The prevalence of MIH in the permanent dentition of Hong Kong Chinese children was 2.8%. Children with MIH showed higher caries experience in the permanent dentition than the general population of similar age.

The present study shows that, when there is a talon cusp on a primary maxillary lateral incisor, a high proportion of the underlying permanent successors can be expected to exhibit odontogenic abnormalities.

This paper reviews the nomenclature, prevalence, definition, etiology, association with other dental anomalies, diagnosis and treatment planning of talon cusp in the primary anterior teeth. Most of the reported cases have involved the primary maxillary central incisors. However, talon cusps on the primary maxillary lateral incisors are associated with high percentages of anomalies in the permanent successors. This paper reported three such rare cases and dentists should be aware of such additional anomalies.

Children with true talon cusps on the permanent maxillary incisors were more frequently affected by supernumerary teeth in the anterior maxilla. Further studies with a larger sample are needed to confirm a true association.

Ehlers-Danlos syndrome (EDS) comprises a group of generalised connective tissue disorders. Deficiency or alteration of the collagen present in the tissues results in some classic signs such as skin hyper extensibility, joint hypermobility, and vascular fragility. Multiple supernumerary teeth, congenitally missing teeth, and odontogenic keratocysts have been reported in some patients with EDS. To the author's knowledge, transposition of permanent canines has not previously been reported in any case of EDS. This case report presents the dental findings of a sporadic case of classic-type EDS in a 14-year-old Chinese male who had transposition of a permanent maxillary canine as well as the presence of two supernumerary premolars in the mandible.