Objective:To compare the efficacy of robot system-assisted versus freehand screw revision for ankylosing spondylitis (AS) with lower cervical fractures.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 57 patients with AS combined with lower cervical fractures admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, and Qilu Hospital of Shandong University, including 46 males and 11 females, aged 38-77 years [(65.4±9.5)years]. Injury segments involved C 3 in 7 patients, C 4 in 13, C 5 in 25, C 6 in 10, and C 7 in 2. All the patients underwent revision surgery, among whom, 22 patients were treated with robot system-assisted cervical pedicle screw placement (robot nailing group, with 190 screws), and 35 with freehand cervical pedicle screw placement (freehand nailing group, with 300 screws). The operative duration, intraoperative bleeding volume, frequency of intraoperative fluoroscopy, incision length, and length of hospital stay of the two groups were compared; the time of single nscrew insertion, the number of single nail revisions, the distance between screws and the anterior cortex, the accuracy of screw placement of grade 0 and grade 0+1 were recorded in the two groups. The visual analogue scale (VAS), Japanese Orthopedic Society (JOA) score, neck dysfunction index (NDI), American Spine Injury Association (ASIA) classification before operation, at 3 days, 3 months after operation and at the last follow-up were compared between the two groups. The complication rate was also noted. Results:All the patients were followed up for 12-16 months [(14.3±2.1)months]. The operative duration, intraoperative bleeding volume, and frequency of intraoperative fluoroscopy were (186.4±12.9)minutes, (486.1±68.6)ml, and (3.4±1.3)times in the robot nailing group, which were shorter or less than (206.7±14.4)minutes, (660.3±45.2)ml, and (13.5±3.6)times in the freehand nailing group ( P<0.01). The incision length was (9.4±2.4)cm in the robot nailing group, longer than (5.6±1.2)cm in the freehand nailing group ( P<0.01), and the length of hospital stay was (3.7±0.4)days, shorter than (4.4±1.4)days in the freehand nailing group ( P<0.01). The length of single nail insertion, the number of single nail revision, and the distance between the screws and the front cortex were (6.5±0.4)minutes, (1.1±0.1)times, and (3.5±1.3)mm in the robot nailing group, which were shorter or less than (11.6±0.2)minutes, (1.5±0.2)times, and (12.4±4.7)mm in the freehand nailing group ( P<0.01). The accuracy of the screw placement in the robot nailing group was 90.0% (171/190) and 95.8% (182/190) with level 0 and 0+1 screws, better than 80.0% (240/300) and 89.0% (267/300) in the freehand nailing group ( P<0.05). There was no significant difference in VAS, JOA score, NDI, or ASIA grading between the two groups before operation ( P>0.05). The VAS, JOA, and NDI scores at 3 days after operation were (3.1±0.6)points, (12.1±1.2)points, and (15.6±2.9)points, respectively in the robot nailing group, which were better than (5.0±1.4)points, (11.3±1.1)points and (22.5±3.7)points, respectively in the freehand nailing group ( P<0.05). No statistically significant difference was observed in the ASIA grade between the two groups at 3 days after operation ( P>0.05). There were no significant differences in VAS, JOA, NDI scores, or ASIA grading between the two groups at 3 months after operation and at the last follow-up ( P>0.05). Compared with those before operation, the VAS, JOA, NDI scores, and ASIA grading were significantly improved at 3 days, 3 months after operation and at the last follow-up in the two groups, which were further improved with the passage of time. Two patients in the robot nailing group had pneumonia, with a complication rate of 9% (2/22), while 2 patients in the freehand nailing group had dural sac rupture and cerebrospinal fluid leakage and 3 had lung infection after operation, with a complication rate of 14% (5/35) ( P<0.05). Conclusion:Compared with freehand nailing, the robot system-assisted nailing revision for AS with lower cervical fracture has more advantages in terms of the operative duration, length of hospital stay, intraoperative bleeding volume, frequency of intraoperative fluoroscopy nailing speed and accuracy, screw holding force, early pain relief, function restoration, and complication rate, despite longer surgical incision.

Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

Objective To explore the effects of evidence-based nursing combined with multi-dimensional health education on negative emotions and postoperative rehabilitation of patients undergoing elective surgery for cholecystolithiasis.Methods A total of 100 patients with cholecystolithiasis who underwent elective surgery in Yixing Traditional Chinese Hospital Medicine from September 2023 to August 2024 were selected.The patients were assigned to control group and observation group by PEMS3.1 for Windows completely random(two groups and multiple groups)program,with 50 cases in each group.The control group received routine nursing,and the observation group received evidence-based nursing combined with multidimensional health education on the basis of routine nursing.The intervention duration of the two groups was 7 days.Visual analogue scale(VAS)scores,negative emotions(self-rating anxiety scale[SAS]and self-rating depression scale[SDS]),postoperative complications,and postoperative rehabilitation were compared between the two groups.Results The VAS scores at 24 h and 72 h after surgery were lower than those at 6 h after surgery in both groups,especially in the observation group(P<0.05).The scores of SAS and SDS in both groups after intervention were significantly decreased compared with those before intervention,and the scores of negative emotions in the observation group after intervention were significantly lower than those in the control group(P<0.05).The total incidence of gastrointestinal discomfort,biliary fistula and wound infection/bleeding in the observation group was significantly lower than that in the control group(4.00%vs.18.00%,P<0.05).The time of getting out of bed,the time of anal exhaust,the time of resuming normal diet and the time of hospitalization in the observation group were significantly lower than those in the control group(P<0.05).Conclusion The combination of evidence-based nursing and multi-dimensional health education during perioperative period of cholecystolithiasis surgery can reduce postoperative pain,improve the positive attitude of treatment,reduce complications,and promote the recovery of the disease.

Objective To explore the feasibility and safety of ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer.Methods Totally 84 patients who underwent ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer were enrolled,and the technical success rate,complete ablation rate,complication rate,pain relief rate and survival time,etc.were observed.Results The median age of 84 cases was 61.5 years.Totally 86 tumors,including 44.19％(38/86)at the head/neck and 55.81％(48/86)at the body/tail of pancreas were detected,and a total of 85 ablation sessions were performed with the median ablation energy applied per tumor of 9.90(1.08,21.60)kJ and the complete ablation rate of 42.86％(36/84).The technical success rate was 100％(85/85).Thirty-nine complication events occurred in 25 cases,no ablation-related death.Among 34 patients underwent ablation mainly for pain symptoms,the pain score decreased from(6.22±1.12)points before treatment to(1.94±1.64)points after treatment(P＜0.001).During 6.8(3.3,12.9)months' follow-up,the mean survival time was(8.5±6.7)months,and all 47 patients died due to tumor progression.Conclusion Ultrasound-guided percutaneous microwave ablation was safe and feasible for unresectable pancreatic cancer.

