantly differ in maxillary reconstructions, however, CE successfully reconstructed significantly larger defects (179.5 versus 74.6cm3, P = 0.020) than NCRs. Deviating from NCR, the authors propose an algorithm considering anatomical location, extent of resection, and patient age for soft tissue selection. This algorithm yielded improved mandibular reconstructive outcomes and no increase in complications rate in maxillary reconstruction despite larger resection defects. Furthermore, the authors' initial findings demonstrate that CE is a safe option for pediatric maxillary and mandibular reconstruction that may, in addition, facilitate improved form and function.

One-stage prosthodontically driven jaw reconstruction in patients with benign and malignant pathologies: A 7- to 11-year cohort study.

One stage functional jaw reconstructionis defined as the resection and reconstruction of segmental defects in conjunction with the placement of dental implants in an ideal prosthetic position and loaded with a provisional restoration, during one surgical procedure. The aim of the study is to describe clinical outcomes of patients who underwent one stage functional jaw reconstruction. Patients who underwent one-stage functional jaw reconstruction, from January 2013 to March 2016 were recalled in 2022 and 2023. Planning and execution for the reconstruction utilized either analogue or digital techniques. Outcome parameters recorded were treatment-related outcomes at patient level, implant-related outcomes and patient-reported outcome measures. Eighteen patients underwent one-stage jaw reconstruction with a total of 57 implants. Four patients had maxillary and 14 had mandibular reconstructions. Ten patients underwent postoperative radiotherapy. Ten patients were planned using analogue and eight by digital planning. Three patients had partial flap necrosis, three patients had plate fractures, implant loss was seen in one patient and four patients died during the period. A functional prosthesis was provided in 16 out of the 18 patients. One-stage functional jaw reconstruction is a predictable method for providing rehabilitation with successful outcomes at 7-11 years. However, caution should be exercised when the treatment modality is carried out in patients with malignant pathologies who have undergone radiotherapy.

Postoperative facial prediction for mandibular defect based on surface mesh deformation

Objectives: This study aims to introduce a novel predictive model for the post-operative facial contours of patients with mandibular defect, addressing limitations in current methodologies that fail to preserve geometric features and lack interpretability.Methods: Utilizing surface mesh theory and deep learning, our model diverges from traditional point cloud approaches by employing surface triangular mesh grids. We extract latent variables using a Mesh Convolutional Restricted Boltzmann Machines (MCRBM) model to generate a three-dimensional deformation field, aiming to enhance geometric information preservation and interpretability.Results: Experimental evaluations of our model demonstrate a prediction accuracy of 91.2 %, which represents a significant improvement over traditional machine learning-based methods.Conclusions: The proposed model offers a promising new tool for pre-operative planning in oral and maxillofacial surgery. It significantly enhances the accuracy of post-operative facial contour predictions for mandibular defect reconstructions, providing substantial advancements over previous approaches.

Long-term outcomes in virtual surgical planning for mandibular reconstruction: A cost-effectiveness analysis.

This study is an economic evaluation comparing virtual surgical planning (VSP) utilization to free hand mandibular reconstruction (FHR) for advanced oral cavity cancer, for which the cost effectiveness remains poorly understood. The proposed clinical benefits of VSP must be weighed against the additional upfront costs. A Markov decision analysis model was created for VSP and FHR based on literature review and institutional data over a 35-year time horizon. Model parameters were derived and averaged from systematic review and institutional experience. VSP cost and surgical time saving was incorporated. We accounted for long-term risks including cancer recurrence and hardware failure/exposure. We calculated cost in US dollars and effectiveness in quality-adjusted-life-years (QALYs). A health care perspective was adopted, discounting costs and effectiveness at 3%/year. Deterministic and probabilistic sensitivity analyses tested model robustness. In the base case scenario, total VSP strategy cost was $49,498 with 8.37 QALYs gained while FHR cost was $42,478 with 8.27 QALY gained. An incremental cost-effectiveness ratio (ICER), or the difference in cost/difference in effectiveness, for VSP was calculated at $68,382/QALY gained. VSP strategy favorability was sensitive to variations of patient age at diagnosis and institutional VSP cost with one-way sensitivity analysis. VSP was less economically favorable for patients >75.5 years of age or for institutional VSP costs >$10,745. In a probabilistic sensitivity analysis, 55% of iterations demonstrated an ICER value below a $100,000/QALY threshold. VSP is economically favorable compared to FHR in patients requiring mandibular reconstruction for advanced oral cancer, but these results are sensitive to the patient's age at diagnosis and the institutional VSP cost. Our results do not suggest if one "should or should not" use VSP, rather, emphasizes the need for patient selection regarding which patients would most benefit from VSP when evaluating quality of life and long-term complications. Further studies are necessary to demonstrate improved long-term risk for hardware failure/exposure in VSP compared to FHR.

