OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.

Fibula osteoseptocutaneous flap has been widely used for oncologic bony reconstruction of both the mandible and maxilla. Early and late morbidities of the donor side such as leg weakness, ankle instability, limited ankle mobility, tibial stress fractures or incision area pain are well documented; however, there is a lack of information about the effects of fibula grafting on patient quality of life. To address this issue, a scoping literature search in the PubMed electronic database was performed to identify all relevant studies and reviews in the period between 2010 and 2022. The potential discomforts after free fibula grafting and their impact on different domains of everyday living were identified and evaluated. The present literature review indicates that donor site morbidity can negatively impact patients\' quality of life, albeit generally classified as minor. However, the functional and aesthetic benefits of oromandibular reconstruction clearly outweigh the associated sequelae. Nevertheless, the authors of this review highlight the importance of a comprehensive clinical evaluation of the donor site besides the recipient site during follow-up examinations. This would help to subjectively evaluate the functional and esthetical limitations of a patient\'s site and promptly detect morbidities that could lead to long-term complications.

Background: Defects of the ascending ramus of the mandible, including the condylar head and neck or the whole temporomandibular joint (TMJ), are difficult to reconstruct. Reconstruction is mainly based on the use of alloplastic joint prosthesis, costochondral grafting, distraction osteogenesis of the dorsal part of the mandibular ramus, or osseous microvascular flaps of various origin. With the objective of developing a method that overcomes the restrictions of these methods, we recently introduced a sequential chimeric flap consisting of a lateral femoral condyle flap (LFC) and deep circumflex iliac artery flap (DCIA) for reconstruction of up to half of the mandible and the condylar head and neck. Methods: The chimeric flap was used in four patients with the following diagnoses: therapy-refractory osteomyelitis, extended recurrent odontogenic keratozyst, Goldenhar syndrome, and adenocarcinoma of the parotid gland. After a diagnostic workup, LFC and DCIA flaps were harvested in all patients and used in a sequential chimeric design for the reconstruction of the mandibular body and condylar head and neck. Results: Follow-up from at least 24 months up to 70 month after surgery showed a successful reconstruction in all four patients. The LFC provided a cartilaginous joint surface, allowing for a satisfactory masticatory function with a stable occlusion and unrestricted mouth opening and preserved or regained lateral and medial excursions in all patients. The DCIA allowed for a bony reconstruction anatomically resembling a non-atrophied mandibular body. No flap-related complications were observed. Conclusions: The sequential chimeric LFC and DCIA flap is an appropriate method for reconstructing up to half of the mandible and the condylar head and neck. It is suitable in cases where alloplastic joint replacement cannot be used or where other methods have failed. Due to the necessity of harvesting two flaps, the burden of care is increased, and a careful indication is required. The technique is reserved for maxillofacial surgeons who have already gained significant experience in the field of microsurgery.

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.

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.

BACKGROUND: Computer-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.
METHODS: Six 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.
RESULTS: Two-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.
CONCLUSIONS: This 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.

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BACKGROUND: Osteoradionecrosis (ORN) of the mandible is an unfortunate potential sequela of radiotherapy for head and neck cancer. In advanced cases of ORN, mandibulectomy, and free fibula flap reconstruction are required. We hypothesized that patients undergoing fibula free flap reconstruction and mandibulectomy for ORN pose unique challenges and experience more complications than patients undergoing fibula free flaps after oncologic mandibulectomy.
METHODS: After IRB approval, we created a database of all free fibula flaps for mandible reconstruction from April 2005 through February 2019. Medical records were retrospectively reviewed for patient and surgical characteristics and postoperative outcomes.
RESULTS: Four-hundred seventy-nine patients met the inclusion criteria (168 ORN vs. 311 non-ORN patients). Propensity-matching was performed based on age, BMI, smoking status, preoperative chemotherapy, and virtual surgery planning use, which yielded 159 patients in each group. ORN patients received more double-skin-island fibula flaps than non-OR patients (20.8% vs. 5.7%, p < 0.001). Recipient artery other than the facial artery was utilized more commonly in ORN patients (42.1% vs. 17.0%, p < 0.001). In the unmatched cohort, ORN patients had higher rates of delayed wound healing (26.2% vs. 16.8%, p = 0.01) and surgical site infections (21.4% vs. 13.2%, p = 0.02). Rates of flap loss, return to the operating room, hematoma, operative time, and length of stay were similar between the groups. On logistic regression analysis, osteoradionecrosis was an independent risk factor for delayed wound healing.
CONCLUSIONS: Based on these data, mandibular reconstruction with fibula flaps for osteoradionecrosis appears more complicated than mandible reconstruction following de novo cancer resection. Surgeons should anticipate employing two skin islands for intraoral and extraoral resurfacing, utilizing unconventional recipient vessels, and managing the delayed wound healing that ensues more commonly than non-ORN patients.

