Systems-level computational modeling in ischemic stroke: from cells to patients.

Ischemic stroke, a significant threat to human life and health, refers to a class of conditions where brain tissue damage is induced following decreased cerebral blood flow. The incidence of ischemic stroke has been steadily increasing globally, and its disease mechanisms are highly complex and involve a multitude of biological mechanisms at various scales from genes all the way to the human body system that can affect the stroke onset, progression, treatment, and prognosis. To complement conventional experimental research methods, computational systems biology modeling can integrate and describe the pathogenic mechanisms of ischemic stroke across multiple biological scales and help identify emergent modulatory principles that drive disease progression and recovery. In addition, by running virtual experiments and trials in computers, these models can efficiently predict and evaluate outcomes of different treatment methods and thereby assist clinical decision-making. In this review, we summarize the current research and application of systems-level computational modeling in the field of ischemic stroke from the multiscale mechanism-based, physics-based and omics-based perspectives and discuss how modeling-driven research frameworks can deliver insights for future stroke research and drug development.

Differential Expression of Noncoding RNAs Revealed Enhancer RNA AC016735.2 as a Potential Pathogenic Marker of Congenital Microtia Patients.

PURPOSE: Congenital microtia is a complex maxillofacial malformation with various risk factors. This study aimed to find potential pathogenic noncoding RNAs for congenital microtia patients. METHODS: We collected 3 pairs of residual ear cartilage samples and corresponding normal ear cartilage samples from nonsyndromic congenital microtia patients for microarray experiments. The differentially expressed RNAs were screened, and enrichment analysis and correlation expression analysis were performed to elucidate the function of the differentially expressed genes (DEGs). We further investigated the most significantly differentially expressed long noncoding RNA (lncRNA), AC016735.2, through follow-up analyses including RT-qPCR and Western blotting, to validate its differential expression in residual ear cartilage compared with normal ear cartilage. SiRNA was designed to study the regulatory role of AC016735.2, and cell proliferation experiments were conducted to explore its impact on residual ear chondrocytes. RESULTS: Analysis of the microarray data revealed a total of 1079 differentially expressed RNAs, including 305 mRNAs and x lncRNAs, using a threshold of FC>1.5 and P<0.05 for mRNA, and FC>1.0 and P<0.05 for lncRNA. Enrichment analysis indicated that these genes are mainly involved in extracellular matrix regulation and embryonic development. AC016735.2 showed the highest differential expression among the eRNAs, being upregulated in residual ear cartilage. It acts in cis to regulate the nearby coding gene ZFP36L2, indirectly affecting downstream genes such as BMP4, TWSG1, COL2A1, and COL9A2. CONCLUSION: Significant differences were observed in the expression of lncRNAs and mRNAs between residual ear cartilage and normal auricular cartilage tissues in the same genetic background of congenital microtia. These differentially expressed lncRNAs and mRNAs may play crucial roles in the occurrence and development of microtia through pathways associated with extracellular matrix regulation and gastrulation. Particularly, AC016735.2, an eRNA acting in cis, could serve as a potential pathogenic noncoding gene.

Free Dermal Fat Grafting: A Novel Technique for the Correction of Nasolabial Folds During Facelift Surgery.

BACKGROUND: Traditional facelift surgery does not behave well in the correction of nasolabial folds, which is a common clinical problem and needed to be improved. OBJECTIVES: To investigate the effect of free dermal fat grafting during facelift surgery for the treatment of nasolabial folds. METHODS: This prospective cohort study involved 80 patients with moderate to severe nasolabial folds and facial skin dermatolysis. Fifty of them underwent facelift surgery combined with free dermal fat grafting, and 30 of them underwent traditional facelift surgery. These patients were followed up 2 months, 6 months, and 1 year after the surgery to evaluate the effect. RESULTS: The difference in Wrinkle Severity Rating Scale (WSRS) scores, assessed at each follow-up, between the patients who underwent and did not undergo free dermal fat grafting during facelift surgery, was statistically significant. For patients who underwent free dermal fat grafting during facelift surgery, the WSRS scores assessed at 2 months, 6 months, and 1 year after the surgery were significantly different from those before the surgery. The analytic results of FACE-Q indicated a high level of overall satisfaction rate. No major complications were recorded. CONCLUSIONS: Free dermal fat as a filler for nasolabial folds can achieve excellent therapeutic effect. The combination of facelift surgery with free dermal fat grafting for the treatment of nasolabial folds can provide very good long-term results and a high patient satisfaction rate for patients with symptoms of facial aging such as facial dermatolysis, obvious wrinkles, and deep nasolabial folds.

