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.