Epidemiological studies have highlighted an association between periodontitis and osteoporosis. However, the mechanism underlining this association remains unclear. Here, we revealed significant differences in the salivary microbiota between periodontally healthy individuals and periodontitis patients, with periodontitis patients exhibiting increased salivary microbiota diversity and an elevated abundance of pathogenic bacteria. Using an ovariectomized (OVX) mouse model, we demonstrated that the salivary microbiota from periodontitis patients exacerbated bone destruction by modulating the gut microbiota. Metabolomic analysis revealed that the periodontitis-associated salivary microbiota suppressed tryptophan metabolism. The tryptophan metabolite indole-3-lactic acid (ILA) directly inhibited osteoclast formation and differentiation. In OVX mice treated with periodontitis salivary microbiota, supplementation with ILA effectively suppressed osteoclastogenesis and alleviated the detrimental effects of periodontitis-associated salivary microbiota on systemic bones. In summary, our data demonstrate that periodontitis can affect systemic bone metabolism via the oral-gut axis and that ILA supplementation serves as a potential therapeutic option to mitigate these adverse effects.
Tooth developmental anomalies are a group of disorders caused by unfavorable factors affecting the tooth development process, resulting in abnormalities in tooth number, structure, and morphology. These anomalies typically manifest during childhood, impairing dental function, maxillofacial development, and facial aesthetics, while also potentially impacting overall physical and mental health. The complex etiology and diverse clinical phenotypes of these anomalies pose significant challenges for prevention, early diagnosis, and treatment. As they usually emerge early in life, long-term management and multidisciplinary collaboration in dental care are essential. However, there is currently a lack of systematic clinical guidelines for the diagnosis and treatment of these conditions, adding to the difficulties in clinical practice. In response to this need, this expert consensus summarizes the classifications, etiology, typical clinical manifestations, and diagnostic criteria of tooth developmental anomalies based on current clinical evidence. It also provides prevention strategies and stage-specific clinical management recommendations to guide clinicians in diagnosis and treatment, promoting early intervention and standardized care for these anomalies.
Chronic obstructive pulmonary disease (COPD), a disease responsible for early mortality worldwide, is well accepted to be associated with periodontitis epidemiologically. Although both of the diseases are the multi-microbial inflammatory disease, the precise underlying mechanisms by which periodontitis influences the progression of COPD remains largely unknown. Here, we established COPD accompanied with periodontitis mouse models and observed the pronounced progress in pulmonary symptoms and histopathology, characterized by poorer respiratory function, thickened bronchial walls, and increased neutrophils infiltration in lung tissue. Mechanistically, periodontitis pathogen Porphyromonas gingivalis (P. gingivalis) relocated in the lung through the respiratory tract and LPS from P. gingivalis promoted the secretion of chemokines CXCL2 and G-CSF of alveolar epithelial cells through NF-κB and p38 MAPK pathways to recruit neutrophils. Furthermore, exposure to P. gingivalis of infiltrated neutrophils released matrix metallopeptidase-8 (MMP-8) and neutrophil elastase (NE), which aggravated airway inflammation and tissue damage. These findings indicated that periodontitis could exacerbate COPD via its pathogen P. gingivalis, which translocated in the lung and stimulated neutrophil chemotaxis and activation in the lung.

