Enhanced angiogenesis induced by diffusible angiogenic growth factors released from human dental pulp explants of orthodontically moved teeth

Abstract

The aim of this study was to determine if diffusible angiogenic growth factors were released in human dental pulp during orthodontic tooth movement. These factors, if diffusible, could induce angiogenesis in other tissues, and may then be isolated and identified. The pulps from 14 premolar teeth treated with straight wire fixed orthodontic appliances for 2 weeks were compared with those of 14 untreated control premolar teeth from the same subjects. Following tooth extraction and sectioning, 1-mm horizontal sections of pulp tissue were embedded in collagen with 1-mm sections of rat aorta and co-cultured in growth media for up to 4 weeks. Sections of rat aorta alone were also cultured. Angiogenic changes in the form of microvessel growth were observed by light microscopy. Microvessel identification was confirmed by electron microscopy and by immunohistochemistry using staining for factor VIII-related antigen marker for endothelial cells. When compared at days 5, 10, and 14 of co-culture, the number of microvessels was significantly greater in the pulps from orthodontically moved teeth than in those from the control teeth. The number of rat aorta microvessels was also significantly greater when co-cultured with pulp from orthodontically moved teeth than with pulp from control teeth and when compared with control cultures of rat aorta alone. There were no significant differences in microvessel numbers between the rat aorta co-cultured with pulp from control teeth and control cultures of rat aorta alone. These results indicate an increase in angiogenic growth factors in the pulp of orthodontically moved teeth, and the enhanced response of the rat aorta when co-cultured with this pulp shows that these factors appear to be diffusible.

Effects of Intrusive Force on Selected Determinants of Pulp Vitality

“…[2][3][4][5][6][7] Other authors have reported a significant increase in functional pulpal blood vessels, as well as an increase in the angiogenic growth factors of affected pulp. [8][9][10][11] The most commonly used parameters in the study of tissue response to orthodontic force have been measurements of pulpal vasculature and changes in blood flow. Human pulp blood flow has been shown with the use of laser Doppler flowmetry to decrease significantly or to remain stable after intrusive force activation.…”

Mechanical Stress Activates Proinflammatory Cytokines and Antioxidant Defense Enzymes in Human Dental Pulp Cells

“…However, excess mechanical force can fracture restored teeth and ultimately lead to tooth loss. Furthermore, previous studies have found that mild inflammatory-type responses (21), angiogenic changes, or growth factors are produced in HDP cells in response to orthodontic force (22,23); however, specific cytoprotection or stress responses in HDP cells have not been investigated to date. Therefore, this study was conducted to evaluate the effects of mechanical stress on the expression of proinflammatory cytokines and cytoprotective antioxidant genes to elucidate the molecular mechanisms involved in the relevant signaling pathways in HDP cells.…”

Role of Angiogenesis in Endodontics: Contributions of Stem Cells and Proangiogenic and Antiangiogenic Factors to Dental Pulp Regeneration

“…Higher capillary shear stress also increases the expression of VEGF and angiogenesis in skeletal muscles (46). Derringer et al (47,48) detected an increase in the number of microvessels in pulp tissue of orthodontically moved teeth that was due to the elevation of the angiogenic growth factors. They later used a combination of 5 neutralizing antibodies against VEGF, FGF-2, PDGF, epidermal growth factor (EGF), and TGF-β to assess the angiogenesis process in human dental pulp of orthodontically moved teeth (49).…”