Relationship between malocclusion, soft tissue profile, and pharyngeal airways: A cephalometric study.

BACKGROUND AND OBJECTIVE: The recent years have been marked by a search for new interrelations between the respiratory function and the risk of the development of malocclusions, and algorithms of early diagnostics and treatment have been developed. The aim of the study was to evaluate the relationships between hard and soft tissues and upper airway morphology in patients with normal sagittal occlusion and Angle Class II malocclusion according to gender.

MATERIALS AND METHODS: After the evaluation of clinical and radiological data, 114 pre-orthodontic patients with normal or increased ANB angle, were randomly selected for the study. The cephalometric analysis was done by using the Dolphin Imaging 11.8 computer software.

RESULTS: Comparison of the cephalometric values of soft tissue and airway measurements performed statistically significant negative correlation between the width of the upper pharynx and the ANB angle was found: the ANB angle was decreasing with an increasing width of the upper pharynx. The airways showed a statistically significant negative correlation between the width of the lower pharynx and the distance from the upper and the lower lips to the E line. Logistic regression analysis was performed to evaluate significant factors that could predict airway constriction. The upper pharynx was influenced by the following risk factors: a decrease in the SNB angle, an increase in the nose tip angle, and younger age; while the lower pharynx was influenced by an increase in the distance between the upper lip and the E line and by an increase in the upper lip thickness.

CONCLUSIONS: During critical period of growth and development of the maxillofacial system, the patients with oral functional disturbances should be monitored and treated by a multidisciplinary team consisting of a dentist, an orthodontist, a pediatrician, an ENT specialist, and an allergologist. Cephalometric analysis applied in our study showed that Angle Class II patients with significantly decreased facial convexity angle, increased nasomental, upper lip-chin, and lower lip-chin angles, and upper and lower lips located more proximally to the E line more frequently had constricted airways.