Otodental dysplasia: a "new" ectodermal dysplasia.

Otodental dysplasia is an ectodermal dysplasia characterized by abnormal crown morphology of the teeth and sensorineural hearing loss. It was documented in six generations of a kindred of Italian extraction. Thirty-three of the 119 examined family members were affected. Twenty-six persons had characteristic dental anomalies combined with a hearing loss. Two had the dental anomalies alone, four had a hearing loss only and one of those with dental anomalies could not be tested for hearing. The teeth of the 29 with dental anomalies had large, bulbous crowns. The normal relationship between cusps and grooves was obliterated. Molars, both deciduous and permanent, were involved. Deciduous canines were large and bulbous. Absence of premolars was documented in 14 of the 29 individuals with abnormal teeth. Those premolars which were present were frequently small. Radiographs of the teeth showed denticles and taurodontia. Twenty-six of the 30 individuals with a hearing loss had concomitant dental anomalies. Of the four with isolated hearing loss, one was proven to have the syndrome. The remaining three were conjectured to be affected. The age of onset of the hearing deficit ranged from early childhood to middle age. The results of a chi-square test supported autosomal dominant inheritance. The pleiotropy in this syndrome is postualed to be due to a genetic defect in the neuroectoderm.