Gender differences in the growing, abnormal, and aging jaw

FBXO11 regulates bone development

FBXO11 is the substrate-recognition component of a ubiquitin ligase complex called SKP1-cullin-F-boxes. The role of FBXO11 in bone development is unexplored. In this study, we reported a novel mechanism of how bone development is regulated by FBXO11. FBXO11 gene knockdown by lentiviral transduction in mouse pre-osteoblast MC3T3-E1 cells leads to reduced osteogenic differentiation, while overexpressing FBXO11 accelerates their osteogenic differentiation in vitro. Furthermore, we generated two osteoblastic-specific FBXO11 conditional knockout mouse models, Col1a1-ERT2-FBXO11KO and Bglap2-FBXO11KO mice. In both conditional FBXO11KO mouse models, we found FBXO11 deficiency inhibits normal bone growth, in which the osteogenic activity in FBXO11cKO mice is reduced, while osteoclastic activity is not significantly changed. Mechanistically, we found FBXO11 deficiency leads to Snail1 protein accumulation in osteoblasts, leading to suppression of osteogenic activity and inhibition of bone matrix mineralization. FBXO11 knockdown in MC3T3-E1 cells reduced Snail1 protein ubiquitination and increased Snail1 protein accumulation in the cells, which eventually inhibited osteogenic differentiation. In conclusion, FBXO11 deficiency in osteoblasts inhibits bone formation through Snail1 accumulation, inhibiting osteogenic activity and bone mineralization.

Deep learning: A primer for dentists and dental researchers

OBJECTIVES

Despite deep learning's wide adoption in dental artificial intelligence (AI) research, researchers from other dental fields and, more so, dental professionals may find it challenging to understand and interpret deep learning studies, their employed methods, and outcomes. The objective of this primer is to explain the basic concept of deep learning. It will lay out the commonly used terms, and describe different deep learning approaches, their methods, and outcomes.

METHODS

Our research is based on the latest review studies, medical primers, as well as the state-of-the-art research on AI and deep learning, which have been gathered in the current study.

RESULTS

In this study, a basic understanding of deep learning models and various approaches to deep learning is presented. An overview of data management strategies for deep learning projects is presented, including data collection, data curation, data annotation, and data preprocessing. Additionally, we provided a step-by-step guide for completing a real-world project.

CONCLUSION

Researchers and clinicians can benefit from this study by gaining insight into deep learning. It can be used to critically appraise existing work or plan new deep learning projects.

CLINICAL SIGNIFICANCE

This study may be useful to dental researchers and professionals who are assessing and appraising deep learning studies within the field of dentistry.

Global Noncoding microRNA Profiling in Mice Infected with Partial Human Mouth Microbes (PAHMM) Using an Ecological Time-Sequential Polybacterial Periodontal Infection (ETSPPI) Model Reveals Sex-Specific Differential microRNA Expression

Periodontitis (PD) is a polymicrobial dysbiotic immuno-inflammatory disease. It is more prevalent in males and has poorly understood pathogenic molecular mechanisms. Our primary objective was to characterize alterations in sex-specific microRNA (miRNA, miR) after periodontal bacterial infection. Using partial human mouth microbes (PAHMM) (Streptococcus gordonii, Fusobacterium nucleatum, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) in an ecological time-sequential polybacterial periodontal infection (ETSPPI) mouse model, we evaluated differential mandibular miRNA profiles by using high-throughput Nanostring nCounter® miRNA expression panels. All PAHMM mice showed bacterial colonization (100%) in the gingival surface, an increase in alveolar bone resorption (p < 0.0001), and the induction of a specific immunoglobin G antibody immune response (p < 0.001). Sex-specific differences in distal organ bacterial dissemination were observed in the heart (82% male vs. 28% female) and lungs (2% male vs. 68% female). Moreover, sex-specific differential expression (DE) of miRNA was identified in PAHMM mice. Out of 378 differentially expressed miRNAs, we identified seven miRNAs (miR-9, miR-148a, miR-669a, miR-199a-3p, miR-1274a, miR-377, and miR-690) in both sexes that may be implicated in the pathogenesis of periodontitis. A strong relationship was found between male-specific miR-377 upregulation and bacterial dissemination to the heart. This study demonstrates sex-specific differences in bacterial dissemination and in miRNA differential expression. A novel PAHMM mouse and ETSPPI model that replicates human pathobiology can be used to identify miRNA biomarkers in periodontitis.

Correlation between symphyseal morphology and mandibular growth

Background:

This study sought to assess symphyseal morphology in adolescents with different mandibular growth patterns (MGPs) in order to see if a relation exists.

Materials and Methods:

In this study the symphyseal parameters (height, depth, and ratio) of normal subjects were compared with four groups with malocclusion (cl III vertical, cl II vertical, cl III horizontal, and cl II horizontal). These groups (15 samples each) were matched (for sex and cervical maturation stage [CVMS]) based on their cephalograms and patient charts. Growth patterns were differentiated by seven vertical parameters and the Wylie analysis. After confirmation of normality of the groups and similarity of their variances the two-way analysis of variance (ANOVA) was used for analysis of data assessed by adjusted chi-square (P < 0.001). The comparison of cases with the normal group was performed by the Dunnett method. Intraclass Correlation Coefficient (ICC) was used for evaluation of intraobserver reliability.

Results:

We found the symphyseal ratio to have a significant correlation with the MGP (P < 0.001). The symphyseal ratio (Height/Depth) was small in a mandible with vertical growth pattern Cl II or Cl III. Conversely, a horizontal growth pattern of a Cl II or Cl III mandible was associated with a larger ratio of the symphysis in comparison with the normal group. The symphyseal ratio was also found to be greater in females.

Conclusion:

The symphyseal ratio was found to be strongly associated with the MGP.