Immune System Acts on Orthodontic Tooth Movement: Cellular and Molecular Mechanisms

Abstract

Orthodontic tooth movement (OTM) is a tissue remodeling process based on orthodontic force loading. Compressed periodontal tissues have a complicated aseptic inflammatory cascade, which are considered the initial factor of alveolar bone remodeling. Since skeletal and immune systems shared a wide variety of molecules, osteoimmunology has been generally accepted as an interdisciplinary field to investigate their interactions. Unsurprisingly, OTM is considered a good mirror of osteoimmunology since it involves immune reaction and bone remolding. In fact, besides bone remodeling, OTM involves cementum resorption, soft tissue remodeling, orthodontic pain, and relapse, all correlated with immune cells and/or immunologically active substance. The aim of this paper is to review the interaction of immune system with orthodontic tooth movement, which helps gain insights into mechanisms of OTM and search novel method to short treatment period and control complications.

Periodontal ligament cells-derived exosomes promote osteoclast differentiation via modulating macrophage polarization

“…Orthodontic tooth movement (OTM) occurs in the periodontal steady-state microenvironment through bone remodeling 1 . Periodontal ligament cells (PDLCs) are the most common cells in the periodontal tissues 2 , 3 .…”

“…OTM is widely recognized as a good reflection of bone immunology because it involves both immune responses and bone remodeling 11 . The interaction between immunity and osteoclasts is of great significance during OTM 1 , 12 . Macrophages, derived from monocytes 13 , are important members of the immune system 14 and play crucial roles in tissue repair and inflammation suppression 15 .…”

Orthodontic System Modeled and Simulated with the Lingual Technique to Assess Tooth Forces

“…With the help of osteoimmunology, the correlation between bone and soft tissue remodeling and the body’s immune reaction caused by OTM is analyzed. Thus, by understanding the mechanisms of OTM, orthodontic practice can be improved by the emergence of faster, more efficient, and more comfortable treatments with fewer side effects for patients [ 52 ].…”

Irisin reduces orthodontic tooth movement in rats by promoting the osteogenic potential in the periodontal ligament

“…This finding suggests that irisin might attenuate the activity of osteoclasts, which is in line with a previous study showing that irisin inhibits osteoclast differentiation via downregulation of RANK ( 36 ). Further, during OTM, the interaction between innate immune cells and osteoclasts is crucial ( 37 ). To promote the formation of osteoclasts, the ratio of M1/M2 macrophages is increased, thus leading to a more pronounced pro-inflammatory effect ( 38 , 39 ).…”