Modified adenoid grading system for evaluating adenoid size in children: a prospective validation study.

Nasal endoscopy is the best choice for evaluation of adenoid size, but very few studies published on the endoscopic quantitative assessment. This study aimed to newly propose and validate a modified adenoid grading system (MAGS) with the existing endoscopic scoring methods of adenoid size. A prospective study on children with chronic mouth breathing and having endoscopic nasal examination was conducted. Digital images obtained during endoscopic examination were evaluated with the traditional method and the MGAS. Adenoid size was also evaluated by intraoperative nasal endoscopy among those underwent adenoidectomy. One hundred and thirty patients were enrolled. The MAGS showed high inter-rater reliability with a Kappa score of 0.869. Sixty of 130 patients underwent adenoidectomy and assessed with intraoperative nasal endoscopy. The MAGS significantly correlated to the percentage of nasopharyngeal obstruction of intraoperative endoscopy (Spearman's r = 0.796, gamma coefficient = 0.94), and the percentage of choanal obstruction of preoperative endoscopy (Spearman's r = 0.816, gamma coefficient = 0.859). Our findings suggest that the MAGS has high reliability and validity for assessment of adenoid size. It may be a more suitable and reliable grading system for endoscopic evaluation of adenoid size.