Relationships among pharyngeal airway morphology, craniocervical posture and anterior teeth position in hyperdivergent skeletal Class Ⅱ female adults

To explore the relationships among pharyngeal airway morphology, craniocervical posture, and anterior teeth position in hyperdivergent skeletal Class Ⅱ female adults and provide a reference for orthodontic clinical diagnosis and treatment.

Lateral cephalometric radiographs of 104 untreated skeletal Class Ⅱ (ANB ≥ 4.7°) female adults were included and divided into a hyperdivergent group (MP-SN ˃ 37°) (n = 52) and a normodivergent group (29° ≤ MP-SN ≤ 37°) (n = 52) by mandibular plane angle. The pharyngeal airway sagittal size, craniocervical angulation and anterior teeth position of the two groups were measured.

Compared to the normodivergent group, hyperdivergent subjects exhibited narrower nasopharyngeal, velopharyngeal, and glossopharyngeal airways (P<0.05) and larger craniocervical angulations (P<0.05). In the hyperdivergent group, the nasopharyngeal airway sagittal size was negatively correlated with craniocervical angulations (P<0.05), while the hypopharyngeal airway sagittal size was positively correlated with craniocervical angulations in the hyperdivergent group and normodivergent group (P<0.05). In both groups, craniocervical angulations were negatively related to the labiolingual inclination of the upper incisors (P<0.05) but positively related to the inclination of the occlusal plane (P<0.05).

Hyperdivergent skeletal Class Ⅱ female adults had narrower upper airways and more extended craniocervical posture, which was correlated with pharyngeal airway morphology and anterior teeth position simultaneously. These results suggested that there were correlations among respiratory efficiency, craniocervical posture and dentofacial morphology.