A preliminary study of the mechanical properties of 3D-printed personalized mesh titanium alloy prostheses and repair of hemi-mandibular defect in dogs.

This study is a preliminary investigation exploring the mechanical properties of three-dimensional (3D)-printed personalized mesh titanium alloy prostheses and the feasibility of repairing hemi-mandibular defects. The ANSYS 14.0 software and selective laser melting (SLM) were used to produce personalized mesh titanium alloy scaffolds. Scaffolds printed using different parameters underwent fatigue property tests and scanning electron microscopy (SEM) of the fracture points. Models of hemi-mandibular defects (encompassing the temporomandibular joint) were created using beagle dogs. Freeze-dried allogeneic mandibles or 3D-printed personalized mesh titanium alloy prostheses were used for repair. Gross observation, computed tomography (CT), SEM, and histological examinations were used to compare the two repair methods. The prostheses with filament diameters of 0.5 and 0.7 mm could withstand 14,000 times and >600,000 cycles of alternating stresses, respectively. The truss-structure scaffold with a large aperture and large aperture ratio could withstand roughly 250,000 cycles of alternating forces. The allogeneic mandible graft required intraoperative shaping, while the 3D-printed mesh titanium alloy prostheses were personalized and did not require intraoperative shaping. The articular disc on the non-operated sides experienced degenerative changes. No liver and kidney toxicity was observed in the two groups of animals. The 3D-printed mesh titanium alloy prostheses could effectively restore the shape of the mandibular defect region and reconstruct the temporomandibular joint.

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

BACKGROUND: Segmental mandibulectomy and reconstruction of resulting defect can be performed via intraoral approach (IOA) or extraoral approach (EOA). Both approaches have advantages, disadvantages, indications, and contraindications to consider during their selection. OBJECTIVE: To compare IOA vs EOA of segmental mandibulectomy and microvascular reconstruction with fibula free flap (FFF). METHODS: We 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 Derriford Appearance Scale (DAS59) were assessed during follow-up. RESULTS: Ameloblastoma was the most frequent diagnosis (52.9% managed by IOA vs 70.6% by EOA); FFF was frequently positioned as double barrel (94.1% managed by IOA vs 88.2% by EOA). Compared with EOA group, IOA group had less intraoperative blood loss (mean difference [MD] = -112.2, 95% confidence interval [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). CONCLUSION: Both IOA and EOA were found safe and feasible, presenting similar perioperative features and postoperative outcomes. Patients managed with IOA were more satisfied with aesthetic outcomes than patients managed with EOA. In the absence of simultaneous immediate implant during mandibular FFF reconstruction, after stability of FFF on the defect site, patients should always be referred to an implantologist and/or prosthodontist for teeth restoration to improve functional and aesthetic outcomes.

Dimensional changes in free gingival grafts at implant sites in the reconstructed mandible: a retrospective study.

OBJECTIVE: To evaluate the dimensional changes in free gingival grafts (FGG) at implant sites in mandibular reconstruction patients. METHODS: Patients who received FGG 4 months after implant placement in the reconstructed mandible with no keratinized mucosa (KM) present were invited for re-examination after 36.7 ± 16.8 months (3.06 ± 1.4 years). Immediately after graft extraction (T0), graft width (GW), graft length (GL), graft thickness (GT), graft dimension (GD), and vertical bone height were documented. Re-examination (T1) included clinical examinations (GW, GL, GD, peri-implant probing depths, and modified Sulcus Bleeding Index), radiographic examination (marginal bone level), and medical chart review. RESULTS: Twenty patients and 62 implants (47 in fibula flaps and 15 in iliac flaps) were included. A significant decrease in GW (51.8%), GL (19.2%), and GD (60.2%), were found between T0 and T1 (p < .001). The univariate analysis showed that GW change was not significantly associated with reconstruction technique, baseline GL, baseline GT, baseline GD, implant location, or type of prosthesis. Implant survival rate of 100% was observed at follow-up. CONCLUSIONS: Within the limitations of the study, free gingival grafts at implant sites in the reconstructed mandible undergo dimensional change that result in a reduction of approximately 60% of the original graft dimension. Graft width decreased over 50%. CLINICAL RELEVANCE: FGG is the standard of care intervention for increasing the amount of KM around implants. This study was the first to evaluate the dimensional change in FGG at implant sites in mandibular reconstruction patients after a medium-term follow-up. CLINICAL TRIAL REGISTRATION: Clinical trial registration is not applicable as this study comprehends a retrospective analysis.

