A method of three-dimensional measurement in an oral cavity includes conducting three-dimensional measurement on a measurement range in an oral cavity, detecting a measurement site in which measurement information is insufficient in a measurement result acquired in the three-dimensional measurement, notifying a start position at which re-measurement on the measurement site detected is to be started, re-measuring an area starting from the start position such that the area encompasses the measurement site, and adapting at least one characteristic site having characteristic information in a re-measurement result from the re-measuring, and at least one characteristic site having characteristic information in the measurement result from the three-dimensional measurement with respect to each other such that three-dimensional measurement information is created on the measurement range.
