Objective To evaluate the efficacy of elastic appliances in the early correction of Class Ⅱmalocclusions in the replacement dentition.Methods A total of 15 children aged 7-9 years who were admit-ted to the Affiliated Stomatology Hospital of Southwest Medical University from June 2018 to August 2023 were selected as the observation group,and 15 children who were consulted but not treated in the hospital dur-ing the same period were selected as the control group.The changes of bone tissue,dental and alveolar tissue,soft tissue and occlusal relationship before and after treatment were evaluated in the two groups.In addition,X-ray images of the observation group were collected every 8 to 10 months for the whole process dynamic mo-nitoring.Results Before treatment,there was no significant difference in all indexes between the two groups(P＞0.05).After treatment,there were statistical significances in the upper and lower alveolar base Angle(ANB),mandibular branch length(GO-CO),mandibular height(ANS-Me),mandibular position(S-GO),up-per central incisor inclination(U1-NA Angle),upper central incisor inclination convexity(U1-NA),lower central incisor process distance(L1-APo),the Z Angle and FH-N'Pg'Angle of soft tissue between the two groups(P＜0.05).After treatment,the covering OB and covering OJ in the observation group were lower than those in the control group,and the proportion of ClassⅠ patients in molar relationship was higher than that in the control group,with statistical significance(P＜0.05).After 3-4 years of treatment,ANB gradual-ly decreased,and the anterior-basilar plane-mandibular plane Angle(SN-MP)remained basically stable,and had a slight decreasing trend in the later period.The U1-NA Angle and the lower central incisor inclination(L1-NB Angle)were close to the normal mean during the whole treatment.Conclusion Using elastic appli-ances to treat patients with early replacement Class Ⅱ malocclusion,after 3-4 years monitoring and guid-ance,it can effectively improve the molar relationship,promote forward jaw growth,and create a harmonious and aesthetically pleasing facial soft tissue.

Objective: To investigate the difference in intestinal microbiome between children with atopic dermatitis (AD) and healthy children. Methods: Totally, 35 children with AD were enrolled from the Department of Dermatology, Jiading Hospital of Traditional Chinese Medicine from April 2015 to April 2017, and 27 healthy children served as control group. Total DNA was extracted from the feces of the subjects, and the V3-V4 region of the 16S rRNA gene of the bacteria was amplified by PCR. High-throughput sequencing was performed using the Illumina Miseq sequencing platform to analyze the diversity of bacterial flora. The top 15 abundant bacteria were determined at phylum, genus, and species levels, and compared between the two groups. Statistical analysis was carried out using Wilcoxon rank sum test. Results: The intestinal microbiome in the two groups mainly consisted of Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria. At the phylum level, the abundance of Bacteroidetes and Fusobacteria was significantly lower in the AD group (29.16% ± 19.96%, 0.06% ± 0.17%, respectively) than in the healthy control group (39.06% ± 15.98%, 0.50% ± 1.71%, respectively, P = 0.042, 0.041) . At the genus level, the abundance of Bacteroides was significantly lower in the AD group (23.77% ± 18.08%) than in the healthy control group (33.1% ± 15.75%, P = 0.029) . There was no significant difference in the distribution of the top 15 abundant species between the two groups (all P > 0.05) . Conclusion There are some differences in the composition of intestinal microbiome and relative abundance of bacteria between children with AD and healthy children.