|1. (b) Radiograph taken with the tube positioned further distally shows that the
image of |3 is further distally. The image of |3 has shifted in the same direction as the
tube shift:|3 is therefore nearer to the film than |1, i.e. it is palatal to the line of the
arch. (c) Diagrammatic representation of how a palatally positioned tooth moves
'with' the tube from left to right.
950H
Fig. 14.19 (a) and (b) This combination of views allows the use of vertical and
horizontal parallax to assess ectopic canines.