Palatal disjunction with Hyrax in pediatric mouth-breathers with posterior crossbite: report of three clinical cases.

Abstract

Introduction: Mouth breathing has a prevalence of between 11% and 56% in children. Its main causes include adenotonsillar hypertrophy and allergic disorders, commonly leading to underdevelopment of the upper jaw, posterior crossbite, and high palate. Among the orthodontic treatments described in the literature, palatal expansion with Hyrax stands out. Objective: To describe the clinical treatment of palatal expansion with Hyrax in pediatric patients with mouth breathing and posterior crossbite. Case Presentation: Three cases treated multidisciplinarily with otolaryngology are presented. Patient 1: 8-year-old female with narrow maxilla, right posterior crossbite, and deep palate; she received medication and maxillary expansion with Hyrax after diagnosis of mouth breathing due to allergic disorders by Otolaryngology. Patients 2 (6-year-old female) and 3 (9-year-old male) were diagnosed with mouth breathing associated with adenotonsillar hypertrophy; surgery was performed to remove the nasal obstruction, followed by expansion with Hyrax due to narrow palate and posterior crossbite.  In all three cases, maxillary expansion improved the transverse relationship of the arch, corrected malocclusion, and increased nasal space, with improvements in breathing patterns. Conclusions: The results demonstrated that an interdisciplinary approach combining medical or surgical treatment of respiratory conditions with palatal expansion achieves an adequate transverse relationship, promotes the development of the nasomaxillary complex, and improves respiratory function, highlighting the importance of comprehensive management in these cases.