Genetic revolution in oral and dental health: The gene that shapes our smiles and dental evolution was found

An international scientific team led by King's College London has revealed that congenital missing teeth, deformities and excess tooth formation in humans are caused by rare variants in the gene called C2CD3. The research, published in the journal PNAS, also offered vital clues as to why birds lost their teeth during evolution.

Research findings showed that the C2CD3 gene is responsible for the construction of microstructures called "primary cilia" that act as antennas on cells and process developmental signals. When this gene is disrupted, the functioning of the basic signaling mechanism called Sonic hedgehog (SHH), which determines the position of the teeth in the jaw, is disrupted.

If the gene loses its function, an interesting picture emerges in mice and humans: While SHH activity increases in the upper jaw, leading to the formation of extra teeth (supernumerary teeth), activity decreases in the lower jaw, causing tooth deficiency (hypodontia). This documents that a single gene can produce opposing anatomical consequences depending on position in the jaw.

The most exciting part of the study in terms of evolutionary biology was the experiments on chicken embryos. In bird species that do not have teeth under normal conditions, tooth-like structures were found to develop in talpid2 mutant chicken embryos carrying the C2CD3 mutation.

Development and evolution expert Prof. Dr. Abigail Tucker reported that birds did not completely lose the biological mechanism of teething during the evolution process, only that the genetic switch that governed this process was turned off or suppressed over time.

Scientists emphasize that the data obtained will be a breakthrough in the treatment of patients born with dental anomalies. It is stated that by mapping cellular signaling pathways, craniofacial (skull and face) developmental disorders and complex dental anomalies can be treated at the molecular level in the future.