Mechanical stretch preconditioned adipose-derived stem cells elicit polarization of anti-inflammatory M2-like macrophages and improve chronic wound healing.

Transplantation of adipose-derived stem cells (ASCs) is a promising option in the field of chronic wounds treatment. However, the effectiveness of ASCs therapies has been hampered by highly inflammatory environment in chronic wound areas. These problems could be partially circumvented using efficient approaches that boost the survival and anti-inflammatory capacity of transplanted ASCs. Here, by application of mechanical stretch (MS), we show that ASCs exhibits increased survival and immunoregulatory properties in vitro. MS triggers the secretion of macrophage colony stimulating factor (M-CSF) from ASCs, a chemokine that is linked to anti-inflammatory M2-like macrophages polarization. When the MS-ASCs were transplanted to chronic wounds, the wound area yields significantly faster closure rate and lower inflammatory mediators, largely due to macrophages polarization driven by transplanted MS-ASCs. Thus, our work shows that mechanical stretch can be harnessed to enhance ASCs transplantation efficiency in chronic wounds treatment.

Combining Patient-specific Implant With Malar Reduction to Repair Mid-facial Asymmetry Caused by Craniofacial Fractures in Asians.

Mid-facial asymmetry caused by bone defect or deformation resulted from craniofacial fracture was a common secondary complication needed to repair. Patient-specific implant (PSI) designed with the unaffected side as a template is a good choice to repair this kind of facial asymmetry. However, in Asians, the broad and prominent zygomatic bone in unaffected side is not an optimal template, because the oval facial shape was considered as a more attractive appearance in Asian esthetic concept. To repair the mid-facial asymmetry and to improve the facial contour, the authors combined PSI implantation with malar reduction in one-stage surgery. The authors referred the facial proportion index (the optimal ratio of mid and lower face was 1.27) as a basis for preoperative precise design to determine the ideal facial shape of unaffected side, and used mirror image overlay technique with the ideal shape of unaffected side as a template to design the PSI. With this surgical strategy, patients not only can repair facial asymmetry but also can get a more attractive appearance.

Hoarseness and arytenoid dislocation: A rare complication after facial bony contouring surgery.

BACKGROUND: Arytenoid dislocation is a rare complication after endotracheal intubation and may result in permanent hoarseness, which cannot be tolerated during cosmetic surgeries, such as facial bony contouring surgery. This study aimed to identify the clinical characteristics of this patient subgroup and share the process of diagnosis and treatment. METHODS: We retrospectively collected the medical records of patients who underwent facial bony contouring surgery under general anesthesia with endotracheal intubation from September 2017 to July 2022. We divided the patients into a nondislocation group and a dislocation group. Demographic, anesthetic, and surgical characteristics were collected and compared. RESULTS: 441 patients were enrolled, and 5 (1.1%) were diagnosed with arytenoid dislocation. The patients in the dislocation group were more likely to be intubated with the video laryngoscope (P = 0.049), and head-neck movement during surgery may predispose patients to arytenoid dislocation (P = 0.019). The patients in the dislocation group were diagnosed around 5-37 days after surgery. Three of them regained their normal voice after close reduction, and two recovered with speech therapy. CONCLUSION: Arytenoid dislocation may result from multiple factors instead of one high-risk factor. Head-neck movement, the skills and experience of anesthetists, the time of intubation, and the use of intubation tools may all predispose patients to arytenoid dislocation. To acquire timely diagnosis and treatment, patients should be fully informed of this complication before surgery and observed closely afterward. Any postoperative voice or laryngeal symptoms lasting more than 7 days need a specialist evaluation.

Changes in Facial Symmetry Following Computer-Assisted Secondary Correction of Craniofacial Fractures.

