Читать книгу Biological Mechanisms of Tooth Movement - Группа авторов - Страница 75
Vasodilatation and angiogenesis response to orthodontic forces
ОглавлениеBlood flowing through the tooth is confronted with a unique environment. The dental pulp is encased within a rigid, noncompliant shell and its survival is dependent on the blood vessels that access the interior of the tooth through the apical foramen. As a consequence of these unusual environmental constraints, changes in pulpal blood flow or vascular tissue pressure can have serious implications for the health of the dental pulp (Kim, 1990).
The changes occurring in respiration in the dental pulp tissue while it is being subjected to orthodontic force have been reported (Hamersky et al., 1980). Kvinnsland et al. (1989) described a detectable increase in the pulpal blood flow in rats caused by an orthodontic appliance. Rana et al. (2001) found apoptosis in dental pulp tissues of rats undergoing orthodontic stress, whereas Derringer et al. (1996) observed an increase in angiogenesis in human dental pulp tissue following orthodontic force application. Further, aspartate aminotransferase, a cytoplasmic enzyme that is released extracellularly upon cell death, was elevated in the pulp of orthodontically treated teeth (Perinetti et al., 2004). The role of the vascular system and blood circulation incident to OTM has been studied by several investigators. It was concluded that orthodontic force might stimulate vasodilatation in dental pulp tissues (Yamaguchi and Kasai, 2007). The processes that occur in the dental pulp, which were explored in in vivo and in vitro studies, are summarized in Table 4.3.