The potential role of cfDNA-related innate immune responses in postoperative bone loss after alveolar bone grafting

Abstract

The purpose of treating alveolar bone cleft is to restore a normal maxilla structure. Multiple factors have been identified that can affect the success of alveolar bone grafting. However, with consistent treatment modifications, the surgical outcomes have been improved, but alveolar bone loss still exists. Thus, a new aspect should be found to solve this problem. As alveolar bone belongs to the periodontal tissues, the mechanism of the alveolar bone loss after bone grafting in patients with alveolar bone cleft may be similar to the development of alveolar bone loss in periodontitis. Cell-free DNA (cfDNA) has been demonstrated as a key promoter of alveolar bone loss during periodontal inflammation. We hypothesized that cfDNA-related innate immune responses could be a major inducement for postoperative bone loss after alveolar bone grafting. In this perspective, we preliminarily proved the potential association between cfDNA, TLR9 pathway, and alveolar bone grafting operation, and it might verify that surgical trauma could accumulate cfDNA, which can further activate cellular TLR9 signaling.

Impact of Circulating Cell-Free DNA (cfDNA) as a Biomarker of the Development and Evolution of Periodontitis

“…In fact, a study conducted by Huang et al [ 4 ] showed the relationship between high levels of cfDNA and elevated alveolar bone destruction in patients affected by periodontitis. In another study conducted by Huang et al [ 66 ], it was found that cfDNA actively participates in bone resorption. The authors evaluated this activity by measuring the cfDNA level in GCF of patients during the post-operative 24 h in the sites where bone grafting was inserted.…”

“…The authors evaluated this activity by measuring the cfDNA level in GCF of patients during the post-operative 24 h in the sites where bone grafting was inserted. From the results of this evaluation, it was observed that the bone loss obtained after the alveolar bone grafting may be related to increased cfDNA levels in GCF [ 66 ].…”

“…The discovery related to the presence of cfDNA in periodontitis has opened the possibility to a new therapy that uses cfDNA as a target, in particular for the treatment of bone loss [ 66 ] and inflammation in periodontitis. In a study conducted by Huang et al [ 4 ], it was discovered that with the deletion of cfDNA in the periodontal pockets, the level of cfDNA in saliva and serum decreased.…”