Final answer:
The abnormal number of teeth can be caused by genetic conditions, trauma, infections, tumors, or dental diseases. Genetics may result in hyperdontia, whereas physical obstructions or developmental disruptions could lead to hypodontia. Oral infections impacting dental health can also interfere with tooth count.
Step-by-step explanation:
An abnormal number of teeth, also known as hyperdontia or hypodontia, can be caused by various factors. During our lifetimes, we have two sets of teeth: the deciduous teeth (baby teeth) and permanent teeth. Normally, the 20 deciduous teeth are replaced by 32 permanent teeth in a process that typically occurs between age 6 and 12. However, certain conditions and genetic factors can lead to deviations from this normal count.
Genetic conditions such as Gardner's syndrome or cleidocranial dysplasia can cause a higher number of teeth, while downgrading factors like trauma, infections, or tumors can affect the growth and number of teeth either by physically obstructing the eruption or by altering the developmental pathways of tooth formation. Oral infections, caused bythe overgrowth of oral bacteria such as Streptococcus and Actinomyces species, can also interfere with normal tooth development if they lead to significant dental diseases such as dental caries, tartar, or gingivitis.