Accuracy of the tongue blade test in patients with suspected mandibular fracture.

The inter-observer reliability and accuracy of the tongue blade test (TBT) for the identification of patients with mandibular fracture was prospectively evaluated using radiographic diagnosis as the gold standard. A consecutive sample of 110 patients presenting to the emergency department of a teaching county hospital was studied. Patients with uninterpretable x-rays, known diagnosis of mandibular fracture, or inability to cooperate for the test were excluded. Bilateral ability to crack a wooden tongue blade held between the teeth was scored as a negative test. Fifty-three patients had mandibular fractures. In the study group, the TBT had a sensitivity of 95.7%; a specificity of 63.5%; a positive predictive value of 66.2%; a negative predictive value of 95.2%; and an accuracy of 77.3%. The TBT provided contributory evidence useful in screening patients for mandibular fracture.