Patients often present to the Emergency Department for mandibular blunt trauma. Usually these patients have soft tissue swelling at the point of impact. In mandibular body fractures, the fracture line often extends to the alevolar ridge. This may cause a gap between a pair of lower teeth (photo above).
In patients with jaw pain, mild swelling, and normal dentition, is there a way to avoid imaging these patients to rule-out a mandible fracture?
Trick of the Trade: Tongue Blade Test
A screening maneuver for mandibular fractures is the “tongue blade test.” Most patients with mandibular fractures will not be able to exert much bite force because of pain. The masseters are considered the strongest muscles in the body, and normal adults can usually easily bend and break a tongue blade, which is clenched between their teeth. Patients with mandible fractures are unable to perform this task without extreme discomfort, and difficulty performing this task should be considered at high risk for a mandible fracture.
Trick Variant
Traditionally, patients have been asked to hold the tongue depressor between their teeth and the practitioner tries to break it. Instead, let the patient try to break the tongue blad on their own, since it gives them more control and elicits less anxiety. In a prospective series of 110 patients with suspected mandible fracture, the test was found to be approximately 96% sensitive and 65% specific (1).
1. Alonso LL, Purcell TB. Accuracy of the tongue blade test in patients with suspected mandibular fracture. J Emerg Med. 1995 May-Jun;13(3):297-304.
This trick of the trade was published in ACEP News and first-authored by my innovative friend Dr. Matt Lewin. Tongue blade photos courtesy of Dr. Lewin.
