To investigate the features of alveolar bone morphology of mandibular central incisors in high-angle adult females using cone-beam computed tomography (CBCT) and evaluate the influence of aging in these patients.

CBCT and lateral cephalometric images of 142 untreated adult female patients were selected and grouped by facial growth pattern. The number of high-angle cases was increased to 164 to further explore the difference within high-angle adult females who were divided into two groups according to age. The indexes of alveolar bone height and thickness in the lower incisor region and inclination of the lower incisors were measured by Dolphin software. The data was statistically analyzed.

Compared with the average-angle group, the high-angle group had a lower alveolar bone attachment level (P < 0.05) and less bone thickness at the root apex level (P < 0.05). The thickness of lingual alveolar bone decreased with labial inclination of the lower incisors in both the high-angle and average-angle groups (r = -0.251, P = 0.025; r = -0.428, P = 0.001, respectively). In hyperdivergent female patients, the middle-aged group had a lower attachment level of alveolar bone than the young group (P < 0.05), but no significant difference in bone thickness at the root apex level (P > 0.05) was found between the two groups.

High-angle adult females had thinner mandibular anterior alveolar bone with significantly lower attachment levels. Aging and inclination of lower incisors influenced bone morphology and should be taken into careful consideration.

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.