UG Model Analysis Measurement of Proclination

Measurement of proclination by direct method

The model to be analyzed is kept on the table. A set square is used so that the edge of the set square is perpendicular to the floor and touches the labial surface of the most proclined teeth. The proclination is measured from the deepest point in the sulcus to the edge of the set square. (Fig 12)

FIG 12 : Measurement of proclination of incisors

In the upper arch, the anteriors are ideally slightly proclined, so, whatever is the proclination value, 2mm (normal proclination of upper incisor) is subtracted and the remaining value is the proclination to be corrected. Retroclined anteriors are measured as negative proclination (Fig 13)

FIG 13 : Negative proclination measurement in case of retroclined incisors

In contrast with the upper, the lower teeth are supposed to be upright on the basal bone therefore there is no subtraction in the lower arch.

We have to remember that the proclination value that we get is the value on one side of the arch. So, to get the total proclined value, we have to multiply by 2 if the proclination is equal on both sides. In some cases the two central incisors have different proclination values, in such cases we have to take the mean of the values. (Fig 14)

FIG 14 : Measurement of proclination of differently inclined incisors

There, will also be some cases where only one central incisor is proclined and other teeth are normally inclined where we have to calculate it as crowding.