Chi Yang

Center For Oral & Maxillofacial Surgery, Georgia, United States

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Publications (113)149.17 Total impact

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    ABSTRACT: The aim of this study was to introduce a modified endoscopic lift of the floor of the maxillary sinus in beagles. Twelve operations (bilateral and randomly chosen) were done in 6 beagles each in the test group (modified endoscopic operation), and the control group, in which the operation was done with an osteotome. All operations were evaluated by two indices of safety (perforation of the sinus membrane and nasal bleeding) and 3effective indices (the intraoperative height after lifting, volume of bone grafts, and dislocation of the sinus grafts). The sinus membrane was not perforated and there were no nasal bleeds in either group. The intraoperative height after lifting was 13.7 (0.8) mm in the test group and 9.1 (0.5) mm in the control group, so it was significantly higher in the test group than the control group (p=0.0001). Similarly, the volume of bone graft was 0.9 (0.04) ml in the test group and 0.5 (0.02) ml in the control group (p=0.0001). The volume of the anterior and posterior bone grafts in the implant cavity in the test group did not differ significantly (p=0.102), while there were significant differences in the control group (p=0.002). Endoscopic lifting of the floor of the maxillary sinus is a safe and effective approach based on direct observation in beagles.
    British Journal of Oral and Maxillofacial Surgery 08/2014; · 2.72 Impact Factor
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    ABSTRACT: The objectives of this study were to introduce the classification of osteochondroma of the mandibular condyle based on computed tomographic images and to present our treatment experiences.
    The Journal of craniofacial surgery. 08/2014;
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    ABSTRACT: We have modified a canine model for raising the floor of the maxillary sinus by selecting a new surgical approach, and have evaluated the model with computed tomographic (CT) scans and endoscopy. Preoperative CT scans were taken of two beagle cadavers and four healthy, live beagles. The CT data were entered into Simplant software to select a candidate site for a surgical incision located between the first molar and the greater palatine foramen. All animals had the floor of the maxillary sinus raised from the candidate site. During the operation an endoscope was put outside the candidate site and into the maxillary sinus through a lateral puncture to record the condition of the Schneiderian membrane and the position of the candidate site. Postoperative CT scans were used to measure the position of the site, and the positions were compared. Eleven variables were measured on the coronal and sagittal sections. The two most important variables were the mean (SD) horizontal distance from the candidate site to the palatal alveolar ridge (8.1 (0.9)mm) and the residual bone height (2.0 (0.4)mm). There were no significant differences in the anteroposterior or internal-external position of the candidate site. Intraoperative endoscopic views showed the intact, white, and opaque membrane from the candidate site, and the movement of the membrane in the middle of the sinus floor from the lateral puncture. The candidate site is therefore an ideal surgical approach for raising the floor of the maxillary sinus, and the canine model is suitable for research in this area.
    British Journal of Oral and Maxillofacial Surgery 07/2014; · 2.72 Impact Factor
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    ABSTRACT: The study aims to identify the impact of sialolith formation by reviewing the foreign body induced sialolithiasis treated by sialoendoscopic intervention.
    The Journal of craniofacial surgery. 07/2014; 25(4):1372-1375.
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    ABSTRACT: The aim of this study was to introduce our classification of the neurovascular compression (NVC) in trigeminal neuralgia and the radiologic indications for microvascular decompression (MVD) based on magnetic resonance tomographic angiography.
    The Journal of craniofacial surgery. 07/2014; 25(4):e384-e388.
