## 3 Results  
At the end of the treatment, all patients had an improvement in clinical parameters relating to nocturnal breathing (Table 2). Pre-treatment cephalometric data are summarized in Table 3. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Skeletal Variables** & \\ \hline \hline OVJ (mm) & Horizontal distance between the incisal edge of upper and lower incisor \\ \hline
1’MAX (grades) & Angle identified by the intersection of the axis of the upper incisor and the bispinal plane \\ \hline
1s-N-FH (mm) & Distance between the upper incisor and the N–FH line (Frankfurt plane) \\ \hline
1i-N-FH (mm) & Distance between the lower incisor and the N–FH line (Frankfurt plane) \\ \hline
1i’MAND (grades) & Angle identified by the intersection of the axis of the lower incisor and the mandibular plane \\ \hline
1s-A-Po (mm) & Distance between the upper incisor and the A–Po line \\ \hline
1i-A-Po (mm) & Distance between the lower incisor and the A–Po line \\ \hline
1s’1i (grades) & Angle identified by the intersection of the axes of the upper and lower central incisors \\ \hline Ul-E-line (mm) & Distance between upper lip (Ul point) and [PERSON]’s aesthetic line (tip of nose–tip of chin) \\ \hline LI-E-line (mm) & Distance between upper lip (LI point) and [PERSON]’s aesthetic line (tip of nose–tip of chin) \\ \hline Upper airway space & \\ dimensions & \\ \hline Nasopharynx (mm) & Distance from a point on the posterior contour of the soft palate to the point closest to the posterior wall of the pharynx \\ \hline Oropharynx (mm) & Distance from the intersection of the posterior edge of the tongue and the lower edge of the mandible to the point closest to the posterior wall of the pharynx \\ \hline Hypopharynx (mm) & Distance from a point on the posterior base of the tongue to the point closest to the posterior wall of the pharynx \\ \hline PNS-P (mm) & Distance between the lowest point of the soft palate (P) and the posterior nasal spine (PNS) \\ \hline MP-H (mm) & Distance between the mandibular plane (MP) and the hyoid bone (H) \\ \hline PH L (mm) & Distance between the base of the epiglottis (Eb) and the tip of the tongue (Tt) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Study Group**} \\ \hline  & **T0** & **T1** & \\ \hline
**Clinical Condition Associated to the Onset of** & _n/20_ & _n/20_ & **Difference between** \\
**Sleep-Disordered Breathing** & **(\%)** & **(\%)** & **T0 and T1 (\%)** \\ \hline Allergy & 7/20 & 6/20 & \multirow{2}{*}{\(-5\)} \\  & (35) & (30) & \\ \hline Rhinitis & 3/20 & 2/20 & \multirow{2}{*}{\(-5\)} \\  & (15) & (10) & \\ \hline Roncopathy & 8/20 & 3/20 & \multirow{2}{*}{\(-25\)\({}^{*}\)} \\  & (40) & (15) & \\ \hline Apnea & 12/20 & 6/20 & \multirow{2}{*}{\(-30\)\({}^{*}\)} \\  & (60) & (30) & \\ \hline Other sleep disorders & 6/20 & 3/20 & \multirow{2}{*}{\(-15\)\({}^{*}\)} \\  & (30) & (15) & \\ \hline \hline \end{tabular} \({}^{*}\) = statistical significance.  
\end{table} 
Table 2: Clinical conditions associated with the onset of sleep-disordered breathing in the study group, with their frequency. The results of cephalometric changes observed post treatment are reported in Table 4 for the study group and in Table 5 for the control group. In the study group (Table 4), statistically significant changes were mainly found in the variables indicating the size of the airways, while not many other variations were found, except for the sagittal position of the maxilla and mandible in relation to the cranial base (SNA, SNB, and ANB angles). In the control group (Table 5), on the other hand, there were more generalized variations in the craniofacial morphology, compared to the study group, regarding the sagittal and vertical position of the maxilla, the position of the teeth, and the size of the airways.