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Third molar agenesis relates to human craniofacial form.
Georgios Kanavakis1,2, Ragda Alamoudi3, Elias S Oeschger3
1Department of Orthodontics and Pediatric Dentistry, UZB-University School of Dental Medicine, University of Basel, CH-4056 Basel, Switzerland.
European Journal of Orthodontics
|October 23, 2023
Summary
Missing third molars are strongly linked to altered craniofacial shape, affecting the maxilla and mandible. This association suggests a generalized effect potentially tied to human evolutionary trends.
Area of Science:
- Orthodontics
- Anthropology
- Genetics
Background:
- Third molars (wisdom teeth) play a role in craniofacial development.
- Variations in third molar presence may influence overall facial structure.
- Understanding these relationships is crucial for orthodontic diagnosis and treatment planning.
Purpose of the Study:
- To investigate the association between the presence/absence of third molars and craniofacial morphology.
- To determine if third molar agenesis impacts cranial base, maxilla, and mandible shape.
Main Methods:
- Utilized cephalometric images from 470 individuals (194 males, 276 females).
- Analyzed 127 landmarks to define craniofacial, cranial base, maxillary, and mandibular shapes.
- Employed multivariate regression to assess the effect of third molar agenesis on shape principal components, controlling for age and sex.
Main Results:
- A significant association was found between third molar agenesis and craniofacial shape in both sexes.
- Individuals with missing third molars exhibited less facial convexity, shorter anterior facial height, and more retrusive maxilla and mandible.
- Shape alterations were observed even in the opposing jaw when third molar agenesis was unilateral.
Conclusions:
- Third molar formation is strongly associated with generalized craniofacial shape.
- This effect may reflect an evolutionary trend towards smaller teeth and craniofacial structures in modern humans.
- Future research should consider the limitations of 2D data and the specific population studied (White-European subjects).
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