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    ABSTRACT: Exostosis osteochondroma is usually resected with the whole condyle even part of it is not involved. This study was to report the effect of using digital template in the assistant of resection while protecting the uninvolved condyle. We used computer-aided design technique in the assistant of making preoperative plan of a patient with giant condylar osteochondroma of exogenous type, including determining the boundary between the tumor and the articular surface of condyle, and designing the virtual tumor resection plane, surgical approach, and remove-out path of the tumor. The digital osteotomy template was made by rapid prototyping technique based on the preoperative plan. Postoperative CT scan was performed and merged with the preoperative CT by the Proplan 1.3 system to evaluate the accuracy of surgical resection with the guide of digital template. The osteotomy template was attached to the lateral surface of condyle accurately, and the tumor was removed totally by the guide of the template without injuries to adjacent nerves and vessels. Postoperative CT showed that the osteochondroma was removed completely and the unaffected articular surface of condyle was preserved well. The merging of postoperative and preoperative CT by Proplan 1.3 system showed the outcome of the operation matched with the preoperative planning quite well with an error of 0.92 mm. There was no sign of recurrence after 6 months of follow-up. The application of digital template could improve the accuracy of the giant condylar tumor resection and help to preserve the uninvolved condyle. The use of digital template could reduce injuries to the nerves and vessels as well as save time for the operation.
    The Journal of craniofacial surgery 04/2014; · 0.81 Impact Factor
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    ABSTRACT: In order to understand the status and characteristics of dental education in Europe, America and China, and clarify the shortcomings of dental education in China, this study selected Columbia University, Vienna Medical University and Shanghai Jiao Tong University College of Stomatology as representatives. The similarities and differences of the three institutions were compared through investigating education background and education model, in order to provide references for dental education. Supported by Medical Education Research Projects of Shanghai Jiao Tong University College of Stomatology(YB120913).
    Shanghai kou qiang yi xue = Shanghai journal of stomatology 02/2014; 23(1):110-112.
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    ABSTRACT: A costochondral graft (CCG) is usually used for condylar reconstruction in children with temporomandibular joint (TMJ) ankylosis. The aim of the present study was to introduce the application of a digital occlusal splint (DOS) in the assistance of CCG to treat ankylosis and mandibular deviation simultaneously. We designed and implemented a retrospective cohort study and enrolled a sample of growing pediatric patients with unilateral TMJ ankylosis and mandibular deviation who were treated for CCG at our department. The predictor variable was preoperative three-dimensional treatment planning and splint construction (DOS) compared with intraoperative treatment planning and splint fabrication (conventional occlusal splint [COS]). The primary outcome variables were the postoperative ramus height and chin deviation correction measured using Proplan CMF, version 1.3 software. The secondary outcome variable was the treatment time. Data from the 2 methods were compared using the Statistical Package for Social Sciences software package, version 13.0. A total of 8 children, 4 with a COS and 4 with a DOS were included in the present study. The treatment time was significantly longer in the COS group (mean 9.625 hours) than in the DOS group (mean 6.75 hours). The ramus height and chin deviation correction after surgery were more accurate in the DOS group (mean 2.09 mm and 1.29°, respectively) than in the COS group (mean 5.44 mm and 3.27°, respectively) but without significance (P > .05). The preoperative fabrication of DOSs compared with the intraoperative fabrication of COSs resulted in a shorter treatment time and improved mandibular deviation correction in the treatment of children with unilateral TMJ ankylosis.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 01/2014; · 1.58 Impact Factor
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    ABSTRACT: OBJECTIVE To investigate the diagnostic accuracy of magnetic resonance imaging (MRI) for perforation of temporomandibular joint (TMJ). METHODS Consecutive 1845 patients (2524 joints) diagnosed as internal derangement(ID) of TMJ were collected from April 2003 to March 2010 in our department. All the patients were examined by MRI and treated by arthroscopy or open surgeries. The findings of interpreting MRI were recorded as positive, suspicious and negative according to the MRI radiographic criteria. After comparing the findings of MRI with those of arthroscopy or open surgeries, the numbers of true positive, true negative, false positive and false negative were obtained. Through SPSS16.0, receiver operator characteristic curve(ROC curve) was made with 1-specificity as abscissa and the sensitivity as ordinate, and the area under the ROC curve was calculated. According to the area, the diagnostic value of MRI was evaluated. RESULTS Arthroscopic or open surgeries findings confirmed that 207 joints had disc perforation among all joints. MRI findings showed 189 joints were positive, 197 joints suspicious, and 2138 joints negative. The true positive accuracy of MRI findings was 102/189 while true negative accuracy was 2075/2138. 42 of the 197 suspicious joints had perforation. The area under the ROC curve was 0.808(0.77, 0.85), P < 0.05. CONCLUSION We concluded that MRI proved to be a good modality to diagnose disc perforation of TMJ, and the diagnostic result of disc perforation by MRI had certain guiding significance in our clinical work.