Jaw in a day surgery: early experience with 19 patients at an Australian tertiary referral center.

BACKGROUND: The Jaw-in-a-Day (JIAD) procedure aims to achieve immediate functional occlusion via a single-stage approach to maxillofacial reconstruction. While JIAD has gained popularity since its inception by Levine and colleagues, efficacy and outcome data remain limited. In this report, we discuss our experience with the JIAD technique at an Australian tertiary referral centre. METHODS: A retrospective review of all JIAD procedures performed from April 2022 to December 2023 was conducted. Clinicopathologic data reviewed included demographic information, primary diagnosis, anatomical site of disease, and history of pre-operative radiotherapy. Outcome measures of interest included operative time, number of implants placed, post-operative complications and implant survival. RESULTS: Nineteen patients were identified for the study. Two maxillary and 17 mandibular JIAD procedures were performed. The most common indications were squamous cell carcinoma (n = 8) and ameloblastoma (n = 5). Surgical complications included recipient site wound infection (n = 3), flap dehiscence (n = 2), haematoma formation (n = 1), and neck abscess associated with partial flap failure (n = 1). No total flap failures were identified. Of the 55 total implants placed, one implant failure occurred 2-months post-operatively. No loss of irradiated implants (n = 21) was observed. The median time to adjuvant radiotherapy was 57 days (range, 32-61). Eighteen of 19 patients (95%) achieved immediate dental rehabilitation, and 15/19 patients (79%) retained a functional prosthesis by the end of the follow-up period. CONCLUSIONS: Our series supports the feasibility of single-stage reconstruction for both benign and malignant indications. Further research is required to understand the long-term functional, aesthetic, and health-related quality-of-life outcomes with the JIAD technique.

Can Prophylactic Tracheostomy be Avoided in Advanced Oral Cancer Surgery for Airway Management? An Experience and Guidelines from a Tertiary Care Facility.

Aim: To evaluate the surgical and postoperative management strategies that contribute to minimizing the need for prophylactic tracheostomy for airway management in advanced oral cancer surgery. Methods: A retrospective review of the patients who underwent surgery for advanced oral cancer, in our institution from February 2015 to January 2024. Results: In the present review, 66 patients (males, n = 54; females, n = 12; mean age 50.3 years) who were operated for advanced oral cancer (T3, T4 oral squamous cell carcinoma and osteosarcoma of the mandible requiring mandibular resection) in our institution were included. 60 patients (90.9%) had reconstruction after segmental resection of the mandible without the need for prophylactic tracheostomy. Out of these, eighteen patients (27.27%) required segmental resection of the mandible crossing midline. Six patients (9.1%) underwent prophylactic tracheostomy, of which two patients had unilateral tumor and four patients had tumor crossing midline. Comparison of hospital stays between patients who underwent prophylactic tracheostomy and those who did not yielded mean durations of 13.3 days and 7.6 days, respectively. Conclusion: Except a subset of patients with old age, obesity, bulky neck, and those with respiratory compromise, following the present guidelines, prophylactic tracheostomy can be avoided in patients undergoing surgery for advanced oral cancer.

Fabrication of a 3D-Printed Interim Bite Splint for a Hemimandibulectomy Patient: A Case Report.

