Smiling is one of the best ways that humans (and some animals) convey their emotions; one of the major organs that show when we do this are our teeth! This being the case it is important to many people how their teeth look, but it is also very important that our teeth are healthy and able to perform their basic function. No one's teeth are the same and the variations have clinical importance (Brook et al., 2014). Different variations in tooth size, number, and shape are determined during dental devlopment and are affected by genes and by the environment (Brook et al., 2014). The tissues that have the biggest role in this process are the enamel knots (Brook et al., 2014). These tissues signal to the nearby cells (including the tooth germ) to proliferate and fold (Brook et al., 2014). This process creates the shape and size of the teeth (Brook et al., 2014). These enamel knots are influenced by genetics and the evnrionement and that is what can lead to many variations of dental morphology (Brook et al., 2014).
Early detection and treatment can lead to less issues and less need for other treatments in the future (Brook et al., 2014). This is why it is important to check and diagnose people's teeth early in order to start treatment planning early for issues such as supernumerary teeth and hypodontia (Brook et al., 2014).
Supernumerary teeth are diagnosed based on how big a tooth is compared to the rest of its counterparts (Brook et al., 2014). Examples of both of these teeth types can be seen below in Figure 1 (Brook et al., 2014). These teeth can be many different shapes and most remain unerupted in the gumline (Brook et al., 2014). Hypodontia is having congenitally missing teeth as well as smaller than "normal" tooth size all around (Brook et al., 2014). Interestingly the greater the number of teeth missing the smaller the average tooth size (Brook et al., 2014). Understanding the physiology behind these variations in teeth morphology will allow dentists and researchers to have and create better ways to discover these variations early and new treatment options.
Brook, A. H., Jernvall, J., Smith, R. N., Hughes, T. E., & Townsend, G. C. (2014). The dentition: the outcomes of morphogenesis leading to variations of tooth number, size and shape. Australian dental journal, 59 Suppl 1, 131–142. https://doi-org.dml.regis.edu/10.1111/adj.12160
This is a super interesting topic! It's quite unique how everyone has different variations in their teeth which can be useful such as in forensic anthropology and identifying remains just from looking at dental records. Supernumerary teeth in particular are interesting as it is also known as hyperdontia, or having more teeth than normal. They are generally linked to various congenital genetic disorders and can vary in morphology based on their location and size as you mentioned. It would be interesting to look into what exactly occurs as a result of supernumerary teeth. From a study by Subasioglu et. al. in 2015, hyperdontia can lead to various issues such as crowding, root resorption, malocclusion, nasal cavity eruption, and much more. It's interesting to see the scale of how an extra tooth can have no effect to severe effects on our oral health.
ReplyDeleteSubasioglu A, Savas S, Kucukyilmaz E, Kesim S, Yagci A, Dundar M. Genetic background of supernumerary teeth. Eur J Dent. 2015 Jan-Mar;9(1):153-158. doi: 10.4103/1305-7456.149670. PMID: 25713500; PMCID: PMC4319293.