Objective:To compare the efficacy of robot system-assisted versus freehand screw revision for ankylosing spondylitis (AS) with lower cervical fractures.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 57 patients with AS combined with lower cervical fractures admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, and Qilu Hospital of Shandong University, including 46 males and 11 females, aged 38-77 years [(65.4±9.5)years]. Injury segments involved C 3 in 7 patients, C 4 in 13, C 5 in 25, C 6 in 10, and C 7 in 2. All the patients underwent revision surgery, among whom, 22 patients were treated with robot system-assisted cervical pedicle screw placement (robot nailing group, with 190 screws), and 35 with freehand cervical pedicle screw placement (freehand nailing group, with 300 screws). The operative duration, intraoperative bleeding volume, frequency of intraoperative fluoroscopy, incision length, and length of hospital stay of the two groups were compared; the time of single nscrew insertion, the number of single nail revisions, the distance between screws and the anterior cortex, the accuracy of screw placement of grade 0 and grade 0+1 were recorded in the two groups. The visual analogue scale (VAS), Japanese Orthopedic Society (JOA) score, neck dysfunction index (NDI), American Spine Injury Association (ASIA) classification before operation, at 3 days, 3 months after operation and at the last follow-up were compared between the two groups. The complication rate was also noted. Results:All the patients were followed up for 12-16 months [(14.3±2.1)months]. The operative duration, intraoperative bleeding volume, and frequency of intraoperative fluoroscopy were (186.4±12.9)minutes, (486.1±68.6)ml, and (3.4±1.3)times in the robot nailing group, which were shorter or less than (206.7±14.4)minutes, (660.3±45.2)ml, and (13.5±3.6)times in the freehand nailing group ( P<0.01). The incision length was (9.4±2.4)cm in the robot nailing group, longer than (5.6±1.2)cm in the freehand nailing group ( P<0.01), and the length of hospital stay was (3.7±0.4)days, shorter than (4.4±1.4)days in the freehand nailing group ( P<0.01). The length of single nail insertion, the number of single nail revision, and the distance between the screws and the front cortex were (6.5±0.4)minutes, (1.1±0.1)times, and (3.5±1.3)mm in the robot nailing group, which were shorter or less than (11.6±0.2)minutes, (1.5±0.2)times, and (12.4±4.7)mm in the freehand nailing group ( P<0.01). The accuracy of the screw placement in the robot nailing group was 90.0% (171/190) and 95.8% (182/190) with level 0 and 0+1 screws, better than 80.0% (240/300) and 89.0% (267/300) in the freehand nailing group ( P<0.05). There was no significant difference in VAS, JOA score, NDI, or ASIA grading between the two groups before operation ( P>0.05). The VAS, JOA, and NDI scores at 3 days after operation were (3.1±0.6)points, (12.1±1.2)points, and (15.6±2.9)points, respectively in the robot nailing group, which were better than (5.0±1.4)points, (11.3±1.1)points and (22.5±3.7)points, respectively in the freehand nailing group ( P<0.05). No statistically significant difference was observed in the ASIA grade between the two groups at 3 days after operation ( P>0.05). There were no significant differences in VAS, JOA, NDI scores, or ASIA grading between the two groups at 3 months after operation and at the last follow-up ( P>0.05). Compared with those before operation, the VAS, JOA, NDI scores, and ASIA grading were significantly improved at 3 days, 3 months after operation and at the last follow-up in the two groups, which were further improved with the passage of time. Two patients in the robot nailing group had pneumonia, with a complication rate of 9% (2/22), while 2 patients in the freehand nailing group had dural sac rupture and cerebrospinal fluid leakage and 3 had lung infection after operation, with a complication rate of 14% (5/35) ( P<0.05). Conclusion:Compared with freehand nailing, the robot system-assisted nailing revision for AS with lower cervical fracture has more advantages in terms of the operative duration, length of hospital stay, intraoperative bleeding volume, frequency of intraoperative fluoroscopy nailing speed and accuracy, screw holding force, early pain relief, function restoration, and complication rate, despite longer surgical incision.

Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

Objective To explore the feasibility and safety of ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer.Methods Totally 84 patients who underwent ultrasound-guided percutaneous microwave ablation for unresectable pancreatic cancer were enrolled,and the technical success rate,complete ablation rate,complication rate,pain relief rate and survival time,etc.were observed.Results The median age of 84 cases was 61.5 years.Totally 86 tumors,including 44.19％(38/86)at the head/neck and 55.81％(48/86)at the body/tail of pancreas were detected,and a total of 85 ablation sessions were performed with the median ablation energy applied per tumor of 9.90(1.08,21.60)kJ and the complete ablation rate of 42.86％(36/84).The technical success rate was 100％(85/85).Thirty-nine complication events occurred in 25 cases,no ablation-related death.Among 34 patients underwent ablation mainly for pain symptoms,the pain score decreased from(6.22±1.12)points before treatment to(1.94±1.64)points after treatment(P＜0.001).During 6.8(3.3,12.9)months' follow-up,the mean survival time was(8.5±6.7)months,and all 47 patients died due to tumor progression.Conclusion Ultrasound-guided percutaneous microwave ablation was safe and feasible for unresectable pancreatic cancer.

