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 To investigate the effects of peroxisome proliferator activated receptor-gamma(PPARγ)gene silen-cing in human bone marrow stromal cells(HS-5)on hematopoietic function in bone marrow-suppressed mice,and to explore the potential mechanisms involved.Methods A bone marrow-suppressed mouse model was established by whole-body X-ray irradi-ation.Two hours after modeling,the mice were randomly divided into three groups:experimental group(intravenous injection of PPARγ RNAi-interfered HS-5 cells through the tail vein),control group(intravenous injection of PPARγ RNAi-uninterfered HS-5 cells through the tail vein),and blank group(intravenous injection of an equal amount of saline through the tail vein),with 5 mice in each group.Peripheral blood routine tests were performed before,24 hours after,1 week after,and 2 weeks after radio-therapy.In vitro osteogenic and adipogenic induction was performed in cells,and the cells were divided into experimental group(PPARγ RNAi-interfered HS-5 cells),control group(PPARγ-uninterfered HS-5 cells),and blank group(HS-5 cells without os-teogenic/adipogenic induction).Osteogenic/adipogenic staining was observed.The effects of PPARγ gene-silenced HS-5 cells on mouse bone marrow hematopoietic stem cells(HSCs)were detected by CCK-8 proliferation assay.The groups included experi-mental group(PPARγ RNAi-interfered HS-5 cells were co-cultured with mouse HSCs after 3 days of osteogenic induction dif-ferentiation),positive control group(HS-5 cells treated with 50 μmol/L PPARγ inhibitor were co-cultured with mouse HSCs af-ter 3 days of osteogenic induction differentiation),negative control group(PPARγ RNAi-uninterfered HS-5 cells were co-cul-tured with mouse HSCs after 3 days of osteogenic induction differentiation),and blank group(Mouse HSCs were cultured alone without co-culturing with HS-5 cells).Results After radiotherapy,the hematological parameters of mice in each group showed a decreasing trend initially,and then increased.One week after radiotherapy,there were significant differences in platelet and white blood cell levels among the three groups(experimental group＞control group＞blank group,all P＜0.05).Two weeks after radiotherapy,there were significant differences in the percentage of adipocyte vacuole area among the three groups(experi-mental group＜control group＜blank group,all P＜0.05).Pearson correlation analysis showed a negative correlation between hematological parameters and PPARγ expression levels(all P＜0.05),as well as a negative correlation between hematological parameters and the percentage of adipocyte vacuole area(all P＜0.05).After in vitro osteogenic/adipogenic induction differenti-ation,compared to the control group,the experimental group showed a significantly lower proportion of orange-red cells and a significantly higher proportion of red calcium nodules.After 3 days of osteogenic induction differentiation,the experimental group,positive control group,and negative control group of human bone marrow stromal cells were co-cultured with mouse HSCs,while HSCs were solely cultured in the blank group.The results showed that after 24 h,48 h and 72 h of co-culture,the A values of mouse HSC cells in the experimental group and positive control group were higher than those in the negative control group and blank group(all P＜0.05).Conclusion Silencing of the PPARγ gene in HS-5 cells implanted into bone marrow-sup-pressed mice contributes to enhanced hematopoietic function in mice.After interference and silencing of the PPARγ gene,the os-teogenic differentiation ability of HS-5 cells is enhanced,while the adipogenic differentiation ability is weakened.Furthermore,osteogenic-induced HS-5 cells can further enhance the proliferation capacity of mouse HSCs.

Since the 1970s, the laboratory animal industry in Suzhou has gone through five stages: its inception, emergence, growth, transformation, and scaling up. It began with the manufacturing of caging equipment for laboratory animals, initially by imitation and later through independent innovation. The industry evolved from sporadic factories to clustered enterprises, gradually growing and opening up the export market for caging equipment. In the 21st century, with industrial upgrading and transformation, purification systems and related products began to develop, and industry organizations emerged. As China has modernized, the rise of automation and intelligent production has led to technological innovation in enterprises and the emergence of various outsourcing services in the laboratory animal industry, driving the large-scale development of the industrial chain. After nearly half a century of growth, the laboratory animal industry in Suzhou has formed a complete industrial chain, including the production of laboratory animals, caging equipment, feed and bedding materials, design and construction of laboratory animal facilities, quality testing of laboratory animals and environments, and animal experimentation services. Laboratory animal breeding equipment, the core of the industry, has reached the level of developed countries, and the industry's scale and influence are unmatched in China. Since the 21st century, biopharmaceuticals have become the "No.1 industry" in the development of Suzhou. With government support, the guidance of the local economy, and the assistance from universities and research institutes, the animal experiment outsourcing industry has begun to cluster in Suzhou. The continuous influx of CROs has driven the construction of large-scale laboratory animal facilities, and key research projects have been initiated, significantly enhancing the industry's R&D capabilities. The Suzhou laboratory animal industry has quickly expanded alongside the "No. 1 industry," creating a unique "Suzhou Path" for laboratory animals. Over nearly fifty years, the laboratory animal industry in Suzhou has been essential to the rapid development of the biopharmaceutical industry in Suzhou and China.

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.