Absorbable Suture Anchor Technique: A Method for Postblepharoplasty Lower Eyelid Ectropion Treatment.

ABSTRACT: Postblepharoplasty ectropion is a very complex problem to deal with because its relevance is far to be only a functional complaint. Therefore, the best surgical approach requires both aesthetic and functional consideration. Here, we introduce the absorbable suture anchor technique, which can meet both needs, and its surgical procedure is simple and effective and has excellent stability for long-term results. This series included only ectropion patients caused by lower eyelid blepharoplasty, with or without receiving revision surgery. Forty-seven cases (64 eyes) were treated by a single surgeon through this method. Forty-six patients (97.9%) displayed adequate correction of the eyelid ectropion and a marked degree of improvement both in aesthetic terms and with regard to the functional disorders reported. One patient (2.1%) presented complications but brought under control after drainage and dressing change. His previous symptoms were also largely relieved. Absorbable suture anchor technique is an effective, minimally invasive, and safe method to correct postblepharoplasty ectropion.

In this study, we describe an absorbable suture anchor technique and its outcomes in the repair of ectropion caused by lower eyelid blepharoplasty. From December 2017 to January 2021, 47 patients (64 eyes) with lower eyelid ectropion were treated with this technique (mean age, 43 years; age range, 27­61 years). This series included only patients with ectropion caused by lower eyelid blepharoplasty, with or without revision surgery. Patients were assessed with the Ectropion Grading Scale and distraction test preoperatively. All patients first underwent the release of middle lamellar adhesions and scar tissue, and then, the absorbable suture anchor technique was used to suspend the lower eyelid; 9 patients also underwent eyelid wedge excision because of severe lower eyelid laxity. The success rate was 100% for grade I­III and V ectropion and 95% for grade IV. The overall success rate was 98%. In terms of correction iterations, the success rate 100% for patients undergoing their first reconstructive surgery and 90% for patients who had 1 or more reconstructive surgeries. Surgical success was defined in terms of the Ectropion Grading Scale and clinical examination. One patient (1 eye) developed a lower eyelid tissue infection that was controlled with drainage and dressing changes; his previous symptoms were largely relieved. The absorbable suture anchor technique is an effective, minimally invasive, and safe method for correcting postblepharoplasty lower eyelid ectropion.

Revision Operation of the Unsatisfactory Microtia Reconstruction With Autologous Costal Cartilage.

BACKGROUND: Revision operation of the unsatisfactory microtia reconstruction is 1 of the most difficult revision operations in plastic surgery. This study discussed the cases about revision operation of the unsatisfactory or failed ear reconstruction using autologous costal cartilage and residual. METHODS: A prospectively maintained database of all consecutive patients who underwent secondary total ear reconstruction from 2013 to 2020 was reviewed. Demographic data and outcomes were assessed. RESULTS: Thirty-six patients with microtia met the inclusion criteria. The age of the patients who underwent secondary reconstruction ranged 6 to 56 years. The follow-up duration was from 1 to 8 years. Primary reconstruction using costal cartilage was performed in 34 cases, and Medpor (porous high-density polyethylene) were used in 2 cases. All 36 cases were treated with costal cartilage as the revision. One-stage revision was performed in 27 cases, including scaffold covered by superficial temporal fascia flap in 9 cases, retroauricular fascia flap in 12 cases and superficial temporal plus retroauricular fascia flap in 5 cases. Nine cases were renovated with expanders by stages, of which 8 cases were covered by retroauricular fascia and 1 case was covered by expanded skin flap. Complications occurred in 2 cases, and 1 patient was not satisfied with the partial scaffold repair. CONCLUSIONS: The effect of revision operation of ear reconstruction with costal cartilage is satisfactory, and different methods of ear reconstruction are indicated in different operation conditions, and the revision surgery requires adequate preoperative evaluation.Level of Evidence: Level IV, therapeutic study.

The Morphology and Bending Behavior of Regenerated Costal Cartilage with Kawanabe-Nagata Method in Rabbits - the Short Term Result of an Experimental Study.

