[Mathematical description of the three-dimensional axis of the root canal of human teeth].

The objective of the present study was to describe root canal axes of natural human teeth mathematically. Two views (clinical and proximal) radiographs were taken from extracted human teeth. Geometry defines the 90-degree turn-around image pairs as Monge images. These Monge images of the root canals were positioned using photogrammetric methods. Each well-ordered axis pair of a given root canal was put into a common coordinate system resulting in three-dimensional polynomial function of the actual root canal. Testing differences between determined and repeatedly determined axes of ten samples by statistical analysis did not show any significant differences. Evaluation of data gained on a large number of samples may also yield a new type of classification.