OBJECTIVE: For patients without dysfunctions, the main purpose of secondary correction for craniofacial fractures is restoring facial symmetry. Computer-assisted surgery techniques including virtual surgical planning and intraoperative navigation provide the help to restore the bony symmetry as much as possible. The authors retrospectively quantitatively analyzed patients who received computer-assisted secondary correction for craniofacial fractures on facial symmetry pre and postoperation. METHODS: This observational study reviewed the medical records of 17 patients requiring secondary correction for craniofacial fractures. Pre and postoperative computed tomography data were used to quantitatively analyze the changes in facial symmetry and enophthalmos. RESULT: All patients enrolled in this study showed mid-facial asymmetry but without dysfunctions except for enophthalmos, and 5 patients had bone defects in the frontal-temporal area. The corrective surgical techniques were different for each patient according to their specific condition. Virtual surgical planning with or without intraoperative navigation was performed for all patients. Compared with the preoperative condition, their facial symmetry was significantly improved. The maximum discrepancy value between the affected side and the mirrored unaffected side decreased from 8.10 ± 2.69 to 3.74 ± 2.02 mm postoperatively, and the mean discrepancy value decreased from 3.58 ± 1.29 to 1.57 ± 0.68 mm. In addition, the Enophthalmos Index decreased from 2.65 to 0.35 mm. CONCLUSION: This observational study objectively demonstrated that computer-assisted secondary correction for craniofacial fractures can significantly improve facial symmetry. And the authors recommend that virtual surgical planning and intraoperative navigation should be a must step in craniofacial fracture correction.

The application of augmented reality in plastic surgery training and education: A narrative review.

Continuing problems with fewer training opportunities and a greater awareness of patient safety have led to a constant search for an alternative technique to bridge the existing theory-practice gap in plastic surgery training and education. The current COVID-19 epidemic has aggravated the situation, making it urgent to implement breakthrough technological initiatives currently underway to improve surgical education. The cutting edge of technological development, augmented reality (AR), has already been applied in numerous facets of plastic surgery training, and it is capable of realizing the aims of education and training in this field. In this article, we will take a look at some of the most important ways that AR is now being used in plastic surgery education and training, as well as offer an exciting glimpse into the potential future of this field thanks to technological advancements.

Efficacy and Safety of Expanded Polytetrafluoroethylene Implantation in the Correction of Long-Term Posttraumatic Enophthalmos.

SUMMARY: Long-term enophthalmos is a common orbital fracture sequela. Various autografts and alloplastic materials have been studied in posttraumatic enophthalmos repair. However, expanded polytetrafluoroethylene (ePTFE) implantation in late enophthalmos repair has rarely been reported. The authors report novel use of ePTFE for late posttraumatic enophthalmos repair. This retrospective study included patients with posttraumatic long-term enophthalmos who underwent hand-carved ePTFE intraorbital implantation for enophthalmos correction. Computed tomography data were collected preoperatively and at follow-up. The volume of ePTFE, the degree of proptosis (DP), and enophthalmos were measured. Postoperative and preoperative DP and enophthalmos were compared using the paired t test. The correlation between ePTFE volume and DP increment was established using linear regression. Complications were identified by chart review. From 2014 to 2021, 32 patients were included, with a mean follow-up of 19.59 months. The mean volume of implanted ePTFE was 2.39 ± 0.89 mL. After surgery, the DP of the affected globe improved significantly, from 12.75 ± 2.12 mm to 15.06 ± 2.50 mm ( P < 0.0001). A significant linear correlation was found between ePTFE volume and DP increment ( P < 0.0001). Enophthalmos was substantially ameliorated from 3.35 ± 1.89 mm to 1.09 ± 2.07 mm ( P < 0.0001). Twenty-five patients (78.23%) had postoperative enophthalmos of less than 2 mm. Infection and implant dislocation were not observed. The authors concluded that ePTFE intraorbital implantation exhibited long-term efficacy and safety for late posttraumatic enophthalmos repair and represents an effective and predictable alternative. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Application of Segmented Template in Three-Dimensionally Guided Mandibular Angle Osteotomy.

