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Published on: November 5, 2021
Genetic basis of tooth agenesis
1Institute of Dentistry, Biomedicum, University of Helsinki, Helsinki, Finland. pekka.nieminen@helsinki.fi
Summary
Tooth agenesis, a common developmental anomaly, often affects the last developing teeth. Genetic studies have identified mutations in rare cases, suggesting complex genetic mechanisms for common forms like third molar agenesis.
Area of Science:
- Developmental Biology
- Human Genetics
- Dental Science
Background:
- Tooth agenesis (hypodontia) is a frequent human developmental anomaly.
- It commonly affects third molars, incisors, and premolars, typically those developing latest.
- This pattern suggests quantitative defects in dental development.
Purpose of the Study:
- To explore the genetic basis of tooth agenesis.
- To understand the molecular mechanisms underlying both rare and common forms of hypodontia.
Main Methods:
- Review of molecular genetics studies on tooth agenesis.
- Analysis of identified gene mutations (e.g., MSX1, PAX9, AXIN2, EDA) in familial severe agenesis and syndromes.
- Examination of gene dose effects and signaling pathway disruptions.
Main Results:
- Mutations in MSX1, PAX9, AXIN2, and EDA are linked to rare, severe tooth agenesis (oligodontia).
- Gene mutations can cause reduced gene dosage or inactivation of signaling pathways.
- Phenotypes suggest both overall reduced odontogenic potential and tooth class-specific mechanisms.
Conclusions:
- While rare forms have identified genetic causes, common hypodontia requires further investigation.
- Novel genes are likely involved in common forms like third molar agenesis and hypodontia of incisors/premolars.
- Understanding these genetic factors is crucial for addressing dental developmental anomalies.
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