Third Molar Agenesis Is Associated with Facial Size
Department of Orthodontics and Dentofacial Orthopedics, University of Bern, CH-3010 Bern, Switzerland
Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, GR-11527 Athens, Greece
Department of Pediatric Oral Health and Orthodontics, UZB—University School of Dental Medicine, University of Basel, CH-4058 Basel, Switzerland
Department of Orthodontics, Tufts University School of Dental Medicine, Boston, MA 02111, USA
Authors to whom correspondence should be addressed.
These authors contributed equally to this study.
Academic Editor: De-Li Shi
Received: 14 June 2021
Revised: 8 July 2021
Accepted: 9 July 2021
Published: 12 July 2021
Missing third molars is a common occurrence in modern humans with a prevalence of approximately 20% in the general population. The absence of those teeth, however, is not found in other human predecessors. Therefore, there is speculation whether the congenital absence of third molars is part of an evolutionary mechanism that leads to smaller jaws, smaller and fewer teeth, or if their absence is associated with more local developmental factors. In this study, we assessed the size of the cranial base, the maxilla, the mandible and the entire craniofacial complex in individuals missing one or more third molars and compared them with a group with no missing teeth. We showed that in cases with one or more missing third molars, there is a significant decrease in the size of the maxilla, the mandible as well as the entire facial configuration. Additionally, the more missing third molars, the smaller the jaws and the face were. These findings suggest that isolated third molar agenesis is part of a developmental mechanism related to craniofacial size reduction. Whether this mechanism is part of an evolutionary process in humans remains to be seen.