    Journal of Cranio-Maxillofacial Surgery 01/2014; · 1.61 Impact Factor
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    ABSTRACT: Anterior disc displacement is one of the most common conditions affecting the temporomandibular joint. In our previous publications we have reported on the basic technical elements of disc repositioning surgery. However, this article presents some critical modifications that have allowed us to perform this procedure safely and successfully over the past three years.
    Journal of Oral and Maxillofacial Surgery. 01/2014;
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    ABSTRACT: Objective To investigate the difference of serological profile in pSS and their correlation with the clinical characteristics of parotid glands. Methods This retrospective study includes 289 patients who fulfilled the 2002 American-European Consensus Group Criteria for pSS. The patients were categorized by the clinical features of parotid glands: Group1 (massive group), Group 2 (infection group), Group 3 (swelling group) and Group 4 (others). The demographic data and serological profiles among these groups were compared. Statistical analyses of the results between groups were performed using the Student t test, Fisher’s exact test, chi-square and analysis of variance. Results There was a difference of serological profile in the different clinical characteristics of parotid glands of pSS. Serum Ig G value of Group 1 was the greatest, and complement C4 was lowest in the four groups. Serum Ig E value of Group 2 was the greatest and ESR of Group 3 was the greatest in the four groups. Conclusion This study has determined the differences of serological profile in the different clinical features of parotid glands of pSS patients, which may help advance our understanding of the disease and improve patient management.
    Journal of Cranio-Maxillofacial Surgery 01/2014; · 1.61 Impact Factor
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    ABSTRACT: Objective To evaluate the stability of our custom-made prosthesis by establishing the model of sheep total temporomandibular joint(TMJ) replacement. Methods Six sheep were included in our study. Spiral computed tomography (CT) data of all sheep was obtained and transformed into 3-dimensional model by surgicase5.0 software preoperatively. Total TMJ prostheses were made based on the skull model. Ultra-high molecular weight polyethylene was used to make glenoid fossa lining, while titanium alloy to prefabricate mandibular retention handle and titanium plate over glenoid fossa. Cobalt-chromium-molybdenum alloy was also used to prefabricate the condyle. The right sides of all sheep, as the experimental group, were carried out total TMJ replacement, while the left sides were as the control group. The bone in both experimental and control side were excised after 3 and 6 months. scanning electron microscope(SEM) was used to observe the interface between bone and prosthesis. Van Gieson staining and immunohistochemical staining(IHC) were used respectively to observe the interface of titanium screw and bone and the expression of alkaline phosphatase(ALP). Results SEM and Van Gieson staining showed that there was immature bone and osteoid formed in the interface of prosthesis and bone after 3 months. While after 6 months, there was osseointegration between them. IHC showed that the expression of ALP in the experimental side was much higher than in the control side after 3 months and its expression decreased after 6 months with no difference from the control side. Conclusion The custom-made TMJ prosthesis which was designed and manufactured by ourselves has good stability after total TMJ replacement.
