Evaluation of the Upper Airway Morphology in Patients with Class II Malocclusion Using 3-Dimentional Computed Tomography

Introduction: It is common nowadays that respiratory functions are highly relevant to the orthodontic diagnosis and the treatment plan, besides their effects on the stability of the treatment results. So it is important to have a better and more deeply analysis of the upper airway morphology in our patients, especially, in class II patients where the upper airway could be affected by the pressures against the dentition, dental arch form, and the possibly direction of mandibular and maxillary growth. Objective: The aim of this study was to evaluate the size and areas of the upper airways in adults with skeletal Class II malocclusion, using three dimensional computed tomography (3DCT) and to compare the cross-sectional measurements and cephalometric variables with skeletal class I group, to investigate possible relationships between the upper airway and anteroposterior growth type. Materials and methods: Our Sample's consisted of 36 adults (15males, 21 females) who were selected from patients who were ordinary undergoing 3DCT for non-orthodontic nor otolaryngology purpose and didn’t have orthodontic treatment. The anteroposterior positions of both the maxilla and the mandible were evaluated with the ANB angle, AF-BF distance, Wits appraisal to divide our subjects into 2 groups: (1) skeletal Class I patient’s with2 >ANB<5, and (2) skeletal Class II patients with ANB >5. Then we calculated Pearson's Correlation to investigate the possible relationship between the upper airway measurements and the Cephalometric measure-ments determining anteroposterior growth patterns. Results: we found statistically significant correlation between nasopharyngeal airway measurements and the cephalometric measurements determining anteropos-terior growth patterns. The depth and area of NA showed negative correlation with ANB, WITS, AF-BF (p＜0.05). We also found that this depth and area were smaller in class II. We didn’t see significant differences between males and females in airway measurements. Conclusions: The skeletal Class II malocclusion had a narrower nasopharyngeal airway than the Class I group, there is a statistically significant correlation between nasopharyngeal airway measurements and the cephalometric measurements determining anteropos-terior growth patterns.