BACKGROUND: The procedure of mandibular angle osteotomy (MAO) via an intraoral approach is challenging and experience-dependent due to the limited field of view and inadequate operational space. Uncertainty about the osteotomy line and plane can lead to severe complications. A three-dimensional printed guidance template based on a computer-assisted preoperative simulation is a potential solution to this problem. The current study aims to retrospectively investigate the feasibility and accuracy of using a custom-made segmented template to guide the osteotomy plane during the procedure. METHODS: Sixty patients who had segmented template-guided MAO were included in the study. Preoperative simulation using the custom-designed template and postoperative computed tomography were collected and parameters, including mandibular angle, gonion distance, and the mandibular plane angle were measured. A paired t tests and intraclass correlation coefficients (ICCs) were used to evaluate the efficacy, accuracy, and symmetry of the results. All complications were reviewed. RESULTS: The patients had a significantly larger mandibular angle and narrower gonion distance postoperatively. Preoperative simulations and postoperative outcomes were compared; ICCs were larger than 95% indicating significant agreement. Bilateral postoperative comparisons of the mandible also demonstrated excellent agreement (ICC > 95%). Numbness in the chin area was the most frequent complication but all recovered by 3 months postoperatively. CONCLUSIONS: The custom-made template can guide the osteotomy plane during the MAO procedure and achieve favorable accuracy and symmetry. Direct contact of the saw with the guidance template not only facilitates control of the osteotomy line but also the oblique angle of the osteotomy plane. This methodology may be a feasible and effective tool for mandibular contouring.

A Novel Study on Alar Mobility of HAN Female by 3dMD Dynamic Surface Imaging System.

AIM: The aim of this study is to conduct a quantitative analysis on alar mobility of HAN females and provided referenced materials for alar dynamic aesthetic. METHODS: One hundred and fifty healthy HAN females without rhinoplasty, nasal injury, nasal deformity and craniofacial deformity were included in this study. 3dMD surface imaging system was used for anthropometric analysis. All participants were instructed to perform the desired dynamic facial expression from rest to maximum smile without reveling teeth and recorded by 3dMD dynamic surface imaging system simultaneously. Two frames of rest status and alar maximum enlargement were selected for measuring alar width, alar base width and inner-canthal distance. The difference between two status represented alar mobility, which was generated through equation: [Formula: see text]. RESULTS: Alar mobility consisted of alar flaring mobility and alar base mobility. The alar flaring mobility was (9.49 ± 4.90)%, reference range was(1.45, 17.53)% and regression equation between rest and maximum smile was Y = 7.953 + 0.886X (R2 = 0.641, p = 0.000); the alar base mobility was (17.94 ± 10.44)%, reference range was (0.88, 35.00)% and regression equation between rest and maximum smile was Y = 4.481 + 0.966X (R2 = 0.528, p = 0.000. CONCLUSION: Asian alar anatomy has great distinction from Caucasian, processing conspicuous alar movement and damaging alar aesthetic dynamically. This study novelly defined alar mobility by three-dimensional anthropometric analysis, providing objective references for alar dynamic aesthetic and arousing plastic surgeons' attention on keeping balance of static and dynamic aesthetic in rhinoplasty. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Midfacial Soft Tissue Changes After Reduction Malarplasty: A Computed Tomographic Study.

BACKGROUND: The reduction malarplasty has become one of the most popular esthetic surgeries among Asian women to improve facial contour. However, it is still controversial whether midfacial soft tissue changes after surgery, and more studies are needed. METHODS: This retrospective observational study reviewed 30 patients who underwent L-shaped reduction malarplasty during January 2018 and August 2019. The preoperative and postoperative soft tissue thickness and the angle of nasolabial fold of the midfacial were assessed using photographs, three-dimensional skull computerized tomography images, and the Wrinkle Severity Rating Scale. RESULTS: The postoperative average level of nasolabial fold angle was lower than that observed in preoperative conditions, with the difference being statistically significant (t = -10.262, P < 0.001). The postoperative fifth and sixth layers of soft tissue in the midface were significantly higher than those observed in preoperative tissues. CONCLUSIONS: Although L-shaped reduction malarplasty has evident effects on soft tissue changes of middle face, they are within acceptable ranges and do not affect patient satisfaction.