Exploring CT pixel and voxel size effect on anatomic modeling in mandibular reconstruction

BackgroundComputer-aided modeling and design (CAM/CAD) of patient anatomy from computed tomography (CT) imaging and 3D printing technology enable the creation of tangible, patient-specific anatomic models that can be used for surgical guidance. These models have been associated with better patient outcomes; however, a lack of CT imaging guidelines risks the capture of unsuitable imaging for patient-specific modeling. This study aims to investigate how CT image pixel size (X-Y) and slice thickness (Z) impact the accuracy of mandibular models.MethodsSix cadaver heads were CT scanned at varying slice thicknesses and pixel sizes and turned into CAD models of the mandible for each scan. The cadaveric mandibles were then dissected and surface scanned, producing a CAD model of the true anatomy to be used as the gold standard for digital comparison. The root mean square (RMS) value of these comparisons, and the percentage of points that deviated from the true cadaveric anatomy by over 2.00 mm were used to evaluate accuracy. Two-way ANOVA and Tukey-Kramer post-hoc tests were used to determine significant differences in accuracy.ResultsTwo-way ANOVA demonstrated significant difference in RMS for slice thickness but not pixel size while post-hoc testing showed a significant difference in pixel size only between pixels of 0.32 mm and 1.32 mm. For slice thickness, post-hoc testing revealed significantly smaller RMS values for scans with slice thicknesses of 0.67 mm, 1.25 mm, and 3.00 mm compared to those with a slice thickness of 5.00 mm. No significant differences were found between 0.67 mm, 1.25 mm, and 3.00 mm slice thicknesses. Results for the percentage of points deviating from cadaveric anatomy greater than 2.00 mm agreed with those for RMS except when comparing pixel sizes of 0.75 mm and 0.818 mm against 1.32 mm in post-hoc testing, which showed a significant difference as well.ConclusionThis study suggests that slice thickness has a more significant impact on 3D model accuracy than pixel size, providing objective validation for guidelines favoring rigorous standards for slice thickness while recommending isotropic voxels. Additionally, our results indicate that CT scans up to 3.00 mm in slice thickness may provide an adequate 3D model for facial bony anatomy, such as the mandible, depending on the clinical indication.

Patient-specific Implants Improve Volumetric Surgical Accuracy Compared to Stock Reconstruction Plates in Modern Paradigm Virtual Surgical Planning of Fibular Free Flaps for Head and Neck Reconstruction

BackgroundVirtual surgical planning (VSP) for composite microvascular free flaps has become standard of care for oncologic head and neck reconstruction. Controversy remains as to the use of three-dimensional (3D)-printed titanium patient specific implants (PSI) versus hand-bent stock reconstruction plates. Proponents of PSIs cite improved surgical accuracy, reduced operative times, and improved clinical outcomes. Detractors purport increased cost associated with PSIs and presumed equivalent accuracy with less expensive stock plates. PurposeThe study purpose was to measure and compare the 3D-volumetric accuracy of PSI versus stock reconstruction plates among subjects undergoing VSP-guided mandibular fibular free flap reconstruction. Study Design/Setting/SampleA retrospective cohort study of subjects undergoing VSP-guided fibular free flap reconstructions at Mayo Clinic between 2016-2023 was performed. Subjects were excluded for non-VSP guidance, midfacial reconstruction, non-fibular free flaps, and lack of requisite study variables. Predictor VariableThe primary predictor was the type of reconstruction plate utilized (PSI versus stock plate). Main Outcome VariableThe main outcome was volumetric surgical accuracy of the final reconstruction compared to the preoperative surgical plan by root mean square error (RMSE) calculation. Lower RMSE values indicated a higher surgical accuracy. CovariatesCovariates included age, sex, race, smoking status, ASA classification, Charlson Comorbidity Index, preoperative diagnosis, and number of fibular segments. AnalysisDifferences in surgical accuracy were assessed between pre- and post-operative segmented scans using volumetric overlays from which RMSE values were calculated. Univariate and multivariate modeling of plate type to RMSE calculation was performed. Statistical significance set to p<0.05. ResultsTotal of 130 subjects were identified, 105 PSI and 25 stock plates. Calculated mean RMSE in millimeters (mm) for stock plates was 1.46 (SD: 0.33) and 1.15 (SD: 0.36) for PSIs. Univariate modeling demonstrated a statistically significant difference in RMSE of 0.31 (95% CI: 0.16-0.47) (p<0.001) equating to a 21.2% (p<0.001) improved volumetric surgical accuracy for PSIs. The association of improved volumetric accuracy with PSIs maintained in all multivariate models controlling for confounding. Conclusion and RelevanceIn modern era VSP-guided head and neck fibular free flap reconstruction, patient-specific 3D-printed titanium implants confer a statistically significant improvement in volumetric surgical accuracy over stock reconstruction plates.

