Abstract
Three cases of mandibular implant overdentures (IODs) were measured for retention by a developed model. A nylon thread was tied through a hole at the midline of the IOD and seated it in the patient's mouth properly. Briefly, a facebow was set on the patient, with its arms firmly held by an assistant. The other end of the thread was tied into a loop, and the thread was inserted through a hole at the Camper's line of the facebow and hooked onto a portable force gauge. The thread was then pulled in parallel with the arms of the facebow by the force gauge until the prosthesis dislodged while the patient opened his mouth. Denture retention was measured five times, and the mean was calculated. Appropriate analysis for validity and reliability of the model was performed, and statistical results showed that it was valid and reliable for measuring the retention of removable mandibular prostheses.