Genetic condition characterized by abnormal
development of teeth (enamel hypoplasia), bones (hypocalcification), and
Autosomal dominant. It is linked to a mutation
on gene locus 17q21.3-q22, which results in altered function of a protein
that has an important role in the development of hair (keratin), teeth
(enamel), and bone (so-called DLX3 protein).
Abnormalities of keratin, enamel, and dentin are
described; however, the pathogenesis of the TDO syndrome is unknown at
Presence of “kinky curly hair,” enamel hypoplasia,
taurodontism (a variation in tooth form characterized by prism-shaped molars with large
pulp spaces), and thick cortical bone.
Three subtypes or phenotypes for TDO have been
TDO-I demonstrates a normal calvarium with thickening of the chondrocranium,
curly hair, delayed dental eruption with enamel hypoplasia and increased
cavities, osteosclerosis, and only occasionally brittle nails. Premature
sagittal craniosynostosis results in dolichocephaly. Calvarial thickness and
density are normal; however, the chondrocranium may show some thickening.
TDO-II demonstrates more pronounced nail dystrophy (either with laminated
splitting of the superficial layers or thick cornification), sparse, curly
hair, and thickening and sclerosis of the calvaria. Males may show narrowing
of the ear canal. In contrast to TDO-I, not only is dental eruption
precocious, but also, in addition to the enamel hypoplasia, the dentin is
TDO-III demonstrates increased calvarial density and macrocephaly. Patients
have an increased incidence of dental caries and abscess formation. Sagittal
synostosis may result in dolichocephaly. Nails may be brittle or demonstrate
increased cornification. There is no facial phenotype associated with the
syndrome, although an increase in the length of the body of the mandible has
Assess airway for abnormal anatomy
or trismus related to abscess formation. Inspect dentition for teeth at risk
during airway manipulation.
There are no specific considerations
other than those relating to poor dentition and potential for difficult
airway management in the presence of dental abscesses and trismus. As for other
ectodermal dysplasias associated with dental anomalies, laryngoscopy must be
performed very carefully to avoid any damages to the teeth.
There are no known specific
implications with this condition.
Amelogenesis Imperfecta: An inherited condition
that affects the enamel of the teeth making them soft and thin. The teeth
appear yellow because the dentin is visible through the thin enamel and are
Hypomaturation-Hypoplasia type with Taurodontism Syndrome:
The dental findings are apparently identical to those of tricho-dento-osseus
syndrome from which it differs only by the lack of changes in the hair and
bones. True taurodontism is defined by a change in the mandibular first
Hart TC, Bowden DW, Bolyard J: Genetic linkage of the
tricho-dento-osseous syndrome to chromosome 17q21. Hum Mol Genet
Wright JT, Kula K, Hall K, et al: Analysis of the ...