
MMP-9 deficiency accelerates the progress of periodontitis
Periodontitis is a chronic inflammatory disease caused by periodontopathic bacteria that affects periodontal support tissues.1 If left untreated, it results in loss of periodontal attachment and alveolar bone resorption. Approximately one-half of adults in the United States older than 30 years have periodontal disease.2 Though the disease is initiated by bacterial infection, it activates host defense systems that eventually lead to the degradation of the periodontium. During periodontitis, the disease progress involves further production of pro-inflammatory mediators such as cytokines, proteolytic enzymes like matrix metalloproteinases (MMPs), and their inhibitors.