Periodontitis induces bone formation around alveolar bone in mice.

Area of Science:

• Oral biology
• Periodontology
• Bone biology

Background:

• Periodontitis involves chronic inflammation and alveolar bone loss.
• Buttressing bone formation, a thickened bone structure, is observed around inflammatory lesions.
• The mechanisms driving this new bone formation in periodontitis are not fully understood.

Purpose of the Study:

• To investigate the mechanisms of inflammation-induced buttressing bone formation in periodontitis.
• To elucidate the role of receptor activator of nuclear factor kappa B ligand (RANKL) in this process.

Main Methods:

• A ligature-induced mouse model of periodontitis was used.
• Models for marginal and apical periodontitis were established.
• Micro-computed tomography (μCT), histological, and histomorphometric analyses were performed.
• Inhibition of RANKL was studied using antibody injections.

Main Results:

• Both periodontitis models exhibited inflammation-induced bone resorption and new bone formation.
• Extensive osteoclastic and osteoblastic activities were observed.
• RANKL inhibition suppressed both bone resorption and formation.
• Newly-formed bone structure and mass were maintained post-suture removal.

Conclusions:

• Receptor activator of nuclear factor kappa B ligand (RANKL)-dependent osteoclast activity regulates inflammation-induced bone formation in periodontitis.
• Bone formation may involve both modeling-based apposition and remodeling-based coupling.
• Three-dimensional analysis of bone morphology is crucial for periodontal diagnosis.