Objective To analyze the current state of medication literacy among elderly patients with chronic diseases in urban areas of Beijing,identify its key influencing factors,and propose targeted improvement measures.Methods From February 1 to June 30,2023,a questionnaire survey was conducted among elderly chronic disease patients in 193 communities across 15 districts of Beijing using a convenience sampling method.Data was collected through face-to-face interviews,with a total of 787 questionnaires distributed and 755 valid responses received.The logistic regression analysis model was employed to systematically identify and evaluate the factors affecting patients'medication literacy.Results Among the 755 valid questionnaires collected,53.25%(402 cases)of patients met the medication literacy criteria.Regression analysis results showed that multiple factors significantly influenced medication literacy among elderly patients with chronic diseases,including using rural cooperative medical care or self-payment methods(OR=1.669,P=0.039),retaining medication instructions(OR=0.519,P=0.038),checking medication instructions before use(OR=1.993,P<0.01),and possessing the ability to understand medication instructions(partial understanding OR=2.805,P=0.038;fully understanding OR=3.084,P=0.022)as positive influencing factors;whereas having 2 to 3 chronic diseases(OR=0.574,P=0.039),taking 3 to 5 medications(OR=1.845,P=0.015),and experiencing drug-related problems(OR=1.993,P<0.01)were identified as negative influencing factors.Conclusion Multiple factors influence medication literacy among elderly patients with chronic diseases.To ensure the safety and efficacy of their medication use,It is recommended to implement targeted measures.These include revising patient medication guidance leaflets tailored to age,enhancing patients'understanding of drug instructions,and strengthening medication guidance and social support systems.

Background and Aims:Sonodynamic therapy(SDT)is an emerging tumor treatment method that primarily utilizes low-intensity ultrasound(US)to activate sonosensitizers,leading to the production of cytotoxic reactive oxygen species(ROS)that kill cells.This study was conducted with an attempt to develop a novel nanoparticle(NPs)formulation containing a sonosensitizer and the small interfering RNA(siRRS1)of tumor-related gene RRS1 to observe its anticancer effects on colon cancer,to provide new strategies for colon cancer treatment. Methods:RRS1 RNA-Seq data were downloaded from the TCGA and GEO databases,and clinical pathological data were collected from 80 patients with colon cancer at Hunan Provincial People's Hospital.The expression of RRS1 in colon cancer and its relationship with prognosis were analyzed.The proliferation and apoptosis of colon cancer cells transfected with siRRS1 were observed.The sonosensitizer tetra(4-carboxyphenyl)porphyrin(TCPP),gene carrier DSPE-PEI,and siRRS1 were assembled into TCPP@DSPE-PEI-siRRS1 NPs(T@D-siRRS1 NPs).After structural characterization and examination of cellular uptake and ROS generation capabilities in vitro,the anticancer effects of T@D-siRRS1 NPs on colon cancer were assessed in cell experiments and tumor-bearing mouse models. Results:Both database analysis and clinical specimen testing indicated that RRS1 expression in colon cancer tissues was higher than that in adjacent normal tissues,and high expression was associated with poor prognosis(HR=1.88,95％CI=1.27-2.79,P=0.002).Univariate and multivariate analyses showed that RRS 1 mRNA expression was an independent risk factor for overall survival in colon cancer patients(HR=1.354,95％CI=1.447-2.215,P=0.031).Knockdown of RRS1 significantly reduced the proliferation capacity of colon cancer cells and increased apoptosis(both P＜0.05).Characterization results showed that the particles were uniform and stable;T@D-siRRS1 NPs entered cells through endocytosis,where TCPP could generate singlet oxygen(1O2)under ultrasound irradiation.Subsequent in vitro and in vivo experimental results demonstrated that transfection with NPs carrying siRRS1 or TCPP(T@D-control siRNA,T@D-siRRS1)combined with US resulted in varying degrees of growth inhibition in colon cancer cells,with the T@D-siRRS1 NPs+US treatment showing the strongest effect(all P＜0.05).Moreover,no significant damage was observed in the vital organs of mice treated with T@D-siRRS1 NPs+US. Conclusion:T@D-siRRS1 NPs plus US integrate SDT and gene therapy,producing an effective synergistic cytotoxic effect on colon cancer cells.Additionally,T@D-siRRS1 NPs demonstrate good safety and biocompatibility,suggesting potential for clinical application.

