Ectopic eruption of the first permanent molar: Predictive factors for irreversible outcome.

INTRODUCTION: The present study aimed to analyze possible factors involved in irreversible (IRR) ectopic eruption (EE) of the first permanent molar and explore potential predictors for the IRR outcome. METHODS: Children aged 4-11 years, with at least 1 EE and who took their first panoramic radiograph before the age of 8 years, were selected in this study. The subjects were assigned to the self-correcting (SC) and IRR groups. Patients' age, sex, distribution of EE, and accompanying dental anomalies were recorded. Eruptive angulation (EA) of the first permanent molar, the grade of root resorption in the second deciduous molar, the magnitude of impaction index (MOII), and horizontal distance were measured on the panoramic radiographs. Chi-square tests and independent-sample t test were used for nominal and continuous variables, respectively. The receiver operative characteristic curve was used to determine the critical value. RESULTS: A total of 406 children with 634 first permanent molars, presenting EE, were enrolled, with 61.3% of the teeth in the SC group. Sex of children with EE and distribution of EE were not relevant to the IRR outcome. The presence of supernumerary teeth might be a protective factor for the IRR outcome. The increasing severity of root resorption in the second primary molar indicated an IRR outcome. A higher MOII and a larger EA suggested an IRR outcome with moderate-to-high quality. The horizontal distance exhibited debatable results, with a low predictive quality. CONCLUSION: Close monitoring and early intervention would benefit children with increasing severity of distal atypical resorption in the second primary molar, higher MOII, and larger EA.

[Effects of dynamic nutrition support on energy metabolism, immune function and stress response after oral and maxillofacial tumor surgery].

PURPOSE: To observe the effect of dynamic nutrition support on postoperative energy metabolism, immune function and stress response in patients with oral and maxillofacial tumors. METHODS: Fifty-six patients with oral and maxillofacial tumor surgery were randomly divided into experimental group and control group (28 in each group). Patients in the experimental group received dynamic enteral and parenteral nutrition support according to the stress period after surgery, ω-3 fish oil fat milk injection and glutamine were added in the nutrition support program. Patients in the control group were given routine postoperative enteral and parenteral camp support. Energy metabolism, immune function and stress indexes were detected 1 day before surgery, 2 days after surgery and 7 days after surgery, respectively. SPSS 19.0 software package was used to analyze the data. RESULTS: Energy metabolism indexes in the experimental group were higher than the control group on day 2 after PA surgery and day 7 after ALB and PA surgery, while energy metabolism indexes in the experimental group were lower than the control group on day 2 and day 7 after FPG and TG surgery with significant difference(P<0.05). The levels of IgA, IgG, IgM, CD3+, CD4+ and CD4+/CD8+ in the experimental group were higher than those in the control group 7 days after surgery, with significant differences (P<0.05). The levels of CRP, TNF- and IL-6 in the experimental group were lower than those in the control group 7 days after surgery, and the difference was significant(P<0.05). There was no significant difference in postoperative complications between the two groups. CONCLUSIONS: Dynamic nutrition support can improve postoperative energy metabolism of patients with oral and maxillofacial tumors, improve immune function, and alleviate stress response.

A multiomics approach to study the associations between microbial communities and functions and dental caries / 口腔疾病防治

@#The pathogenic mechanisms by which oral microbial communities affect the occurrence and development of dental caries remain unclear. Applications that make use of high-through put sequencing technologies and metaomics approaches to research dental caries etiology can provide new ideas about disease prevention and treatment. In this article, we review advanced research presented in metaomics studies, including genomic, metagenomic, metatranscriptomic, metaproteomic and metabolomics studies of dental caries.

