Facial vascular visualization enhancement based on optical detection technology.

OBJECTIVE: This study aims to develop a facial vascular enhancement imaging system and analyze vascular distribution in the facial region to assess its potential in preventing unintended intravascular injections during cosmetic facial filling procedures. METHODS: A facial vascular enhancement imaging system based on optical detection technology was designed, and volunteers were recruited. The system was utilized to detect and analyze vascular distribution in various anatomical regions of the faces. The vascular visualization-enhanced images generated by the system were compared with visible light images to validate the vascular visualization capability of the system. Additionally, the reliability of vascular visualization was assessed by comparing the observed vascular patterns in the vascular visualization-enhanced images with those in near-infrared light images. RESULTS: Thirty volunteers were recruited. The vascular visualization-enhanced images produced by the system demonstrated a significant capacity to identify vascular morphology and yielded a higher vessel count compared to visible light images, particularly in the frontal, orbital, perioral, mental, temporal, cheek, and parotid masseter regions (p < 0.05). The temporal region exhibited the highest vascular density, followed by the cheek region and then the frontal region. Reliability analysis of vascular visualization enhancement indicated that the system's imaging of facial vasculature not only demonstrated reliability but also enhanced physicians' visual perception. CONCLUSION: Blood vessel distribution varies across facial regions. The facial vascular enhancement imaging system facilitates real-time and clear visualization of facial vasculature, offering immediate visual feedback to surgeons. This innovation holds promise for enhancing the safety and effectiveness of facial filling procedures.

ScRNA-seq links dental fibroblasts heterogeneity with mechanoresponsiveness.

BACKGROUND AND OBJECTIVE: Periodontal ligament (PDL) and dental pulp (DP) share a common origin but have distinct biological and mechanical functions. To what extent the mechanoresponsive property of PDL can be attributed to its unique transcriptional profiles of cellular heterogeneity is unclear. This study aims to decipher cellular heterogeneity and distinct mechanoresponsive characteristics of odontogenic soft tissues and their underlying molecular mechanisms. MATERIALS AND METHODS: A single-cell comparison of digested human periodontal ligament (PDL) and dental pulp (DP) was performed using scRNA-seq. An in vitro loading model was constructed to measure mechanoresponsive ability. Dual-luciferase assay, overexpression, and shRNA knockdown were used to investigate the molecular mechanism. RESULTS: Our results demonstrate striking fibroblast heterogeneity across and within human PDL and DP. We demonstrated that a tissue-specific subset of fibroblasts existed in PDL exhibiting high expression of mechanoresponsive extracellular matrix (ECM) genes, which was verified by an in vitro loading model. ScRNA-seq analysis indicated a particularly enriched regulator in PDL-specific fibroblast subtype, Jun Dimerization Protein 2 (JDP2). Overexpression and knockdown of JDP2 extensively regulated the downstream mechanoresponsive ECM genes in human PDL cells. The force loading model demonstrated that JDP2 responded to tension and that knockdown of JDP2 effectively inhibited the mechanical force-induced ECM remodeling. CONCLUSIONS: Our study constructed the PDL and DP ScRNA-seq atlas to demonstrate PDL and DP fibroblast cellular heterogeneity and identify a PDL-specific mechanoresponsive fibroblast subtype and its underlying mechanism.

Reciprocating Rasp for Use in Mandibular Anterior Subapical Osteotomy.

The article describes a reciprocating rasp used in the mandibular anterior subapical osteotomy. Over the past 2 years, reciprocating rasp osteotomy was introduced in the Oral and Craniomaxillofacial Surgery Department of Shanghai Ninth People's Hospital. No complication such as bleeding, wound infection, or tissue necrosis has been encountered. The use of reciprocating rasp avoids iatrogenic damage to adjacent structures and reduces the time spent operating mandibular anterior subapical osteotomy. Therefore, it is recommended for mandibular anterior subapical osteotomy.

