)2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University University, Zitten 02101, Libya; [EMAIL_ADDRESS] (D.M. )2 Department of Chemistry, Faculty of Chemistry, Alsmarya University, Zitten 02101, Libya; mjie@ualconditions such as obstructive sleep apnea (OSA) [3], which is associated with cognitive, behavioral, stroke-related, hypertension-based, and cardiovascular complications [4; 5; 6]. Maxillary expansion has been a widely used intervention for addressing these abnormalities. Traditional methods such as rapid maxillary expansion (RME), slow maxillary expansion (SME) using traditional orthodontic appliances, and surgically assisted rapid maxillary expansion (SARME) have shown varying degrees of success [7; 8]. Previous research has demonstrated that RME can improve nasal airway volume by widening the nasal cavity and reducing resistance to airflow [9; 10]. However, recurrence after RME and adverse effects such as edema, pain, and mucosal irritation remain serious concerns [11]. Additionally, while SARME is effective for severe cases, its invasiveness limits its use in pediatric populations. SME offers an alternative by applying gentler forces, promoting more stable outcomes and allowing sufficient time for bone formation in the intermaximillary suture [8; 12; 13]. This physiological approach is often favored by both clinicians and patients [14]. However, SME has traditionally been implemented using fixed appliances, which may cause discomfort and are less esthetically appealing, particularly for younger patients [15]. Recently, clear aligners have emerged as a potential alternative option in orthodontics, including maxillary expansion [15; 16; 17]. These devices are not only more comfortable and hygien but also provide superior esthetics, making them particularly attractive for children and their parents [16; 17]. Despite their growing adoption, the effect of clear aligners on maxillary intermal distance and nasal airway volume in children has not been investigated. The objectives of this study were to:  
1. Determine the possible changes in the nasal airway volume after maxillary arch expansion with clear aligners using cone-beam computed tomography (CBCT) and compare the experimental group's results to a control group without treatment. 2. Assess the maxillary intermalor distance changes associated with maxillary expansion using clear aligners in children. 3. Investigate possible correlations between intermalor distance changes and changes in nasal airway volume after maxillary expansion using clear aligners.