Objective To investigate the tongue movement during swallowing in skeletal Class Ⅲ adult patients using M-mode altrasonography combined with cushion scanning technique.Methods Tongue movement during swallowing in 20 skeletal Class Ⅲ adult patients(11 females,9 males,mean age 20.5 years)and 11 healthy adults(8 females,3 males,mean age 23.5 years)was examined with M-mode ultrasonography combined with cushion scanning technique.The results were compared.Results Compared with mature swallowers,the skeletal Class Ⅲ aduh patients had longer phase 2[(0.24±0.07)s],phase 3[(1.17±0.21)s],longer total duration[(1.98±0.24)s],faster speed in phase 1 [(3.20±1.30)mm/s],and smaller range in phase 5[(0.38±0.28)mm].Condusions The skeletal Class Ⅲ aduh patients had distinctly difierent tongue movements during swallowing.