Correspondence Between Subjective and Linear Measurements of the Palatal Airway on Lateral Cephalometric Radiographs

Objective: To evaluate the correlation between and significance of 2 methods of palatal airway assessment on lateral cephalographs. Design: Diagnostic lateral cephalometric imaging study that took place from January 1, 2006, to December 31, 2007. Setting: American University of Beirut Medical Center. Patients: Children with chronic mouth breathing referred by a pediatric otolaryngologist. for cephalometric evaluation by participating orthodontists. Main Outcome Measures: Two distances were measured on the digitized lateral cephalographs between the adenoid and soft palate: the shortest adenoid distance (SAD) and the most convex adenoid distance (CAD). The palatal airway was assessed on a grade-1 to grade-3 scale independently by the referring otolaryngologist and an orthodontist. Results: A total of 200 children were included in the study (127 boys and 73 girls; mean age, 6 years; age range, 1.71-12.62 years). High correlations were observed between the airway ratings gathered by both examiners (r=0.96) and between SAD and CAD (r=0.92). Significant correlations were noted between the palatal airway grade and the SAD and CAD measurements (r=-0.73 and r=-0.79, respectively). Shortest adenoid distance measures of 2 mm or less corresponded mostly to grade 3 obstruction and were more prevalent in patients younger than 6 years. Age was inversely proportional to both the grade and SAD (P<.001). Conclusions: Both methods are reliable for assessment of airway obstruction by the adenoid. Because SAD and CAD are highly correlated, we recommend the use of SAD as a more readily identifiable distance on cephalometric radiographs. Removal of adenoids when SAD is less than 2 mm may be indicated because this condition reflects a severe airway obstruction associated with potential changes in dentofacial structure.