Accuracy of lateral cephalogram for diagnosis of adenoid hypertrophy and posterior upper airway obstruction: A meta-analysis

Abstract

Introduction: Accurate diagnosis of adenoid hypertrophy and posterior upper airway obstruction using a lateral cephalogram is challenging. No universal guidelines for assessing adenoidal enlargement and upper airway obstruction have been established. We performed a meta-analysis to assess the diagnostic accuracy of a lateral cephalogram for adenoid hypertrophy.

Methods: After searching a wide range of electronic databases and screening titles and abstracts, we evaluated full papers describing potentially eligible studies according to predefined inclusion criteria. Quality assessment was conducted by adapting the Quality Assessment of Diagnostic Accuracy Studies-2 checklist, and a 2 × 2 contingency table was constructed based on these results. Two authors independently judged the studies and extracted the data. The diagnostic accuracy of a lateral cephalogram for adenoid hypertrophy and posterior upper airway obstruction was calculated using a bivariate meta-analysis model. The Q-test and I² index were used to test the heterogeneity.

Results: Nine studies were included in the meta-analysis. The pooled sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio were 0.86 [95% confidence interval (CI): 0.76-0.92], 0.59 (95% CI: 0.42-0.73), 9.00 (95% CI: 5-17), 2.1 (95% CI: 1.5-3.0), and 0.24 (95% CI: 0.15-0.37), respectively. The area under the summary receiver operator characteristic curve was 0.83 (95% CI: 0.80-0.86). Meta-regression analysis revealed that the sample size and study design significantly contributed to the heterogeneity of sensitivity.

Conclusions: Our findings suggest that the lateral cephalogram exhibits very good diagnostic accuracy (area under the curve: 0.86) for the diagnosis of adenoid hypertrophy and posterior upper airway obstruction. Nevertheless, the rate of false-positive diagnoses should be further considered.

Keywords: Adenoids; Cephalogram; Meta-analysis; Nasopharynx; Radiography.