BACKGROUND: The chest wall deformity is a well-known complication following costal cartilage harvest with the biomechanical factor considered to be a cause of this donor-site morbidity. Kawanabe-Nagata method is a widely-accepted approach to prevent the deformity. However, knowledge about the biomechanical properties of regenerated costal cartilage is limited, and the value of reimplantation of autologous costal cartilage blocks is not clear. METHODS: The fifth costal cartilage on both sides of six male, 8 weeks of age, New Zealand white rabbits were harvested with the perichondrium preserved intact in situ. The perichondrium was sutured to form a perichondrial pocket and part of the excised costal cartilage was cut into 0.5 mm cartilage blocks and returned to the perichondrial pocket of left side. The animals were sacrificed 16 weeks postoperatively and the regenerated and a piece native costal cartilage was harvested for morphological and three point bending test. RESULTS: There was no remarkable chest wall deformity in all animals, and there were no apparent differences in the appearance of the regenerated cartilage with and without reimplantation autologous cartilage blocks. The elastic modulus of native cartilage was significantly higher than the regenerated cartilage. The stiffness of regenerated cartilage without reimplantation was higher than that of with reimplantation, but this difference was not significant. CONCLUSIONS: The stiffness of regenerated cartilage was significantly lower than the native cartilage. Reimplantation of autologous cartilage blocks was not superior to that without reimplantation in regard to restoring the volume defect and strengthening the regenerated cartilage.

Two-stage orthogonality based estimation for semiparametric varying-coefficient models and its applications in analyzing AIDS data.

Semiparametric smoothing methods are usually used to model longitudinal data, and the interest is to improve efficiency for regression coefficients. This paper is concerned with the estimation in semiparametric varying-coefficient models (SVCMs) for longitudinal data. By the orthogonal projection method, local linear technique, quasi-score estimation, and quasi-maximum likelihood estimation, we propose a two-stage orthogonality-based method to estimate parameter vector, coefficient function vector, and covariance function. The developed procedures can be implemented separately and the resulting estimators do not affect each other. Under some mild conditions, asymptotic properties of the resulting estimators are established explicitly. In particular, the asymptotic behavior of the estimator of coefficient function vector at the boundaries is examined. Further, the finite sample performance of the proposed procedures is assessed by Monte Carlo simulation experiments. Finally, the proposed methodology is illustrated with an analysis of an acquired immune deficiency syndrome (AIDS) dataset.

Surgical correction of cryptotia combined with an ultra-delicate split-thickness skin graft in continuity with a full-thickness skin rotation flap.

BACKGROUND: Cryptotia is a common congenital ear deformity in Asian populations. In cryptotia, a portion of the upper ear is hidden and fixed in a pocket of the skin of the mastoid. Here we describe our method for cryptotia correction by using an ultra-delicate split-thickness skin graft in continuity with a full-thickness skin rotation flap. PATIENTS AND METHODS: We developed a new method for correcting cryptotia by using an ultra-delicate split-thickness skin graft in continuity with a full-thickness skin rotation flap. Following ear release, the full-thickness skin rotation flap is rotated into the defect, and the donor site is covered with an ultra-delicate split-thickness skin graft raised in continuity with the flap. RESULTS: All patients exhibited satisfactory release of cryptotia. No cases involved partial or total flap necrosis, and post-operative outcomes using this new technique for cryptotia correction have been more than satisfactory. CONCLUSIONS: Our method of using an ultra-delicate split-thickness skin graft in continuity with a full-thickness skin rotation flap to correct cryptotia is simple and reliable.

Three-dimensional autologous cartilage framework fabrication assisted by new additive manufactured ear-shaped templates for microtia reconstruction.

