In order to alleviate problems arising from the dynamic deformation of thin microelectromechanical systems (MEMS) micromirrors and to realize full circumferential scanning (FCS) that is highly desired in some clinic applications, such as gastrointestinal and intravascular investigations, three prototypes of polygonal pyramidal reflector-based MEMS microscanners have been developed and are described. The cascaded chevron-beam electrothermal actuator, comb-drive electrostatic actuator with double T-shaped spring mechanism, and comb-drive electrostatic actuator with resonating mechanism were investigated in detail as a means to drive a polygonal microreflector. The polygonal microreflector, which has multiple facets on its surface, was fabricated through a route involving KOH wet-etching processing and diamond-turning soft lithography technologies. The assembly process of the actuators and the microreflector is also presented. Near-FCS capability can be realized by all the three different MEMS devices. A peak scanning speed up to 180 Hz and a maximum optical scanning angle of 240 deg were achieved by the electrostatic-resonating MEMS microscanner.