Objective: To examine the hypodontia in orthodontic patients and to investigate the correlation between the hypodontia and skeletal class. Methods:The hypodontia were determined by panoramic radiographs,and skeletal class were evaluated by lateral cephalograms. The correlation between the hypodontia and skeletal class were analyzed by statistic methods. Results:The number of hypodontia in anterior upper arch was higher than those in lateral upper arch and the number of hypodontia in anterior lower arch was higher than those in lateral upper arch (P

Objective Among the factors affecting embryo implantation, oxidative stress is one that receives much medical attention. The purpose of the study was to explore the effect of H2 O2 on the endometrial stromal cells ( ESCs) in the decidual mouse model of oxidative stress of ESCs. Methods Primary ESCs cultured by enzymatic digestion with a mesh filter were divided into a control, an experimental, and a model group. Decidualization was induced in the mice of the experimental and model groups by inter-vention with 10 nM E2 and 1μmol/L P4 for 72 h in vitro. Then, the animals of the model group were treated with different concentra-tions of H2 O2 for 4 hours. The primary ESCs were identified by immunohistochemistry, the expression of dPRP mRNA determined byRT-PCR, the proliferation of the decidual ESCs treated with H2 O2 analyzed by CCK-8, and the level of ROS detected by flow cytometry. Results Primary mouse ESCs were successfully isolated, cultured, and identified, which were shaped like spindles and polygons, radial-ly aligned under the microscope. Immunofluorescence analysis showed positive expression of vimentin and negative expression of cytokeratin. The purity of the primary mouse ESCs was ( 96. 3 ± 0. 49 )%. Theexpression of dPRP mRNA was significantly higher in the ESCs treated with E2 and P4 than in the control (0.0002±0.0000 vs 1.0010±0.0011, P<0.01). H2O2 at ≥150μmol/L suppressed the proliferation of the decidual ESCs by 6.9% (P<0.05), and in a concen-tration-dependent manner, reaching the maximum inhibition rate of 70.6% at the concentration of 300μmol/L. The level of intracellular ROS was markedly increased in the ESCs treated with H2O2 at 50μmol/L (27.77±4.20) and 100μmol/L (43.57±6.58), with statisti-cally significant difference from that in the control group (17.47±0.61) (P=0.001). Conclusion H2O2 at 100μmol/L can signifi-cantly elevate the intracellar ROS level without affecting the proliferation of decidual primary ESCs, and therefore can be used for estab-lishing the model of oxidative stress of ESCs in decidual mice.