One of the most prevalent congenital abnormalities of the craniofacial region, cleft lip and palate(CLP) accounts for about 15% of all congenital deformities globally. The accompanying facial traits of children with CLP include a retrognathic maxilla and midface hypoplasia, which leads to diminished upper airway dimensions that do not improve even with surgical treatment. In children, the primary cause of respiratory problems is the obstruction of upper airway which is relieved by Rapid Maxillary Expansion (RME) which is also frequently employed to address the transverse deficiency. However, comparative studies show that Slow Maxillary Expansion(SME) provide more controlled anterior expansion than RME and is also equally effective in increasing pharyngeal airway volume in growing patients. Both Ni-Ti palatal expander and Aligners effectively causes SME, but aligners provide an added advantage to improve the alignment of dentition simultaneously with expansion. In this study, we will be doing a comparative assessment of volumetric airway changes in cleft lip and palate patients when treated with aligners and Ni-Ti palatal expander.