BACKGROUND: Vascularized free tissue transfer has been established as an effective method in the reconstruction of mandibular defects. However, a limited understanding of its efficacy in pediatric patients persists due to its infrequent presentation. The aim of this study is to systematically consolidate the survival and infection rates of free flaps in pediatric mandibular reconstruction.
METHODS: A systematic literature search was conducted on Ovid Medline, Embase, and Cochrane Library for studies published up to January 2024. We included peer-reviewed studies reporting on survival and infection outcomes associated with free flap mandibular reconstruction in pediatric patients (<18 years). We performed a random-effects meta-analysis with the inverse-variance weighted approach to estimate survival and infection rates. Heterogeneity was assessed by I2, and publication bias was examined using Egger\'s test.
RESULTS: A total of 26 studies, reporting on 463 free flaps and 439 pediatric patients with a mean age of 10.7 years, were included in our study. Most free flaps originated from the fibula (n = 392/463, 84.7%) and benign tumors were the most common cause for mandibular reconstruction (n = 179/463, 38.7%). The pooled estimate for survival of flaps was 96% (95% CI: 93-97, I2 = 0%), and recipient-site infections were estimated to occur in 9% (95% CI: 6-13, I2 = 0%) of cases. The most common reported complications within the study timeframe were early malocclusion (n = 28/123, 21.4%) and bite abnormalities (18/131, 13.7%).
CONCLUSIONS: Free tissue transfer for mandibular reconstruction in pediatric patients is effective and safe. Further research is required to explore functionality following mandibular reconstruction in diverse pediatric populations.

OBJECTIVE: The aim of this study was to investigate the selected biomechanical properties of semi-anatomic implant plate made of biostable glass fiber-reinforced composite (GFRC) for mandibular reconstruction. Two versions of GFRC plates were tested in vitro loading conditions of a mandible segmental defect model, for determining the level of mechanical stress at the location of fixation screws, and in the body of the plate.
METHODS: GFRC of bidirectional S3-glass fiber weaves with dimethacrylate resin matrix were used to fabricate semi-anatomic reconstruction plates of two GFRC laminate thicknesses. Lateral surface of the plate followed the contour of the resected part of the bone, and the medial surface was concave allowing for placement of a microvascular bone flap in the next stages of the research. Plates were fixed with screws to a plastic model of the mandible with a large segmental defect in the premolar-molar region. The mandible-plate system was loaded from incisal and molar locations with loads of 10, 50, and 100 N and stress (microstrain, με) at the location of fixation screws and the body of the plate was measured by strain gauges. In total the test set-up had four areas for measuring the stress of the plate.
RESULTS: No signs of fractures or buckling failures of the plates were found during loading. Strain values at the region of the fixation screws were higher with thick plate, whereas thin plates demonstrated higher strain at the body of the plate. Vertical displacement of the mandible-plate system was proportional to the loading force and was higher with incisal than molar loading locations but no difference was found between thin and thick plates.
CONCLUSIONS: GFRC plates withstood the loading conditions up to 100 N even when loaded incisally. Thick plates concentrated the stress to the ramus mandibulae region of the fixation screws whereas the thin plates showed stress concentration in the angulus mandibulae region of the fixation and the plate itself. In general, thin plates caused a lower magnitude of stress to the fixation screw areas than thick plates, suggesting absorption of the loading energy to the body of the plate.