Reliability of upper pharyngeal airway assessment using dental CBCT: a systematic review

Background: Upper airway analysis is an often-cited use of cone beam computed tomography (CBCT) imaging in orthodontics. However, the reliability of this process in a clinical setting is largely unknown. Objective: Our objective was to systematically review the literature to evaluate the reliability of upper pharyngeal airway assessment using dental CBCT. Search methods: MEDLINE, EMBASE, Web of Science, and Google Scholar were searched through June 2015. Selection criteria: Human studies that measured reliability of upper airway assessment in patients using CBCT as part of the study protocol were considered. Data collection and analysis:Results: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) was followed. Data were collected on overall study characteristics and measurements, CBCT unit and machine settings used, and examination characteristics of the included studies. Methodological quality of the included studies was evaluated. Results: Forty-two studies were evaluated, representing the CBCT scans of 956 patients. Studies included a wide variety of patients and CBCT machines with various scan settings. Only five studies were deemed high quality. The available evidence indicates that under specific restricted conditions there is moderate to excellent intra- and inter-examiner reliability. Airway volume demonstrated greater intra- and inter-examiner reliability than did minimum cross-sectional area. However, significant methodological limitations of the current literature, most importantly a lack of manual orientation of the images and selection of threshold sensitivity in study protocols, suggest that reliability has not been adequately established. Conclusions: The current literature reports moderate to excellent reliability, with airway volume having higher reliability than minimum cross-sectional area. However, only limited aspects of the process of airway analysis have been evaluated, indicating that further research is required to adequately establish the reliability of upper pharyngeal airway assessment of patients using dental CBCT.