Congenitally Missing Teeth
Congenitally missing teeth are teeth that are missing at birth whether inherited or caused by the environment.
Missing teeth are one of the most common developmental problems in children. Nearly 20% of the U.S. population has congenitally missing third molars (Wisdom teeth). The adult teeth are more frequently affected than the baby teeth. Absence of baby teeth occurs in 0.5% to 0.9% of the population. As a rule, when a baby tooth is missing, its permanent counterpart will also be absent.
Missing teeth can occur in an isolated fashion, or as part of a syndrome. Isolated cases of missing teeth can be familial or sporadic in nature. There are more than 49 syndromes which are associated with missing teeth.
Specific terms are used to describe the nature of missing teeth. Oligodontia is the lack of tooth development of 6 or more permanent teeth, without an associated systemic disorder. Hypodontia is the absence of 6 or less teeth, but is usually part of a more complex set of developmental problems. Most cases of missing teeth involve hypodontia.
Researchers have recently discovered a number of genes and gene products which control communication between and within the cells that are necessary for tooth formation. These gene products affect the DNA.
Mistakes (mutations) in the genes which help produce teeth can cause missing teeth. Recent studies have found that mutations in two regulatory genes cause missing teeth. These genetic mistakes may then be passed on from generation to generation as inheritance traits.