Designing Porous Ion Emitters for Thermal Ionization Mass Spectrometry: Evaluating Metal-Organic Frameworks.

This work describes the first exploration of metal-organic frameworks (MOFs) as "next-generation" ion emitters for thermal ionization mass spectrometry (TIMS). MOFs were identified as promising candidates for this application given the synthetic control over their desired structural properties. This tunability results in well-ordered, high-surface-area, high-porosity frameworks with targeted sorption affinities. Here, we explored an aluminum-based, bipyridine-containing MOF (MOF-253) with and without incorporating a high work function metal, rhenium (Re). After analysis of an Nd-bearing MOF, we hypothesized that the well-dispersed, sponge-like interconnected network of the degraded structure would enhance Nd ionization more than traditional TIMS loading techniques (i.e., phosphoric acid). Compared to filaments loaded with phosphoric acid that require an additional benzene carburization step, the Nd ionization efficiencies (atoms detected relative to atoms loaded) for heated filaments loaded with MOF-253 were similar (∼1%). Electron microscopy after TIMS analysis demonstrated that the MOF was retained on the filament. While these results are preliminary, they demonstrate that MOFs have potential to enhance ionization and exceed the performance of traditional loading techniques by forming nanoporous ion emitters. Thus, further experimentation is likely to exceed this performance through more specific selection of the base MOF structure and modifications to porosity and composition. This work represents a novel application of MOFs and a next step in the pursuit of advanced thermal ionization with potential to expand across the periodic table.

Effect of Swell1 on regulating chondrocyte hypertrophy during the condylar osteochondral development process in mice.

Chondrocyte hypertrophy is a significant factor in cartilage development, yet the molecular mechanism for cell volume expand during the process is remains unclear. In the present study, the relationship between Swell1, a cell volume regulated anion channel, and chondrocyte hypertrophy was explored. The results reveal that the spatiotemporal expression of Swell1 was similar with the development process of hypertrophic chondrocytes in condyles. Through Col10a1 mediated knock out of Swell1 in hypertrophy chondrocytes, we found that there are less obvious boundary between different condylar cartilage layers in which increased hypertrophic chondrocytes were scattered in all three cartilage layers. The cortical bone mass and bone mineral density in the subchondral bone significantly increased. Additionally, knock out of Swell1 could increase the expression of OCN in the femur condyle. Based on the aforementioned findings, a conclusion could be drawn that Swell1 is a significant factor in chondrocyte hypertrophy during the condylar osteochondral development process, and there was some difference between the mandibular and femur condyles, which will provide some new clues for understanding the development of cartilage and related diseases.

Glomerular filtration rate early after liver transplantation independently predicts atherosclerotic events.

Cardiovascular disease (CVD) is an important cause of mortality among liver transplantation (LT) recipients; however, the data on CVD risk stratification following LT are limited. Thus, the primary aim of this study was to evaluate the association between decline in renal function early after LT and atherosclerotic events. This retrospective study included all patients receiving LT between 2007 and 2019. Early renal function was quantified as estimated glomerular filtration rate (GFR) 6 months after LT. The primary endpoint for the study was a composite atherosclerotic cardiovascular event of three-point major adverse cardiovascular events (MACEs), which includes nonfatal myocardial infarction (MI), nonfatal stroke, or death from CVD. A total of 553 LT recipients met entry criteria. After a median follow-up of 74 months (interquartile range 46-111), 94 (17%) LT recipients died and CVD-associated death occurred in 20 patients. MACE-3 occurred in 66 (12%) patients, with nonfatal MI being the most common event (n = 30). A strong inverse relationship between early GFR and MACE-3 was noted in unadjusted analysis with hazard ratio (HR) 0.96 (95% confidence interval [CI] 0.95-0.98; p = 0.0001) and remained significant even after accounting for age, sex, coronary artery disease, diabetes mellitus, hypertension, calcineurin inhibitor use, and Framingham Risk Score (FRS; HR 0.96, 95% CI 0.95-0.97; p = 0.0001 per unit increase in GFR). Furthermore, an independent interaction between GFR, FRS, and likelihood of developing an MACE-3 was noted. GFR 6 months following LT is a strong predictor of developing atherosclerotic events. This relationship is independent of traditional CVD risk stratification models (e.g. FRS) and thus has the potential to be incorporated into CVD risk assessment after LT but requires further validation.

