The differences in microbiota between periodontitis and health have been extensively studied; however, knowledge about how the microbiota shifts from shallow to deep periodontal pockets remains limited despite its clinical importance in disease progres-sion and management. Patients diagnosed with stage III periodontitis commonly pre-sent varied probing depths (PD) within the same oral cavity, reflecting localized disease severity. This study aims to analyze the microbiome of subgingival plaques at various PDs in periodontitis patients. Subgingival plaques were collected from sixteen healthy subjects (health group) and periodontal pockets of sixteen stage III periodontitis pa-tients (PD 0–3 mm, PD 4–5 mm and PD 6–9 mm groups). A total of 64 subgingival plaque samples underwent 16S rRNA gene sequencing. The PD 6–9 mm group exhib-ited significantly higher alpha diversity than the health group, and distinct subgingival microbial community structures were observed in periodontitis patients, regardless of probing depth. The relative abundance of specific genera differed notably between health and periodontitis states; Corynebacterium and Cardiobacterium decreased, whereas Schaalia increased in shallow pockets (PD 0–3 mm) of periodontitis relative to the health group. Co-occurrence network analysis on the species level revealed that the PD 4–5 mm group had the most complex interspecies interactions, followed by the PD 6–9 mm and PD 0–3 mm groups. These findings indicate significant variations in mi-crobial diversity, composition, and interspecies interactions associated with periodon-tal health and periodontitis severity, highlighting their potential relevance for clinical diagnosis and targeted therapeutic strategies.

Early childhood caries (ECC) significantly impacts the physical and mental health of children. Saliva stands as a critical model for investigating the pathogenesis of caries disease since it reflects both host and microbial dynamics. However, the specific contributions of salivary host factors to ECC have not been fully understood. In this study, we monitored a prospective cohort of 3-4 year-old healthy children for 12 months, who either stayed caries-free or developed caries. Deep quantitative proteomics analysis of saliva was conducted at both recruitment and end point of the cohort to investigate the molecular mechanisms underlying ECC etiology and identify potential biomarkers for caries prediction. Proteomics analysis identified a total of 2873 proteins and revealed involvement of immune response, dental structure repair, and regeneration, as well as interactions with microorganisms during caries pathogenesis. Characteristic salivary proteins were identified in caries-susceptible children prior to caries development. An ECC prediction panel of proteins keratin 3 (KRT3) and mucin 21 (MUC21) was established and further validated through another independent cohort. This study illuminated the role of the complex salivary microenvironment in caries etiology and offered a prognostic tool for early ECC prediction, thus facilitating the precise prevention and control of ECC to ultimately reduce its incidence.

Caries is the most prevalent chronic disease affecting oral health in preschool children. In this 12-month prospective cohort study of 3–4-year-olds, we investigated the community-level bacterial–fungal interkingdom interactome and its role in cariogenic microenvironments, using 16S rRNA gene (bacterial) sequencing and ITS2 gene (fungal) sequencing of unstimulated saliva. Longitudinal analysis identified 19 key bacterial and fungal species that were associated with both caries progression and clinical features. Salivary bacteria Desulfovibrio, Bacteroides heparinolyticus, Alloprevotella, Anaerobiospirillum, and fungus Candida tropicalis not only showed altered abundances during caries development but also correlated with severity of caries, establishing diagnostic microbial signatures for caries prediction. The salivary mycobiome exhibited highly active and complex intra-network interactions in the caries-active state, suggesting that fungal networks may drive the broader community-wide microbiota interaction network in the caries state. Metabolic profiling further revealed distinct pathway shifts before and after caries onset. The findings demonstrate that caries progression follows ecological succession governed by cross-domain interactions. This study highlighted the fungal network’s important role in driving dysbiosis, advancing the current understanding of early childhood caries beyond bacterial-centric models, and also highlighted fungi not only as modulators but as active contributors to cariogenesis, which could guide future antimicrobial strategies.

Introduction: This study aimed to evaluate the impact of orthodontic extraction treatment on mandibular third molar impaction by measuring changes in angulation before and after treatment in patients receiving extraction versus non-extraction orthodontic therapy. Methods: A retrospective analysis was conducted on 30 patients who completed fixed orthodontic treatment at the Department of Stomatology, Deyang People's Hospital, between 2018 and 2023. Patients were divided into two groups, with 15 included in the extraction group and 15 in the nonextraction group. Pre- and post-treatment orthopantomograms (OPGs) were analyzed, with each mandibular third molar quadrant considered an independent sample. Changes in the α-angle of mandibular third molars were compared between the groups. Results: The mean change in α-angle was -2.42° ± 8.32° in the non-extraction group and 4.85° ± 9.53° in the extraction group, with a statistically significant difference between the two groups (p < 0.05). Discussion: Whether orthodontic extraction treatment facilitates third molar eruption remains a topic of ongoing debate. Differences in conclusions across studies may be attributed to variations in sample selection, patient age, growth stage, anchorage strategies, and imaging methodology. Our study design attempted to control for these variables by matching participants by age, sex, and treatment duration, and by ensuring comparable baseline α-angle in both groups to minimize confounding. Further prospective studies based on three-dimensional imaging are still needed in the future to validate our conclusions. Conclusion: Orthodontic treatment involving premolar extraction significantly improved the angulation of mandibular third molars compared to non-extraction treatment, potentially reducing impaction severity and enhancing eruption potential.