## 3 Results
### Intrusion (Figure 4, Table 3)  
In intact and reduced periodontitis, both qualitative and quantitative biomechanical behaviors are similar to extrusion. However, there are some visible differences (smaller amount of stress in cervical third) in PDL component, which are specific to the intrusion movement (Figure 4F).  
\begin{table}
\begin{tabular}{l l l c c c c c c c c} \hline \hline
**Resorption (mm)** & & & **0** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** \\ \hline Extrusion & Structure & & 299.40 & **305.05** & **310.70** & **316.35** & **322.00** & **339.60** & **357.25** & **374  
Figure 4: Intrusion—Tresca stress display in dental tissues subjected to 0.6 N for 0, 4, and 8 mm bone loss: (**A**)—dental tissues’ structure, (**B**)—tooth with bracket, (**C**)—tooth without bracket, (**D**)—dentine component, (**E**)—dental pulp and NVB, (**F**)—PDL, (**G**)—bone with alveolar socket.  
\begin{table}
\begin{tabular}{l l c c c c c c c c c} \hline \hline
**Resorption (mm)** & & **0** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** \\ \hline Intrusion & Structure & & **299.40** & **305.05** & **310.70** & **316.35** & **322.00** & **339.60** & **357.25** & **374.87** & **392.50** \\
0.6 N/60 gf & Tooth + bracket & a & 72.03 & 107.67 & 143.31 & 178.98 & 214.60 & 237.27 & 259.94 & 282.61 & 305.30 \\ Stress & & m & 108.00 & 134.65 & 161.30 & 187.95 & 214.60 & 237.27 & 259.94 & 282.61 & 305.30 \\ Amount & & c & 216.10 & 233.63 & 251.15 & 268.67 & 286.20 & 290.97 & 295.75 & 300.52 & 305.30 \\ In each & & C & 288.10 & 296.57 & 305.00 & 313.52 & 322.00 & 328.72 & 335.45 & 342.17 & 348.90 \\ Component & Tooth & a & 60.18 & 93.08 & 125.98 & 158.88 & 191.80 & 210.50 & 229.20 & 247.90 & 266.60 \\  & & m & 90.28 & 115.66 & 141.04 & 166.42 & 191.80 & 210.50 & 229.20 & 247.90 & 266.60 \\  & & c & 120.40 & 144.20 & 168.00 & 191.80 & 215.63 & 228.37 & 241.11 & 253.85 & 266.60 \\  & & C & 240.70 & 246.45 & 225.20 & 257.95 & 263.70 & 281.05 & 298.40 & 315.75 & 333.10 \\  & & a & 44.18 & 74.76 & 105.34 & 135.92 & 166.50 & 187.15 & 207.81 & 228.46 & 249.11 \\  & & m & 44.18 & 74.76 & 105.34 & 135.92 & 166.50 & 187.15 & 207.81 & 228.46 & 249.11 \\  & & c & 107.50 & 130.48 & 135.45 & 176.43 & 199.40 & 211.83 & 224.26 & 236.68 & 249.11 \\  & & C & 54.28 & 57.66 & 61.04 & 66.41 & 67.79 & 69.88 & 71.97 & 74.06 & 76.15 \\ Bone & & a & 37.46 & 43.43 & 49.40 & 55.36 & 61.33 & 62.82 & 64.31 & 65.80 & 67.30 \\  & & m & 37.46 & 38.32 & 39.17 & 40.02 & 40.89 & 43.27 & 45.67 & 48.00 & 50.47 \\  & & c & 149.83 & 153.25 & 156.67 & 160.09 & 163.51 & 164.71 & 165.92 & 167.12 & 168.34 \\  & NVB & NVB & 1.71 & 1.92 & 2.14 & 2.35 & 2.56 & 3.01 & 3.45 & 3.90 & 4.34 \\ Pulp & a & 0.15 & 0.17 & 0.19 & 0.20 & 0.22 & 0.26 & 0.30 & 0.33 & 0.37 \\  & & c & 0.15 & 0.17 & 0.19 & 0.20 & 0.22 & 0.26 & 0.30 & 0.33 & 0.37 \\ PDL & a & 3.00 & 3.49 & 3.98 & 4.46 & 4.96 & 5.78 & 6.62 & 7.43 & 8.25 \\  & & m & 3.00 & 5.21 & 5.51 & 6.31 & 7.41 & 7.62 & 7.83 & 8.04 & 8.25 \\  & & c & 5.22 & 6.68 & 8.15 & 9.61 & 11.07 & 12.91 & 14.75 & 16.58 & 18.43 \\ \hline Intrusion & Structure \% & & **100** & **100** & **100** & **100** & **100** & **100** & **100** & **100** & **100** \\
0.6 N/60 gf & Tooth + bracket \% & a & **24.06** & **35.30** & **46.12** & **56.58** & **66.65** & **69.87** & **72.76** & **75.39** & **77.78** \\ Stress \% & & m & 36.07 & 44.14 & 51.92 & 59.41 & 66.65 & 69.87 & 72.76 & 75.39 & 77.78 \\ Reaching & & c & 72.18 & 76.59 & 80.83 & 84.93 & 88.88 & 85.68 & 82.79 & 80.17 & 77.78 \\ Each & & C & **96.23** & **97.22** & **98.17** & **99.11** & **100.00** & **96.80** & **93.90** & **91.28** & **88.89** \\ \hline \hline \end{tabular}
\end{table}
Table 3: Maximum stress average values (KPa) produced by orthodontic forces in tooth structure and dentine-cementum.