BACKGROUND: During microtia reconstruction, the intraoperative design of the cartilage framework is important for the appearance and symmetry of the bilateral auricles. Templates (traditionally, the X-ray film template) are usually utilized to complete the task, which can provide cues regarding size, cranioauricular angle and positioning to the surgeons. With a combination of three-dimensional (3D) scanning and additive manufacturing (AM) techniques, we utilized two different ear-shaped templates (sheet moulding and 3D templates) during the fabrication of 3D-customized autologous cartilage frameworks for auricle reconstruction. METHODS: Forty unilateral microtia patients were included in the study. All the patients underwent auricle reconstruction using the tissue-expanding technique assisted by the new AM templates. Images were processed using computer-aided design software and exported to print two different AM ear-shaped templates: sheet moulding and 3D. Both templates were assisted by the 3D framework fabrication. The 3D images of each patient's head were captured preoperatively using a 3D scanner. X-ray film templates were also made for the patients. The lengths and widths of the contralateral auricles, X-ray film and sheet moulding templates were measured in triplicate. The error of the template and the contralateral auricle were used to compare the accuracy between the two templates. RESULTS: Between January and May 2014, 40 unilateral microtia patients aged 6-29 years were included in this study. All patients underwent auricle reconstruction using autogenous costal cartilage. The sterilized AM templates were used to assist in the framework fabrication. The operative time was decreased by an average of 15 min compared with the method assisted by the X-ray film template. Postoperative appearance evaluation (based on five indexes: symmetry, length, width, cranioauricular angle and the substructure of the reconstructed ear) was performed by both the doctors and the patients (or their parents). Follow-up (ranging from 9 to 18 months) showed that all of the patients obtained satisfactory results with life-like 3D configuration and symmetric cranioauricular angle. The follow-up showed that no surgery-related complications occurred. Comparing the accuracy of the X-ray film and sheet moulding templates, the average errors of length were 1.8 mm ± 1.44 mm and 0.39 mm ± 0.35 mm, respectively, and the average width errors were 1.32 mm ± 0.88 mm and 0.3 mm ± 0.47 mm, respectively. The new sheet moulding template was more accurate than the X-ray template. CONCLUSIONS: The new sheet-moulding template is much more accurate than the traditional X-ray film template. Framework fabrication assisted by accurate 3D and informative AM templates contributed to individualized cartilage framework fabrication and satisfactory results.

Surgical correction of constricted ear combined with Stahl's ear.

Constricted ear combined with Stahl's ear is a rare ear deformity, which is a kind of complex congenital auricular deformity. From 1 January 2007 to 1 January 2014, 19 patients with constricted ear combined with Stahl's ear (Spock ear) were enrolled in this study, most of which were unilaterally deformed. To correct the deformity, a double Z-shaped skin incision was made on the posterior side of the auricle, with the entire layer of cartilage cut parallel to the helix traversing the third crus to form a fan-shaped cartilage flap. The superior crura of the antihelix were shaped by the folding cartilage rim. The cartilage of the abnormal third crus was made part of the new superior crura of antihelix, and the third crus was eliminated. The postoperative aesthetic assessment of the reshaped auricle was graded by both doctors and patients (or their parents). Out of the 19 patients, the number of satisfying cases of the symmetry, helix stretch, elimination of the third crus, the cranioauricular angle, and the substructure of the reshaped ears was 14 (nine excellent and five good), 16 (six excellent and 10 good), 17 (eight excellent and nine good), 15 (five excellent and 10 good), and 13 (two excellent and 11 good), respectively. With a maximum of a 90-month follow-up, no complication was observed. The results of the study suggested that this rare deformity could be corrected by appropriate surgical treatment, with a satisfied postoperative appearance.

Three-dimensional chest computed tomography analysis of thoracic deformities in patients with microtia.

OBJECTIVE: The objective of this study was to identify the incidence and characteristics of congenital thoracic deformities in patients with microtia and to investigate the interaction between microtia and thoracic deformities. METHODS: A total of 239 consecutive patients received a preoperative three-dimensional chest computed tomography (3-D chest CT). A retrospective study was performed with the clinical and imaging data from March 2013 to December 2013. Pearson χ(2) test and Spearman analysis were used to analyze the interaction between microtia and thoracic deformities. RESULTS: With the 3-D chest CT images, a total of 68 cases (28.5%) were documented with thoracic deformities including 60 cases (25.1%) with rib anomalies, 20 cases (8.4%) with spinal deformities, and 12 cases (5.0%) with both rib anomalies and spinal deformities. The incidence of rib anomalies (P = 0.049) and spinal deformities (P = 0.000) varied with grades of microtia. The incidence of rib anomalies was slightly positively correlated with the incidence of spinal deformities in patients with microtia (r = 0.243). CONCLUSIONS: The incidence of congenital thoracic deformities was high in patients with microtia. We observed a higher incidence of thoracic deformities in patients with a more serious grade of microtia. Microtia with thoracic deformities may involve a new syndrome previously undiscovered or just another extension with the very wide spectrum of microtia.

Reconstruction of full-thickness lower eyelid defect using superficial temporal artery island flap combined with auricular cartilage graft.