Differential fuel utilization in liver transplant recipients and its relationship with non-alcoholic fatty liver disease.

Metabolic flexibility is the ability to match biofuel availability to utilization. Reduced metabolic flexibility, or lower fatty acid (FA) oxidation in the fasted state, is associated with obesity. The present study evaluated metabolic flexibility after liver transplantation (LT). METHODS: Patients receiving LT for non-alcoholic steatohepatitis (NASH) (n = 35) and non-NASH (n = 10) were enrolled. NASH was chosen as these patients are at the highest risk of metabolic complications. Metabolic flexibility was measured using whole-body calorimetry and expressed as respiratory quotient (RQ), which ranges from 0.7 (pure FA oxidation) to 1.0 is (carbohydrate oxidation). RESULTS: The two cohorts were similar except for a higher prevalence of obesity and diabetes in the NASH cohort. Post-prandially, RQ increased in both cohorts (i.e. greater carbohydrate utilization) but peak RQ and time at peak RQ was higher in the NASH cohort. Fasting RQ in NASH was significantly higher (0.845 vs. 0.772, p < .001), indicative of impaired FA utilization. In subgroup analysis of the NASH cohort, body mass index but not liver fat content (MRI-PDFF) was an independent predictor of fasting RQ. In NASH, fasting RQ inversely correlated with fat-free muscle volume and directly with visceral adipose tissue. CONCLUSION: Reduced metabolic flexibility in patients transplanted for NASH cirrhosis may precede the development of non-alcoholic fatty liver disease after LT.

Two-dimensional nanovermiculite and polycaprolactone electrospun fibers composite scaffolds promoting diabetic wound healing.

BACKGROUND: Promoting diabetic wound healing is still a challenge, and angiogenesis is believed to be essential for diabetic wound healing. Vermiculite is a natural clay material that is very easy to obtain and exhibits excellent properties of releasing bioactive ions, buffering pH, adsorption, and heat insulation. However, there are still many unsolved difficulties in obtaining two-dimensional vermiculite and using it in the biomedical field in a suitable form. RESULTS: In this study, we present a versatile organic-inorganic composite scaffold, which was constructed by embedding two-dimensional vermiculite nanosheets in polycaprolactone electrospun fibers, for enhancing angiogenesis through activation of the HIF-1α signaling pathway and promoting diabetic wound healing both in vitro and in vivo. CONCLUSIONS: Together, the rational-designed polycaprolactone electrospun fibers-based composite scaffolds integrated with two-dimensional vermiculite nanosheets could significantly improve neo-vascularization, re-epithelialization, and collagen formation in the diabetic wound bed, thus promoting diabetic wound healing. This study provides a new strategy for constructing bioactive materials for highly efficient diabetic wound healing.

Mandibular stability and condylar changes following orthognathic surgery in mandibular hypoplasia patients associated with preoperative condylar resorption.

