Chi Yang

Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, Shanghai Shi, China

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Publications (119)155.94 Total impact

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    ABSTRACT: The study was aimed to determine and optimize the parameters for the MR fast imaging employing steady-state acquisition (FIESTA) sequence, which was to obtain an acceptable image to evaluate the value of the movement of the temporomandibular joint (TMJ). In this investigation, 20 volunteers were examined to determine and optimize the parameters of the FIESTA sequence. Then, 160 TMJs from 80 patients with temporomandibular joint disorders (TMD) of clinical suspicion were consecutively performed by both static MRI and dynamic FIESTA MRI on the oblique sagittal position. The FIESTA MR images of TMJs were obtained from a slow, consecutive, free and open-closed movement. Based on the cycles of TMJ movements during the process of FIESTA MRI (90seconds), we classified all TMJs into 2 groups: cycles of open-closed mouths less than or equal to 3 (group 1) and more than 3 (group 2). Each image was marked level 1-3 by its quality. Meanwhile, the location of articular disc, mandibular condyle, motive artifact, "jumping sign" and the joint effusion in each TMJ were assessed respectively. By dynamic FIESTA MRI among 160 TMJs, 92 TMJs (57.50%) were in group 1 and 68 TMJs were (42.50%) in group 2. There were statistically significant differences between group 1 and group 2(p<0.05). It was shown that the number of "level 3" in group 1 was greater than group 2, and the number of "level 1" in group 1 was less than group 2. The phenomenon of motion artifact and "jumping sign" were much significantly higher in group 2 than those in group 1 (p<0.01). Furthermore, in all of the "jumping sign" cases, the phenomenon of "jumping sign" was significantly higher in group ADDwR than in group ADDw/oR (p<0.01). There was a statistically significant correlation between disc-condyle complex in "jumping sign" phenomenon and group ADDwR (r=0.621, p<0.05). The data with the false matching rate of 31.52% showed that the maximum motion range on the dynamic imaging was greater than the static imaging. Among 160 TMJs, joint effusions of 37 TMJs (23.13%) were identified by dynamic FIESTA-MRI. Among 79 TMJs with ADDw/oR(anterior disc displacement without reduction),42 sides were operated with Maxillofacial arthroscopy surgery. The surgical result was in agreement with the MR result. Most TMJs images with a slow free open-close movement (cycles≦3) could be successfully obtained by the dynamic FIESTA MRI. The FIESTA MRI might be considered as an additional method to evaluate the movement of the articular disk and the mandibular condyle. Copyright © 2014. Published by Elsevier Inc.
    Magnetic resonance imaging. 11/2014;
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    ABSTRACT: To investigate the prevalence of mandibular asymmetry (MA) within the symptomatic unilateral anterior disc displacement (ADD) patients, and analyze the influence TMJ factors of the MA severity.Methods Patients aged under 20 years old with symptomatic unilateral ADD and asymptomatic volunteers with normal disc-condyle relationship diagnosed by magnetic resonance imaging (MRI) were included in this study. Posteroanterior cephalometric radiographs were taken to measure MA. Condylar height, disc length and disc displacement were measured by MRI. The prevalence and severity of MA were compared between the ADD and the control groups. The correlation between the severity of MA with the amount of condylar height shortage, disc deformity and distance of disc displacement were also evaluated within the ADD group.ResultsThere were 165 cases in the unilateral ADD group, and 156 cases in the control group. One hundred and nineteen cases had MA which accounted 72.12% (119/165) in the ADD group; while in the control group, only 25.64% (40/156) exhibited MA. The mean horizontal menton deviation and condylar height shortage in the unilateral ADD group were significantly larger than that in the control group (5.62mm vs. 4.19mm; 3.14mm vs. 1.32mm, p<0.01). The severity of MA was significantly correlated with the amount of disc displacement, disc deformity and condylar height shortage (correlation coefficient: 0.80, 0.70, and 0.82).ConclusionMA is much more common and severe in young unilateral ADD patients. The severity of MA is correlated with the height of condyle and the status of the disc.
    Journal of Cranio-Maxillofacial Surgery 10/2014; · 1.61 Impact Factor
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    ABSTRACT: The aim of this study was to compare the disc positions and condylar changes induced by different stretching forces in the modified animal model for anterior disc displacement (ADD) of the temporomandibular joint.
    The Journal of craniofacial surgery. 10/2014;
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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 10/2014; · 1.61 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 09/2014; · 1.28 Impact Factor
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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: To design and manufacture digital templates to guide Biomet total alloplastic joint replacement surgery (Biomet, Warsaw, IN) and evaluate the clinical efficacy.
    Journal of Oral and Maxillofacial Surgery 08/2014; · 1.28 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 07/2014; · 1.28 Impact Factor
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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: To retrospectively analyze the advantages and disadvantages of radiographic methods commonly used for diagnostic of condylar fractures.
    07/2014; 49(7):434-9.
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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: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s.
    International Journal of Clinical and Experimental Medicine 01/2014; 7(10):3320-3326. · 1.42 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

Publication Stats

242 Citations
155.94 Total Impact Points

Institutions

  • 2010–2014
    • Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine
      Shanghai, Shanghai Shi, China
  • 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
  • 2002–2005
    • Second Military Medical University, Shanghai
      Shanghai, Shanghai Shi, China