Terminology for Absence of Teeth
The complete absence of all teeth is called anodontia, while partial absence of teeth is termed hypodontia (fewer than 50% missing) or oligodontia (more than 50% missing). 1
Specific Terminology Based on Extent
Complete Absence
- Anodontia refers to the congenital absence of all teeth, affecting both primary and permanent dentitions 1
- This is an extremely rare clinical condition, primarily associated with congenital diseases such as ectodermal dysplasia 1
- Total anodontia represents the most severe form of numerical dental anomalies 2
Partial Absence
- Hypodontia describes the developmental absence of one or more teeth, but less than 50% of the total dentition 1
- Oligodontia indicates the presence of less than 50% of teeth (meaning more than 50% are missing) 1
- The second premolar is the most commonly missing tooth in hypodontia cases, excluding third molars 3
Clinical Context for Edentulism
Acquired Tooth Loss
- When referring to areas where teeth have been lost (rather than never developed), the term edentulous is used 1
- A shortened dental arch specifically describes dentition with reduced or complete absence of molars and/or premolars 1
- Posterior edentulous areas commonly result from tooth extraction due to periodontitis, with maxillary molars being the most frequently lost tooth type 1
Important Clinical Distinctions
The key distinction is between congenital absence (anodontia/hypodontia/oligodontia) versus acquired tooth loss (edentulous). 1, 4 This differentiation is critical because:
- Congenital absence requires evaluation for underlying genetic or syndromic conditions, particularly ectodermal dysplasia 1, 5
- Acquired edentulism typically results from dental neglect, caries, or periodontal disease and concentrates heavily in older age groups (86.3% of edentulous persons are 45 years or older) 4