Cheek retractor 4.5 inch, Net Weight of Instrument 1.32 oz.: Access to the working area is among the first steps of dental procedures ranging from surgical implant placement to cosmetic teeth whitening, and the use of a cheek retraction system is a great way to help the patient keep his or her mouth open while you're working. Dental cheek retractors lock in place to hold the patient's mouth open throughout the time you are working.