IADR Abstract Archives

Dynamic Changes in Orthodontic Tooth Movement in Rats: 3D Analysis

Objectives: To evaluate the changing pattern of orthodontic tooth movement (OTM) throughout time with a constant orthodontic force (OF) by an improved 3D analysis in a rat model, overcoming the limitations of previous 2D analysis.
Methods: Six adult male Wistar rats were randomly assigned to two groups by implanting a mini-screw in one hemimaxilla (split-mouth design). In Group 1 (n=6) a constant OF (25 g) was applied between the upper first molar (M1) and the mini-screw. In Group 2 (n=6) no force was applied on the contralateral hemimaxilla (control). All rats were longitudinally followed up with in vivo micro-CT before OTM (baseline, T0), after 10 (T1), 17 (T2), 24 (T3) and 31 days (T4). The OTM and bone mineral density (BMD) were measured with in 3D by a rigid voxel-based superimposition method. Values were compared between different timepoints and experimental sides by repeated measures MANOVA.
Results: M1 displaced significantly more in Group 1, while the other teeth didn’t. Increased tipping of M1 was observed at T0-T1 and T3-T4, while at T1-T3 bodily movement was predominant. OTM had a significant effect on BMD (P=0.03*) but time did not (P=0.10). BMD was significantly lower in Group 1 at all timepoints except for baseline. Interestingly, BMD in Group 1 decreased at T1 but increased gradually from T1 to T4, parallel to the changing pattern of M1 displacement.
Conclusions: The changing pattern of OTM is not constant throughout time. Initially, M1 displacement was mainly due to tipping, while after BMD decreasing at T1, bodily movement dominated. The later increase of BMD from T2 to T4 led to a mix of bodily movement and tipping in M1 displacement.

2021 Continental European and Scandinavian Divisions Meeting (Brussels, Belgium, Hybrid)
Brussels, Belgium, Hybrid
2021
0050
Orthodontics Research
  • Zong, Chen  ( KU Leuven , Leuven , Belgium )
  • Van Dessel, Jeroen  ( UZ Leuven , Leuven , Belgium )
  • Vande Velde, Greetje  ( KU Leuven , Leuven , Belgium )
  • Willems, Guy  ( UZ Leuven , Leuven , Belgium )
  • Cadenas De Llano Pérula, Maria  ( UZ Leuven , Leuven , Belgium )
  • NONE
    Oral Session IN PERSON
    Orthodontics
    Friday, 09/17/2021 , 02:30PM - 03:30PM