Full-thickness lower eyelid defect is one of common surgical diseases, which may lead to exposure keratopathy, corneal ulceration, and blindness. The aim of this study was to investigate the effect of superficial temporal artery island flap combined with auricular cartilage graft on the repair of full-thickness lower eyelid defect.In this study, the reconstructions in 6 patients who had unilateral full-thickness lower eyelid defects due to ocular traumas or surgical resections of malignant tumors were carried out. The island flap of the frontal branch of superficial temporal artery reconstructed the outer layer and the total lower lid was supported with the plane of an auricular cartilage strip, offering a proper contour and physical strength to maintain a normal eyelid height. The follow-up time ranged from 6 to 24 months. No major complications including partial or total flap necrosis, signs of infection, venous congestion, and hematoma were seen in any of the patients, and all cases have been reconstructed well both aesthetically and functionally, showing esthetic eyelid contour, good color, and texture match.Superficial temporal artery island flap combined with auricular cartilage graft is a useful method functionally and cosmetically for the reconstructions of full-thickness lower eyelid defects because of its advantages including rich vascularity based on superficial temporal artery, wide pedicle rotational arc, which could be transferred throughout the face region, good eyelid contour with color and texture match, limited donor-site scar, and minimal postoperative morbidity.

Preliminary clinical research with thoracic deformities in microtia / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the characteristics and incidence of the thoracic deformities in patients with microtia.</p><p><b>METHODS</b>In Plastic Surgery Hospital, we conducted a retrospective study of the clinical and radiographical data of 300 patients with microtia from March 2013 to October 2014. Pearson χ2 test was used to analyze the relationship among deformities of ribs and spine, as well as microtia.</p><p><b>RESULTS</b>A total of 78 (26.0%) patients were documented with rib deformities, 26 patients (8.7%) had spinal deformities, and 17 patients (5.7% )had both. The incidence of rib deformities in microtia I, II, and III was 7.1% (2/28), 26.7% (62/232) and 35.0% (14/40) respectively. The incidence of spinal deformities in microtia I, II, and III was 3.6% (1/28), 6.5% (15/232) and 25.0% (10/40 respectively. The patients with microtia III were found to have a higher incidence of ribs and spinal deformities than those with microtia II, patients with microtia II were found to have a higher incidence of ribs and spinal deformities than those with microtia I (P < 0.05).</p><p><b>CONCLUSIONS</b>The incidence of ribs and spinal deformities is high in patients with microtia. The poorer one auricle developed, the higher the incidence of thoracic deformities.</p>

[Reconstruction of large vermilion defects with buccinator myomucosal flap].

OBJECTIVE: To investigate a novel method for the reconstruction of large vermilion defects. METHODS: Based on the size and shape of the defects, a buccinator myomucosal flap pedicled with the junction of buccinator and orbicularis oris in the oral commisure was designed and rotated to reconstruct the large vermilion defects. The upper bound of the flap is at least 1 cm away from the stensen's duct. The width is about 2.5-3.0 cm, and the length is as far as to arrive the raphe pterygomancibularis. The donate site is directly closed primarily. There is no need for secondary pedicle division. RESULTS: From July 2003 to April 2013, 14 cases with large vermilion defects was reconstructed with this method. No flap necrosis occurred with primary healing. 5 cases were followed up with an average follow up period of 1 year (0.5-3 years). The apprearance and function of the reconstructed vermilion were satisfactory without any apparent donor site defect. The patients were satisfied with both the functional and cosmetic results. CONCLUSION: The buccinator myomucosal flap is a simple and ideal method for reconstruction of large vermilion defects, especially for the defects closed to the commisure.

Expanded post-auricular skin flap combined with autologous rib cartilage framework for correction of concha-type microtia / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the clinical effect of the method by using an expanded post-auricular skin flap combined with autologous rib cartilage framework for correction of concha-type microtia.</p><p><b>METHODS</b>The operation were performed in three stages. The expander was implanted under post-auricular skin at the first stage and expanded skin flap was formed. At the second stage, the expander was taken out and the expanded skin flap was transferred with autologous rib cartilage framework and skin graft for correction of microtia. At the third stage, the reconstructed ear was revised and new concha was formed.</p><p><b>RESULTS</b>From August 2008 to August 2011, 108 cases with 113 concha-type microtia were corrected by this method. All patients healed primarily and were followed up for 6 months to 3 years. The reconstructed ears had a good appearance and position, and were symmetric to ear on the healthy sides.</p><p><b>CONCLUSIONS</b>Using expanded post-auricular skin flap combined with autologous rib cartilage framework is a reliable method for concha-type microtia.</p>

[Effect of vacuum drainage on the blood circulation of expanded flap in ear reconstruction].

