Orthodontic Mechanotransduction and the Role of the P2X7 Receptor

dc.contributor.advisorKatona, Thomas R.
dc.contributor.authorViecilli, Rodrigo F.en_US
dc.contributor.otherChen, Jie
dc.contributor.otherRoberts, W. Eugene, Jr.
dc.contributor.otherHartsfield, James K., Jr.
dc.contributor.otherBidwell, Joseph
dc.date2009en_US
dc.date.accessioned2009-08-18T17:22:15Z
dc.date.available2009-08-18T17:22:15Z
dc.date.issued2009
dc.degree.date2009
dc.degree.disciplineSchool of Dentistryen
dc.degree.grantorIndiana Universityen_US
dc.degree.levelPh.D.en_US
dc.descriptionIndiana University-Purdue University Indianapolis (IUPUI)en_US
dc.description.abstractThe first part of the study describes the development of a microCT based engineering model to study orthodontic responses. The second part investigated the relationship between orthodontic stimulus, root resorption and bone modeling. It was hypothesized that stress magnitudes are insufficient to portray the mechanical environment and explain the clinical response; directions also play a role. An idealized tooth model was constructed for finite element analysis. The principal stress magnitudes and directions were calculated in tipping and translation. It was concluded that within the same region of root, PDL and bone, there can be compression in one structure, tension in another. At a given point in a structure, compression and tension can coexist in different directions. Magnitudes of compression or tension are typically different in different directions. Previously published data presenting only stress magnitude plots can be confusing, perhaps impossible to understand and/or correlate with biological responses. To avoid ambiguities, a reference to a principal stress should include its predominant direction. Combined stress magnitude/direction results suggest that the PDL is the initiator of mechanotransduction. The third part of this project tested the role of the P2X7 receptor in the dentoalveolar morphology of C57B/6 mice. P2X7R KO (knockout) mice were compared to C57B/6 WT to identify differences in a maxillary molar and bone. Tooth dimensions were measured and 3D bone morphometry was conducted. No statistically significant differences were found between the two mouse types. P2X7R does not have a major effect on alveolar bone or tooth morphology. The final part examines the role of the P2X7 receptor in a controlled biomechanical model. Orthodontic mechanotransduction was compared in wild-type (WT) and P2X7R knock-out (KO) mice. Using Finite Element Analysis, mouse mechanics were scaled to produce typical human stress levels. Relationships between the biological responses and the calculated stresses were statistically tested and compared. There were direct relationships between certain stress magnitudes and root resorption and bone formation. Hyalinization and root and bone resorption were different in WT and KO. Orthodontic responses are related to the principal stress patterns in the PDL and the P2X7 receptor plays a significant role in their mechanotransduction.en_US
dc.identifier.urihttps://hdl.handle.net/1805/1931
dc.identifier.urihttp://dx.doi.org/10.7912/C2/1452
dc.language.isoen_USen_US
dc.subjectOrthodontics
dc.subjectGenetics
dc.subjectEngineering
dc.subjectFinite element
dc.subjectMouse
dc.subject.meshTooth Movement -- methodsen_US
dc.subject.meshReceptors, Purinergic P2 -- physiologyen_US
dc.subject.meshMechanotransduction, Cellular -- physiologyen_US
dc.subject.meshBone Remodeling -- physiologyen_US
dc.subject.meshPeriodontal Ligament -- physiopathologyen_US
dc.subject.meshRoot Resorption -- etiologyen_US
dc.titleOrthodontic Mechanotransduction and the Role of the P2X7 Receptoren_US
dc.typeThesisen
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