OBJECTIVES: To evaluate postoperative mandibular stability and condylar changes in patients with mandibular hypoplasia and preoperative condylar resorption (CR) undergoing orthognathic surgery. MATERIALS AND METHODS: Fifty-four patients were included in this retrospective study. Computed tomography (CT) scans were acquired preoperatively (T0), 2-7 days immediate postoperatively (T1), and at least 1 year postoperatively (T2). Three-dimensional (3D) cephalometric analysis and measurements of condylar angle, volume, and position (joint spaces) were performed. A 2-mm mandibular relapse was deemed clinically acceptable. We also analyzed the correlations between relapse and postoperative CR and susceptible factors using a multivariate logistic regression model. RESULTS: The results showed one year after the surgery, the average mandibular relapse was 1.0 mm (p < 0.05), and the average reduction of condylar volume was 152.4 mm3 (12.7%). Condyle-fossa relationships were improved immediately after the surgery, with a tendency of returning to their original state in the follow-up (p < 0.05). Anteroposterior advancement at point B (B-CP advancement) at T1 and superior joint space (SJS) at T0 were significantly correlated with mandibular relapse, and postoperative CR was mainly associated with vertical increasement at point B (B-AP increasement) at T1. The optimal cut-off values were as follows: 1.6 mm for SJS, 4.2 mm for B-CP advancement, and 1.8 mm for B-AP increasement. Concomitant advancement Genioplasty showed no significant correlation with relapse and postoperative CR. CONCLUSIONS: While patients with mandibular hypoplasia and preoperative CR were vulnerable to further condylar resorption after mandibular advancement, the treatment outcomes were generally clinically acceptable. Postoperative relapse was associated with a larger than 4.2 mm of mandibular advancement measured at B-CP and a larger than 1.6 mm of superior joint space measured at SJS, and postoperative CR was associated with a larger than 1.8 mm of mandibular vertical increasement measured at B-AP. CLINICAL RELEVANCE: The findings of this study suggested that the mandibular advancement might be limited to 5 mm for patients with preoperative CR. A concomitant advancement genioplasty might also be considered to achieve a better facial profile in these patients.

Precise Intraoral Condylectomy With the Guide of Three-Dimensional Printed Template in a Mandibular Condylar Hyperplasia Patient.

PURPOSE: This study aimed to introduce an innovative method for mandibular condylectomy. A customized three-dimensional (3D) printed template is used to perform precise condylectomy in an intraoral approach. METHODS: Condylectomy combined with orthognathic surgery was used for the treatment of facial asymmetry secondary to unilateral condylar hyperplasia. The customized 3D printed osteotomy guide was placed with an intraoral approach under endoscopy, in order to perform a precise condylectomy. RESULT: With the customized 3D printed template, the condylectomy was performed more precisely, and the conventional extraoral incision was avoided. The osteotomy line was accurately transferred from the virtual surgical plan to the real surgery, which assured the precise resection. CONCLUSIONS: The intraoral approach combined with a 3D printed template provides a novel solution to perform the condylectomy precisely.

Collaborative Control Method and Experimental Research on Robot-Assisted Craniomaxillofacial Osteotomy Based on the Force Feedback and Optical Navigation.

OBJECTIVE: Surgical robot has advantages in high accuracy and stability. But during the robot-assisted bone surgery, the lack of force information from surgical area and incapability of intervention from surgeons become the obstacle. The aim of the study is to introduce a collaborative control method based on the force feedback and optical navigation, which may optimally combine the excellent performance of surgical robot with clinical experiences of surgeons. MATERIALS AND METHODS: The CMF ROBOT system was integrated with the force feedback system to ensure the collaborative control. Force-velocity control algorithm based on force feedback was designed for this control method. In the preliminary experimental test, under the collaborative control mode based on force feedback and optical navigation, the craniomaxillofacial surgical robot entered the osteotomy line area according to the preoperative surgical plan, namely, right maxillary Le Fort I osteotomy, left maxillary Le Fort I osteotomy, and genioplasty. RESULTS: The force sensor was able to collect and record the resistance data of the cutting process of the robot-assisted craniomaxillofacial osteotomy assisted in real time. The statistical results showed that the repeatability of collaborative control mode was acceptable in bilateral maxillary Le Fort I osteotomies (right, P =0.124>0.05 and left, P =0.183>0.05) and unfavorable in genioplasty ( P =0.048<0.05). CONCLUSION: The feasibility of robot-assisted craniomaxillofacial osteotomy under the collaborative control method based on the force feedback and optical navigation was proved in some extent. The outcome of this research may improve the flexibility and safety of surgical robot to meet the demand of craniomaxillofacial osteotomy.

