The invention relates to an intraoral interface structure (100) for arrangement between an ultrasound transducer (36) of an intraoral scanning device (1) and a tooth region (90) or residual tooth region to be scanned, and for transmitting ultrasound waves from the transducer (36) to the tooth region (90) or residual tooth region, the intraoral interface structure (100) comprising: a frame member (102) defining an interior space (104) therein, the frame member (102) being adapted to be placed over the tooth region (90) or residual tooth region, such that the tooth region (90) or residual tooth region is at least partially received in said interior space (104), wherein the interior space (104) is adapted to be filled with a coupling medium (164) for impedance matching, the frame member (102) comprising an acoustic window (108) and a rim (106) around the acoustic window (108) for forming a receiving portion for a section of an intraoral scanning device (1), and first and second leg portions (110, 112) extending from said rim (106) for contacting opposing sides of the tooth region (90) or residual tooth region or tissue or bone adjacent to it such that the intraoral scanning device (1) is able to be supported thereat.
