Figure 1.
1. Sella (S); 2. Nasion (N); 3. Subspinale (A); 4. Supramentale (B); 5: Anterior nasal spine (ANS); 6: Posterior nasal spine (PNS); 7: Apex of the mesiobuccal root of UM (UMA); 8: Mesiobuccal cuspid of UM (UMC); 9: Apex of the root of upper incisor (UIA); 10: Edge of upper incisor (UIE); 11: Menton (Me); 12: Point of tangency of mandibular plane.
Table 1.
Cephalometric variables and definitions.
Figure 2.
Analysis of UM/PP-12 in groups with different physiologic factors.
The change in UM angulation during orthodontic treatment (i.e., the dependent variable) significantly differed with gender, age and molar relationship.
Table 2.
Upper anchorage loss as a function of selected physiologic characteristics.
Figure 3.
Analysis of UM/PP-12 in groups with different treatment strategies.
The change in UM angulation during orthodontic treatment (i.e., the dependent variable) significantly differed between patients with and without maxillary premolar extraction.
Table 3.
Upper anchorage loss as a function of selected treatment-related factors.
Table 4.
Frequently used cephalometric variables.
Table 5.
Results of multiple linear regression analysis of UM/PP-12 and correlated variables.
Figure 4.
Simulations of the early treatment of patients with different initial upper molar (UM) angulations.
Patients with different UM angulations would show different responses to the same treatment. a. In patients with more distally tipped UMs, the mesial tipping moment from the deflected NiTi archwire into the 0° buccal tube would tip the molars forward to occupy the extraction space, and thus, constitute anchorage loss. b. In patients with extremely mesially tipped UMs, the moment from a straight archwire in 0° buccal tubes would tip the UMs backward.