Inherited dental anomalies and abnormalities.

A considerable body of evidence exists to suggest that genes play a dominant role in the etiology of the dental anomalies reviewed. It has been postulated that some kind of genetically controlled interrelationship may exist for some of these coincidental dental anomalies, as evidenced by their frequency of association. It has also been speculated that a "common genetic defect" may give rise to different phenotypic manifestations, including missing, malformed, and even ectopic and malpositioned teeth. The maxillary teeth that develop in the critical marginal areas of the dental lamina, namely the lateral incisors, canines and second premolars, seem most susceptible. Such dental anomalies may be symptoms of an inheritable developmental disturbance of tooth structures. Knowing that these dental anomalies can be inherited, a familial history and early clinical or radiographic detection of one anomaly, could alert parents and clinicians to the high likelihood of detection of other defects in the same individual and similar defects in other family members. Early diagnosis is important so that interceptive pediatric and orthodontic opportunities in relation to missing, malformed and ectopically erupting teeth are not overlooked. Further family studies are necessary to reveal the mode of inheritance of some of these dental anomalies and twin studies comparing monozygous and dizygous twins would enable an estimation of the extent of their inheritance.