Fiber Flexibility Reconciles Matrix Recruitment and the Fiber Modulus to Promote Cell Mechanosensing.

The mechanical interaction between cells and the extracellular matrix is pervasive in biological systems. On fibrous substrates, cells possess the ability to recruit neighboring fibers, thereby augmenting their own adhesion and facilitating the generation of mechanical cues. However, the matrices with high moduli impede fiber recruitment, restricting the cell mechanoresponse. Herein, by harnessing the inherent swelling properties of gelatin, the flexible gelatin methacryloyl network empowers cells to recruit fibers spanning a broad spectrum of physiological moduli during adhesion. The high flexibility concurrently facilitates the optimization of fiber distribution, deformability, and modulus, contributing to the promotion of cell mechanosensing. Consequently, the randomly distributed flexible fibers with high moduli maximize the cell adhesive forces. This study uncovers the impact of fiber recruitment on cell mechanosensing and introduces fiber flexibility as a previously unexplored property, offering an innovative perspective for the design and development of novel biomaterials.

The change of state-trait anxiety among patients undergoing orthognathic surgery: A longitudinal study.

INTRODUCTION: This study aimed to assess state-trait anxiety level changes in Chinese patients with dentofacial discrepancies before and after orthognathic surgery and to explore the feasibility of developing a reference index for the preoperative screening of postoperative patients with high anxiety. METHODS: A total of 96 Chinese patients with dentofacial discrepancies who underwent orthognathic surgery were included in this study. Data were collected before orthognathic surgery and at 2 weeks (T2), 3 months, and 6 months (T4) after surgery using the State-Trait Anxiety Inventory. Receiver operating characteristic and linear regression analyses were performed to screen for preoperative indicators of postoperative high-state anxiety. RESULTS: State-trait anxiety levels in patients with dentofacial discrepancies decreased after surgery (F = 18.95, P <0.01; F = 6.90, P <0.01). Trait Anxiety Inventory can be used to screen patients with high-state anxiety from T2 to T4 (area under cover 95% confidence interval: T2, 0.74 [0.62-0.86]; 3 months, 0.79 [0.69-0.90]; T4, 0.77 [0.66-0.87], P <0.01), corresponding to cutoff values of 48.5, 46.5, and 45.5, respectively. CONCLUSIONS: All participants' state-trait anxiety levels improved after surgery compared with their preoperative levels. Preoperative trait anxiety levels can be used as a reference indicator to screen patients who may have high-state anxiety levels after orthognathic surgery. The creation of a screening scale will assist health care professionals to more pertinently help patients with high anxiety.

[Mandibular condyle localization in orthognathic surgery based on mandibular movement trajectory and its preliminary accuracy verification].

OBJECTIVE: To establish and assess the precision of pre-surgical condyle position planning using mandibular movement trajectory data for orthognathic surgery. METHODS: Skull data from large-field cone beam computed tomography (CBCT) and dental oral scan data were imported into IVSPlan 1.0.25 software for 3D reconstruction and fusion, creating 3D models of the maxilla and mandible. Trajectory data of mandibular movement were collected using a mandibular motion recorder, and the data were integrated with the jaw models within the software. Subsequently, three-dimensional trajectories of the condyle were obtained through matrix transformations, rendering them visually accessible. A senior oral and maxillofacial surgeon with experience in both diagnosis and treatment of temporomandibular joint disease and orthognathic surgery selected the appropriate condyle position using the condyle movement trajectory interface. During surgical design, the mobile mandibular proximal segment was positioned accordingly. Routine orthognathic surgical planning was completed by determining the location of the mandibular distal segment, which was based on occlusal relationships with maxilla and facial aesthetics. A virtual mandible model was created by integrating data from the proximal and distal segment bone. Subsequently, a solid model was generated through rapid prototyping. The titanium plate was pre-shaped on the mandibular model, and the screw hole positions were determined to design a condylar positioning guide device. In accordance with the surgical plan, orthognathic surgery was performed, involving mandibular bilateral sagittal split ramus osteotomy (SSRO). The distal segment of the mandible was correctly aligned intermaxillary, while the proximal bone segment was positioned using the condylar positioning guide device and the pre-shaped titanium plate. The accuracy of this procedure was assessed in a study involving 10 patients with skeletal class Ⅱ malocclusion. Preoperative condyle location planning and intraoperative positioning were executed using the aforementioned techniques. CBCT data were collected both before the surgery and 2 weeks after the procedure, and the root mean square (RMS) distance between the preope-rative design position and the actual postoperative condyle position was analyzed. RESULTS: The RMS of the condyle surface distance measured was (1.59±0.36) mm (95%CI: 1.35-1.70 mm). This value was found to be significantly less than 2 mm threshold recommended by the expert consensus (P < 0.05). CONCLUSION: The mandibular trajectory may play a guiding role in determining the position of the mandibular proximal segment including the condyle in the orthognathic surgery. Through the use of a condylar positioning guide device and pre-shaped titanium plates, the condyle positioning can be personalized and customized with clinically acceptable accuracy.