Using gelatin/curcumin nano-fiber membranes as scaffolds in a subcutaneous model for tissue engineered cartilages.

Engineered cartilage has several applications in treating cartilage ossification, however, its use is restricted clinically. We explored the feasibility of engineered cartilage in constructing tissues using gelatin/curcumin nano-fiber membranes as scaffolds in subcutaneous models. We constructed cartilage with gelatin nano-fiber membrane (control group) and gelatin/curcumin nano-fiber membrane (experimental group) as scaffolds. After the material was implanted into the back of BALB/c mice, gross view observation was performed. Histological examination was performed 3 and 12 weeks after implantation in vivo, and cartilage formation at different time points was compared. Gross observation showed that compared to the control group, the vascularization of nearby tissues in the experimental group was significantly inhibited. The Scanning electron microscope observation showed that the chondrocytes in both groups adhered well. The growth curve of the chondrocytes showed that curcumin had no significant effect on cell growth. Histological observation showed that the cell-material complexes in both groups had cartilage lacuna formation at 3 and 12 weeks. However, compared with that of the control group, the experimental group showed obvious absorption and thicker cartilage matrix with more homogenization. Gelatin/curcumin scaffolds were successfully used to construct engineered cartilage tissues in subcutaneous animal models. Our findings demonstrate that curcumin-loaded scaffolds have great clinical applications.

HoloLens-Based Vascular Localization System: Precision Evaluation Study With a Three-Dimensional Printed Model.

BACKGROUND: Vascular localization is crucial for perforator flap transfer. Augmented reality offers a novel method to seamlessly combine real information with virtual objects created by computed tomographic angiography to help the surgeon "see through" the skin and precisely localize the perforator. The head-mounted display augmented reality system HoloLens (Microsoft) could facilitate augmented reality-based perforator localization for a more convenient and safe procedure. OBJECTIVE: The aim of this study was to evaluate the precision of the HoloLens-based vascular localization system, as the most important performance indicator of a new localization system. METHODS: The precision of the HoloLens-based vascular localization system was tested in a simulated operating room under different conditions with a three-dimensional (3D) printed model. The coordinates of five pairs of points on the vascular map that could be easily identified on the 3D printed model and virtual model were detected by a probe, and the distance between the corresponding points was calculated as the navigation error. RESULTS: The mean errors were determined under different conditions, with a minimum error of 1.35 mm (SD 0.43) and maximum error of 3.18 mm (SD 1.32), which were within the clinically acceptable range. There were no significant differences in the errors obtained under different visual angles, different light intensities, or different states (static or motion). However, the error was larger when tested with light compared with that tested without light. CONCLUSIONS: This precision evaluation demonstrated that the HoloLens system can precisely localize the perforator and potentially help the surgeon accomplish the operation. The authors recommend using HoloLens-based surgical navigation without light.

A Novel Evaluation Model for a Mixed-Reality Surgical Navigation System: Where Microsoft HoloLens Meets the Operating Room.

HoloLens-based mixed-reality surgical navigation system (MR-SNS) technology has made great progress. However, the methodology for evaluating users' perceptions concerning the safety, comfort, and efficiency of MR-SNS is still in its infancy. This study was intended to develop a method to systematically evaluate an existing MR-SNS system during actual clinical applications. This method differs from other existing methods currently used in industry, education, and device maintenance. Based on analytical hierarchy process theory and ergonomics evaluation methods, in this article, we propose a novel multicriteria evaluation model for a HoloLens-based MR-SNS. The model includes factors such as comfort, safety, and effectiveness, and is performed in an actual clinical application. A comprehensive experimental platform and scoring system that can analyze all indicators was built. The validation test showed no statistically significant differences in the accuracy of the 3 different movement patterns (P = .95, P > .05). However, the static pattern showed the best accuracy. In addition, no significant difference (P = .68, P > .05) in accuracy was found under 4 kinds of illuminance. A comparison of the results of this evaluation model and the input from experts who use the HoloLens-based MR-SNS in hospitals, indicated that this model has good precision (100%), recall (80%), and F1-measure (88.89%). The results highlighted the full efficacy of the proposed model in determining whether this system can be used in clinical trials to provide indicators for preliminary ex ante feasibility studies. This article describes the lessons learned from conducting this evaluation study of MR-SNS as part of the design process.

