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Open Access Correspondence

Examination of Submental Space as an Alternative Method of Airway Assessment (Submental Sign)

Mihan J Javid

Author Affiliations

Department of Anesthesiology, Tehran University of Medical Sciences, Imam Khomeini medical center, End of Keshavarz Boulevard, Tehran, Iran

BMC Research Notes 2011, 4:221  doi:10.1186/1756-0500-4-221

Published: 29 June 2011



Difficult airway especially failed intubation has been associated with a high incidence of mortality and morbidity. Most of mortalities occur when an anaesthesiologist encounters an unanticipated difficult airway.


In 1999, a 23 yr. old, 65 kg weight and 170 cm height female patient had been scheduled for arthroscopy. Despite totally normal airway assessment (thyromental distance, mouth opening, jaw and neck movement ...) I was astonished by encountering a grade IV Cormack - Lehane laryngoscopic view. Tracheal intubation was impossible and ventilation was very difficult.

On attempt to attain a better laryngoscopic view, while manipulating submandibular region I encountered a bulky noncompliant submental space (Submental Sign). This event made me more alert regarding this finding. Thereafter I noted for this sign throughout the past years and I found it very helpful.

These findings encouraged me to write this report, and suggest a routine examination of submental space in order to keep the safety of the patient at the heart of the care we provide.


Evaluation of the submental space is suggested as an alternative predictor of difficult airway and routine examination of the submental space is of value in airway assessment.