OBJECTIVE: To investigate the effect of vacuum drainage on blood circulation of expanded skin flap, so as to confirm suitable negative pressure for ear reconstruction. METHODS: 21 patients (Auricular Reconstructive Center of Plastic Surgery Hospital, PUMC) were randomly divided into A, B, C 3 groups to receive vacuum drainage of: -20, -40 and -60 kPa, respectively. The length and width of reconstructed ears,which represented the swelling degree, were measured instantly and 5, 10 days postoperatively. The changes were calculated and reflected venous drainage of flaps. The temperature of proximal (concha) and distal (helix) part of the expanded flaps, which represented the arterial blood supply of flaps, was detected by infrared thermography after operation. RESULTS: Five days after operation [(1.48 +/- 0.47) mm, (0.36 +/- 0.06) mm] and immediately [(1.67 +/- 0.69) mm, (0.40 +/- 0.16) mm)] , the changes of the length and width of reconstructed ear in group B was significantly low, while there was no statistically difference between group A and C (P > 0.05). The data between 10 days and 5 days after operation showed the same result. Along with the increase of the negative pressure, the swelling degree of reconstructed ears decreased firstly and then increased reversely ( P < 0.01 ). The flap temperature of reconstructed ears increased (P < 0.01), especially in proximal (concha) part (P < 0.01) , when the negative pressure increased (0 to -60 kPa). CONCLUSIONS: Vacuum drainage has effect on both the venous drainage and blood supply. Negative pressure of -40 kPa can improve both the blood supply and venous drainage. It should be as reference for clinical application.

[Ear reconstruction after rupture of postauricular expanded flap].

OBJECTIVE: To summarize the principles of ear reconstruction after rupture of postauricular expanded flap. METHODS: The rupture of the postauricular expanded flap was graded as I-IV degree. For flap rupture of I and II degree, the ear reconstruction was performed immediately with autogenous cartilage framework. For flap rupture of III degree, topical and systemic treatment should be done to relieve the redness and swelling. Then the ear reconstruction was performed. For flap rupture of IV degree, the expanded postauricular flap was smoothened. Ear reconstruction was performed 3 months later. RESULTS: There were 67 cases with flap rupture, including 43 cases as I and II degree, 17 cases as III degree and 7 cases as IV degree. Ear reconstruction with autogenous cartilage framework was performed in 43 cases, with Medpor framework in 17 cases. Flap smoothing and secondary ear reconstruction with autogenous cartilage framework was performed in 7 cases. The results were satisfactory with complications in 4 cases (7%), which resolved after treatment. Primary healing was achieved in all the patients. CONCLUSIONS: Good result could be achieved in ear reconstruction, even after flap rupture. Proper treatment should be adopted according to the rupture degree.

Local polynomial estimation of heteroscedasticity in a multivariate linear regression model and its applications in economics.

Multivariate local polynomial fitting is applied to the multivariate linear heteroscedastic regression model. Firstly, the local polynomial fitting is applied to estimate heteroscedastic function, then the coefficients of regression model are obtained by using generalized least squares method. One noteworthy feature of our approach is that we avoid the testing for heteroscedasticity by improving the traditional two-stage method. Due to non-parametric technique of local polynomial estimation, it is unnecessary to know the form of heteroscedastic function. Therefore, we can improve the estimation precision, when the heteroscedastic function is unknown. Furthermore, we verify that the regression coefficients is asymptotic normal based on numerical simulations and normal Q-Q plots of residuals. Finally, the simulation results and the local polynomial estimation of real data indicate that our approach is surely effective in finite-sample situations.

[Application of bi-pedicled frontal expanded flap for cervical cicatricial contracture].

OBJECTIVE: To investigate the therapeutic effect of bi-pedicled frontal expanded flap for cervical cicatricial contracture. METHODS: Tissue expanders were implanted under frontal muscle. After expansion, the frontal flaps were designed based on bilateral superficial temporal vessels and were transferred to the neck wound. The cervical spine movement and the mento-cervical angle was measured and analyzed by SPSS16.0 and t test. RESULTS: From September 2006 to May 2010, 7 patients were treated by this method. The range of active cervical movement was improved in all direction. The mento-cervical angle decreased from (152.7 +/- 1.9) to (90.7 +/- 2.2) degrees after operation. The patients were followed up for 5 months to 3 years with satisfactory result and no contracture recurrence. CONCLUSIONS: The bi-pedicled expanded frontal flap has a reliable blood supply and is very suitable for cervical cicatricial contracture with good functional and esthetic results, leaving less morbidity at donor site.