The aim of the study was to investigate the thickness of the masseter muscles in stroke patients when compared to a control group (CG). Hospitalised stroke patients (18 men, 13 women; age 69.0 +/- 12.7 years) were compared to a CG (13 men, 11 women; age 68.8 +/- 10.8 years) composed to correspond to in age, gender and dental state. The thickness of the masseter muscle was recorded by means of a real-time ultrasound scanner on both sides, twice under contraction and twice in relaxed condition. In the stroke patients, the thickness of the masseter muscle of the affected side (aff) was smaller than the one of the non-affected side (non-aff) both, under contraction (aff 13.1 +/- 2.4 mm; non-aff 13.8 +/- 2.3 mm, P