Periodontitis as a Model for Inflammatory Uncoupling of Bone Remodeling.

Area of Science:

• Osteoimmunology
• Bone Biology
• Mechanobiology

Background:

• Periodontitis, an oral biofilm-driven disease, causes alveolar bone loss.
• Bone loss in periodontitis is a pathological uncoupling of bone remodeling, with excessive resorption and inadequate formation.
• This review repositions periodontitis within inflammatory skeletal diseases.

Purpose of the Study:

• Synthesize mechanistic insights into periodontal bone loss.
• Explore the role of osteoimmunology, bone biology, and mechanobiology.
• Discuss therapeutic shifts toward restoring physiological coupling.

Main Methods:

• Review of current literature on periodontitis and bone remodeling.
• Analysis of molecular pathways involved in osteoclastogenesis and osteoblastogenesis.
• Comparison with other inflammatory skeletal diseases.

Main Results:

• Excessive osteoclastogenesis is driven by receptor activator of nuclear factor kappa-B ligand (RANKL) and inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-17A).
• Persistent activation of NF-κB and MAPK pathways enhances osteoclast activity.
• Inflammatory mediators suppress osteoblast function by inhibiting key signaling pathways (Runx2, Osterix, Wnt/β-catenin) and upregulating inhibitors (sclerostin, DKK1).
• Disruption of osteoclast-osteoblast coupling mechanisms (ephrinB2/EphB4, semaphorin signaling) and osteocyte dysfunction exacerbate bone loss.

Conclusions:

• Periodontitis exemplifies an immune-driven imbalance in bone remodeling.
• Alveolar bone's unique characteristics make it susceptible to inflammatory uncoupling.
• Periodontitis serves as a model for understanding and targeting inflammatory bone loss in broader skeletal diseases.