A system for intraoral scanning includes a display, a processing unit, and a scanner to generate scan data and viewfinder images of an intraoral cavity. The processing unit is to: receive the scan data and the viewfinder images; generate a 3D model of the intraoral cavity using the intraoral scan data; output the 3D model to the display; output the viewfinder images to the display; determine which portions of the intraoral cavity have been scanned; determine a current field of view of the scanner; determine, based on the current field of view and the determined portions of the intraoral cavity that have been scanned, a visual indicator that provides guidance for positioning and orienting the field of view of the scanner; and output the visual indicator to the display.