Association Between Lipoprotein Particles and Atherosclerotic Events in Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease,1 is independently associated with increased risk of cardiovascular disease (CVD), which is the leading cause of mortality in patients with NAFLD.2 This is likely caused by the centrality of the liver in lipid homeostasis. Prior cross-sectional studies have shown that NAFLD is associated with perturbations in lipid profile and atherogenic lipoprotein subparticles.3 Although statins improve lipid profile and CVD-associated mortality, residual CVD risk has been demonstrated in major statin trials.4,5 A key contributor to this residual risk is the limited ability of the standard lipid profile to precisely quantify atherogenic lipoprotein subparticles, such as small dense low-density lipoprotein (sdLDL), which might confer higher atherogenic risk. There are currently no studies evaluating the longitudinal impact of sdLDL on atherosclerotic events in NAFLD. Thus, we conducted a prospective study in patients with histologically confirmed NAFLD to better define the relationship among NAFLD, residual CVD risk, and sdLDL.

The phylogenetic relationship within SARS-CoV-2s: An expanding basal clade.

The COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) whose origin is still shed in mystery. In this study, we developed a method to search the basal SARS-CoV-2 clade among collected SARS-CoV-2 genome sequences. We first identified the mutation sites in the SARS-CoV-2 whole genome sequence alignment. Then by the pairwise comparison of the numbers of mutation sites among all SARS-CoV-2s, the least mutated clade was identified, which is the basal clade under parsimony principle. In our first analysis, we used 168 SARS-CoV-2 sequences (GISAID dataset till 2020/03/04) to identify the basal clade which contains 33 identical viral sequences from seven countries. To our surprise, in our second analysis with 367 SARS-CoV-2 sequences (GISAID dataset till 2020/03/17), the basal clade has 51 viral sequences, 18 more sequences added. The much larger NCBI dataset shows that this clade has expanded with 85 unique sequences by 2020/04/04. The expanding basal clade tells a chilling fact that the least mutated SARS-CoV-2 sequence was replicating and spreading for at least four months. It is known that coronaviruses have the RNA proofreading capability to ensure their genome replication fidelity. Interestingly, we found that the SARS-CoV-2 without its nonstructural proteins 13 to 16 (Nsp13-Nsp16) exhibits an unusually high mutation rate. Our result suggests that SARS-CoV-2 has an unprecedented RNA proofreading capability which can intactly preserve its genome even after a long period of transmission. Our selection analyses also indicate that the positive selection event enabling SARS-CoV-2 to cross species and adapt to human hosts might have been achieved before its outbreak.

Error Analysis of Robot-Assisted Orthognathic Surgery.

OBJECTIVE: Orthognathic surgery is an effective method to correct the dentomaxillofacial deformities. The aim of the study is to introduce the robot-assisted orthognathic surgery and demonstrate the accuracy and feasibility of robot-assisted osteotomy in transferring the preoperative virtual surgical planning (VSP) into the intraoperative phase. METHODS: The CMF robot system, a craniomaxillofacial surgical robot system was developed, consisted of a robotic arm with 6 degrees of freedom, a self-developed end-effector, and an optical localizer. The individualized end-effector was installed with reciprocating saw so that it could perform osteotomy. The study included control and experimental groups. In control group, under the guidance of navigation system, surgeon performed the osteotomies on 3 skull models. In experimental group, according to the preoperative VSP, the robot completed the osteotomies on 3 skull models automatically with assistance of navigation. Statistical analysis was carried out to evaluate the accuracy and feasibility of robot-assisted orthognathic surgery and compare the errors between robot-assisted automatic osteotomy and navigation-assisted manual osteotomy. RESULTS: All the osteotomies were successfully completed. The overall osteotomy error was 1.07 ±â€Š0.19 mm in the control group, and 1.12 ±â€Š0.20 mm in the experimental group. No significant difference in osteotomy errors was found in the robot-assisted osteotomy groups (P = 0.353). There was consistence of errors between robot-assisted automatic osteotomy and navigation-assisted manual osteotomy. CONCLUSION: In robot-assisted orthognathic surgery, the robot can complete an osteotomy according to the preoperative VSP and transfer a preoperative VSP into the actual surgical operation with good accuracy and feasibility.

