Conclusion
A reliable method of estimating
the nasopharyngeal depth will lend confidence and clarity to healthcare
providers of important nasopharyngeal diagnostic tests and will guide
other applications relying on accurate blind estimations of this
distance, including nasogastric tube placement and NP temperature probe
placement. This study has demonstrated a
near 1:1 ratio of nasopharyngeal
depth to the tragus-to-philtrum coronal plane distance and has
confirmed its persistence between
sex and ethnicity in subgroup analysis. As such, individually optimized
nasopharyngeal depth seems to be a supportive tool for safe NP
procedures and can be clinically predicted by simply measuring the
distance from the tragus to a plane perpendicular to the philtrum on a
lateral view.