Eruption of impacted permanent upper incisors after removal of of supernumerary teeth.

In a retrospective study of 63 patients, an attempt is made to determine in how many cases retained permanent upper incisors erupt after the removal of supernumerary teeth, and what predisposing and etiological factors are of importance. It proved that the eruption of a supernumerary tooth positively contributed to the chance of a spontaneous eruption of the permanent incisors. No relationship could be demonstrated between the age of a patient from whom supernumeraries were extracted, the number of supernumeraries, the extent of root formation, marked apical displacement and the chance of spontaneous eruption of the permanent incisors. It also proved that only in 1 out of 2 children did spontaneous eruption occur after removal of the supernumeraries. It therefore seems advisable to provide all impacted upper incisors with a cervical ligature of bracket with twined wire sling during the first operation in order to create the possibility for orthodontic traction if spontaneous eruption of the incisor does not occur, and thus to prevent a second operation for the child.