Thesis (Ph. D.)--University of Maryland, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Maryland, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.D.S.)--University of Adelaide, 1985. / Includes bibliographical references (leaves 184-220).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 96-101).

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1957.

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1956.

Mechanical stress has been shown to play a role in bone remodelling during orthodontic tooth movement. Receptor activator of nuclear factor kβ - ligand (RANKL), osteoprotegerin (OPG), monocyte colony stimulating factor (M-CSF) and interleukin 1-β (IL-1β) play key roles in the regulation of bone remodelling, but the role of these cytokines in orthodontic tooth movement is poorly understood. Aim: The aim of this experiment was to examine the response of periodontal ligament (PDL) fibroblasts in monolayer culture to intermittent tensile stress as regards RANKL, OPG, M-CSF and IL-1β production. Methods: Human PDL fibroblasts were dissected from premolars extracted for orthodontic purposes. Explants were seeded out in 1cm wells and grown to confluence in Dulbecco�s modification of Eagle�s medium, containing 10% foetal calf serum and antibiotics, at 37�C in a humidified atmosphere of 5% CO₂/95% air. Upon reaching confluence, the cells were passaged into sequentially larger flasks. Fibroblasts were passaged 6 times. After reaching confluence in T175 flasks, the cells were detached and plated at a cell density of 10⁵/dish in 35mm Bioflex� Plates coated with type 1 collagen. The cells were placed under a continuous uni-axial strain of 12% for 6s of every 90s by a Flexercell FX 4000C[TM] for 0, 12, 24 and 48 hours. Cells were then detached and stored in RNAlater. Quantitative RT-PCR was used to determine the mRNA of the cytokines of interest. Results: Tensile force led to the down regulation of mRNA expression for OPG and IL-1β at 12 and 24 hours respectively, while M-CSF was up-regulated at 6 hours. RANKL was not detected at a significant level for quantification. Conclusion: This osteoclastic-type response indicates the complexity of mechanotransduction in an in vitro setting. Acknowledgments: This research was supported by the New Zealand Dental Research Foundation, the New Zealand Lottery Grants Board and the New Zealand Association of Orthodontists.

Mechanical stress has been shown to play a role in bone remodelling during orthodontic tooth movement. Receptor activator of nuclear factor kβ - ligand (RANKL), osteoprotegerin (OPG), monocyte colony stimulating factor (M-CSF) and interleukin 1-β (IL-1β) play key roles in the regulation of bone remodelling, but the role of these cytokines in orthodontic tooth movement is poorly understood. Aim: The aim of this experiment was to examine the response of periodontal ligament (PDL) fibroblasts in monolayer culture to intermittent tensile stress as regards RANKL, OPG, M-CSF and IL-1β production. Methods: Human PDL fibroblasts were dissected from premolars extracted for orthodontic purposes. Explants were seeded out in 1cm wells and grown to confluence in Dulbecco�s modification of Eagle�s medium, containing 10% foetal calf serum and antibiotics, at 37�C in a humidified atmosphere of 5% CO₂/95% air. Upon reaching confluence, the cells were passaged into sequentially larger flasks. Fibroblasts were passaged 6 times. After reaching confluence in T175 flasks, the cells were detached and plated at a cell density of 10⁵/dish in 35mm Bioflex� Plates coated with type 1 collagen. The cells were placed under a continuous uni-axial strain of 12% for 6s of every 90s by a Flexercell FX 4000C[TM] for 0, 12, 24 and 48 hours. Cells were then detached and stored in RNAlater. Quantitative RT-PCR was used to determine the mRNA of the cytokines of interest. Results: Tensile force led to the down regulation of mRNA expression for OPG and IL-1β at 12 and 24 hours respectively, while M-CSF was up-regulated at 6 hours. RANKL was not detected at a significant level for quantification. Conclusion: This osteoclastic-type response indicates the complexity of mechanotransduction in an in vitro setting. Acknowledgments: This research was supported by the New Zealand Dental Research Foundation, the New Zealand Lottery Grants Board and the New Zealand Association of Orthodontists.