# Long-Term Stability of Class II Malocclusion Treated with Maximly Molar Distalization
## 3 Results  
This study tested the hypothesis that maxillary first molar distalization achieved through orthodontic treatment can be maintained in the long term, and that dentoalveolar measurements remain stable after treatment. The mean and standard deviation values of the chronological ages of the individuals included in this study at T1, T2, and T3 are presented in Table 1. The average treatment period was 3.0 years, and the long-term follow-up period was 6.1 years. The values for the T1, T2, and T3 periods are shown in Table 2. The mean and standard deviations with changes in the cephalometric and model measurements relative to T2-T1, T3-T2, and T3-T1 are summarized in Table 3.  
\begin{table}
\begin{tabular}{l l l l} \hline  & **T1** & **T2** & **T3** \\ \hline  & \(\textbf{Mean}\pm\textbf{SD}\) & \(\textbf{Mean}\pm\textbf{SD}\) & \(\textbf{Mean}\pm\textbf{SD}\) \\ \hline \hline \(\textbf{SNA}^{\circ}\) **(1)** & \(78.70\pm 2.78\) & \(79.10\pm 2.95\) & \(79.44\pm 3.01\) \\ \(\textbf{SNB}^{\circ}\) **(2)** & \(75.88\pm 2.69\) & \(76.37\pm 2.78\) & \(76.73\pm 2.87\) \\ \(\textbf{ANB}^{\circ}\) **(3)** & \(2.81\pm 1.53\) & \(2.72\pm 1.53\) & \(2.73\pm 1.49\) \\ \hline \(\textbf{SN-MP}^{\circ}\) **(4)** & \(\textbf{33.41}\pm\textbf{3.65}\) & \(34.22\pm 3.75\) & \(33.10\pm 4.13\) \\ \(\textbf{SN-OP}^{\circ}\) **(5)** & \(17.40\pm 3.66\) & \(17.71\pm 3.59\) & \(17.17\pm 3.52\) \\ \(\textbf{U6-PP}^{\circ}\) **(2)** & \(74.16\pm 5.50\) & \(75.79\pm 5.01\) & \(76.21\pm 5.11\) \\ U6-PP mm **(14)** & \(17.73\pm 1.77\) & \(19.07\pm 1.85\) & \(19.46\pm 1.90\) \\ \(\textbf{U6-ANS mm}\) **(15)** & \(\textbf{31.29}\pm\textbf{2.27}\) & \(33.05\pm 2.23\) & \(32.74\pm 2.24\) \\ \hline U6-X mm **(10)** & \(58.58\pm 3.40\) & \(61.62\pm 3.57\) & \(62.87\pm 3.85\) \\ \hline \(\textbf{U6-Y mm}\) **(11)** & \(31.57\pm 4.34\) & \(32.14\pm 4.89\) & \(33.63\pm 5.01\) \\ \hline \(\textbf{U1-PP}^{\circ}\) **(6)** & \(110.53\pm 5.55\) & \(111.40\pm 5.22\) & \(111.82\pm 4.88\) \\ \hline \(\textbf{U1-PP}\) **(12)** & \(27.27\pm 2.70\) & \(28.65\pm 2.90\) & \(28.91\pm 2.77\) \\ \hline \(\textbf{U1-ANS mm}\) **(13)** & \(0.21\pm 2.00\) & \(-0.01\pm 1.84\) & \(-0.14\pm 1.91\) \\ \hline \(\textbf{U1-X mm}\) **(8)** & \(68.80\pm 4.52\) & \(71.95\pm 4.58\) & \(72.97\pm 4.70\) \\ \hline \(\textbf{U1-Y mm}\) **(9)** & \(62.84\pm 5.31\) & \(64.93\pm 5.47\) & \(66.05\pm 5.80\) \\ \hline \(\textbf{Overjet mm}\) **(16)** & \(3.91\pm 1.72\) & \(2.82\pm 0.68\) & \(3.13\pm 0.84\) \\ \hline \(\textbf{Overbite mm}\) **(17)** & \(3.17\pm 1.39\) & \(2.49\pm 0.59\) & \(2.45\pm 1.27\) \\ \hline \(\textbf{Arch length mm}\) **(19)** & \(71.93\pm 3.72\) & \(75.28\pm 3.60\) & \(74.59\pm 3.56\) \\ \hline \(\textbf{Irregularity index mm}\) **(20)** & \(9.92\pm 3.64\) & \(0.02\pm 0.14\) & \(2.57\pm 1.75\) \\ \hline \(\textbf{Right molar relationship}\) **mm (18)** & \(2.67\pm 1.36\) & \(0.01\pm 0.85\) & \(0.29\pm 0.82\) \\ \hline \(\textbf{Left molar relationship mm}\) & \(2.16\pm 1.45\) & \(-0.27\pm 1.01\) & \(-0.26\pm 1.20\) \\ \hline \end{tabular}
\end{table}
Table 2: Mean cephalometric and model measurements at T1, T2, and T3.