Mandibular continuity defects can result in varying degrees of cosmetic disfigurement. Restoration of form and function may require surgical reconstruction of the affected area. While surgical reconstruction may improve the overall prognostic outcomes for the patient, the definitive prosthetic phase can commence only after a substantial time lag for adequate hard/soft tissue healing. This interim phase often challenges the patient's masticatory ability. The traditional reconstruction of hemimandibulectomy defects has its own limitations. This case report describes the fabrication of a 3D-printed bite splint for a patient with limited mouth opening and significant malocclusion due to surgical over-correction. The prosthesis given served as an appliance to improve the masticatory ability of the patient.

An innovative method for three-dimensional bone reconstruction of the anterior mandible with preserved dentition using an allogeneic bone block: A 6-month follow-up.

BACKGROUND: Bone defects around the teeth affect a large portion of the population. Bone regeneration in the area of existing teeth is completely different from that in an edentulous area. To date, no method has been developed for three-dimensional (3D) bone reconstruction in regions with preserved teeth. OBJECTIVES: This study aimed to radiologically evaluate the results of the new method of 3D mandibular bone reconstruction in preserved dentition using a custom-made allogeneic bone block with a 6-month follow-up. MATERIAL AND METHODS: Alveolar ridge dimensions were radiographically assessed before and 6 months after reconstruction using cone beam computed tomography (CBCT) scans in 32 patients (192 teeth). Reconstruction used a bone block that had been previously planned and prepared using CAD/CAM technology. RESULTS: The observed changes in alveolar bone dimensions were highly significant in most cases (p < 0.001). The closer to the tooth root apex, the lower the bone growth in the sagittal dimension (average of the mean values for each tooth examined in the measured heights): CEJ2: 2.9 mm, ½ CEJ2: 2.7 mm, » CEJ2: 1.9 mm, and API: 1.4 mm. The maximum bone growth in the vertical dimension was observed on tooth 43 (9.9 mm), followed by 32 (9.8 mm), 33 (8.5 mm), 31 (8.4 mm), 42 (8 mm), and 41 (7 mm). The degree of decrease in vestibular dehiscence of the bone was greater the closer the tooth was to the midline (average of -3.8 mm and -3.4 mm for the central incisors; average of -2.8 mm and -2.6 mm for the lateral incisors; average of -2.6 mm and -2.5 mm for the canines). CONCLUSIONS: The results prove that it is possible to prevent bone dehiscence in patients undergoing orthodontic treatment, increasing the ability and effectiveness of covering recessions and improving the morphology of the lower part of the face.

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.

Risk Factors for Plate Infection, Exposure, and Removal in Mandibular Reconstruction.

OBJECTIVE: Mandibular plate reconstruction (MPR) is often indicated after tumor ablation, osteoradionecrosis excision, and traumatic bone loss to restore oral functionality and facial cosmetics. There are limited analyses identifying risk factors that lead to plate infection (PIn), exposure, and removal ("plate complications"). STUDY DESIGN: Retrospective cohort study. SETTING: Academic tertiary medical center. METHODS: Patients who underwent MPR from 2013 to 2022 were identified. Risk factors for plate complications were analyzed based on demographic, clinical, intraoperative, and postoperative factors. Multivariable analysis was conducted with logistic regression. Survival analysis was conducted with a Cox model. RESULTS: Of the 188 patients analyzed, 48 (25.5%) had a plate complication [infection: 22 (11.7%); exposure: 23 (12.2%); removal: 35 (18.6%)]. Multivariate analysis revealed predictive associations between at least 1 plate complication and the following variables: smoking status, soft tissue defect size, number of plates, average screw length, and various postoperative complications. Other associations approached the threshold for significance. Prior and adjuvant radiation therapy, type of free flap, stock versus custom plates, and perioperative antibiotic prophylaxis regimens were not associated with plate complications. No plate complication was independently associated with lower overall survival. PIn (hazard ratio, HR: 7.99, confidence interval, CI [4.11, 15.54]) and exposure (HR: 3.56, CI [1.79, 7.08]) were independently associated with higher rates of plate removal. CONCLUSION: Plate complications are relatively common after MPR. Smoking history, specific disease characteristics, hardware used during surgery, and postoperative complications may help identify higher-risk patients, but additional larger-scale studies are needed to validate our findings and resolve discrepancies in the current literature.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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 OF EVIDENCE: Level 4 Laryngoscope, 2024.

