Objective: To investigate the associations of screen time (ST) and dietary behavior with sleep quality among first-year junior high school students, and further analyze the joint exposure effect of weekend ST and dietary usage, so as to provide scientific evidence for improving adolescent sleep quality and developing related health intervention measures. Methods: From September 19 to October 18, 2023, a combination of cluster sampling and convenience sampling method was used to select 733 first-year junior high school students from 4 public junior high schools in Jinshan District, Shanghai. ST on weekdays and weekends of students was investigated. The Chinese Diet Quality Questionnaire and the Pittsburgh Sleep Quality Index were applied to assess dietary behaviors and sleep quality. Binary Logistic regression was used to analyze the associations of ST and dietary behavior with sleep quality during weekdays and weekends. Results: The proportion of students with high level ST was 31.8% on weekdays and 65.3% on weekends. Students with poor dietary quality accounted for 45.3%, and the detection rate of poor sleep quality was 14.6 %. Binary Logistic regression analysis showed that, compared with students with low level ST on weekend and good dietary quality, those with high level ST on weekend and those with poor dietary quality had increased risks of poor sleep quality [ OR (95% CI )=1.89(1.10-3.26), 2.30(1.47-3.58), both P <0.05]. Combined exposure showed that compared to students with good diet quality and low level ST on weekend, students with good dietary quality and high level ST on weekend, those with poor dietary quality and low level ST on weekend, and those with poor dietary quality and high level ST on weekend also had increased risks of poor sleep quality [ OR (95% CI )=3.00(1.25-7.25), 4.07(1.60-10.33), 5.72(2.37-13.81), all P <0.05]. Conclusion Excessive weekend ST and poor dietary quality are associated with poor sleep quality among first-year junior high school students, and their co-occurrence further increases the risk.

Objective:To compare the effect of temporal external fixator and digital guide plate in the immediate reconstruction of mandibular defect after segmental mandibulectomy.Methods:The clinical data of all patients who received segmental mandibulectomy and immediate mandibular reconstruction with free vascularized bone graft by a single surgical team in the Department of Oral & Maxillofacial-Head & Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from August 2016 to December 2017 were retrospectively analyzed. According to different auxiliary methods, the patients were divided into temporal external fixator (TEF) group and computer aided design-manufacture (CAD-CAM) group. The width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were measured by CT before and one month after surgery, and the difference before and after surgery was calculated to evaluate the surgical effect. SPSS 19.0 was used for statistical analysis, and the data were expressed as Mean ± SD. Independent sample t-test was used for comparison of indexes of surgical time and surgical effect evaluation between the two groups, and P<0.05 indicated statistically significant differences. Results:A total of 29 patients were enrolled, including 13 patients in TEF group, 4 males and 9 females, aged (47.7±14.5) years, including 7 ameloblastomas, 2 squamous cell carcinomas, 2 abnormal proliferation of bone fibers, 1 rhabdomyosarcoma and 1 osteosarcoma. In the CAD-CAM group, there were 16 cases, including 11 males and 5 females, aged (42.4±19.7) years, including 10 ameloblastomas, 3 squamous cell carcinomas, 1 osteoblastoma, 1 otogenic fibromyxoma and 1 osteosarcoma. The bone grafts in 29 patients were all alive, the wounds healed primarily, and the occlusal relationship and facial contour of the patients were fine. After 3 years follow-up, there were no postoperative complications and tumor recurrence. The function of the supply area was not affected. The operative time was (7.12±1.40) h in the TEF group and (4.72±1.10) h in the CAD-CAM group, and the difference between the two groups was statistically significant ( P<0.01). In the TEF group, the difference of the width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were (1.08±1.12) mm, (2.08±1.61) mm, (1.77±3.15) mm, respectively; CAD-CAM group were (0.88±1.15) mm, (0.94±1.34) mm, (0.87±1.47) mm, respectively, and there was no statistical significance between the two groups ( P>0.05). Conclusions:It took significantly longer to perform immediate mandibular reconstruction assisted by TEF than that assisted by CAD-CAM in surgery, but both groups achieved better surgical results. It is simpler and more effective to use TEF when time is urgent or technology is too limited to carry out preoperative digital design.

Objective:To compare the effect of temporal external fixator and digital guide plate in the immediate reconstruction of mandibular defect after segmental mandibulectomy.Methods:The clinical data of all patients who received segmental mandibulectomy and immediate mandibular reconstruction with free vascularized bone graft by a single surgical team in the Department of Oral & Maxillofacial-Head & Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from August 2016 to December 2017 were retrospectively analyzed. According to different auxiliary methods, the patients were divided into temporal external fixator (TEF) group and computer aided design-manufacture (CAD-CAM) group. The width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were measured by CT before and one month after surgery, and the difference before and after surgery was calculated to evaluate the surgical effect. SPSS 19.0 was used for statistical analysis, and the data were expressed as Mean ± SD. Independent sample t-test was used for comparison of indexes of surgical time and surgical effect evaluation between the two groups, and P<0.05 indicated statistically significant differences. Results:A total of 29 patients were enrolled, including 13 patients in TEF group, 4 males and 9 females, aged (47.7±14.5) years, including 7 ameloblastomas, 2 squamous cell carcinomas, 2 abnormal proliferation of bone fibers, 1 rhabdomyosarcoma and 1 osteosarcoma. In the CAD-CAM group, there were 16 cases, including 11 males and 5 females, aged (42.4±19.7) years, including 10 ameloblastomas, 3 squamous cell carcinomas, 1 osteoblastoma, 1 otogenic fibromyxoma and 1 osteosarcoma. The bone grafts in 29 patients were all alive, the wounds healed primarily, and the occlusal relationship and facial contour of the patients were fine. After 3 years follow-up, there were no postoperative complications and tumor recurrence. The function of the supply area was not affected. The operative time was (7.12±1.40) h in the TEF group and (4.72±1.10) h in the CAD-CAM group, and the difference between the two groups was statistically significant ( P<0.01). In the TEF group, the difference of the width of mandible, length of mandibular body and vertical dimension of inferior 1/3 face were (1.08±1.12) mm, (2.08±1.61) mm, (1.77±3.15) mm, respectively; CAD-CAM group were (0.88±1.15) mm, (0.94±1.34) mm, (0.87±1.47) mm, respectively, and there was no statistical significance between the two groups ( P>0.05). Conclusions:It took significantly longer to perform immediate mandibular reconstruction assisted by TEF than that assisted by CAD-CAM in surgery, but both groups achieved better surgical results. It is simpler and more effective to use TEF when time is urgent or technology is too limited to carry out preoperative digital design.