indicated in order to minimize further damage to the permanent successor.
Intrusive luxation
This is the most common type of injury. The aim of investigation is to establish the
direction of displacement by thorough radiological examination. If the root is
displaced palatally towards the permanent successor then the primary tooth should be
extracted to minimize the possible damage to the developing permanent successor. If
the root is displaced buccally then periodic review to monitor spontaneous re-eruption
should be allowed (673HFig. 12.8 (a) and (b)). Review should be weekly for a month then
monthly for a maximum of 6 months. Most re-eruption occurs between 1 and 6
months and if this does not occur then ankylosis is likely and extraction is necessary
to prevent ectopic eruption of the permanent successor (674HFig. 12.9).
Exarticulation (Avulsion)
Replantation of avulsed primary incisors is not recommended due to the risk of
damage to the permanent tooth germs. Space maintenance is not necessary following
the loss of a primary incisor as only minor drifting of adjacent teeth occurs. The
eruption of the permanent successor may be delayed for about 1 year as a result of
abnormal thickening of connective tissue overlying the tooth germ.
675H
Fig. 12.8 (a) A 4-year-old boy with
complete intrusion of the upper right
incisor. (b) 6 months post-trauma, the
tooth has spontaneously re-erupted.676H
Fig. 12.9 Severe intrusion of an upper
primary central incisor necessitating
extraction.