A scan model that is a mathematical model to simulate an imaging process performed by an x-ray imaging device that created a two-dimensional x-ray image of at least one tooth is generated. The scan model uses an initial estimate of one or more parameters of the x-ray imaging device. The one or more parameters include a scan angle parameter indicative of a scan angle of the x-ray imaging device. A two-dimensional contour of a three-dimensional model is adjusted to cause a first component of the two-dimensional contour to approximately align with a second component of the two-dimensional x-ray image. The scan model is calibrated based on data obtained from adjusting the two-dimensional contour.