Evaluation of the Dimensional Accuracy of Robot-Guided Laser Osteotomy in Reconstruction with Patient-Specific Implants-An Accuracy Study of Digital High-Tech Procedures.

Background/Objective: With the rapid advancement in surgical technologies, new workflows for mandibular reconstruction are constantly being evaluated. Cutting guides are extensively employed for defining osteotomy planes but are prone to errors during fabrication and positioning. A virtually defined osteotomy plane and drilling holes in robotic surgery minimize potential sources of error and yield highly accurate outcomes. Methods: Ten mandibular replicas were evaluated after cutting-guided saw osteotomy and robot-guided laser osteotomy following reconstruction with patient-specific implants. The descriptive data analysis summarizes the mean, standard deviation (SD), median, minimum, maximum, and root mean square (RMS) values of the surface comparison for 3D printed models regarding trueness and precision. Results: The saw group had a median trueness RMS value of 2.0 mm (SD ± 1.7) and a precision of 1.6 mm (SD ± 1.4). The laser group had a median trueness RMS value of 1.2 mm (SD ± 1.1) and an equal precision of 1.6 mm (SD ± 1.4). These results indicate that robot-guided laser osteotomies have a comparable accuracy to cutting-guided saw osteotomies, even though there was a lack of statistical significance. Conclusions: Despite the limited sample size, this digital high-tech procedure has been shown to be potentially equivalent to the conventional osteotomy method. Robotic surgery and laser osteotomy offers enormous advantages, as they enable the seamless integration of precise virtual preoperative planning and exact execution in the human body, eliminating the need for surgical guides in the future.

Osteo-cutaneous Scapula Flap for Mandibular Reconstruction: A Reliable Alternative in Difficult Situations

Osteo-cutaneous Scapula Flap for Mandibular Reconstruction: A Reliable Alternative in Difficult Situations

Antiresorptive agents enhance ossification of free flap reconstructions of the mandible: a radiological retrospective cohort study.

The aim of this study was to investigate the effect of antiresorptive agents on the ossification of reconstructed mandibles by free bone grafts for the first time. A total of 38 reconstructions of the jaw were retrospectively evaluated for ossification between bone segments by two raters based on postoperative panoramic radiographs. The study group (n = 13) had segmental resection of the mandible and free bone flap reconstruction due to medication-related osteonecrosis of the jaw (MRONJ). The control group (noMRONJ, n = 25) comprised segmental mandibular resections and free bone flap reconstructions due to tumors, chronic osteomyelitis, or trauma without any radiation. Ossification time and influencing factors were evaluated. Both duration of surgery (346 ± 90min. vs. 498 ± 124min.; p < 0.001) and hospitalization (8.7 ± 2.8 days vs. 13.4 ± 5.3 days, p = 0.006) were shorter in the MRONJ group compared to the noMRONJ group. Ossification after mandibular reconstruction was significantly faster in the MRONJ study group [224 days, interquartile range (IQR) 175-287] compared to the control group (288 days, IQR 194-445; p < 0.001). Moreover, good initial contact between the segments resulted in faster ossification (p < 0.001) in the MRONJ group. Ossification rate between original and grafted bone or between grafted bone segments only did not differ in both the study and control groups (MRONJ, p = 0.705 vs. control, p = 0.292). The type of antiresorptive agent did not show any significance for ossification. The rate of wound healing disturbances did also not differ between the study and control groups (p = 0.69). Advanced MRONJ (stage 3) can be resected and reconstructed safely with free microvascular bone flaps. Antiresorptive agents enhance the ossification of the bone segments. Optimal initial contact of the bone segments accelerates bone healing. Surgery and hospitalization are markedly shortened in this vulnerable group of MRONJ patients compared to oncologic patients.