Is immediate dental implant in fibula free flap beneficial for implant survival and osteoradionecrosis in jaw reconstruction?

OBJECTIVES: This study aimed to compare the risk of osteoradionecrosis and implant survival in oral cancer patients undergoing immediate dental implants during jaw reconstruction, termed "Jaw in a Day" (JIAD), with those receiving no implants or delayed implants (non-JIAD). PATIENTS & METHODS: Clinicopathologic data were collected from prospectively enrolled JIAD patients (n = 10, 29 implants) and retrospectively from non-JIAD patients (n = 117, 86 implants). Survival analyses were performed to assess implant survival and osteoradionecrosis-free survival. RESULTS: Osteoradionecrosis occurred in 0 % of JIAD cases compared to 19.3 % in non-JIAD cases without implants and 71.4 % in non-JIAD cases with delayed implants (p = 0.008). Osteoradionecrosis-free survival was significantly better in the JIAD group than the non-JIAD group (p = 0.0059). Implants in the JIAD group all survived regardless of radiation therapy (29/29, 100 %) and 95.1 % (58/61) of implants survived in delayed implants in non-irradiated fibula without radiotherapy. Meanwhile, only 11 of 25 implants placed in irradiated fibula flaps survived, even when the implants were placed after a median time interval of 624 days after radiotherapy, and none of them were earlier than 360 days. The survival analysis revealed a significant difference (p < 0.0001). CONCLUSION: JIAD appears to offer superior outcomes in terms of implant survival and osteoradionecrosis prevention compared to delayed implant placement. Placing implants in irradiated fibula, even after years, significantly poses high risk of implant failure and osteoradionecrosis. JIAD represents a promising approach for optimal rehabilitation, particularly in oral cancer patients requiring postoperative radiotherapy. Proper positioning and orientation of implants and flaps are crucial for implant survival.

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.

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.

Influence of bite force and implant elastic modulus on mandibular reconstruction with particulate-cancellous bone marrow grafts healing: An in silico investigation.

This study aims to investigate tissue differentiation during mandibular reconstruction with particulate cancellous bone marrow (PCBM) graft healing using biphasic mechanoregulation theory under four bite force magnitudes and four implant elastic moduli to examine its implications on healing rate, implant stress distribution, new bone elastic modulus, mandible equivalent stiffness, and load-sharing progression. The finite element model of a half Canis lupus mandible, symmetrical about the midsagittal plane, with two marginal defects filled by PCBM graft and stabilized by porous implants, was simulated for 12 weeks. Eight different scenarios, which consist of four bite force magnitudes and four implant elastic moduli, were tested. It was found that the tissue differentiation pattern corroborates the experimental findings, where the new bone propagates from the superior side and the buccal and lingual sides in contact with the native bone, starting from the outer regions and progressing inward. Faster healing and quicker development of bone graft elastic modulus and mandible equivalent stiffness were observed in the variants with lower bite force magnitude and or larger implant elastic modulus. A load-sharing condition was found as the healing progressed, with M3 (Ti6Al4V) being better than M4 (stainless steel), indicating the higher stress shielding potentials of M4 in the long term. This study has implications for a better understanding of mandibular reconstruction mechanobiology and demonstrated a novel in silico framework that can be used for post-operative planning, failure prevention, and implant design in a better way.

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

OBJECTIVES: To investigate soft-to-hard tissue response following mandibular reconstruction and to develop a predictive model for projecting soft tissue movement. MATERIALS AND METHODS: 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. RESULTS: 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 ± 1.38 mm. 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. CONCLUSIONS: 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. CLINICAL RELEVANCE: 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. CLINICAL TRIAL REGISTRATION: This study was registered on the Chinese Clinical Trial Registry (registration number: ChiCTR2100054103).

From medical imaging to 3D printed anatomical models: a low-cost, affordable 3D printing approach.