Evaluation of soft tissue prediction accuracy for orthognathic surgery with skeletal class III malocclusion using maxillofacial regional aesthetic units.

OBJECTIVES: This study aimed to evaluate the soft tissue prediction accuracy of patients undergoing orthognathic surgery to correct skeletal class III malocclusion using maxillofacial regional aesthetic units. MATERIALS AND METHODS: Pre- and postoperative cone-beam computed tomography (CBCT) and 3D facial scans were taken for 58 patients who had undergone orthognathic surgery. The preoperative 3D facial scan was integrated with the preoperative CBCT using ProPlan CMF software. The software simulated the surgery and generated postoperative soft tissue prediction. The simulated 3D facial scan was then compared with the actual 3D facial scan obtained at least 6 months after the surgery by the maxillofacial regional aesthetic units and the facial soft tissue landmark points. RESULTS: The anatomical regions of the upper lip, lower lip, chin, right external buccal and left external buccal prediction were above 2.0 mm. As for the soft tissue landmarks, at chl, chr, ls, stm and li, the position of predicted scan was higher than that of the actual postoperative scan. CONCLUSIONS: The accuracy of 3D soft tissue predictions using ProPlan CMF software in Skeletal III patients was clinically satisfactory according to maxillofacial regional aesthetic units combined with facial soft tissue landmark points. However, the accuracy of prediction still needed improvement in some areas. CLINICAL RELEVANCE: The accuracy of soft tissue prediction can be analyzed more clearly through maxillofacial regional aesthetic units so that clinicians have a deeper understanding of the use of the software to predict soft tissue change after orthognathic surgery.

Morphological Changes in Total and Inferior Part of Maxillary Sinus After Le Fort I Osteotomy, as Determined by Cone-Beam Computed Tomography.

To investigate morphological changes of the total and inferior part of the maxillary sinus following Le Fort I osteotomy. 21 skeletal class II and 49 skeletal III patients who underwent orthognathic surgery were enrolled in this retrospective study. Cone-beam computed tomography taken before (T1) and 6 to 24 months after (T2) orthognathic surgery were imported into Mimics 20.0 software to analyze morphological changes of the total and inferior part of the maxillary sinus. Volume of the whole maxillary sinus was significantly reduced after surgery ( P ≤0.008), while the volume of the inferior part of the maxillary sinus was significantly greater than before surgery ( P ≤0.004). Maxillary sinus floor moved occlusally after Le Fort I osteotomy. Movement in the pitch direction of the posterior maxilla affected the state of the maxillary sinus mucosa after orthognathic surgery. Le Fort I osteotomy exerts a significant impact on the morphology of the total and inferior part of the maxillary sinus.

Early and 1-year postsurgical stability and its factors in patients with complicated skeletal Class â ¢ malocclusion treated by conventional and surgery-first approach: A prospective cohort study.

