A retrospective evaluation of the eruption of impacted permanent incisors after extraction of supernumerary teeth
Leila Leyland /Puneet Batra / F Wong / R Llewelyn

Aims. Delayed eruption of teeth may be caused by the presence of one or more supernumerary teeth. The purpose of this study was to evaluate findings, predisposing factors and differentiate different techniques used that affect the outcome following removal of supernumerary teeth. A comprehensive literature review was also undertaken.
Methods. A longitudinal retrospective study was carried out at the Royal Liverpool Children’s Hospital. A total of 120 patients were identified from the general anesthesia records that had supernumeraries extracted. Only 43 cases had delayed eruption of teeth caused by supernumeraries. The pre and post extraction record data collected were the gender, radiographic assessment, position of the supernumerary, age at time of referral and extraction of the supernumerary, age at time of eruption of theimpacted tooth and the orthodontic and surgical management.
Results. The mean age of referral was 9.1 years with a male to female ratio of 4.4:1. There was a greater predilection for supernumeraries to be on the left side and be positioned palatally. Tuberculate type supernumeraries were the most frequent followed by the conical type. Spontaneous eruption of the impacted tooth occurred in 49% of cases. Eruption of the impacted tooth within eighteen months following removal of the supernumerary was observed in 91% of cases. The chronological age and space availability were the two factors that were critical in determining if eruption was spontaneous following removal of the supernumerary.
Conclusions. The findings of this study reiterates the fact that given early referral, sufficient space and time, the majority of teeth prevented from erupting by a supernumerary tooth would erupt spontaneously following removal of the supernumerary alone. Randomized multi-centre prospective studies are suggested.