OBJECTIVE: To share our experience in creating precise anatomical models using available open-source software. METHODS: An affordable method is presented, where from a DICOM format of a computed tomography, a segmentation of the region of interest is achieved. The image is then processed for surface improvement and the DICOM format is converted to STL. Error correction is achieved and the model is optimized to be printed by stereolithography with a desktop 3D printer. RESULTS: Precise measurements of the dimensions of the DICOM file (CT), the STL file, and the printed model (3D) were carried out. For the C6 vertebra, the dimensions of the horizontal axis were 55.3 mm (CT), 55.337 mm (STL), and 55.3183 mm (3D). The dimensions of the vertebral body were 14.2 mm (CT), 14.551 mm (STL), and 14.8159 mm (3D). The length of the spinous process was 18.2 mm (CT), 18.283 mm (STL), and 18.2266 mm (3D), while its width was 8.5 mm (CT), 8.3644 mm (STL), and 8.3226 mm (3D). For the C7 vertebra, the dimensions of the horizontal axis were 58.6 mm (CT), 58.739 mm (STL), and 58.7144 mm (3D). The dimensions of the vertebral body were 14 mm (CT), 14.0255 mm (STL), and 14.2312 mm (3D). The length of the spinous process was 18.7 mm (CT), 18.79 mm (STL), and 18.6458 mm (3D), and its width was 8.9 mm (CT), 8.988 mm (STL), and 8.9760 mm (3D). CONCLUSION: The printing of a 3D model of bone tissue using this algorithm is a viable, useful option with high precision.

OBJETIVO: Compartir nuestra experiencia para crear modelos anatómicos precisos utilizando software con licencia abierta disponibles. MÉTODOS: Se presenta un método asequible, en donde a partir de un formato DICOM de una tomografía computarizada se logra una segmentación de la región de interés. Posteriormente se procesa la imagen para una mejora de superficie y se realiza la conversión de formato DICOM a STL. Se logra la corrección de errores y se optimiza el modelo para luego ser impreso por medio de estereolitografía con una impresora 3D de escritorio. RESULTADOS: Se efectuaron mediciones precisas de las dimensiones del archivo DICOM (TC), del archivo STL y del modelo impreso (3D). Para la vértebra C6, las dimensiones del eje horizontal fueron 55.3 mm (TC), 55.337 mm (STL) y 55.3183 mm (3D). Las dimensiones del cuerpo vertebral fueron 14.2 mm (TC), 14.551 mm (STL) y 14.8159 mm (3D). La longitud de la apófisis espinosa fue de 18.2 mm (TC), 18.283 mm (STL) y 18.2266 mm (3D), mientras que su ancho fue de 8.5 mm (TC), 8.3644 mm (STL) y 8.3226 mm (3D). Para la vértebra C7, las dimensiones del eje horizontal fueron 58.6 mm (TC), 58.739 mm (STL) y 58.7144 mm (3D). Las dimensiones del cuerpo vertebral fueron 14 mm (TC), 14.0255 mm (STL) y 14.2312 mm (3D). La longitud de la apófisis espinosa fue de 18.7 mm (TC), 18.79 mm (STL) y 18.6458 mm (3D), y su ancho fue de 8.9 mm (TC), 8.988 mm (STL) y 8.9760 mm (3D). CONCLUSIÓN: La impresión de un modelo en 3D de tejido óseo mediante este algoritmo resulta una opción viable, útil y con una alta precisión.

Mandibular revascularization using a humeral periosteal free flap: A technical note.

The vascularized periosteal free flap transposes a non-irradiated soft tissue with neoangiogenesis, bone induction, and osteogenesis qualities. A surgical technique using a humeral periosteal free flap is described for the treatment of recurrent osteoradionecrosis of the lower jaw. The humeral periosteal free flap is a technique associated with low morbidity. The procedure described avoids sacrificing major vessels as seen in other common flap procedures. Hence, this revascularization approach is equivalent to a prevention technique that should be considered early in the development of osteoradionecrosis to avoid further damage and challenging reconstruction.

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

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. CONCLUSION: 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.

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.

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.