INTRODUCTION: This study aimed to compare postsurgical stability between conventional (CSA) and surgery-first (SFA) approaches and investigate its prognostic factors in patients with a skeletal Class Ⅲ extraction. METHODS: Twenty and 19 patients treated with LeFort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) with premolar extraction were enrolled in SFA and CSA groups, respectively. Serial cone-beam computed tomography images obtained before surgery, immediately after surgery (T1), 3 months after surgery, and 12 months after surgery were used for 3-dimensional quantitative analysis. The condyle was segmented for analyzing volumetric changes. Repeated measures analysis of variance, independent t test, and chi-square test were used to compare time-course and intergroup differences. Pearson and Kendall correlation and multivariate linear regression analyses were used to explore prognostic factors affecting skeletal stability. RESULTS: In both CSA and SFA, postsurgical relapse mainly occurred in the mandible sagittal and vertical dimensions and during the first 3 months after surgery. Stability in SFA was significantly less than that in CSA. Intraoperatively, inferolateral condylar displacement with proximal segment inwards, clockwise rotation, and return movements after surgery were observed regardless of the treatment approach. The condylar volume remained stable over time. Multivariate regression analysis showed that posterior vertical dimension (VD) at T1 (-1.63 mm), surgical amount of mandibular setback (-10.33 mm), surgical condylar downwards displacement (-1.28 mm), and anterior overjet at T1 (6.43 mm) were the most important predictors of early mandibular relapse (r2 = 0.593). CONCLUSIONS: The risk of early relapse could be reduced by controlling the anterior, middle, and posterior constraints provided by the prediction model.

[Analysis of ALPL gene variant in a patient with infantile hypophosphatasia].

OBJECTIVE: To explore the genetic basis for a girl featuring bone and tooth mineralization disorder, premature deciduous teeth, rickets and short stature. METHODS: Genomic DNA was extracted and subjected to high-throughput whole exome sequencing. Suspected variants were confirmed by Sanger sequencing. Impact of potential variants was analyzed with bioinformatic software. RESULTS: The child was found to carry compound heterozygous missense variants of the ALPL gene, including c.1130C>T (p.A377V), a known pathogenic mutation inherited from her father, and c.1300G>A (p.V434M) inherited from her mother, which was unreported previously and predicted to be likely pathogenic based on standards and guidelines from the American College of Medical Genetics and Genomics (PM2+PM5+PP3+PP4). CONCLUSION: The compound heterozygous variants of c.1130C>T (p.Ala377Val) and c.1300G>A (p.Val434Met) of the ALPL gene probably underlay the disease in this child. Above finding has enriched the spectrum of ALPL gene variants.

miR-30a-5p inhibits osteogenesis and promotes periodontitis by targeting Runx2.

BACKGROUND: Periodontitis is the most extensive chronic inflammatory bone resorption disease. MiRNAs offer a potential way for potential therapy. Indeed, miR-30a-5p had an increasing expression in periodontitis gingivae, but whether it promotes osteogenesis and inhibits inflammation remains unknown. METHODS: Periodontitis model was exhibited by wire ligation and verified by micro-CT and HE staining; qPCR was used to detect the expression of miR-30a-5p; miR-30a-5p inhibitors and mimics were transfected into MC3T3-E1 cell line by lipofectamine 3000; The dual luciferase reporter gene experiment and RIP experiment were used to detect the relationship between miR-30a-5p and Runx2; Rescue experiment was used to verify the relationship between miR-30a-5p and Runx2. RESULTS: Periodontitis model was exhibited successfully and miR-30a-5p was overexpressed at the bone and gingival tissues of this model. miR-30a-5p inhibitors not only promoted the osteogenesis but also relieved inflammation. Runx2 is a target of miR-30a-5p by dual luciferase reporter gene experiment and RIP experiment. Rescue experiments revealed that miR-30a-5p inhibitors would promote osteogenesis and relieve inflammation by targeting Runx2 in inflammation of MC3T3-E1 cell line. CONCLUSIONS: That all suggested that miR-30a-5p-mediated-Runx2 provided a novel understanding of mechanism of periodontitis.