    Journal of Cranio-Maxillofacial Surgery 01/2014; · 1.61 Impact Factor
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    ABSTRACT: Our aim was to explore the incidence of rupture after arthroscopic repositioning of the disc of the temporomandibular joint (TMJ) by reviewing magnetic resonance images (MRI) of the TMJ taken before and after operation, and to investigate correlations retrospectively. We studied 247 patients with anterior disc displacement of the TMJ, and categorised them into 3 groups based on the postoperative MRI. The first group comprised those whose disc ruptured after repositioning, the second those who had a possible rupture of the disc after repositioning, and the third had no rupture of the disc after repositioning. Age, sex, duration of symptoms, maximum incisal mouth opening, whether the anterior disc displacement was unilateral or bilateral, and the Wilkes stage, were included in the analysis. The incidence of rupture (5/247) was 2%. Weak points at the intermediate zone of the disc were found in 4 of the 5 joints. The patients whose discs ruptured were significantly younger than the other 2 groups (p = 0.001). There was no statistically significant difference in preoperative duration of symptoms and mouth opening among the groups. The proportions of unilateral and bilateral disc displacement (p = 0.047) and Wilkes stage (p = 0.027) differed among the 3 groups. The Wilkes stages was significantly more advanced in the ruptured group than in the other 2 groups (p = 0.027) with 4/5 being bilateral. The weak point in the intermediate zone of the disc on MRI could be a sign of rupture. Teenagers and young adults with anterior disc displacement without reduction, particularly those in whom it is bilateral, are at a higher risk of a rupture after repositioning of the disc by arthroscopy.
    British Journal of Oral and Maxillofacial Surgery 01/2014; · 2.72 Impact Factor
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    ABSTRACT: This study aims to evaluate the effect of using free fat grafts in preventing adhesion in the temporomandibular joint (TMJ) disc anchor and to observe the outcomes of free fat. Six 3-month-old mini-pigs were included in our study. The left joints were the experimental sides which had undergone releasing the anterior attachments, and free fat from the front of the ear lobe was grafted to the anterior gap. The right joints were the control group, where only the anterior attachments were released. MRIs were carried out and the maximal passive mouth openings were measured before operation, 3 months, and 6 months after operation. The joint tissues and fat specimens were excised after 3 and 6 months. The volume of fat was measured and hematoxylin and eosin (HE) staining was performed. Maximal passive mouth openings were analyzed with SPSS software package by Wilcoxon signed rank test. Maximal passive mouth openings were reduced gradually after 3 and 6 months, accompanied with the deviation of the mandible to the right side. There were significant differences between the 3 groups (P < 0.01). HE staining showed that the surface of the experimental joints was smooth while there was adhesion formation in the control joints. The volume of fat reduced respectively to 67.7% and to 42.6% after 3 and 6 months. HE staining showed new fat lobules were formed after 6 months with obvious fibrosis among the lobules. This study suggested that free fat can survive steadily 6 months after operation, with a surviving volume about 42.6% and it can also prevent adhesion formation in the TMJ disc anchor.
    The Journal of craniofacial surgery 01/2014; 25(1):253-7. · 0.81 Impact Factor
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    ABSTRACT: Purpose Evaluate the effectiveness of computer-generated surgical templates for precise bone removal in the treatment of temporomandibular joint (TMJ) ankylosis with a medially displaced condyle. Methods Patients found to have a medially displaced condylar head and lateral bony fusion between January 2012 and January 2014 were included in the study. ProPlan CMF 1.4 software (Materialise Medical, Leuven, Belgium) was used to design the osteotomies for the lateral bony fusion while protecting the medial condylar head. Surgical templates were fabricated to transfer the design to the operation and the effectiveness evaluated post-operatively using CT scan comparisons. Results :In 5 surgeries with a total of 7 joints the surgical templates fit well and accurately guided the osteotomies. The skull base, external auditory canal, major vessels and residual condyle were well protected. Postoperative CT difference-analysis calculated an average difference of 1.044mm. Conclusions Computer-assisted surgical templates were able to accurately guide bone removal, protect the residual condylar head, skull base and external auditory canal in the treatment of TMJ ankylosis.
