Developing Three-Dimensional Upper Airway Normative Values Using Fixed and Interactive Thresholds

Hypothesis: There is no difference in the airway volume and minimum cross sectional area (MCSA) measured using fixed threshold compared to interactive threshold in pediatric patients between the ages of 7 and 17. Objective: To develop 3D upper airway normative volumetric and MCSA values using both techniques in pediatric patients. Methods: 81 CBCT scans of Caucasian pediatric patients who sought orthodontic treatment were obtained. Scans were divided into two age groups (7-11 and 12-17 years) to reflect different stages of pubertal growth. We utilized two popular and reliable 3D airway analysis software programs, one that employs an interactive threshold technique (Dolphin 3D) and the other employs a fixed threshold technique (Invivo5). Results: Comparing Dolphin 3D and Invivo5, there were significant mean differences between all volumetric, area and linear measurements (p < 0.01), except for airway length and sagittal dimension of MCSA. A positive significant moderate correlation was found between age and total airway volume and length (r > 0.5, p < 0.001). Conclusions: Upper airway volumetric, area and linear measurements for pediatric non-obstructive sleep apnea subjects were reported as an attempt to establish normative values. Threshold dependent measurements (volumes and areas) were consistently larger in Dolphin 3D, while the total airway length, which is non-threshold dependent, was similar in both programs. We also found age-related significant associations with airway volume and length, but not with MCSA. IRB#: 2016-0754