Carine Bourassa1, Yara K Hosein2, Steven I Pollmann3, Khadry Galil4, Richard N Bohay5, David W Holdsworth6, Ali Tassi7. 1. Private practice, Gatineau, Quebec, Canada. 2. Division of Graduate Orthodontics, Western University, London, Ontario, Canada. 3. Robarts Research Institute, Western University, London, Ontario, Canada. 4. Department of Clinical Anatomy, Western University, London, Ontario, Canada. 5. Division of Oral Medicine and Radiology, Western University, London, Ontario, Canada. 6. Departments of Surgery and Medical Biophysics, Bone and Joint Institute, Robarts Research Institute, Western University, London, Ontario, Canada. 7. Division of Graduate Orthodontics, Western University, London, Ontario, Canada. Electronic address: ali.tassi@schulich.uwo.ca.
Abstract
INTRODUCTION: This experiment was undertaken to assess the primary stability of orthodontic miniscrews inserted at different sites in human cadaveric palatal bone for temporary skeletal anchorage, and to determine the effect of bone quality and quantity on their primary stability using microcomputed tomography imaging. METHODS: A total of 10 cadaveric maxillary hard palates were used for insertion of 130 orthodontic miniscrews (VectorTAS; Ormco, Orange, Calif; length, 6 mm; diameter, 1.4 mm). Upon insertion, maximal insertion torque (IT) was recorded. Imaging (microcomputed tomography) was performed before and after insertion for assessment of bone quality and quantity parameters (bone mineral density [BMD], bone thickness [BT], and length of screw engagement [LSE]). Differences in each parameter were assessed at the various insertion sites. Correlations between IT and measurements of BMD, BT, and LSE were evaluated. RESULTS: Significant differences (P < 0.001) were found among insertion sites for IT, BT, and LSE, but not for BMD (P = 0.004). Correlations were found between IT and BMD (rs = 0.42; P < 0.001), IT and BT (rs = 0.58; P < 0.001), and IT and LSE (rs = 0.58; P < 0.001). Most perforations of miniscrews into the nasal cavity occurred posterior to the permanent second premolars. CONCLUSIONS: The primary stability of orthodontic miniscrews in the palate is affected by bone quality and quantity, with higher primary stability obtained anterior to the second premolars and parasagittally at the level of the permanent first molars.
INTRODUCTION: This experiment was undertaken to assess the primary stability of orthodontic miniscrews inserted at different sites in human cadaveric palatal bone for temporary skeletal anchorage, and to determine the effect of bone quality and quantity on their primary stability using microcomputed tomography imaging. METHODS: A total of 10 cadaveric maxillary hard palates were used for insertion of 130 orthodontic miniscrews (VectorTAS; Ormco, Orange, Calif; length, 6 mm; diameter, 1.4 mm). Upon insertion, maximal insertion torque (IT) was recorded. Imaging (microcomputed tomography) was performed before and after insertion for assessment of bone quality and quantity parameters (bone mineral density [BMD], bone thickness [BT], and length of screw engagement [LSE]). Differences in each parameter were assessed at the various insertion sites. Correlations between IT and measurements of BMD, BT, and LSE were evaluated. RESULTS: Significant differences (P < 0.001) were found among insertion sites for IT, BT, and LSE, but not for BMD (P = 0.004). Correlations were found between IT and BMD (rs = 0.42; P < 0.001), IT and BT (rs = 0.58; P < 0.001), and IT and LSE (rs = 0.58; P < 0.001). Most perforations of miniscrews into the nasal cavity occurred posterior to the permanent second premolars. CONCLUSIONS: The primary stability of orthodontic miniscrews in the palate is affected by bone quality and quantity, with higher primary stability obtained anterior to the second premolars and parasagittally at the level of the permanent first molars.
Authors: Maha S Al Amri; Hanadi M Sabban; Doaa H Alsaggaf; Fahad F Alsulaimani; Ghassan A Al-Turki; Mohammad S Al-Zahrani; Khalid H Zawawi Journal: Ann Saudi Med Date: 2020-08-06 Impact factor: 1.526