The Short Root Anomaly (SRA) is an often under-recognized disorder. Early recognition is important since preventive measures can reduce root resorption.


The condition is often detected during childhood.



(1) The condition is more common in females.

(2) Other family members are affected.

(3) The central incisors of the maxilla are always affected, with a reduced relative root length (R/C ratio). Other teeth (canines, promolars) may also be affected.

(4) The roots are characteristically plump in shape.

(5) The affected teeth may undergo root resorption, especially if the teeth are subjected to increased stress.

(6) With increased root resorption the teeth become loose and can be lost.


Calculation of the relative root length on an A-P X-ray:

(1) R = vertical length of the root in mm in midpoint

(2) C = vertical length of the crown in mm in midpoint

(3) m = distrance from center of the tooth to the edge at the junction of the root and crown


R/C =

= (R - m) / (C - m)

R/C Ratio

Short Root Anomaly

> 1.6


1.3 to 1.6


< 1.3



Preventive measures following early detection:

(1) Protect maxillary central incisors from strong masticatory stress.

(2) Avoid pressure fom other teeth (due to crowding, dislocation, etc).

(3) Avoid traumatic occlusion.


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