Different groups of people eat different things. Different groups of people also differ genetically. What one eats is part of their environment. So, there is a G and E (genes and environment) interaction between races/ethnies in regard to the shape of their teeth. Yes, one can have a different shape to their teeth, on average, compared to their co-ethnics if they eat different things from them as that is one thing that shapes the development of teeth.
It is very difficult to ascertain the race of an individual through their dentition, but there are certain dental characters which can lead to the identification of race. Rawlani et al (2017) show that there are differences in the dentition of Caucasians, Negroids, Mongoloids and Australoids.
One distinct difference that Monogloid teeth have is having a “shovel” or “scoop” appearance. They also have larger incisors than Caucasoids, while having shorter anatomic roots with better-developed trunks. Caucasoids had a “v” shape to their teeth, while their anterior teeth were “chisel shaped”; 37 percent of Caucasoids had a cusp on the carabelli cusp. Rawlani et al (2017) also note that one study found that 94 percent of Anglo-Saxons had four cusps compared to five for other races. Australoids had a larger arch size (but relatively smaller anterior teeth), which accommodates larger teeth. They have the biggest molars of any race; the mesiodistal diameter of the first molar is 10 percent larger than white Americans and Norweigian Lapps. Negroids had smaller teeth with more spacing, they are also less likely to have the Carabelli cusp and shovel incisors. They are more likely to have class III malocclusion (imperfect positioning of the teeth when the jaw is closed) and open bite. Blacks are more likely to have bimaxillary protrusion, though Asians do get orthodontic surgery for it (Yong-Ming et al, 2009).
Rawlani et al’s (2017) review show that there are morphologic differences in teeth between racial groups that can be used for identification.
When it comes to the emergence of teeth, American Indians (specifically Northern Plains Indians) had an earlier emergence of teeth compared to whites and blacks. American Indian children had a higher rate of dental caries, and so, since their teeth appear at an earlier age compared to whites and blacks, they had more of a chance for their teeth to be exposed to diets high in sugar and processed foods along with lack of oral hygiene (Warren et al, 2016).
Older blacks had more decayed teeth than whites in one study (Hybels et al, 2016). Furthermore, older blacks were more likely than older whites to self-report worse oral hygeine; blacks had a lower number of teeth than whites in this study—which was replicated in other studies—though differences in number of teeth may come down to differences in access to dental care along with dental visits (Huang and Park, 2016). One study even showed that there was unconscious racial bias in regard to root canal treatments: whites were more likely to get root canals (i.e., they showed a bias in decision-making favoring whites), whereas blacks were more likely to get the tooth pulled (Patel et al, 2018).
Kressin et al (2003) also show that blacks are less likely to receive root canals than whites, while Asians were more likely, which lends further credence to the claim of unconscious racial bias. So just like unconscious bias affects patients in regard to other kinds of medical treatment, the same is true for other doctors such as dentists: they have a racial bias which then affects the care they give their patients. Gilbert, Shewchuk, and Litaker (2006) also show that blacks are more likely to have tooth extractions when compared to other races, but people who went to a practice that had a higher percentage of black Americans were more likely to have a tooth extraction, regardless of the individual’s race. This says to me that, since there is unconscious bias in tooth extraction (root canals), that the more black patients a dentist sees the more it is likely that they would extract the tooth of the patient (regardless of race), since they would do that more often than not due to the number of patients they see that are black Americans.
Otuyemi and Noar (1996) showed that Nigerian children had larger mesio-distal crown diameters compared to Briton children. American blacks are more likely to have hyperdontia (extra teeth in the mouth) compared to whites, and are also more likely to have fourth molars and extra premolars (Harris and Clark, 2008). Blacks have slightly larger teeth than whites (Parciak, 2015).
Dung et al (2019) also note ethnic differences in teeth looking at four ethnic groups in Vietnam:
Our study of 4565 Vietnamese children of four ethnic groups (Kinh, Tay, Thai and Muong) showed that most dental arch indicators in males were statistically significantly higher than those in females.
In comparison to other ethnic groups, 12-year-old Vietnamese children had similar dimensions of the upper and lower intercanine and intermolar width to children in the same age group in South China. However, the average upper posterior length 1 and lower posterior length 1 were shorter than those in Africans (Kenyan) and Caucasian (American blacks aged 12). The 12-year-old Vietnamese have a narrower and shorter dental arch than Caucasian children, especially the maxillary, and they need earlier orthodontic intervention.
The size of the mandible reflects the type of energy ingested: decreases “in masticatory stress among agriculturalists causes the mandible to grow and develop differently” (Cramon-Taubadel, 2011). This effect would not only be seen in an evolutionary context. Cramon-Taubadel (2011) writes:
The results demonstrate that global patterns of human mandibular shape reflect differences in subsistence economy rather than neutral population history. This suggests that as human populations transitioned from a hunter-gatherer lifestyle to an agricultural one, mandibular shape changed accordingly, effectively erasing the signal of genetic relationships among populations.
So it seems like the change from a hunter-gatherer lifestyle to one based on plant/animal domestication had a significant effect on the mandible—and therefore teeth—of a population.
So teeth are a bone, and bones adapt. When an individual is young, the way their teeth, and subsequently jaw, are can be altered by diet. Eating hard or soft foods during adolescence can radically change the shape of the teeth (Liebermann, 2013). The harder the stuff one has to chew on will alter their facial morphology (i.e., their jaw and cheekbones) and, in turn, their teeth. This is because the teeth are bones and any stress put on them will change them. This, of course, speaks to the interaction of G and E (genes and environment). There are genes that contribute to differences in dental morphology between populations, and they impact the difference between ethnic/racial groups.
Further making the differences between these groups is what they choose to eat: the hardness or softness of the food they eat in adolescence and childhood can and will dictate the strength of one’s jaw and shape and strength of their teeth in adulthood, though racial/ethnic identification would still be possible.
Racial differences in dentition come down to evolution (development) and what and how much of the population in question eats. The differences in dentition between these populations are, in a way, dictated by what they eat in the beginning years of life. This critical period may dictate whether or not one has a strong or weak jaw. These differences come down to, like everything else, an interaction between G and E (genes and environment), such as the food one eats as an adolescent/baby which would then affect the formation of teeth in that individual. Of course, in countries that have a super-majority of one ethnic group over another, we can see what diet does to an individual in an ethnic group’s teeth.
There are quite striking differences in dentition between races/ethnic groups, and this can and will (along with other variables) lead to correctly identifying the race of an individual in question.