Christoph, Kristina Marie (2016-05). Effects of Transverse, Bodily Movement of Maxillary Premolars on the Surrounding Hard Tissue. Master's Thesis.
Thesis
Dental tipping and subsequent loss of crestal bone is a negative effect of dentoalveolar expansion, performed using any current non-surgical approach. Purpose: This study was designed to produce buccal translation and evaluate the effects on the buccal alveolar bone. Methods: A randomized split-mouth design was utilized with seven adult male beagle dogs. The experimental side received a custom-fabricated cantilever appliance that produced a translatory force through the maxillary second premolar's center of resistance. The contralateral second premolar control received no appliance. The premolars underwent 6 to 7 weeks of buccal translation, followed by 3 weeks of fixed retention. Tooth movements were evaluated by intraoral, radiographic, and model measurements. MicroCT was used to quantify the buccal bone differences. Bone formation and turnover were assessed using fluorescent labeling, H&E staining, TRAP staining, and BSP immunostaining. Results: The applied force (100 g) expanded (1.4 mm) and minimally tipped (4 degrees) the experimental teeth. Lateral translation produced dehiscences at the mesial (2.0 mm) and distal (2.2 mm) roots. Bone thickness decreased at the apical (~0.4 mm), mid-root (~0.4 mm), and coronal (~0.2 mm) levels. Histological sections showed new bone formation extending along the entire periosteal surface of the 2nd premolar's buccal plate. TRAP staining demonstrated greater osteoclastic activity on experimental when compared to control sections. Conclusions: New buccal bone forms on the periosteal surface during tooth translation, but buccal bone width decreases and crestal bone loss occurs.
