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To establish tooth movement boundaries in four directions by a novel morphometric analysis of alveolar bone using conebeam computed tomography (CBCT) images. The aim was to assist clinicians in minimising the occurrence of bone fenestration and dehiscence, thereby facilitating safe and efficient orthodontic treatment.

Impacted teeth are a kind of complex malocclusion, and their incidence differs among different races, sexes and dental positions. The causes of impacted teeth include systemic factors and local factors, such as endocrine disorders, malnutrition, and acute and chronic infectious diseases. Local factors can cause abnormal tooth development or eruption during the process from tooth development to tooth eruption, such as damaged permanent tooth embryos caused by local inflammation or trauma, insufficient eruption space caused by premature loss of deciduous teeth, and eruption disorders caused by local lesions for example hyperplasia or odontoma. The clinical manifestation of impacted teeth is the absence of a permanent tooth in a normal position. We can use cone beam CT (CBCT) to locate the impacted teeth. Comprehensive orthodontic treatment includes surgical-assisted eruption, extraction of retained deciduous teeth or supernumerary teeth, removal of lesions such as odontomas and cysts, and expansion of the orthodontic space. When the dysfunctional local soft and hard tissues are removed during a surgical operation, the tooth still cannot sprout smoothly, and it needs to be assisted by orthodontic traction-guided eruption or extracted and autotransplantation. A clear diagnosis, evaluation of the difficulty of treatment and appropriate treatment are the keys to improving the success rate of treatment. In this paper, the epidemiology, etiology, diagnosis and corresponding treatment methods of impacted teeth will be reviewed, and the orthodontic treatment of impacted teeth will be comprehensively described to provide a reference for clinicians about the treatment of impacted teeth.

Objectives: To evaluate alveolar bone dimensions and its relationship with tooth movement (retraction, intrusion and torque) during orthodontic treatment with fixed appliance and clear aligners. Methods: Thirty‐two patients were included in this retrospective clinical study. Cone beam computed tomography (CBCT) was collected before and after treatment to measure the volume of dehiscence and fenestrations in the maxillary anterior region, anterior alveolar bone thickness and height and degree of tooth movement. Rank‐sum tests were used to compare the differences in alveolar bone defect volumes between clear aligners and fixed appliance, multiple linear regression analysis was used for study evaluation, and kappa statistics were used to assess internal consistency and test‐retest reliability. Results: Post‐operatively, most alveolar bone defects occurred on the labial side. The incidence of bone fenestration was 23.96% in the clear aligner group and 26.18% in the fixed appliance group, which was higher than the incidence of bone dehiscence (5.21%). The labial bone height decreased by 0.272 mm, and the palatal bone height increased by 0.617 mm for every 1 mm downward intrusion of the anterior tooth apex in the fixed appliance group. In the clear aligner group, there was no significant change in the labial bone height, and the palatal bone height decreased by 0.447 mm for every 1 mm of anterior tooth retraction coronally. Conclusions: In the fixed appliance group, anterior tooth intrusion and retraction may have led to alveolar bone resorption by its compression at the cervical level. This study provides a three‐dimensional tooth movement evaluation method by using CBCT. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to investigate the mechanism of N6‐methyladenosine (m6A) in the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) from periodontitis patients. Methods: Differentially m6A‐methylated lncRNA/mRNA profiles were detected by a m6A epitranscriptomic microarray. Bioinformatics analysis was performed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. The transfection efficiency of the lentivirus was detected. The osteogenic activity of PDLSCs from periodontitis patients (PPDLSCs) was assessed. Results: The microarray results showed that 275 lncRNAs and 1292 mRNAs were significantly differentially methylated between PPDLSCs and PDLSCs from healthy people. Among those lncRNAs, lncRNA4114 (transcript_ID: ENST00000444114) showed both reduced m6A methylation levels and expression levels in PPDLSCs. Further bioinformatics analysis predicted that the differentially methylated mRNAs were mainly involved in cell interaction, stem cell pluripotency, and osteogenic differentiation signals. Then, overexpression of methyltransferase like 3 (METTL3) promoted the osteogenic differentiation of PPDLSCs, while knocking down METTL3 showed an inhibitory effect. Furthermore, METTL3 overexpression promotes the stability of lncRNA4114 to upregulate the expression level. Moreover, lncRNA4114 overexpression promoted the osteogenic differentiation of PPDLSCs. Conclusion: METTL3 promotes the osteogenic differentiation of PPDLSCs by regulating the stability of lncRNA4114. [ABSTRACT FROM AUTHOR]

Objective: To analysis the relationship between periodontitis (PD) and oral squamous cell carcinoma (OSCC) by bioinformatic analysis. Materials and Methods: We analyzed the gene expression profiles of PD (GSE16134) from the Gene Expression Omnibus (GEO) database and OSCC samples from TCGA‐HNSC (head and neck squamous cell carcinoma) and identified common differentially expressed genes (DEGs) in PD and OSCC. Then, functional annotation and signaling pathway enrichment, protein interaction network construction, and hub gene identification were performed. Subsequently, the function and signaling pathway enrichment of hub genes, miRNA interaction, and transcription factor interaction analyses were carried out. We analyzed GSE10334 and GSE30784 as validation datasets, and performed qRT‐PCR experiments simultaneously for validation, and obtained 4 hub genes. Finally, immune infiltration analysis and clinical correlation analysis of 4 hub genes and related miRNAs were performed. Results: We identified 31 DEGs (16 up‐regulated and 15 down‐regulated). Four hub genes were obtained by qRT‐PCR and validation dataset analysis, including IL‐1β, CXCL8, MMP12, and MMP13. The expression levels of them were all significantly upregulated in both diseases. The functions of these genes focus on three areas: neutrophil chemotaxis, migration, and CXCR chemokine receptor binding. Key pathways include IL‐17 signaling pathway, chemokine signaling pathway, and cytokine–cytokine receptor interactions pathway. Immune infiltration analysis showed that the expressions of 4 hub genes were closely related to a variety of immune cells. ROC curve analysis indicated that AUCs of 4 hub genes are all greater than 0.7, among which MMP12 and MMP13 were greater than 0.9. Kaplan–Meier survival analysis indicated that worse OS was strongly correlated with CXCL8 and MMP13 high‐expression groups. MMP12 low‐expression group was strongly associated with worse OS. The results of multivariate Cox regression analysis showed that age, N stage, CXCL8, MMP12, and MMP13 were independent prognostic factors for OS. We also identified 3 miRNAs, including hsa‐miR‐19b‐3p, hsa‐miR‐181b‐2‐3p, and hsa‐miR‐495‐3p, that were closely related to 4 hub genes. Hsa‐miR‐495‐3p is closely related to the diagnosis and prognosis of OSCC. Conclusions: We identified 4 hub genes between PD and OSCC, including IL‐1β, CXCL8, MMP12, and MMP13. These genes may mediate the co‐morbid process of PD and OSCC through inflammation‐related pathways such as the IL‐17 signaling pathway. It is worth noting that CXCL8, MMP12, and MMP13 have great significance in the diagnosis and prognosis of OSCC. [ABSTRACT FROM AUTHOR]