OBJECTIVE: To test the hypothesis that palatal bone is not able to support titanium miniscrews (11 mm in length and 2 mm in diameter) when subjected to forces normally generated during orthodontic treatment. MATERIALS AND METHODS: The miniscrew-palatal bone system was modeled and analyzed using the commercial finite element method software ANSYS Multiphysics 10.0; tests were done in both a state of total osseointegration and in the absence of it. Calculations were carried out in both cases in configurations where the miniscrew was inserted into two different palatal regions: in the first it was anchored in one layer of cortical bone and in the underlying trabecular bone; in the second, two layers of cortical bone and the trabecular bone in between were involved. Two different loads were taken into account, 240 gf and 480 gf, both of which are within the normal range for orthodontic treatment, and applied to the miniscrew heads. RESULTS: The results demonstrated that the miniscrew inserted into the palate can be anchored to bone and loaded within normal orthodontic force range without exceeding the stress levels that lead to bone fracture. The osseointegrated system was characterized by a lower level of stress than the nonosseointegrated one, but anchorage within the second layer of cortical bone markedly reduced the stress on the trabecular bone, thereby improving the stability of the implant, also in the absence of osseointegration. CONCLUSIONS: The hypothesis is rejected. Miniscrews loaded within the normal orthodontic force range do not exceed the stress levels that lead to bone fracture.
OBJECTIVE: To test the hypothesis that palatal bone is not able to support titanium miniscrews (11 mm in length and 2 mm in diameter) when subjected to forces normally generated during orthodontic treatment. MATERIALS AND METHODS: The miniscrew-palatal bone system was modeled and analyzed using the commercial finite element method software ANSYS Multiphysics 10.0; tests were done in both a state of total osseointegration and in the absence of it. Calculations were carried out in both cases in configurations where the miniscrew was inserted into two different palatal regions: in the first it was anchored in one layer of cortical bone and in the underlying trabecular bone; in the second, two layers of cortical bone and the trabecular bone in between were involved. Two different loads were taken into account, 240 gf and 480 gf, both of which are within the normal range for orthodontic treatment, and applied to the miniscrew heads. RESULTS: The results demonstrated that the miniscrew inserted into the palate can be anchored to bone and loaded within normal orthodontic force range without exceeding the stress levels that lead to bone fracture. The osseointegrated system was characterized by a lower level of stress than the nonosseointegrated one, but anchorage within the second layer of cortical bone markedly reduced the stress on the trabecular bone, thereby improving the stability of the implant, also in the absence of osseointegration. CONCLUSIONS: The hypothesis is rejected. Miniscrews loaded within the normal orthodontic force range do not exceed the stress levels that lead to bone fracture.
Authors: André Büchter; Dirk Wiechmann; Stefan Koerdt; Hans Peter Wiesmann; Josef Piffko; Ulrich Meyer Journal: Clin Oral Implants Res Date: 2005-08 Impact factor: 5.977
Authors: Christof Holberg; Philipp Winterhalder; Nikola Holberg; Andrea Wichelhaus; Ingrid Rudzki-Janson Journal: Clin Oral Investig Date: 2013-03-16 Impact factor: 3.573
Authors: Christof Holberg; Philipp Winterhalder; Nikola Holberg; Andrea Wichelhaus; Ingrid Rudzki-Janson Journal: J Orofac Orthop Date: 2014-01-23 Impact factor: 1.938
Authors: Mauro Cozzani; Marco Pasini; Francesco Zallio; Robert Ritucci; Sabrina Mutinelli; Laura Mazzotta; Maria Rita Giuca; Vincenzo Piras Journal: Int J Dent Date: 2014-06-11