Читать книгу Biological Mechanisms of Tooth Movement - Группа авторов - Страница 73

The dental pulp is a highly vascularized tissue situated in an inextensible environment surrounded by rigid dentin walls. The pulp vascular system is not only responsible for nutrient supply but also contributes actively to the pulp inflammatory response and subsequent regeneration (Rombouts et al., 2017).

Periodontal and pulpal blood flow increased by rat experimental tooth movement (Kvinnsland et al., 1989) and humans (Sabuncuoglu and Ersahan, 2015). Furthermore, the expression of HIF‐1α and VEGF was enhanced by mechanical force. HIF‐1α and VEGF may play an important role in retaining the homeostasis of dental pulp during OTM (Wei et al., 2015)

Römer et al. (2014) showed the induction of hypoxia in dental pulp after OTM. The induction of oxidative stress in human dental pulp cells showed up‐regulation of the proinflammatory and angiogenic genes Cox‐2, VEGF, IL‐6, and IL‐8. It suggests that OTM affects dental pulp circulation by hypoxia, which leads to an inflammatory response inside treated teeth.

Recent studies reported that an orthodontic force mediated the IL‐17 level in the dental pulp microenvironment (Yu et al., 2016). Therefore, pulp tissue may be expected to undergo a remodeling process after tooth movement.

Figure 4.4 Immunohistochemical staining for CGRP in cat PDL after canine retraction. (a) Control; (b) seven days after tooth movement in tension side; (c) seven days after tooth movement in compression side; (d) 28 days after tooth movement in tension side; (e) 28 hours after tooth movement in compression side.

(Source: Courtesy of Dr. Ze’ev Davidovitch.)