# Effect of the Mandibular Repositioning Appliance (MARA) on Posterior Airway Space (PAS)
## 3 Results
While they are correct in their conclusions, the immense requirements for a lateral cephalogram in a supine position are not suitable for daily routine practice and we therefore compromised by using lateral cephalograms already taken, without exposing our patient to more ionizing radiation or incurring the costs for MRI imaging. [PERSON] et al. demonstrated the significance of CBCT in the diagnosis and treatment planning of individuals with OSA [26]. As part of the overall examination, the authors advised evaluating CBCT images and estimating respiratory tract measurements [26]. Based on the outcomes of [PERSON] et al. 's study, our future study could examine the respiratory tract's modifications on CBCT following MARA treatment [26]. The absence of a control group in this study could be a possible limitation. The control group could consist of patients with Class II malocclusion who were not treated. Since we analyzed cephalometric radiograms before and after orthodontic treatment, we feel that it would be unethical to exclude patients with Class II malocclusion (who have specific functional and aesthetic issues) from receiving orthodontic treatment in order to include them in the control group. The parameters used in this study were based on the parameters from [PERSON] et al. [20]. The authors selected parameters at the P4 level, focusing on the \"mandibular PAS\" according to [PERSON] et al. [21]. Our PAS data were adjusted for outliers (for single negative PAS changes, see Table 3). The resulting PAS diameter increase between T1 and T2 was significant both for the male patients and the female patients (\(p=0.005\) and \(p=0.044\)). Observed PAS changes were less pronounced in the female patients compared to the male patients. Bjork's sum angle reflects the individual growth pattern: if it is less than \(396^{\circ}\), the pattern is horizontal; if it is greater than \(396^{\circ}\), it is vertical. In the male patients (\(388.31\pm 7.0^{\circ}\)), the general growth pattern was more horizontal than in the female patients (\(393.18\pm 7.4^{\circ}\)). [PERSON] et al. [20] found a greater, non-significant decrease (\(-0.89^{\circ}\)) between T1 and T2. The standard deviation (SD) was 3.27, which was about 4.2 times greater than in the present study. Neither study found a significant change in this parameter. There was a tendency for Bjork's sum angle to decrease in the T1 and T2 interval as a result of MARA treatment. Changes in the vertical direction were the opposite of what was expected. The condyles moved down and forward. The pubertal growth spurt is the best time frame for treatment if skeletal effects are wanted. The SNA as a sagittal parameter for the maxilla decreased; the upper jaw thus became more retrognathic between T1 and T2 but not significantly. [PERSON] et al. [20] found an increase (+0.32 \(\pm\) 1.44\({}^{\circ}\), \(p\) = 0.363). Both studies found non-significant changes in the SNA. The SNB as an indicator of the sagittal mandibular position increased non-significantly. The lower jaw became more prognathic between T1 and T2. The headgear effect on the upper jaw induced by the MARA occurs as a consequence of moving point A backwards. The vertical arm of the upper elbow produces pressure on the lower arm. This effect is more noticeable in adult patients in which growth intensity is limited. The MARA intensely stimulates lower jaw growth. The total increase in the length of the lower jaw was between 1.5 mm and 2.6 mm. In their study, [PERSON] et al. showed statistically significant decreases in SNA and ANB, which may have resulted from the maxillary growth restriction that previous researchers had discovered [27]. The amount of forward mandibular development may have been restricted by this \"headgear effect\". Therefore, mandibular anterior posture in relation to the cranial base cannot be the only explanation for the notable increase in airway capacity, dimensions and hyod bone position [27]. In comparing these results with [PERSON] et al.