Publications by authors named "Gang Chai"

Background: This paper presents the authors' team's research on a craniofacial surgical robot developed in China. Initiated in 2011 with government funding, the craniofacial surgical robot project was officially launched in Shanghai, developed jointly by the Ninth People's Hospital affiliated with Shanghai Jiao Tong University School of Medicine and the Shanghai Jiao Tong University medical-engineering team. Currently, based on multiple rounds of model surgeries, animal experiments, and clinical trials, our team is applying for approval as a Class III medical device from the National Medical Products Administration (NMPA).

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Background: Melanoma, a malignant neoplasm originating from melanocytes, is a form of skin cancer with rapidly increasing global incidence, often exacerbated by UV radiation[1]. Particularly, acral melanoma, characterized by its swift metastasis and poor prognosis, underscores the significance of further research into its heterogeneity. Single-cell sequencing has been widely utilized in the study of tumor heterogeneity; however, research related to melanoma remains to be further refined.

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Article Synopsis
  • This study assessed the effectiveness of a maxillofacial surgical robotic system (MSRS) for mandibular angle ostectomy (MAO) compared to conventional surgical techniques.
  • In a controlled experiment with thirty rabbits, the experimental group used the MSRS, while the control group had traditional surgery; parameters like accuracy, setup time, and efficiency were measured.
  • Results showed that the robotic system led to quicker, more accurate procedures, though there was an initial learning curve for inexperienced surgeons, suggesting that with proper training, robotic surgery can enhance surgical outcomes.
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Objective: The aim of the study was to develop and evaluate an automated preoperative planning algorithm based on anatomical landmark point recognition for enhancing the efficiency and intelligence of preoperative planning for mandibular angle osteotomy.

Methods: A retrospective cohort of 34 patients underwent preoperative planning with this algorithm. The present algorithm was developed using a method based on anatomical marker point recognition.

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Background: Cancer-Associated Fibroblasts (CAFs) constitute a heterogeneous group of cells critical for the remodeling of the tumor microenvironment (TME). Given their significant impact on tumor progression, particularly in skin cancers, a deeper understanding of their characteristics and functions is essential.

Methods: This study employed a single-cell transcriptomic analysis to explore the diversity of CAFs within three major types of skin cancer: basal cell carcinoma, melanoma, and head and neck squamous cell carcinoma.

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Article Synopsis
  • Mandible distraction osteogenesis (MDO) is an effective surgical procedure for reconstructing the mandible in patients with mild Hemifacial microsomia (HFM), but the impact on the masseter muscle is not fully understood.
  • A study analyzed the masseter muscle's volume, length, width, and the height of the mandible ramus in 21 HFM patients before and after the MDO procedure over different time intervals.
  • Results showed an initial increase in masseter volume post-surgery, followed by a decrease at the second follow-up, suggesting short-term benefits but indicating that longer-term muscle reconstruction needs more focus for sustained improvement.
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Background: Asian women prefer a smooth and narrowed mandibular appearance. The purpose of the retrospective cohort study is to evaluate guide plate-assisted mandibular angle ostectomy (MAO) in improving mandibular symmetry for Asian female patients with mandibular angle hypertrophy (MAH) with normal occlusal relationship.

Methods: We retrospectively examined 11 patients with asymmetry MAH with normal occlusal relationship who received MAO at Shanghai Ninth People's Hospital between September, 2020, and January, 2022.

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Background: Mandibular tumor surgery necessitates precise osteotomies based on tumor boundaries; however, conventional osteotomies often lack accuracy in predicting osteotomy positions and planes, potentially leading to excessive resection of normal bone tissues or residual tumors, thus compromising postoperative quality of life and clinical outcomes. Robotic-assisted surgery (RAS) augmented with artificial intelligence (AI) offers precise localization capabilities, aiding surgeons in achieving accurate osteotomy positioning. This study aimed to evaluate the feasibility and accuracy of a robotic magnetic navigation system for positioning and osteotomy in an intraoral surgical trial of a mandibular tumor model.

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Background: The reliability and repeatability of stereophotogrammetry and CT in 3-dimensional anthropometric facial analysis were investigated in this study, which also explored the clinical application of supine CT.

Method: In this study, 3D CT and 3dMD stereophotogrammetry were used on 20 healthy volunteers. The fitting distance between stereophotogrammetry and CT scans at landmark points was measured, along with facial feature measurements (Al-Al) face width (Go-Go, Zy-Zy, Ex-Ex), and hemi-face height (Sn-Gn).

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Background: Melanoma, the most lethal form of skin cancer, presents substantial challenges despite effective surgical interventions for in situ lesions. Regulatory T cells (Tregs) wield a pivotal immunomodulatory influence within the tumor microenvironment, yet their impact on melanoma prognosis and direct molecular interactions with melanoma cells remain elusive. This investigation employs single-cell analysis to unveil the intricate nature of Tregs in human melanoma.

