ObjectiveTo understand the epidemiological distribution and gene evolutionary variation of influenza A (H3N2) viruses in Fengxian District, Shanghai, in the surveillance year of 2023, and to provide a reference basis for influenza prevention and control. MethodsThe prevalence of influenza virus in Fengxian District in the 2023 influenza surveillance year (April 2023‒March 2024) was analyzed. The hemagglutinin (HA) gene, neuraminidase (NA) gene, and amino acid sequences of 75 strains of H3N2 influenza viruses were compared with the vaccine reference strain for similarity matching and phylogenetic evolutionary analysis, in addition to an analysis of gene characterization and variation. ResultsIn Fengxian District, there was a mixed epidemic of H3N2 and H1N1 in the spring of 2023, with H3N2 being the predominant subtype in the second half of the year, and Victoria B becoming the predominant subtype in the spring of 2024. A total of 75 influenza strains of H3N2 with HA and NA genes were distributed in the 3C.2a1b.2a.2a.2a.3a.1 and B.4 branches, with overall similarity to the reference strain of the 2024 vaccine higher than that of the reference strain of the 2022 and 2023 vaccine. Compared with the 2023 vaccine reference strain, three antigenic sites and one receptor binding site were changed in HA, with three glycosylation sites reduced and two glycosylation sites added; where as in NA seven antigenic sites and the 222nd resistance site changed with two glycosylation sites reduced. ConclusionThe risk of antigenic variation and drug resistance of H3N2 in this region is high, and it is necessary to strengthen the publicity and education on the 2024 influenza vaccine and long-term monitoring of influenza virus prevalence and variation levels.

Objective: This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite, aiming to provide a reference for clinical treatment. . Methods: This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. CBCT images of eighty-one untreated patients (40 anterior open bite patients and 41 normal overbite patients) with high-angle skeletal Class Ⅱ malocclusion were selected before treatment. Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology, and the differences between the two groups were analyzed. Results: There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group, significant differences were found in the root length of maxillary central incisor （11.12 ± 1.37） mm、mandibular central incisor（10.15 ± 1.09）mm, mandibular lateral incisor（11.27 ± 1.15）mm and mandibular canine（12.81 ± 1.48）mm between the open bite group and the normal overbite group（P<0.05）. On the other hand, the two groups were significantly different in crown-root morphology of the maxillary central incisor (1.10° ± 3.62° vs. 4.53° ± 2.30°, P<0.01) but not in the mandibular central incisor. Conclusion The root length of the maxillary central incisor, mandibular central incisor, mandibular lateral incisor, mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients, and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root. The crown-root angle is smaller, which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱ open bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.

Objective This study aimed to explore the root length of maxillary and mandibular anterior teeth and central incisor crown-root morphology in patients with high-angle skeletal Class Ⅱ open bite,aiming to provide a refer-ence for clinical treatment.Methods This study was reviewed and approved by the Ethics Committee,and informed consent was obtained from the patients.CBCT images of eighty-one untreated patients(40 anterior open bite patients and 41 normal overbite patients)with high-angle skeletal Class Ⅱ malocclusion were selected before treatment.Dolphin software was used to study the root length of maxillary and mandibular anterior teeth and central incisor crown-root mor-phology,and the differences between the two groups were analyzed.Results There was no statistical significance in the root length of maxillary lateral incisor and canine between the open bite group and the normal overbite group,signifi-cant differences were found in the root length of maxillary central incisor(11.12±1.37)mm、mandibular central inci-sor(10.15±1.09)mm,mandibular lateral incisor(11.27±1.15)mm and mandibular canine(12.81±1.48)mm be-tween the open bite group and the normal overbite group(P＜0.05).On the other hand,the two groups were significant-ly different in crown-root morphology of the maxillary central incisor(1.10°±3.62° vs.4.53°±2.30°,P＜0.01)but not in the mandibular central incisor.Conclusion The root length of the maxillary central incisor,mandibular central inci-sor,mandibular lateral incisor,mandibular canine in high-angle Class Ⅱ open bite patients is shorter than that in high-angle Class Ⅱ normal overbite patients,and the long axis of the crown of the maxillary central incisor in high-angle Class Ⅱ open bite patients obviously deviates toward the labial side relative to the long axis of the root.The crown-root angle is smaller,which is beneficial to torque control or adduction movement of the anterior teeth in high-angle Class Ⅱopen bite patients.