Tongue Blade Bite Test Predicts Mandible Fractures

The aim of the study is to evaluate the utility of a simple tongue blade bite test in predicting mandible fractures and use this test as an alternative screening tool for further workup. This is a retrospective chart review. An institutional review board approved the retrospective review of patients evaluated by the Department of Otolaryngology at a single institution for facial trauma performed from November 1, 2011, to February 27, 2014. Patients who had a bite test documented were included in the study. CT was performed in all cases and was used as the gold standard to diagnose mandible fractures. Variables analyzed included age, sex, fracture type/location on CT, bite test positivity, and operative intervention. A total of 86 patients met the inclusion criteria and of those 12 were pediatric patients. Majority of the patients were male (80.2%) and adult (86.0%; average age: 34.3 years). Fifty-seven patients had a negative bite test and on CT scans had no mandible fracture. Twenty-three patients had a positive bite test and a CT scan confirmed fracture. The bite test revealed a sensitivity of 88.5% (95% CI: 69.8-97.6%), specificity of 95.0% (95% CI:86.1-99%), positive predictive value [PPV] of 88.5% (95% CI: 69.8-97.6%), and negative predictive value [NPV] of 95.0% (95% CI: 86.1-99.0%). Among pediatric patients, the sensitivity was 100% (95% CI: 29.9-100%), specificity was 88.9% (95% CI: 68.4-100%), PPV was 75.0% (95% CI: 19.4-99.4%), and NPV was 100% (95% CI: 63.1-100%). The tongue blade bite test is a quick inexpensive diagnostic tool for the otolaryngologist with high sensitivity and specificity for predicting mandible fractures. In the pediatric population, where avoidance of unnecessary CT scans is of highest priority, a wider range of data collection should be undertaken to better assess its utility.