Postoperative Complications of Box-Shift Osteotomy for Orbital Hypertelorism.

OBJECTIVE: To summarize and analyze the postoperative complications of box-shift osteotomy performed at our center for Chinese orbital hypertelorism patients from 2008 to 2017. METHOD: This retrospective study reviews the records of 78 patients with complete medical records and at least 2 years of postoperative follow-up data. Both radiologic and anthropometric assessments were conducted before, 1 month after and 2 years after surgery to evaluate the bony and soft-tissue alterations. Postoperative complications were recorded during hospitalization and at each follow-up visit and divided into 3 groups: acute complications that occurred within 1 month after surgery; early complications that occurred within 6 months after surgery; and long-term complications that occurred within 2 years after surgery. RESULTS: Both bony and soft-tissue alterations were significant at 1 month after surgery. The acute complications that occurred in our center included infection (12.8%), cerebrospinal fluid leakage (29.5%), epilepsy (2.6%), and nasal tip skin necrosis (1.3%). The early complications included strabismus (11.5%) and nasolacrimal duct obstruction (3.8%). The long-term complications included insufficient correction (55.1%), palpable metal implants (92.3%) and a drooping nasal tip (33.9%). Due to the insufficient correction and the continued growth of rib graft, the difference in the hypertelorism index and nasal length, between one month and 2 years postoperatively were statistically significant (P < 0.01). Other radiographic and anthropometric measurements changed with growth without a significance difference between 1 month and 2 years after surgery. CONCLUSION: In this study, we recorded all postoperative complications of box-shift osteotomy. The challenge of our future work is to identify methods for decreasing the incidence of these complications.

Precision of a Novel Craniofacial Surgical Navigation System Based on Augmented Reality Using an Occlusal Splint as a Registration Strategy.

The authors have developed a novel augmented reality (AR)-based navigation system (NS) for craniofacial surgery. In this study, the authors aimed to measure the precision of the system and further analyze the primary influencing factors of the precision. The drilling of holes into the mandibles of ten beagle dogs was performed under the AR-based NS, and the precision was analyzed by comparing the deviation between the preoperational plan and the surgical outcome. The AR-based NS was successfully applied to quickly and precisely drill holes in the mandibles. The mean positional deviation between the preoperative design and intraoperative navigation was 1.29 ± 0.70 mm for the entry points and 2.47 ± 0.66 mm for the end points, and the angular deviation was 1.32° ± 1.17°. The precision linearly decreased with the distance from the marker. In conclusion, the precision of this system could satisfy clinical requirements, and this system may serve as a helpful tool for improving the precision in craniofacial surgery.

A Novel Augmented Reality-Based Navigation System in Perforator Flap Transplantation - A Feasibility Study.

BACKGROUND: In perforator flap transplantation, dissection of the perforator is an important but difficult procedure because of the high variability in vascular anatomy. Preoperative imaging techniques could provide substantial information about vascular anatomy; however, it cannot provide direct guidance for surgeons during the operation. In this study, a navigation system (NS) was established to overlie a vascular map on surgical sites to further provide a direct guide for perforator flap transplantation. METHODS: The NS was established based on computed tomographic angiography and augmented reality techniques. A virtual vascular map was reconstructed according to computed tomographic angiography data and projected onto real patient images using ARToolKit software. Additionally, a screw-fixation marker holder was created to facilitate registration. With the use of a tracking and display system, we conducted the NS on an animal model and measured the system error on a rapid prototyping model. RESULTS: The NS assistance allowed for correct identification, as well as a safe and precise dissection of the perforator. The mean value of the system error was determined to be 3.474 ± 1.546 mm. CONCLUSIONS: Augmented reality-based NS can provide precise navigation information by directly displaying a 3-dimensional individual anatomical virtual model onto the operative field in real time. It will allow rapid identification and safe dissection of a perforator in free flap transplantation surgery.

