Objective To establish an experimental model which was the masticatory myocyte culture and force stimula- tionin vitroand study the proliferation changes of cultured masticatory myocytes caused by mechanical compression in young rat. Methods Flow cytometry (FCM) was used to examine the changes of cellular DNA content and cell cycles of cultured masticatory myocytes.Results The DNA content in experimental groupswas higherthan that in control. Afterthe compressive forcewas ap- plied for 2 hours, the proliferation index (PI) in experimental group became higher than that in control. Under a continuous pres- sure for 4 hours, the PI in 2 000μstrain group reached the maximum (48·9%) butthe PI in 4 000μstrain group reached the min- imum (39·0%).Conclusion The proliferation of masticatory myocytes from young rat increased under certain force and certain period of time, but decreased if the force applied was overloaded.
