## 3 Results
Herein, the results reported for T and VM showed little or no change in stress display areas during periodontal breakdown (Figures 2-6 and Table 2), since the main absorption and dissipation components of the tooth and periodontium are in the dentine-cement structure and periodontal ligament, which agrees with clinical and biomechanical knowledge. The other three analyzed criteria showed unusual stress displays, with changes in stress distribution (increase or decrease), especially in the site of force applied to the bracket, along with the progression of periodontal loss. Nevertheless, S1, S3, and HP (despite their inaccuracies) confirmed the general behavior described by T and VM. Thus, based on this study's qualitative and quantitative results, it seems that periodontal breakdown (0-8 mm) does not influence stress distribution in either the bracket or surrounding enamel component, which is clinically important when treating patients with periodontal disease and assessing the use of various cements for cementing steel brackets. However, during the simulated bone loss, both T and VM showed a small variation (less than 10%) in the amounts of stress: a light increase for intrusion and extrusion, a light decrease for translation and tipping, and consistent stress for rotation. These light variations were also seen for the other three criteria (Table 2). These differences in biomechanical behavior are particularly related to the reduction in periodontal support and the way movements interfere with PDL and bone (i.e., a supposing increased interference in intrusion and extrusion and a decrease in tipping and translation). By correlating the results of this study with other reports [7; 10; 11; 13], a clearer description of the biomechanical stress distribution and absorption during the periodontal breakdown process (i.e., 0-8 mm of loss) is provided. Periodontal support loss is highly correlated with the increase in stress, especially in the periodontal ligament (most important stresses being displayed in the cervical third). Thus, 0.5 N of force was determined the highest stress during orthodontic movements in the cervical third of PDL (nevertheless, a lower than accepted MHP value was obtained), with lower amounts of stress in the apical and middle thirds of PDL, dental pulp, and radicular dentine-cement. Rotation and translation, closely followed by tipping, seem to be the most stressful movements, especially for the periodontal ligament and NVB, with potential ischemic, resorptive, and further tissue loss risks if MHP is exceeded. The tooth's ability (i.e., dentine-cement and coronal dentine components) to absorb and dissipate the stresses produced by orthodontic forces are also confirmed (approx. 86.66-97.5% of stresses before reaching PDL, 97.56-98.25% of stresses before reaching NVB, and 99.59-99.94% before reaching dental pulp [13]). No other studies investigating the aims of this study were found; thus, the correlations with our earlier reports were the only possibility and thus necessary [10; 11; 13]. Few studies [1; 2; 3; 4; 5; 6] about the analysis of stress distribution (shear and tensile) in bracket were found, with FEA analyses being limited to brackets. These studies concentrated on the bracket bond's shear and tensile stress strength under excessive amounts of orthodontic forces without investigating the biomechanical behavior under light forces and the influences of intact and reduced periodontium over the stresses displayed in the surrounding tissues (e.g., the enamel component). Another aspect seen in these studies was that despite the same applied forces being used, the stress distribution in the bracket showed unexplained discrepancies. [PERSON] et al. [5] (maximally central incisor, constructed SS bracket 0.022 in. stainless-steel and titanium with 472,556 elements and 118,045 nodes) assessed the generated torque (4-28.5 N) correlated with deformations of slot walls.