{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T10:36:37Z","timestamp":1791542197244,"version":"4.3.4"},"reference-count":27,"publisher":"The Angle Orthodontist (EH Angle Education & Research Foundation)","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2007,7,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Objective: To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated.<\/jats:p>\n                  <jats:p>Materials and Methods: A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied in vivo to the aforementioned teeth. After extraction, FEMs of these double-rooted teeth were created based on high-resolution microcomputed tomographics (micro CT, voxel size: 35 microns). This high volumetric resolution made the recognition of very small resorption lacunae possible. Scanning electron micrographs of the root surfaces were created as well. This enabled the investigation of advantages and disadvantages of the different imaging techniques from the viewpoint of the examination of root resorption. Using the FEMs, the same loading conditions as applied in vivo were simulated.<\/jats:p>\n                  <jats:p>Results: The results of clinical examination and simulations were compared using the identical roots of the teeth. The regions that showed increased hydrostatic pressure (&amp;gt;0.0047 MPa) correlated well with the locations of root resorption for each tooth. Increased torque resulted in increased high-pressure areas and increased magnitudes of hydrostatic pressure, correlating with the experiments.<\/jats:p>\n                  <jats:p>Conclusion: If hydrostatic pressure exceeds typical human capillary blood pressure in the PDL, the risk of root resorption increases.<\/jats:p>","DOI":"10.2319\/060806-234","type":"journal-article","created":{"date-parts":[[2007,5,9]],"date-time":"2007-05-09T13:31:19Z","timestamp":1178717479000},"page":"653-659","source":"Crossref","is-referenced-by-count":109,"title":["Periodontal Ligament Hydrostatic Pressure with Areas of Root Resorption after Application of a Continuous Torque Moment"],"prefix":"10.2319","volume":"77","author":[{"given":"Ansgar","family":"Hohmann","sequence":"first","affiliation":[{"name":"aResearch Scientist, Department of Orthodontics, University of Ulm, Ulm, Germany"},{"name":"Corresponding author: Mr Ansgar Hohmann, Universit\u00e4tsklinikum Ulm, Department of Orthodontics, ZMK 4, Albert-Einstein-Allee 11, 89081 Ulm, Baden-W\u00fcrttemberg, Germany (ansgar.hohmann@uni-ulm.de)"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Uwe","family":"Wolfram","sequence":"first","affiliation":[{"name":"bResearch Scientist, Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin","family":"Geiger","sequence":"first","affiliation":[{"name":"aResearch Scientist, Department of Orthodontics, University of Ulm, Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Boryor","sequence":"first","affiliation":[{"name":"aResearch Scientist, Department of Orthodontics, University of Ulm, Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Sander","sequence":"first","affiliation":[{"name":"aResearch Scientist, Department of Orthodontics, University of Ulm, Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rolf","family":"Faltin","sequence":"first","affiliation":[{"name":"cAssociate Professor, Department of Orthodontics, Paulista University, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kurt","family":"Faltin","sequence":"first","affiliation":[{"name":"dProfessor and Department Head, Department of Orthodontics, Paulista University, S\u00e3o Paulo, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Franz Guenter","family":"Sander","sequence":"first","affiliation":[{"name":"eProfessor and Department Head, Department of Orthodontics, University of Ulm, Ulm, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1164","reference":[{"key":"2020042120410628800_i0003-3219-077-04-0653-b1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1093\/ejo\/cji090","article-title":"Root resorption associated with orthodontic force in inbred mice: genetic contributions.","volume":"28","author":"Al-Qawasmi","year":"2006","journal-title":"Eur J Orthod"},{"key":"2020042120410628800_i0003-3219-077-04-0653-b2","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1016\/j.ajodo.2005.12.001","article-title":"Physical properties of root cementum: part 6. A comparative quantitative analysis of the mineral composition of human premolar cementum after the application of orthodontic forces.","volume":"129","author":"Rex","year":"2006","journal-title":"Am J Orthod Dentofacial Orthop"},{"key":"2020042120410628800_i0003-3219-077-04-0653-b3","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1007\/BF01579165","article-title":"Root resorption in upper first premolars after application of continuous intrusive forces. Intra-individual study.","volume":"59","author":"Faltin","year":"1998","journal-title":"J Orofac Orthop\/Fortschr Kieferorthop"},{"key":"2020042120410628800_i0003-3219-077-04-0653-b4","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1007\/PL00001936","article-title":"Root resorption in upper first premolars after application of continuous torque moment. Intra-individual study.","volume":"62","author":"Casa","year":"2001","journal-title":"J Orofac Orthop\/Fortschr Kieferorthop"},{"key":"2020042120410628800_i0003-3219-077-04-0653-b5","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.ajodo.2003.11.026","article-title":"Physical properties of root cementum: part 5. 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