Unerupted permanent incisors : prevalence, characteristic features and associated dental anomalies

Abstract

The first study aimed to determine the prevalence, characteristic features and complications associated with the occurrence of unerupted permanent incisors among children and adolescents attending a university dental teaching hospital. A retrospective review was performed on the all the available Clinical records of children and adolescents who had attended the hospital between January 2005 and December 2015. All patients who had at least on unerupted permanent incisor tooth and matched the definition of unerupted permanent incisors were includes. A total of 266 subjects with 320 unerupted permanent incisors were identified. Permanent maxillary central incisors (70.6%) were the most commonly affected teeth. The prevalence of unerupted permanent incisors in children and adolescents attending the university dental teaching hospital was 2.0%. The most common causes for unerupted incisors were dilacerations (n=83, 36.7%) for maxillary central incisors; developmental dental anomalies (n=22; 30.6%) together with unfavourable root development (n=22, 30.6%) for maxillary laterals incisors; and abnormal tooth/tissue ratio (n=11, 50.0%) for mandibular incisors. The majority of the unerupted incisors presented with complications, for which the most common complications associated with unerupted incisors are ectopic/displacement/rotation of the unerupted incisors (46.6%), loss of space (36.9%) and midline shift (27.5%). The second study investigated the association between unerupted permanent incisors and dental anomalies among children and adolescents attending the university dental teaching hospital. The retrospective audit on the presence or absence of any dental anomalies was done from all the available clinical records on the same group of subjects in the first study. A total of 222 out of 320 unerupted permanent incisors (69.4%) were identified from the 15, 987 subjects in the study. Significantly higher proportion of unerupted permanent incisors was associated with the presence of dental anomalies that without (p<0.001). Significantly higher proportion of male patients had unerupted permanent incisors associated with dental anomalies, particularly hyperdontia, ectopic eruption of permanent canine and double tooth when compared to female patients. For the unerupted maxillary central incisors, a significantly higher proportion was associated with the supernumerary teeth (p<0.001); whereas for unerupted maxillary lateral incisors, a significantly greater proportion was associated with ectopic eruption of permanent canines when compared with other groups of dental anomalies (p<0.001). There was no significant difference in the proportion of occurrence of dental anomalies for the unerupted mandibular central and lateral incisors. Increasing the number of unerupted permanent incisors increased the total numbers of dental anomalies (p=0.007; Correlation Coefficient=0.151).