Inclusion Criteria:  No previous tonsillar, nasal or adenoid surgery and orthodontic treatment, Bilateral crossbite and need for RME, Maxillary and mandibular permanent teeth fully erupted, Willingness to participate in the study  Exclusion Criteria:  the presence of adenotonsillectomy due to tonsillar hypertrophy or adenoidal hypertrophy Having nasal/nasopharyngeal /oropharyngeal pathologies, craniofacial syndromes, systemic disease, poor oral hygiene, History of previous orthodontic treatment.