Three-Dimensional Dynamic Analysis of the Facial Movement Symmetry of Skeletal Class III Patients With Facial Asymmetry.

PURPOSE: Dynamic asymmetry has not been as rigorously evaluated as static asymmetry for patients with skeletal deformity but could well be even more important. The aim of the present study was to evaluate the dynamic facial movement of Class III patients with facial asymmetry using a 3-dimensional (3D) motion capture system. MATERIALS AND METHODS: The present cross-sectional study recruited patients with skeletal Class III malocclusion with and without facial asymmetry. A 3D facial motion capture system was used to record the expression process of a maximal smile. Eleven orofacial landmarks were selected to analyze and calculate the cumulative distance and average speed of each landmark during smiling. The predictor variable was mandibular symmetry. The outcome variables consisted of the measurements of each soft tissue landmark and the absolute differences for the paired landmarks between 2 sides. Other variables consisted of descriptive data, including the age and gender of each patient. The data were analyzed using independent t tests and paired t tests. Bonferroni's adjustment was used to control for multiple comparisons. RESULTS: A total of 63 patients were divided into 2 groups, an asymmetric group (n = 46) and a control group (n = 17), according to the degree of skeletal deviation. The difference in the cumulative distance of the bilateral cheilions was statistically significant between the 2 groups (P = .002). The difference for the asymmetric and control groups was 2.06 ± 1.78 mm and 1.00 ± 0.79 mm, respectively. In the asymmetric group, a comparison of the deviated side with the nondeviated side revealed statistically significant differences in the magnitude of motion for the cheilion (P < .01) and midlateral lower lip (P < .01). CONCLUSIONS: The patients with skeletal asymmetry also showed asymmetry in soft tissue functions while smiling. The magnitude of movement in the nondeviated side was greater than that in the deviated side.

Regeneration of the Neocondyle After Free Fibular Flap Reconstruction of the Mandibular Condyle.

PURPOSE: Shifting of the flap position after condylar reconstruction with free fibular flaps is known to occur, but its long-term effects on postoperative esthetic outcomes have not been sufficiently reported. Therefore, in this study, we evaluated the long-term morphologic stability of the free fibular flap neocondyle. PATIENTS AND METHODS: This was a retrospective cohort study. The primary outcome variables were neocondyle regeneration and neocondyle position including the distance between the glenoid fossa and the initial neocondyle (Fo-Co), the distance between the glenoid fossa and the stable neocondyle (Fo-Co'), and shifting of the neocondyle (defined as the distance between the stable neocondyle and the initial neocondyle). The primary predictor variable was time. The other variables were age, gender, diagnosis, and number of fibular segments. Correlation analysis between the predictor variables and outcome variables was performed. RESULTS: The sample was composed of 26 patients (11 male and 15 female patients) with a mean age of 31 years. Diagnosis and number of fibular segments were significantly associated with Fo-Co and Fo-Co' (P < .05). Among the 26 patients, only 11 showed neocondyle regeneration at follow-up (group A) whereas 15 did not (group B). Neocondyle regeneration was significantly associated with patient age (P < .01). Stable Fo-Co and stable time were significantly associated with neocondyle regeneration (P < .05). The mean stable time was significantly shorter in group A (3.64 ± 1.12 months) than in group B (6.67 ± 3.85 months) (P < .05), and the mean Fo-Co' was significantly shorter in group A (13.65 ± 3.94 mm) than in group B (20.68 ± 8.87 mm) (P < .05). CONCLUSIONS: The possibility of neocondyle regeneration is higher in pediatric patients than in adults. Neocondyle regeneration could result in the movement of the neocondyle toward the glenoid fossa with a shorter stable time, which could improve neocondyle repositioning. Repositioning of the neocondyle with free fibular flaps for mandibular condyle defects is a self-adaption process for temporomandibular joint function.

Double-Barrel Fibula Flap Versus Vascularized Iliac Crest Flap for Mandibular Reconstruction.