    Journal of Oral and Maxillofacial Surgery. 01/2014;
  • Dongmei He, Yihua Cai, Chi Yang
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    ABSTRACT: To analyze the main causes of temporomandibular joint (TMJ) ankylosis from condylar fracture in adults through a retrospective study. The history and computed tomographic (CT) scans of patients diagnosed with ankylosis caused by mandibular condyle fracture treated in a closed fashion from 2010 to 2012 were reviewed in the department of oral surgery. According to the relation between the stump of the ramus and the TMJ fossa, condylar fractures were divided into 3 grades: grade 0, in which the ramus stump is in the fossa but without contact to it; grade 1, in which the stump of the ramus is in the fossa and attached to it; and grade 2, in which the stump of the ramus is laterally displaced out of the fossa. Other factors, such as type of condylar fracture, displacement of the fractured fragment, position of the disc, and the presence of concomitant mandibular fractures, also were analyzed for ankylosis development. Of the 51 patients diagnosed with TMJ ankylosis, 13 patients (24 ankylosed joints) had full CT scans from injury to ankylosis, which showed that all condylar fractures were intracapsular fractures (ICFs), with sagittal fractures comprising 70%. Regarding the relation between the stump of the ramus and the TMJ fossa, no joints were classified as grade 0 (0%), 10 joints were classified as grade 1 (41.7%), and 14 joints were classified as grade 2 (58.3%). All discs were displaced with the fracture fragment, and the posterolateral retrodiscal tissue was torn. Among the condyle fractures leading to ankylosis, 77% featured symphysis fractures with widening of the mandibular arch. The relation between the ramus stump and the TMJ fossa plays an important role in the prognosis of condylar fracture. Grade 0 is less likely to cause ankylosis; grade 1 is more likely to cause ankylosis and is the relative indication for surgery; and grade 2 is the strongest predictor of ankylosis and is the absolute indication for surgery. Other risk factors are sagittal ICFs and combined mandibular fractures with widening of the mandibular arch.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 12/2013; · 1.58 Impact Factor
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    ABSTRACT: This study aims to compare the incidence and severity of intra-articular adhesion under arthroscopy between patients with and without a history of joint puncture. Eighty-nine patients with internal derangements of TMJ who underwent arthroscopic disc repositioning and suturing surgery from February 2008 to September 2008 were included in this study. Patients were divided into 2 groups based on whether the patient had undergone joint puncture before surgery or not. The diagnosis of intra-articular adhesion was made according to the manifestation under arthroscopy. Incidence and severity of intra-articular adhesion between these 2 groups was compared. The incidence of intra-articular adhesion in the patients with a history of puncture was 69.23%, which was higher than that in the patients without a history of puncture (24.36%). The difference was statistically significant (P < 0.05). The incidence of severe adhesions in patients with a history of joint puncture was also higher than that in patients without a history of puncture (26.09% vs. 2.56%, P < 0.01). Puncture may increase the risk of intra-articular adhesion in patients with internal derangement.
    The Journal of craniofacial surgery 12/2013; · 0.81 Impact Factor
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    ABSTRACT: The repair of segmental mandibular defects remains challenging in the clinic. Previous studies have shown that cryopreserved bone-derived osteoblasts (CBOs) have good proliferation and osteogenicity. However, whether these cells can be used in the repair of segmental mandibular defects is largely unknown. In this study, we applied CBOs combined with beta-tricalcium phosphate (β-TCP) to repair a segmental mandibular defect in canines and thus established the feasibility of using this type of tissue-bank cell for the repair of large bone defects in the future. Sixteen segmental mandibular defects in 16 animals were made on the right side. Sequential radiographs, computer tomography, polychrome fluorescent labeling, immunohistochemical staining, and histological analysis were used to evaluate the effects of tissue-engineered bone for segmental mandibular defects. Our results demonstrated that CBOs combined with β-TCP promoted bone mineralization and deposition at the early stage, and bony union was achieved in the CBO and fresh bone-derived osteoblast (FBO) groups. However, nonunion and minimal callus were present in the β-TCP group. Furthermore, there was a large amount of newly formed bone in the CBO and FBO groups and in the autogenous bone group. Additionally, osteocalcin immunohistochemistry showed intensive osteocalcin immunoreactivity in the bone matrix of the CBO and FBO groups. These data indicate that CBOs implanted in a scaffold can promote new bone formation, and this tissue-engineered bone can repair critically sized segmental mandibular defects in canines. The use of CBOs combined with β-TCP may be an effective approach for the reconstruction of segmental mandibular defects in the clinic.
