Sınıf'Iı Bölüm 1 Olgularda Crossbow Apareyinin Dentofasiyal Yapılar ve Hava Yolu Üzerine Olan Etkilerinin Konik Işınlı Bilgisayarlı Tomografi Ile İncelenmesi

Abstract

The aims of the present study are to evaluate the skeletal and dental effects of the Crossbow, which is a fixed functional appliance used in the early treatment of the Class II division 1 patients due to mandibular retrusion, and to determine the changes in upper airway with using Cone Beam Computed Tomography (CBCT). For this purpose, 25 patients with Class II division 1 malocclusion were included. The average age was 11.1±1.1 years at the beginning of the treatment. Intraoral and extraoral photographs, dental models, and CBCT images were all obtained from the subjects at the beginning of the treatment (T0) and after debonding the Xbow (T1). Cephalometric data showed that, the Xbow restricted the anterior growth of the maxilla; however there was not an increase in the size of the mandible after treatment. Data of the dental parameters showed palatal tipping of the maxillary incisors, labial tipping of the mandibular incisors, and mesial movement and extrusion of the mandibular molars. Overjet and overbite decreased. Significant distal tipping of the maxillary molars was not observed, however mesial movement of the maxillary molars was inhibited. The cephalometric variables of the upper airway showed significant increase in the oropharynx; however, the nasopharyngeal region and the adenoid tissues were not affected by the treatment. In a 3D analysis of the upper airway, increase in anteroposterior and lateral dimensions of the retroglossal region was observed. The vertical length of the oropharyngeal airway did not change and the oropharyngeal airway volume increased significantly. There was a correlation between the cephalometric variables of the mandible and the oropharyngeal airway volume. When the positive contribution of the Xbow appliance on upper airway was concerned, it is thought that the Xbow is an alternative appliance that can be used in patients with Class II malocclusion due to mandibular retrusion, to prevent breathing and sleep disorders that may develop in the future.