PURPOSE: The double-barrel fibula flap and vascularized iliac crest flap are both commonly used for mandibular reconstruction. The present study compared the usage and reconstruction outcomes of transplanted bone with these 2 methods. PATIENTS AND METHODS: The data from 30 patients who had undergone mandibular osteotomy and reconstruction were retrospectively reviewed. Of the 30 patients, 20 received a vascularized iliac crest flap (group A) and 10 received a double-barrel fibula flap (group B). The following variables were compared between the 2 groups: volume of bone flap (VBF), volume of effective bone flap (VEBF; ie, overlap between the volume of the ideal mandible [VIM] and the VBF), usage of the bone flap (VEBF divided by the VBF), mandibular reconstruction rate (VEBF divided by the VIM), volume of needless bone flap (VNBF; ie, VBF minus VEBF; the VNBF included the volume of needless buccal bone flap [VNBBF] and the volume of needless lingual bone flap [VNLBF]), percentage of alveolar crest restoration (PACR; ie, effective bone flap width divided by ideal alveolar crest width), and height of the bone flap (HBF). The independent-samples t test and the χ2 test were used to compare the variables between the 2 groups. Statistical significance was at P ≤ .05. RESULTS: Usage of the bone flap and the length of the mandibular defect were significantly greater in group B than in group A (P = .039 and P < .001, respectively). The VBF, VNBF, and VNLBF were significantly greater in group A than in group B (P < .001 for both). The mandibular reconstruction rate, VNBBF, PACR, HBF, and tooth implantation rate were comparable between the 2 groups. CONCLUSIONS: The double-barrel fibula flap can effectively restore the height of the alveolar crest, reconstruct longer mandibular defects, and provide a better buccal and lingual appearance compared with the vascularized iliac crest flap. Although the vascularized iliac crest flap can provide sufficient bone quantity, it must be contoured to the mandible.

Selection of Guiding Plate Combined With Surgical Navigation for Microsurgical Mandibular Reconstruction.

PURPOSE: The present study summarized selection of guiding plate combined with surgical navigation for microsurgical mandibular reconstruction. METHODS: Data from preoperative maxillofacial enhanced computed tomography (CT) scans were imported to ProPlan CMF. The authors performed virtual mandibulectomy and superimposed 3-dimensional (3D) iliac images on mandibular defects. Guiding plates including mandibular fixation device, reconstruction plate, guiding model, and occlusal splint for various mandibular hemimandibular central lateral (HCL) defects were fabricated to fix bilateral residual mandible. The model was scanned, and data were imported into ProPlan CMF and the intraoperative navigation system. Through landmark points upon the guiding plate, position of the residual mandible was determined during surgical navigation. Intraoperative navigation was used to implement the virtual plan. Sagittal, coronal, axial, and 3D reconstruction images displayed by the navigation system were used to accurately determine osteotomy sites and osteotomy trajectory during surgery. Surgical probe guidance was used to mark the osteotomy line and transfer the virtual procedure to real-time surgery. Accuracy was evaluated using chromatographic analysis. RESULTS: Different guiding plates combined with surgical navigation could be used for various mandibular defects, including mandibular fixation devices for LCL defects, reconstruction plates for LC/L/C defects, and guiding models and occlusal splints for H/L/LC defects (including mandibular ramus). In our study, average and largest shift of the mandible and osteotomy site was <5 mm. CONCLUSION: The authors summarized different ways of combining guiding plates with surgical navigation for reconstruction of various mandibular defects, which could improve clinical outcomes of this procedure with high accuracy.

Transcriptome profiling of Gerbera hybrida reveals that stem bending is caused by water stress and regulation of abscisic acid.

