Intrusive luxation of primary upper incisors and sequelae on permanent successors: a clinical follow-up study

The purpose of this report is to evaluate the epidemiological aspects of intrusion that occur against upper incisors in primary dentition, to determine the statistic correlation of developmental disturbances to permanent teeth in relation to age of children at the time of trauma.

A retrospective study was performed based on radiographic and clinical data of 34 intruded incisors in 30 patients aged between 12 and 60 months. Baseline data were collected in a questionnaire designed following the guidelines of the IADT-Italy. The descriptive statistical analysis between the different variables was performed with the Chi-squared test and the level of significance was set at 5%. The following parameters were considered: gender, age of patient at the time of injury, emergency treatment, clinical signs (vitality, mobility, spontaneous pain, colour change), presence of complications, degree of spontaneous re-eruption and possible developmental disorders to the following tooth.

Intrusive luxation is not statistically related to gender. During the first 6-month follow-ups, 20 incisors belonging to 12 subjects aged between 12-24 months at the time of intrusion exhibited pulpal necrosis. The highest rate of total spontaneous re-eruption occurred in incisors intruded at 12-24 months. The likelihood of spontaneous re-eruption decreased with the child's age. A significant correlation between mobility at clinical follow-up and developmental disorders in permanent teeth was found, whereas a statistical correlation between age of patient at the time of trauma and sequelae was not pointed out, even if 17 primary incisors intruded at 12-24 months did not develop an arrest of root formation.

The most traumatic intrusions in primary dentition occurs between 12 and 24 months of age, the most common cause being fall while walking. Intruded incisors with moderate mobility developed enamel hypoplasia and ectopic eruption. There was no significant correlation between age at the time of intrusion and type of subsequent developmental disturbances.