## 3 Results  
Intra-examiner and inter-examiner reliability for the measurements of cortical bone thickness and alveolar bone density showed intra-class correlation coefficients of 0.94-0.98 and 0.92-0.97, respectively. The overall success rate of the micro-implants was 85.9%; a total of 347 out of 404 micro-implants were used successfully until the end of the treatment. The mean loading time was 12.4 \(\pm\) 4.3 months. According to the GEE, which compared the factors between the successful and failed micro-implants, the loading protocol (immediate vs. delayed, \(p\) < 0.001) and root proximity (\(p\) < 0.001) were identified as the significant factors (Table 2). Figure 1: Measurement of cortical and cancellous bone density in the axial view: (**a**) Cortical bone density. (**b**) Cancellous bone density. (**c**) Cortical bone thickness. The micro-implants that were loaded immediately had a greater rate of failure; the micro-implants that had type III in [PERSON]'s classification had the greatest failure rate. Contrastingly, cortical bone thickness and bone density did not show significant differences between the successful and failed micro-implants (Table 3). \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Variable** & \multicolumn{3}{c}{**Success**} & \multicolumn{3}{c}{**Failure**} & \multicolumn{3}{c}{**Total**} \\ \hline  & \multicolumn{3}{c}{**\(n\) = 347 (85.89\%)**} & \multicolumn{3}{c}{\(n\) = 57 (14.11\%)**} & \multicolumn{3}{c}{\(n\) = 404} & \(p\) \\ \hline Age & & 23.59 & (5.91\%) & 24.67 & (5.72\%) & 23.74 & (5.89\%) & 0.141 \\ \hline Sex & M & 69 & (19.88\%) & 10 & (17.54\%) & 79 & (19.55\%) & 0.728 \\  & F & 278 & (80.12\%) & 47 & (82.46\%) & 325 & (80.45\%) & 0.728 \\ \hline Anteroposterior skeletal pattern & Class I & 145 & (41.79\%) & 26 & (45.61\%) & 171 & (42.33\%) & \\  & Class II & 174 & (50.14\%) & 27 & (47.37\%) & 201 & (49.75\%) & 0.887 \\  & Class III & 29 & (8.07\%) & 4 & (7.02\%) & 32 & (7.92\%) & \\ \hline Vertical facial pattern & Short & 31 & (9.01\%) & 2 & (3.51\%) & 33 & (8.23\%) & \\  & Normal & 193 & (56.1\%) & 35 & (61.4\%) & 228 & (56.86\%) & 0.380 \\  & Long & 120 & (34.88\%) & 20 & (35.09\%) & 140 & (34.91\%) & \\ \hline Position I & Mx 456 & 217 & (62.54\%) & 28 & (49.12\%) & 245 & (60.64\%) & \\  & Mx 67 & 14 & (4.03\%) & 4 & (7.02\%) & 18 & (4.46\%) & \\  & Mn 456 & 91 & (26.22\%) & 19 & (33.33\%) & 110 & (27.23\%) & 0.439 \\  & Mn 67 & 25 & (7.2\%) & 6 & (10.53\%) & 31 & (7.67\%) & \\ \hline Position II & L-Mxt56 & 112 & (32.28\%) & 9 & (15.79\%) & 121 & (29.95\%) & \\  & L-Mx67 & 3 & (0.86\%) & 2 & (3.51\%) & 5 & (1.24\%) & \\  & L-Mn456 & 48 & (13.83\%) & 7 & (12.28\%) & 55 & (13.61\%) & \\  & L-Mn67 & 15 & (4.32\%) & 2 & (1.75\%) & 16 & (3.96\%) & 0.110 \\  & R-Mx456 & 105 & (30.26\%) & 19 & (33.33\%) & 124 & (30.69\%) & \\  & R-Mx67 & 11 & (3.17\%) & 2 & (3.51\%) & 13 & (3.22\%) & \\  & R-Mn456 & 43 & (12.39\%) & 12 & (21.05\%) & 55 & (13.61\%) & \\  & R-Mn67 & 10 & (2.88\%) & 5 & (8.77\%) & 15 & (3.71\%) & \\ \hline Loading protocol & delayed & 147 & (42.36\%) & 17 & (29.82\%) & 164 & (40.59\%) & \\  & immediate & 200 & (57.64\%) & 26 & (45.61\%) & 226 & (55.94\%) & \textless{}0.001 \\  & no loading & 0 & (0\%) & 14 & (24.56\%) & 14 & (3.47\%) & \\ \hline Root proximity \({}^{*}\) & I & 226 & (65.13\%) & 17 & (30.36\%) & 243 & (60.3\%) & \\  & II & 100 & (28.82\%) & 27 & (48.21\%) & 127 & (31.51\%) & \textless{}0.001 \\  & III & 21 & (6.05\%) & 12 & (21.43\%) & 33 & (8.19\%) & \\ \hline Extraction/non-extraction & Non-Ext & 252 & (72.62\%) & 44 & (77.19\%) & 296 & (73.27\%) & \\  & Ext & 95 & (27.38\%) & 13 & (22.81\%) & 108 & (26.73\%) & 0.491 \\ \hline \end{tabular} \({}^{*}\) Root proximity classified by [PERSON] et al. [19]. Mx, maxilla; Mn, mandible; 456, between first and second premolars or between second premolar and first molar; 67, between first and second molars; L, left; R, right; Non-Ext, non-extraction; Ext, extraction.  
\end{table}