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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.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.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 (ICC95%). Numbness in the chin area was the most frequent complication but all recovered by 3 months postoperatively.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.

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

Irregular craniofacial bone defects caused by craniofacial fractures always result in craniofacial bone and contour asymmetry and should therefore be reconstructed. Polyetheretherketone (PEEK) is an ideal substitute for autologous bone grafts and has been widely used in craniofacial bone defect reconstruction. The precise design of custom-made PEEK implants is particularly important to optimise reconstruction. Herein, the workflow and principles for the design and manufacture of PEEK implants are summarised, and a protocol for the precise design of an irregular craniofacial bone defect PEEK implant is presented. According to the method and principles, the design flow was efficient and could be standardised, and design errors could be avoided as much as possible.

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.

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

OBJECTIVE The purpose of this study was to detect the yield, activity and safety of the stromal vascular fraction (SVF) isolated by a new clinical-grade collagenase with a specific process and to validate the efficacy of the method. MATERIALS AND METHODS For the in vitro study, adipose tissue specimens were obtained from women undergoing elective liposuction (n = 5). The SVF was isolated by new clinical-grade collagenase for the experimental group and research-grade collagenase NB4 for the control group. The surface markers of the SVFs isolated by the two collagenases were detected by flow cytometry. The yield, activity and morphology of the SVFs were compared, together with their proliferation, migration and differentiation. Furthermore, we conducted a clinical trial to evaluate the improvement of skin texture after transplantation of autologous SVF isolated by clinical-grade collagenase. RESULTS There were no statistically significant differences in the yield, viability or morphology of the SVFs isolated by the new collagenase and collagenase NB4. Adipose tissue-derived mesenchymal stem cells (ASCs) surface marker expression was consistent between the two products. The differentiation potential of the cells was not different, which was consistent with previously published results. The SVF isolated by the new collagenase had a higher proliferation and migration. After administration of autologous SVF isolated by the new collagenase, the VISIA score improved significantly with regard to wrinkle scores and texture scores. CONCLUSION We concluded that this new type of clinical-grade collagenase can replace current research-grade products without any negative effect on the yield or function of the SVF, which can be applied to antiaging and rejuvenation of facial skin.

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. 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: $${\text{MOBILITY}} = \frac{{{\text{WIDTH}}_{{{\text{smile}}}} - {\text{WIDTH}}_{{{\text{rest}}}} }}{{{\text{WIDTH}}_{{{\text{rest}}}} }} \times 100\%$$ . 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. 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. 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 .

Summary Background Improving the survival rate of fat grafts is yet a difficult problem in the field of autologous fat transplantation. Prevailing methods such as making nanofat and SVF are time-consuming. Hence, the role of additives application in the improvement of fat graft survival during fat transplantation was considered and preliminarily evaluated in a rabbit animal model. Methods A rabbit animal model was established where rabbit ears were injected with a mixture of 1.5 mL of adipose tissue and 1 mL of saline (group A), 1.5 mL of adipose tissue and 1 mL of botulinum toxin A (BoNTA) (group B), 1.5 mL of adipose tissue and 1 mL of prostaglandin E2 (group C), 1.5 mL of adipose tissue and 1 mL of PDRN (group D) respectively. Then, the extents of neovascularization and inflammation were evaluated on the 7th, 14th, 28th, 42nd, 56th and 70th day after injection by ELISA assays and H&E and immunofluorescence staining. Results The results showed that pre-treatment with BoNTA, prostaglandin E2 and PDRN improved graft volume and weight. The H&E and immunofluorescence staining revealed that BoNTA, prostaglandin E2 and PDRN improved the graft angiogenesis. Simultaneously, TNF-α expression level detected by ELISA was the lowest in the PDRN group. Conclusion Henceforth, the present preliminary study suggests that pre-transplantation treatment with BoNTA, prostaglandin E2 and PDRN can improve the fat graft angiogenesis and graft integrity, whereby the effect of adding PDRN may be significant.

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.

Summary 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 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.

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.

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.

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 robust fault estimation (FE) method is proposed for Lipschitz nonlinear Markov jump system (MJS) based on unknown input observer (UIO). Firstly, the robust UIO is designed under the unknown input and output noise. Then the state estimation error system is established by combining the observer estimated states with real system states. When the error system is stable, the system states and the actuator faults can be estimated simultaneously. Compared with previous studies, the unknown input is not assumed to be decoupled completely and the noise is existed in the output. To solve these cases, the robust H ∞ optimization method is used. A sufficient stability condition of the error system is derived by applying linear matrix inequality (LMI) technique, and the observer gain also can be obtained by solving a set of LMIs. A numerical example shows the effectiveness of the proposed method.

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.

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.

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.