    Clinical Implant Dentistry and Related Research 10/2013; · 3.82 Impact Factor
  • Chuan Lu, Dongmei He, Chi Yang
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    ABSTRACT: External auditory canal bleeding (EACB) after facial trauma has been strongly associated with skull base fractures; however, EACB also can occur with other craniofacial fractures. The aim of this study was to analyze the frequency and causes of EACB in different craniofacial fracture types. The investigators used a retrospective cohort study design and enrolled a sample composed of patients with craniofacial fractures evaluated and treated from April 2006 through December 2011. The predictor variable was fracture type, which was categorized into 4 types: skull base fracture, midface fracture, and mandibular fracture with and without involvement of the condyle. The frequency of EACB among fracture types was compared with SPSS 13.0 (SPSS, Inc, Chicago, IL) and χ(2) test. Computed tomographic (CT) scans were analyzed to determine the cause of EACB. EACB was found in 43 of 573 craniofacial fracture cases, with a frequency of 7.5%. There were 19 EACB sides in 123 skull base fracture cases (15.4%), 26 EACB sides in 150 mandibular fracture cases involving the 196 condyles (13.3%; of these 196 condyles, 92.3% were intracapsular condylar fractures [ICFs]), 2 EACB sides in 150 mandibular fracture cases not involving the condyle (1.3%), and 1 EACB case in 150 midface fracture cases (0.7%). Statistical analysis of EACB frequency for each fracture type showed a significant difference between skull base or mandibular fractures with condylar involvement and midface or mandibular fractures without condylar involvement (P < .05). However, there was no significant difference between skull base and mandibular fractures involving the condyle and midface fracture and mandibular fractures not involving the condyle (P > .05). EACB is uncommon in craniofacial fractures. The frequency varies significantly based on fracture type. Skull base fracture and mandibular ICF are the 2 main causes of EACB.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 09/2013; · 1.58 Impact Factor
  • Yiping Pu, Chuangqi Yu, Chi Yang
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    ABSTRACT: Paragonimiasis is a parasitic disease caused by Paragonimus trematodes, which are typical food-borne zoonoses prevalent in Asia, West Africa, and Latin America. A clinical infection by paragonimiasis usually begins with cough, haemoptysis, and dyspnoea, some of which overlap with symptoms of tuberculosis and other pulmonary disorders. Human paragonimiasis presents as a complex set of symptoms that may result in misdiagnosis and delayed treatment. The parotid is seldom affected. We describe the case of a 5-year-old boy with paragonimiasis who presented with a swelling of the parotid and no pulmonary signs or symptoms.
    British Journal of Oral and Maxillofacial Surgery 09/2013; · 2.72 Impact Factor

Publication Stats

219 Citations
149.17 Total Impact Points

Institutions

  • 2013
    • Center For Oral & Maxillofacial Surgery
      Georgia, United States
  • 2011–2013
    • Renji Hospital
      Shanghai, Shanghai Shi, China
  • 2009–2011
    • Shanghai Jiao Tong University
      • School of Medicine
      Shanghai, Shanghai Shi, China
  • 2010
    • Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine
      Shanghai, Shanghai Shi, China
  • 2002–2005
    • Second Military Medical University, Shanghai
      Shanghai, Shanghai Shi, China