BACKGROUND: Gerbera hybrida is one of the most popular cut flowers in the world; however, stem bending, which always happens when gerbera flower harvested from the field, greatly limits its vase life. To date the molecular mechanisms underlying stem bending remain poorly understood. RESULTS: In this study, we performed high-throughput transcriptome sequencing of gerbera during stem bending using the Illumina sequencing technology. Three cDNA libraries constructed from mRNAs of gerbera stem at stem bending stage 0, 2 and 4 were sequenced. More than 300 million high-quality reads were generated and assembled into 96,492 unigenes. Among them, 34,166 unigenes were functionally annotated based on similarity search with known protein. Sequences derived from plants at different stem bending stages were mapped to the assembled transcriptome, and 9,406 differentially expressed genes (DEGs) were identified. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, specific pathways were identified during the stem bending process, such as phenylpropanoid biosynthesis pathway, phenylalanine metabolism pathway, starch and sucrose metabolism pathway, and plant hormone signal transduction pathway. A total of 211 transcription factors (TFs), including TF families involved in plant senescence, such as NAC, MYB, WRKY, and AP2/ERF members, as well as TFs related to water stress tolerance, were shown to be regulated during stem bending. Gene Onotology (GO) functional enrichment analysis indicated that key genes involved in responses to osmotic and oxidative stresses were also varied in expression during this process. Furthermore, analysis of DEGs involved in the hormone signaling pathways and determination of endogenous abscisic acid (ABA) content showed that stem bending may be an ethylene-independent process, but regulated by ABA. In short, our findings suggested that the stem bending of cut gerbera may be caused by the involvement of water stress and regulation of ABA during the postharvest life. CONCLUSIONS: The transcriptome sequences provide a valuable resource in revealing the molecular mechanism underlying stem bending of cut flower and offer novel genes that can be used to guide future studies for ornamental plant breeding.

[Accuracy Verification of Robot-assisted Mandibular Reconstruction Surgery].

Mandible is an important bone of the head and neck. Mandibular defects not only affect patient's face, but also impede patient's daily functions, such as chewing, speech, and so on. Fibular transplantation for mandibular reconstruction is the common method, which requests high accuracy of bone positioning and posture adjustment. Therefore, a robotic system for mandibular reconstruction surgery with fibula flaps was designed to assist surgeons to hold and locate bones, and the model comparison experiments were conducted. The results showed that the robotic system can assist surgeons for mandibular reconstruction to improve quality of surgery.

Angle-to-Angle Mandibular Defect Reconstruction With Fibula Flap by Using a Mandibular Fixation Device and Surgical Navigation.

PURPOSE: Although free fibula flaps are widely used for mandibular reconstruction, 3-dimensional (3D) position is difficult to control in angle-to-angle mandibular defects. The present study describes a revised approach for angle-to-angle mandibular reconstruction with fibula flaps by using mandibular fixation device and surgical navigation. METHODS: Preoperative maxillofacial and fibular computed tomography (CT) scans were acquired, and CT data were imported into ProPlan CMF software. Virtual mandibulectomy was performed, and 3D fibula image was superimposed on the mandibular defect. The fibula flap was shaped according to virtual parameters and the stereo model. Surgical navigation was used to check and correct shaped segments. Position of the osteotomy lines and relevant parameters regarding the shape of the fibula flap were provided to the surgeon. A mandibular fixation device (Cibei, China) was fixed to bilateral mandibular ramus before mandibulectomy, which maintained normal mandibular width. Under computer navigation guidance, the fibula flap was accurately positioned in 3D direction, and the defect could be precisely reconstructed despite the lack of stable occlusal relationship after osteotomy. RESULTS: Postoperative CT and 3D error analysis revealed that osteotomy lines and reconstruction contour matched well with preoperative planning. Using our method, we precisely recovered the original configuration of the mandible. Bilateral condyles were located in the temporomandibular joint fossae, and normal mandibular width was maintained. Compared with preoperative positions, the average shift on the remaining mandible was 0.803 ±â€Š0.502 mm (largest, 1.886 mm). Average shift in the reconstructed mandible was 0.281 ±â€Š0.300 mm, largest being 2.441 mm. CONCLUSIONS: We describe a novel method for angle-to-angle mandibular reconstruction with free fibula flap. A mandibular fixation device combined with computer-assisted techniques involving surgical navigation improved clinical outcomes of this procedure.

