OBJECTIVES: To evaluate the presence, severity and progression of temporomandibular disorders (TMD) in acquired brain injury (ABI) population and determine the diagnostic accuracy of 3Q/TMD and Fonseca Anamnestic Index (FAI) against the gold standard, Diagnostic Criteria for TMD (DC/TMD). METHODS: ABI individuals were assessed using 3Q/TMD and FAI at admission (n = 73) and Week 4 (n = 52), while DC/TMD was conducted only at Week 4. Diagnostic accuracy, sensitivity and specificity of 3Q/TMD and FAI were calculated against DC/TMD. RESULTS: TMD was detected in 66.0% (3Q/TMD) and 27.8% (FAI) at admission, with mild (75%) to moderate (25%) severity which was mostly pain-related. TMD frequency decreased to 11.3% (3Q/TMD) and 17.3% (FAI) by Week 4. Accuracy rates were 0.82 for 3Q/TMD and 0.83 for FAI. Sensitivity was 0.33 (3Q/TMD) and 0.50 (FAI), while specificity was high at 0.93 (3Q/TMD) and 0.90 (FAI). CONCLUSIONS: TMD presence was higher in an ABI population compared to the general population however the frequency decreased over time. The high specificity and accuracy of 3Q/TMD and FAI indicate their potentials as screening tools but their low sensitivity limits their effectiveness in identifying all TMD cases. Patients with ABI should be assessed for TMD as part of their comprehensive care.