A novel augmented reality system for displaying inferior alveolar nerve bundles in maxillofacial surgery.

Augmented reality systems can combine virtual images with a real environment to ensure accurate surgery with lower risk. This study aimed to develop a novel registration and tracking technique to establish a navigation system based on augmented reality for maxillofacial surgery. Specifically, a virtual image is reconstructed from CT data using 3D software. The real environment is tracked by the augmented reality (AR) software. The novel registration strategy that we created uses an occlusal splint compounded with a fiducial marker (OSM) to establish a relationship between the virtual image and the real object. After the fiducial marker is recognized, the virtual image is superimposed onto the real environment, forming the "integrated image" on semi-transparent glass. Via the registration process, the integral image, which combines the virtual image with the real scene, is successfully presented on the semi-transparent helmet. The position error of this navigation system is 0.96 ± 0.51 mm. This augmented reality system was applied in the clinic and good surgical outcomes were obtained. The augmented reality system that we established for maxillofacial surgery has the advantages of easy manipulation and high accuracy, which can improve surgical outcomes. Thus, this system exhibits significant potential in clinical applications.

The second fat graft has significantly better outcome than the first fat graft for Romberg syndrome: A study of three-dimensional volumetric analysis.

BACKGROUND: Patients with congenital or acquired deformities always need fat graft at least twice to remodel facial contour. The purpose of this study was to objectively evaluate the outcomes of the first and second fat grafts for Romberg syndrome by using three-dimensional (3D) volumetric analysis. METHOD: A retrospective study was conducted using the medical records of 13 patients with Romberg disease who were treated with fat graft twice for facial filling. Patient and surgeon satisfactions were evaluated by comparing the preoperative and postoperative two-dimensional (2D) photographs. The preoperative and postoperative 3D images were analyzed with professional analysis software to calculate the volume discrepancy between them. RESULT: According to the 2D photographs, both patients and the surgeon were more satisfied with the cosmetic results of the second fat graft. There was no significant statistical difference in the injection volumes between the two surgeries (p = 0.1); however, the survival rate of the second fat graft (75.1% ± 7.7%) was much higher than that of the first (43.3% ± 11.1%) with a significant difference (p < 0.01). CONCLUSION: In this study, 3D images were used to objectively evaluate the survival rate of fat graft. The results showed that the second fat graft without any sophisticated procedures could acquire better cosmetic result and volume retention in Romberg syndrome. This study result could serve as a guide for clinical surgeons to forecast the outcome of sequential fat graft for patients with congenital or acquired deformities.

Bone morphogenetic protein is required for fibroblast growth factor 2-dependent later-stage osteoblastic differentiation in cranial suture cells.

BACKGROUND: Understanding the pathophysiological process of calvarial bones development is important for the treatments on relative diseases such as craniosynostosis. While, the role of fibroblast growth factor (FGF) and bone morphogenetic protein (BMP) and how they interacted in osteoblast differentiation remain unclear. METHODS: we digested bone fragments around the coronal and sagittal sutures from newborn rats to harvest suture cells. Markers expression at different osteoblast differentiation stage was analyzed by increasing FGF2 concentration and BMP2 blocking in these cells. RESULTS: BMP2 expression could be stimulated by FGF2 in a dose and time dependent manner. FGF2 stimulation may decrease early marker of osteoblast differentiation (collagen type-1, COL-1) and increase the expression of continuously-expressed or late markers (alkaline phosphatase, ALP; osteocalcin, OC and bone sialoprotein, BSP) to accelerate mineralization. Inhibition of BMP2 signaling by Noggin weakens the effect of FGF2 on induction of later-stage osteoblastic differentiation of cranial suture cells. CONCLUSION: Our data suggest that BMP2 signaling is required for FGF2-dependent induction of later-stage of cranial suture cell osteoblastic differentiation.