Chemical and Isotopic Characterization of Noble Metal Phase from Commercial UO2 Fuel.

We report elemental and isotopic analysis for the noble metal fission product phase found in irradiated nuclear fuel. The noble metal phase was isolated from three commercial irradiated UO2 fuels by chemically dissolving the UO2 fuel matrix, leaving the noble metal phase as the undissolved residue. Macro amounts of this residue were dissolved using a KOH + KNO3 fusion and then chemically separated into individual elements for analysis by mass spectrometry. Though the composition of this phase has been previously reported, this work is the most comprehensive chemical analysis of the isolated noble metal phase to date. We report both elemental and isotopic abundances of the five major components of the noble metal phase (Mo, Tc, Ru, Rh, Pd). In addition, we report a sixth element present in high quantities in this phase, tellurium. Tellurium appears to be an integral component of noble metal particles.

Dlx2 overexpression enhanced accumulation of type II collagen and aggrecan by inhibiting MMP13 expression in mice chondrocytes.

Genetic studies revealed a crucial role of Distal-homebox (Dlx) genes in skeletal development, and our previous study demonstrated overexpressing Dlx2 in neural crest cells led to abnormal cartilage structure, including ectopic cartilage in the maxillary region and nasal bone in mice. The aim of this study was to investigate how Dlx2 overexpression affects chondrogenesis in mouse chondroblast cell line TMC23 and the underlying mechanism. We first demonstrated that Dlx2 expression was upregulated during chondrogenesis in TMC23 cells. Moreover, forced overexpression of Dlx2 in TMC23 cells led to increased accumulation of aggrecan and type II collagen, markers of early chondrocyte differentiation, but had little effect on mRNA and protein levels of Aggrecan and Col2α1, type II collagen gene. Importantly, Dlx2 overexpression decreased mRNA and protein levels of MMP13, a major collagenase degrading aggrecan and type II collagen during late stages of chondrogenesis. Luciferase-reporter and Chromatin-immunoprecipitation analysis demonstrated that MMP13 promoter contained two Dlx2-response elements, and Dlx2 inhibited MMP13 expression by directly binding to these two elements. Based on these observations, we propose that forced overexpression of Dlx2 enhances early chondrocyte differentiation by increasing accumulation of type II collagen and aggrecan, but interferes later stages of chondrocyte differentiation through inhibiting MMP13 expression.

Do Open Reduction and Internal Fixation With Articular Disc Anatomical Reduction and Rigid Anchorage Manifest a Promising Prospect in the Treatment of Intracapsular Fractures?

PURPOSE: In response to the increased attention to soft tissue reduction in the treatment of intracapsular condylar fractures (ICFs), a modified open reduction technique is proposed and its functional and radiographic outcomes were evaluated in this study. PATIENTS AND METHODS: This is a retrospective case series study of patients with all ICF types that were treated with open reduction and internal fixation (ORIF) with articular disc anatomic reduction and rigid anchorage. Inclusion and exclusion criteria were strictly applied. Preoperative and postoperative clinical examinations of malocclusion, maximum incisor opening (MIO), laterotrusion, and temporomandibular disorder symptoms were recorded and analyzed. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to assess articular position and condylar morphology and position. RESULTS: Thirty-four patients with ICFs (47 sides) were treated with the modified ORIF technique. At 6 months of follow-up, no malocclusion was found and the MIO considerably expanded to 3.56 ± 0.13 cm. Only 4 patients (12%) had temporomandibular joint discomfort with mouth opening. Interestingly, for unilateral type B ICFs, the laterotrusion distance to the ORIF sides was notably longer than to the non-ORIF sides. Postoperative CT and MRI showed that all fragments were properly reduced and the condyles were in the normal position. Postoperative anterior disc displacement occurred in 4 sides and condylar morphologic abnormalities (slight surface roughening and articular cartilage absorption) occurred in 3 sides (6.4%). CONCLUSIONS: This modified ORIF technique, which achieved good outcomes after treatment of all ICF types, shows promise for the treatment of ICFs.