Three-Dimensional Accuracy of Virtual Planning and Surgical Navigation for Mandibular Reconstruction With Free Fibula Flap.

PURPOSE: Although free fibula flaps are widely used for mandibular reconstruction, their 3-dimensional position is difficult to control during conventional surgery. We aimed to improve this process by using computer-aided design (CAD) and surgical navigation. PATIENTS AND METHODS: We retrospectively reviewed 29 benign tumor patients who underwent primary unilateral mandibular reconstruction with free fibula flap. They were divided into 3 groups: group A, comprising 10 patients, underwent reconstruction based on the surgeon's experience; group B, comprising 7 patients, underwent reconstruction based on CAD; and group C, comprising 12 patients, underwent reconstruction based on CAD and surgical navigation. Condyle and gonion positions and mandibular angles were measured. Operative times were recorded. RESULTS: Among the 17 patients who underwent condylar resection, the average condyle shift was greater in group A than in groups B and C (P < .05). The average gonion shift was greater in groups A and B than in group C (P < .05). The difference between the reconstructed and contralateral mandibular angles was greater in group A than in groups B and C (P < .05). The mean operative time did not differ among the 3 groups. CONCLUSIONS: CAD can guide mandibular angle remodeling and condyle placement. CAD and surgical navigation increase reconstruction accuracy without prolonging operative time.

A Revised Approach for Mandibular Reconstruction With the Vascularized Iliac Crest Flap Using Virtual Surgical Planning and Surgical Navigation.

PURPOSE: The purpose of this study was to describe a revised approach for mandibular reconstruction with vascularized iliac crest flap using virtual surgical planning and surgical navigation. PATIENTS AND METHODS: Preoperative maxillofacial and iliac non-contrast-enhanced computed tomography (CT) scans were acquired, and CT data were imported into ProPlan CMF software (Materialise, Leuven, Belgium). We performed virtual mandibulectomy and superimposed the 3-dimensional iliac image on the mandibular defect. The surgeon shaped the iliac flap according to virtual parameters and the stereomodel. Surgical navigation was used to check and correct the shaped segments. The position of the osteotomy lines and relevant parameters regarding the shape of the iliac flap also were provided to the surgeon. After computer simulation, a reconstructed mandibular stereomodel was manufactured. A reconstruction plate was prebent and fixed on this model using titanium screws. The model was scanned, data were imported into ProPlan CMF, the mandible was segmented, and data were imported into the intraoperative navigation system. Then, the model was registered with the original CT data, and the reconstruction plate was eliminated. Navigation data were exported into a universal serial bus drive, which was connected to the terminal working station during surgery. Intraoperative navigation was used to implement the virtual plan for patients. The sagittal, coronal, axial, and 3-dimensional reconstruction images displayed by the navigation system were used to accurately determine the osteotomy sites and osteotomy trajectory during surgery. Surgical probe guidance was used to mark the osteotomy line and transfer the virtual procedure to real-time surgery. RESULTS: Using our method, we precisely recovered the original configuration of the mandible. The shift in the reconstructed mandible and plate was less than 5 mm. CONCLUSIONS: We provided a new method for mandibular reconstruction with vascularized iliac crest flap and an individual reconstruction plate using computer-assisted techniques involving surgical navigation, which have the potential to improve the clinical outcomes of this procedure.

A New Procedure Assisted by Digital Techniques for Secondary Mandibular Reconstruction With Free Fibula Flap.