Objective To explore the characteristics and correlation of the chin and airway in females with skeletal Class Ⅱ mandibular retraction for reference for clinical diagnosis and therapy.Methods This study was approved by the hospital Medical Ethics Committee.Forty cases of skeletal Class Ⅱ mandibular retraction adult females with aver-age angle were selected as the research group,and sixty cases of skeletal Class Ⅰ patients with average angle were se-lected as the control group.Cone-beam computed tomography(CBCT)images for all subjects were analyzed using three-dimensional modeling software.Measurements included the chin morphology,position,and upper airway morphology.Results Compared with skeletal Class Ⅰ patients,patients with skeletal Class Ⅱ mandibular retraction had smaller an-terior chin thickness,base bone volume,chin total volume,and larger chin angle,chin depression,chin curvature,and alveolar area with statistically significant differences(P＜0.05).Gn-V,Gn-H,Po-NB distance,and facial angle were smaller,and the Y-axis angle was larger in patients with skeletal Class Ⅱ mandibular retraction with statistically signifi-cant differences(P＜0.05).Upper airway total volume,transverse and sagittal diameter of the glossopharynx upper boundary were smaller in patients with skeletal Class Ⅱ mandibular retraction with statistically significant differences(P＜0.05).The correlation analysis between the morphology and position of the chin and the morphology of the upper airway in patients with Class Ⅱ mandibular retraction showed that there was a negative correlation between chin angle and laryngopharynx length in patients with Class Ⅱ mandibular retraction(r=-0.277,P＜0.01).There was a negative correlation between Po-NB distance and palatopharyngeal length(r=-0.222,P＜0.05).Chin height(r=-0.261,P＜0.01)and basal bone area(r=-0.225,P＜0.05)were negatively correlated with the transverse diameter of the palato-pharyngeal upper boundary.The minimum chin thickness(r=0.245,P＜0.05),chin angle(r=0.249,P＜0.05),and al-veolar area(r=0.213,P＜0.05)were positively correlated with the sagittal diameter of the palatopharyngeal upper boundary.Gn-V(r=0.217,P＜0.05)and Po-NB distance(r=0.208,P＜0.05)were positively correlated with the trans-verse diameter of the glossopharynx upper boundary.Anterior chin thickness was negatively correlated with the sagittal diameter of the laryngopharynx upper boundary(r=-0.211,P＜0.05).Chin depression was negatively correlated with the sagittal diameter of the laryngopharynx lower boundary(r=-0.237,P＜0.05).Chin curvature was positively corre-lated with the transverse diameter of the laryngopharynx lower boundary(r=0.231,P＜0.05).Conclusion Patients with skeletal Class Ⅱ mandibular retraction exhibit thinner chins.The sagittal position of the chin is backward,and the vertical position is upward.Patients with skeletal Class Ⅱ mandibular retraction have a narrow glossopharyngeal airway.There is a correlation between the morphology and position of the chin and the morphology of the upper airway in pa-tients with Class Ⅱ mandibular retraction.