Fig. 3. The balance of tissue neutrophils is essential for periodontal immunity.

A balance in tissue neutrophils is essential for periodontal immunity. Indeed, both neutrophil deficiency and excessive neutrophil recruitment and activation have been linked to periodontitis. As such, patients with Mendelian genetic defects linked to neutropenia or defective neutrophil trafficking present with severe periodontitis at a young age. Moreover, excessive neutrophil activation and recruitment also leads to periodontitis both in the context of Mendelian disease (such as plasminogen deficiency) and in the setting of common forms of periodontitis.