Objective:To investigate the effects of apical periodontitis of mandibular primary molars on the development of mandibu-lar permanent premolars in children in Guangzhou.Methods:335 children aged 4-9 years with apical periodontitis of mandibular pri-molar at one side and normal healthy homologous tooth at another side were included and divided into 2 groups:Group A(n=200)in-cluded the first mandibular premolars and group B(n=135)included the second mandibular premolars.Subgroup A1 and B1 were the apical periodontitis groups,subgroup A2 and B2 were the normal healthy groups.The degree of root destruction of primary teeth,the degree of destruction and development of the dental follicle of permanent teeth,the mesial and distal direction changes,and the eruption height were observed and measured on the panoramic raidiographs,data were statistically analyzed.Results:In the 7-year-old children of A1 and the 6-year-old of B1 groups,the development degree of successor permanent teeth was lower than that of group A2 and group B2 of the same age children respectively(P＜0.05).In the 6-7-year-old children of group A1,the permanent teeth development of boys was slower than that of the girls(P＜0.05).There was no gender difference in dental follicle destruction and malposition of the perma-nent teeth in both A1 and B1 groups(P＞0.05).The proportion of malposition of the successor permanent teeth in group A1 increased with the primary teeth damage degree increace(P＜0.05),while the proportion of malposition of the successor permanent teeth in group B1 showed no significant difference(P＞0.05).Positive correlation between the damage degree of primary teeth and dental follicle of per-manent teeth was observed(rA1=0.41,rB1=0.21,P＜0.05).In boys aged 7-8 years,the succesor permanent teeth eruption in group A1 was higher than that in group A2(P＜0.05),and there was no significant difference between group B1 and group B2(P＞0.05).Conclusion:In the later stages of root stabilization of primary molars,periapical inflammation of primary teeth may cause developmen-tal delay of the succesor permanent teeth,and the delay degree is higher in boys than in girls.With the deterioration of the periapical tissue of primary teeth,the destruction of the dental follicle of permanent teeth may deepen,and the mandibular first premolar is more likely to have abnormal eruption.

Objective:To investigate the effects of apical periodontitis of mandibular primary molars on the development of mandibu-lar permanent premolars in children in Guangzhou.Methods:335 children aged 4-9 years with apical periodontitis of mandibular pri-molar at one side and normal healthy homologous tooth at another side were included and divided into 2 groups:Group A(n=200)in-cluded the first mandibular premolars and group B(n=135)included the second mandibular premolars.Subgroup A1 and B1 were the apical periodontitis groups,subgroup A2 and B2 were the normal healthy groups.The degree of root destruction of primary teeth,the degree of destruction and development of the dental follicle of permanent teeth,the mesial and distal direction changes,and the eruption height were observed and measured on the panoramic raidiographs,data were statistically analyzed.Results:In the 7-year-old children of A1 and the 6-year-old of B1 groups,the development degree of successor permanent teeth was lower than that of group A2 and group B2 of the same age children respectively(P＜0.05).In the 6-7-year-old children of group A1,the permanent teeth development of boys was slower than that of the girls(P＜0.05).There was no gender difference in dental follicle destruction and malposition of the perma-nent teeth in both A1 and B1 groups(P＞0.05).The proportion of malposition of the successor permanent teeth in group A1 increased with the primary teeth damage degree increace(P＜0.05),while the proportion of malposition of the successor permanent teeth in group B1 showed no significant difference(P＞0.05).Positive correlation between the damage degree of primary teeth and dental follicle of per-manent teeth was observed(rA1=0.41,rB1=0.21,P＜0.05).In boys aged 7-8 years,the succesor permanent teeth eruption in group A1 was higher than that in group A2(P＜0.05),and there was no significant difference between group B1 and group B2(P＞0.05).Conclusion:In the later stages of root stabilization of primary molars,periapical inflammation of primary teeth may cause developmen-tal delay of the succesor permanent teeth,and the delay degree is higher in boys than in girls.With the deterioration of the periapical tissue of primary teeth,the destruction of the dental follicle of permanent teeth may deepen,and the mandibular first premolar is more likely to have abnormal eruption.

Members of the genus Anaplasma are important emerging tick-borne pathogens in both humans and animals in tropical and subtropical areas. Here, we investigated the presence of Anaplasma spp. in 621 sheep and 710 goats from six provinces of China. Polymerase chain reaction (PCR) and DNA sequencing were conducted to determine the prevalence of Anaplasma (A.) phagocytophilum, A. ovis and A. bovis targeting the 16S ribosomal RNA or the major surface protein 4 gene. PCR revealed Anaplasma in 39.0% (240/621) of sheep and 45.5% (323/710) of goats. The most frequently detected species was A. ovis (88/621, 14.2% for sheep; 129/710, 18.2% for goats), followed by A. bovis (60/621, 9.7% for sheep; 74/710, 10.4% for goats) and A. phagocytophilum (33/621, 5.3% for sheep; 15/710, 2.1% for goats). Additionally, eight sheep and 20 goats were found to be infected with three pathogens simultaneously. DNA sequencing confirmed the presence of these three Anaplasma species in the investigated areas, and phylogenetic analysis indicated that there was geographic segregation to a certain extent, as well as a relationship between the host and cluster of A. ovis. The results of the present study provide valuable data that helps understand the epidemiology of anaplasmosis in ruminants from China.
Anaplasma ovis ; Anaplasma phagocytophilum ; Anaplasma* ; Anaplasmosis ; Animals ; China* ; Epidemiology ; Goats* ; Humans ; Polymerase Chain Reaction ; Prevalence ; RNA, Ribosomal, 16S ; Ruminants ; Sequence Analysis, DNA ; Sheep*