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This study aimed to probe into the anatomic course of inferior alveolar nerve canal (IANC) in hemifacial microsomia (HFM) on a large scale, morphological observations and further quantitative study were performed. Patients were classified by Pruzansky-Kaban classification. The anatomic course of IANC was analyzed morphologically with three-dimensional (3D) imaging software among 248 patients.

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Background: Mandibular distraction osteogenesis (MDO) is a major part of the treatment for hemifacial microsomia patients. Due to the narrow surgical field of the intraoral approach, osteotomy accuracy is highly dependent on the surgeons' experience. Electromagnetic (EM) tracking systems can achieve satisfying accuracy to provide helpful real-time surgical navigation.

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Introduction: Mandibular distraction osteogenesis, a recommended therapy for hemifacial microsomia, has brought much agony because of its traumatic procedures and peri-osteotomy complications. Our study aims to retrospectively compare piezoelectric osteotome with conventional reciprocal bone saw for hemifacial microsomia patients and validate its meliority in operability, surgical risks and patient outcomes.

Methods: All patients included underwent osteotomies conducted by either piezosurgery or bone saw.

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Purpose: Surgical guide plates can improve the accuracy of surgery, although their design process is complex and time-consuming. This study aimed to use artificial intelligence (AI) to design standardized mandibular angle ostectomy guide plates and reduce clinician workload.

Methods: An intelligence algorithm was designed and trained to design guide plates, with a safety-ensuring penalty factor added.

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Background: Melanoma is typically regarded as the most dangerous form of skin cancer. Although surgical removal of lesions can be used to effectively treat metastatic disease, this condition is still difficult to cure. Melanoma cells are removed in great part due to the action of natural killer (NK) and T cells on the immune system.

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In craniofacial surgery, magnetic navigation systems can effectively extend the doctor's limited visual range, improve their surgical precision, shorten the operation time, and reduce the incidence of surgical complications. Owing to the ease of magnetic navigation, the accuracy of the magnetic navigation system is affected by various equipment in the operating room. Therefore, its large-scale application is lacking because the navigation accuracy requirement can be extremely high during craniofacial surgery.

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Introduction: This study aimed to verify the accuracy and safety of distraction osteogenesis for hemifacial microsomia assisted by a robotic navigation system based on artificial intelligence.

Methods: The small sample early-phase single-arm clinical study, available at http://www.chictr.

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Introduction: This study aims to quantitively analyze mandibular ramus and body deformities, assessing the asymmetry and progression in different components.

Methods: This is a retrospective study on hemifacial microsomia children. They were divided into mild/severe groups by Pruzansky-Kaban classification and into three age groups (<1 year,1-5 years, 6-12 years old).

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The relationship between oxidized lipid metabolism and the immunological function of cancer is well known. However, the functions and regulatory mechanisms of lncRNAs associated with oxidized lipid metabolism in head and neck squamous cell carcinoma (HNSCC) remain to be fully elucidated. In this study, we established an oxidized lipid metabolism-related lncRNA prognostic signature to assess the prognosis and immune infiltration of HNSCC patients.

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Background: In contrast to the most commonly used optical navigation system, electromagnetic navigation has huge potential in operations with a narrow field. The purpose of this experiment was to test and confirm whether the electromagnetic navigation method the authors developed for mandibular angle osteotomy (MAO) met clinical requirements.

Methods: Using a dental splint that could be repeatedly mounted on teeth, registration between surgical plan and actual field was performed automatically.

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The authors browsed through past genetic findings in hemifacial microsomia along with our previously identified mutations in ITGB4 and PDE4DIP from whole genome sequencing of hemifacial microsomia patients. Wondering whether these genes influence mandibular bone modeling by regulation on osteogenesis, the authors approached mechanisms of hemifacial microsomia through this investigation into gene knockdown effects in vitro. MC3T3E1 cells were divided into 5 groups: the negative control group without osteogenesis induction or siRNA, the positive control group with only osteogenesis induction, and 3 gene silenced groups with both osteogenesis induction and siRNA.

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The authors attempt to approach hemifacial microsomia with macroscopic techniques and look for a link between clinical manifestations with pathogenesis. In this study, for the first time mandibular medullary cavities as essential parts of the mandible were intravitally measured based on the 3-dimensional models. A total of 153 patients were included.

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Since our team reported the application of robot-assisted surgery in facial contouring surgery in 2020, further clinical trials with large samples have been conducted. This paper will report the interim results of a single-center, large-sample randomized controlled trial of the first robot developed by our team for facial contouring surgery. Meanwhile, this research field will be systematically reviewed and prospected.

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The purpose of this study was to compare the safety and effect of piezosurgery with conventional osteotomy in a box-shifting procedure for orbital hypertelorism (ORH) correction surgery. This study retrospectively analyzed the clinical record of 10 ORH patients aged from 5 to 12 years, and they were second-degree ORH with an interorbital distance (IOD) of 35 to 37.8 mm.

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