Globodontia in the otodental syndrome: a rare defect of tooth morphology occurring with hearing loss in an eight-year-old

Globodontia is a gross morphologic dental anomaly characterized by ‘globe’-shaped teeth.1 The condition affects the size, shape and number of teeth with the most distinctive feature being bulbous, enlarged crowns of primary canine, primary molar and permanent molar teeth. Taurodontism, hypodontia, delayed eruption, malocclusion and dysmorphic facial characteristics have also been noted. The features of globodontia are summarized in Table 1.

Globodontia is a pathognomonic feature of otodental syndrome,2^,3 a disorder of ectodermal origin first described by Levin et al in 1975.4 Synonymous terms include otodental dysplasia, familial otodentodysplasia and globodontia-deafness syndrome. In this rare, autosomal dominant condition, globodontia occurs with hearing loss.5 Nine families with otodental syndrome have been documented in the literature, including one kindred in which ocular coloboma segregates with the disease (oculo-oto-dental syndrome).2 Single nucleotide polymorphism (SNP) genome scanning of three affected families localized otodental syndrome to chromosome 11q13.3 Haplotype analysis revealed overlapping hemizygous microdeletions and subsequently haploinsufficiency of FGF3 was implicated as the likely cause of otodental syndrome.