PURPOSE: To describe a new procedure assisted by digital techniques for secondary mandibular reconstruction with free fibula flap. METHODS: The 3-dimensional (3D) reconstruction images for vessels were used to demonstrate the vascular diameter and location, which help select the most suitable vein and artery for anastomosis. Maxillary and mandibular stone models of the patient were fabricated and a stable occlusal relationship was determined on an articulator. The 3D tooth model data were scanned using a 3D-optical measuring system, and the obtained stereolithographic (STL) data were imported to Geomagic software. Preoperative maxillofacial and fibular noncontrast-enhanced computed tomography scans were acquired, and the data were imported to ProPlan CMF software. The maxilla and mandible were segmented, and STL data were imported to Geomagic software. The registration function was used to determine the ideal mandibular position. First, with the maxillary position fixed, the maxillary and mandibular models were registered with the maxilla. Then, with the tooth model positions fixed, the mandible was registered with the models. The STL data for the mandible were imported to ProPlan CMF software. Virtual plan and surgical navigation were used to design and correct the mandibular and fibular position. RESULTS: Our technique enabled precise recovery of the original mandibular configuration in this patient. The shift in the reconstructed mandible and fibular segment was <5 mm. CONCLUSIONS: The authors described a new procedure for secondary mandibular reconstruction with a free fibular flap using digital techniques involving surgical navigation, which have the potential to improve the clinical outcomes of this procedure.

Prospects of Robot-Assisted Mandibular Reconstruction with Fibula Flap: Comparison with a Computer-Assisted Navigation System and Freehand Technique.

Background Function and aesthetics have a significant impact on the quality of life in patients undergoing mandibular reconstructive surgery, but achieving satisfactory results remain challenging. The aim of the study is to investigate the feasibility and accuracy of robot-assisted mandibular reconstruction with fibula flap in comparison to that with a computer-assisted navigation system and the freehand technique. Methods Experimental procedures (15 phantom studies and 6 animal experiments) were performed with a custom three-arm robotic system automatically, under the guidance of a computer-assisted navigation system, and by the freehand technique, respectively. The accuracy of the reconstruction was assessed by comparison between the preoperative and postoperative three-dimensional surface virtual models. Results All procedures were successfully performed. In the phantom study, the mean deviation of the fibula implant was 1.221, 1.581, and 2.313 mm, respectively, with the robotic system, the navigation system, and the freehand technique; in the animal experiment the corresponding figures were 1.7697, 1.7847, and 2.0815 mm, respectively. The mean deviation of the proximal mandibular ramus was 1.0420, 1.0532, 1.8800 mm with the robotic system, computer-assisted navigation system, and freehand technique, respectively, and the mean deviation of the distal mandibular segment was 1.1645, 2.7198, and 2.8445 mm, respectively. Conclusions The robotic system is feasible, efficient, and reliable for mandibular reconstruction. The accuracy of the fibula implant orientation with the robotic system was comparable to that with navigation system and superior to that with the freehand technique.

Outcomes of Orbital Floor Reconstruction After Extensive Maxillectomy Using the Computer-Assisted Fabricated Individual Titanium Mesh Technique.

PURPOSE: Orbital floor defects after extensive maxillectomy can cause severe esthetic and functional deformities. Orbital floor reconstruction using the computer-assisted fabricated individual titanium mesh technique is a promising method. This study evaluated the application and clinical outcomes of this technique. PATIENTS AND METHODS: This retrospective study included 10 patients with orbital floor defects after maxillectomy performed from 2012 through 2014. A 3-dimensional individual stereo model based on mirror images of the unaffected orbit was obtained to fabricate an anatomically adapted titanium mesh using computer-assisted design and manufacturing. The titanium mesh was inserted into the defect using computer navigation. The postoperative globe projection and orbital volume were measured and the incidence of postoperative complications was evaluated. RESULTS: The average postoperative globe projection was 15.91 ± 1.80 mm on the affected side and 16.24 ± 2.24 mm on the unaffected side (P = .505), and the average postoperative orbital volume was 26.01 ± 1.28 and 25.57 ± 1.89 mL, respectively (P = .312). The mean mesh depth was 25.11 ± 2.13 mm. The mean follow-up period was 23.4 ± 7.7 months (12 to 34 months). Of the 10 patients, 9 did not develop diplopia or a decrease in visual acuity and ocular motility. Titanium mesh exposure was not observed in any patient. All patients were satisfied with their postoperative facial symmetry. CONCLUSION: Orbital floor reconstruction after extensive maxillectomy with an individual titanium mesh fabricated using computer-assisted techniques can preserve globe projection and orbital volume, resulting in successful clinical outcomes.