A 3D evaluation of the upper airways and sagittal craniofacial pattern: are these two parameters associated?

Numerous studies have been published aiming to investigate the relationship between sagittal craniofacial pattern and the dimensions of upper airway, but with controversial results. The aim of the study is to verify if an association exists between a specific sagittal cranio-facial pattern and smaller dimensions of upper airway, leading so to a possible risk indicator for OSAS development. Ninety-nine cone-beam computed tomographies (CBCT) were selected from adult patients (48 males, 51 females, age range 18- 65 years). Patients were divided into 3 groups, with 33 patients each, according to their skeletal class (I: 1<ANB<3; II: ANB>3; III: ANB<1). The CBCT data were imported into Simplant O&O software as Dicom files. Borders for the oropharynx and for the hypopharynx of which the volumes were calculated, and the total length (L) were defined. Finally, the average cross-sectional area (a-CSA) was defined as the ratio between total volume and total length for each patient. All data were statistically analyzed using GraphPad Software. A significant difference was found between groups for oropharynx, hypopharynx, and total volume, with Class II having smaller airway dimensions. In a gender-based comparison, there was a statistically significant difference between female and male patients of the same group, and between the same gender in different groups. Regarding the total length and the a-CSA, there was a statistically significant difference between the groups. These results indicate that class II and female patients have smaller dimensions of upper airway leading to a possible risk indicator for OSAS development.