Information on the deviation of the roots and trends that deviate from them

Maxillary central incisors curve either towards the labial or palatal aspect at about the apical third level.
Maxillary lateral incisor the apical third tends to curve distally and the canal is often very fine with thin walls.
Maxillary canine
The length of this tooth can be difficult to determine on radiographs as the apex tends to curve labially and the tooth will appear to be shorter than it actually is.
Maxillary first premolar
The roots of these teeth are very delicate and at the apical third they may curve quite sharply buccally palatally, mesially or distally, so instrumentation needs to be carried out with great care
Maxillary second premolar As with the first maxillary premolar the apical third of the root may curve quite considerably, mainly to the distal sometimes buccally
Maxillary first molar
The palatal root has a tendency to curve towards the buccal and the apparent length on a radiograph will be shorter than its actual length
Mandibular second premolar unless the radiograph reveals a sharp distal curve at the apex as shown in the extracted tooth.