Research progress of microbial biomarkers of early childhood caries / 口腔疾病防治

@#The microorganisms in a healthy child’s oral environment survive in certain proportions and form a stable dynamic balance with the host. If this balance is disrupted, some of the microorganisms become cariogenic microbes and cause early childhood caries (ECC). The changes of cariogenic microbes in this process could be used as biomarkers to assess the caries risk of children and forecast the development of ECC. The relative indices of Streptococcus mutans and the closely related Candida albicans, Bifidobacterium and Streptococci sanguinis may be used as biomarkers to diagnose the susceptibility of children to caries. The detection rate and detection level of Lactobacillus may provide a reference for judging the rate of ECC development.

Characterization of the clustered regularly interspaced short palindromic repeats sites in Streptococcus mutans isolated from early childhood caries patients.

OBJECTIVE: The aim of this study was to analyze the characteristics of the clustered regularly interspaced short palindromic repeats (CRISPR) sites in 45 clinical Streptococcus mutans strains and their relationship to the clinical manifestations of early childhood caries (ECC). METHODS: Forty-five S. mutans strains were isolated from the plaque samples taken from sixty-three children. CRISPR sites were sequenced and BLAST was used to compare these sites to those in the CRISPRTarget database. The association between the distribution of CRISPR sites and the manifestation of caries was analyzed by Chi-Square test. Further, biofilm formation (by crystal violet staining) and the synthesis of polysaccharide (by anthrone-sulfuric method) of all clinical isolated S. mutans strains with both CRISPR sites and no CRISPR site were comapared. Finally, acidogenicity and acidurity of two typical strains were determined using pH drop and acid tolerance assays. Biofilm formation and EPS synthesis by two typical strains were compared by 3D CLSM (Confocal Laser Scanning Microscope) assays and the expression of gtf genes were evaluated using qPCR. RESULTS: We found that most of the spacers in the clinical S. mutans strains were derived from Streptococcus phages APCM01 and M102. The number of CRISPR sites in these strains was associated with the clinical manifestations of ECC. Moreover, we found that the biofilm formation and EPS synthesis ability of the S. mutans strains with both CRISPR sites was significant improved. CONCLUSIONS: An association was found between the distribution of CRISPR sites and the clinical manifestations of caries. The CRISPR sites might contribute to the cariogenic potential of S. mutans.

[Expression and distribution of SDF-1 in the soft tissue healing of tooth extraction].

PURPOSE: To observe the expression and distribution of stromal cell derived factor -l (SDF-1) in the soft tissues after tooth extraction, in order to provide new ideas to promote wound healing of tooth extraction. METHODS: Thirty male Wistar rats were randomly divided into 10 groups. After extracting the first molar of left mandibular respectively, immunohistochemistry and RT-PCR technique were used to evaluate the distribution and expression of SDF-1 1, 2, 4, 7 and 10 days after extraction. Data processing was performed using SPSS 12.0 software package. RESULTS: Immunohistochemical staining showed the SDF-1 protein was strongly expressed at the gingival tissues around tooth extraction wound at early stage, mainly in the cytoplasm and intercellular substance of the stratum spinosum and stratum basale, and stained more obviously closer to the stratum basale. Four days after tooth extraction, the expression of SDF-1 in the stratum basale became more evident, and it is also positive inside endothelial cells of granulation tissues. Seven days after tooth extraction, the staining became uniform in the gingival epithelium, and a few positive staining of vascular endothelial cells could be found in lamina propria; Ten days after tooth extraction, the staining characteristics were similar to the normal gingiva. RT-PCR results showed that SDF-1mRNA underwent a biphasic expression change during gingival wound healing. SDF-1 mRNA level reached peak at day 1 after tooth extraction (P<0.01) but decreased by day 2. However, the SDF-1 mRNA level increased again to a peak at day 4 and then returned to a normal level by day 10 (P>0.05). CONCLUSIONS: SDF-1 is involved in the early soft tissue healing process, and may play a role as a promoter in tooth extraction healing. Supported by Young Scientists Award Fund of Shangdong Province(BS2013YY056) and Sci-tech Development Planning Program of Jinan City (2013-60).