Abstract: A process for measuring the dimensions of the buccal cavity with upper and lower jaw dentition uses a scanning device that is at least partially introduced into the buccal cavity. The scanning device is an optical measurement device whose optical signals are converted into electronic signals, which electronic signals can then be evaluated by a computer. A source of optical radiation is located in a preferably extra-oral section of the device, and a projection device with a projection optical system projects optical radiation onto the surfaces and/or the translucent internal volume of the buccal cavity and the colored translucent volume of the teeth. A recording device having a recording optical system records the radiation reflected from the surfaces and/or the translucent internal volume, and an evaluation device preferably located in an extra-oral section of the device evaluates the recorded reflected radiation.