Segmental Maxillary Distraction Osteogenesis With a Hybrid-Type Distractor in the Management of Wide Alveolar Cleft.

OBJECTIVE: To investigate segmental maxillary distraction osteogenesis (DO) with hybrid-type distractor in the management of wide alveolar cleft. PATIENTS AND METHODS: Six patients underwent segmental DO with a hybrid-type distractor. After the success of DO and 3-month consolidation period, removal of the distractor was accompanied by alveolar bone graft with iliac bone. Panoramic radiograph and computed tomography scanning were taken preoperatively (T0) and the day after distractor removal (T1). The crest distance between the long axis of cleft nearby teeth was measured. RESULT: All patients completed the DO period, and the succeeding alveolar bone graft healing was uneventful. The mean cleft distance decrease was 12.05 mm (range: 10.1-13.5 mm). As for the mobility degree record of abutment tooth in the transport segment recorded, 6 patients were grading I° at T0, while 5 patients were grading I° and 1 patient was grading II° at T1. CONCLUSION: Segmental maxillary DO with the hybrid-type distractor is successful to reduce the cleft width in these cases, and it is promising in the treatment of wide dental alveolar cleft, especially for the adult patient.

Computer-Assisted Distraction Osteogenesis in the Treatment of Hemifacial Microsomia.

PURPOSE: To investigate the application of computer-assisted surgical planning and virtual guide in distraction osteogenesis for patients with hemifacial microsomia. METHODS: Eight patients diagnosed with unilateral hemifacial microsomia were enrolled in this study. Preoperative surgical planning and simulation were performed on three-dimensional model. Distraction was simulated on virtual model and the new morphology of the mandible was predicted. Mandibular ramus osteotomy and distractor implant was performed under the guidance of tooth-borne virtual guide. Postoperative evaluation of the intervention was performed by comparison of surgical planning and actual result. RESULTS: Preoperative planning, simulation, osteotomy and distractor implant under the guidance of virtual guide were performed successfully on all patients. Tooth-borne guide defined the osteotomy line and accurate position of distractor. Facial symmetry was greatly improved. The osteogenesis and neomandible contour was checked by postoperative computed tomography, and a good matching with the preoperative planning was achieved. CONCLUSIONS: Computer-assisted surgical planning and intraoperative virtual guide shows its great value in improving the accuracy of distraction osteogenesis and restoring facial symmetry. It is regarded as a valuable technique in this potentially complicated procedure.

Clonal genetic and hematopoietic heterogeneity among human-induced pluripotent stem cell lines.

Induced pluripotent stem cells (iPSCs) hold great promise for modeling human hematopoietic diseases. However, intrinsic variability in the capacities of different iPSC lines for hematopoietic development complicates comparative studies and is currently unexplained. We created and analyzed 3 separate iPSC clones from fibroblasts of 3 different normal individuals using a standardized approach that included excision of integrated reprogramming genes by Cre-Lox mediated recombination. Gene expression profiling and hematopoietic differentiation assays showed that independent lines from the same individual were generally more similar to one another than those from different individuals. However, one iPSC line (WT2.1) exhibited a distinctly different gene expression, proliferation rate, and hematopoietic developmental potential relative to all other iPSC lines. This "outlier" clone also acquired extensive copy number variations (CNVs) during reprogramming, which may be responsible for its divergent properties. Our data indicate how inherent and acquired genetic differences can influence iPSC properties, including hematopoietic potential.