title: Comparative analysis of upper airway volume with lateral cephalograms and cone-beam computed tomography.
abstract: BACKGROUND
  In this study, we aimed to evaluate the adenoidal nasopharyngeal ratio (ANR) on lateral cephalograms by assessing upper airway volumes using cone-beam computed tomography (CBCT) images as the validation method.
  
  
  METHODS
  Fifty-five patients were included in the study, and it was essential that the lateral cephalograms and CBCT images taken at their examinations were not more than 1 week apart. There were 32 subjects in group A (age ≤15 years) and 23 subjects in group B (age >15 years). The ANR was measured on the lateral cephalograms. The area and volumetric measurements of the nasopharynx and the total upper airway were obtained from CBCT images. Repeated measurements of the ANR and airway volume were performed on 10 subjects by 2 observers.
  
  
  RESULTS
  Group A had a higher correlation (r = -0.78) between the ANR and the nasopharynx volume than did group B (r = -0.57). The ANR had a weak correlation with the total upper airway volume (group A, r = -0.48; group B, r = -0.32). Both measurements made on lateral cephalograms and CBCT were highly reproducible in terms of intraobserver and interobserver agreement.
  
  
  CONCLUSIONS
  Based on our results, the measurement of the ANR on lateral cephalograms can be used as an initial screening method to estimate the nasopharynx volumes of younger patients (age ≤15 years).
authors: Radiologist, Department of Oral and Maxillofacial Radiology, Stomatological Hospital, Dalian, China; guest researcher, Oral Maxillofacial Diagnostics and Surgery, Karolinska Institutet, Huddinge, Sweden.
authors: Xin
authors: X
authors: Feng
authors: Professor, Department of Oral and Maxillofacial Radiology, School and Hospital of Stomatology, Peking University, Beijing, China.
authors: Gang
authors: G
authors: Li
authors: Associate professor, Department of Oral and Maxillofacial Radiology, Stomatological Hospital, Dalian, China.
authors: Zhenyu
authors: Z
authors: Qu
authors: Professor, Department of Orthodontics, Stomatological Hospital, Dalian, China.
authors: Lin
authors: L
authors: Liu
authors: Chair, Oral Maxillofacial Diagnostics and Surgery, Karolinska Institutet, Huddinge, Sweden.
authors: Karin
authors: K
authors: Näsström
authors: Associate professor, Oral Maxillofacial Diagnostics and Surgery, Karolinska Institutet, Huddinge, Sweden. Electronic address: Xie.Qi.Shi@ki.se.
authors: Xie-Qi
authors: XQ
authors: Shi
mesh_terms: D000234:Adenoids / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002508:Cephalometry / Q000706:statistics & numerical data*; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D008297:Male; D009305:Nasopharynx / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D015588:Observer Variation; D009929:Organ Size; D010614:Pharynx / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019252:Radiography, Dental, Digital / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult