Objective: To determine the effect of ethnicity in exostosis prevalence, from August 2016 to February 2017.Materials and Methods: Comparative, observational and descriptive approach. Sample size was 900 inhabitants who provided informed consent. Inclusion criteria: born and living in Ticopo, Yucatan, Mexico; age of 10 years or older; male or female; presence or absence of exostosis on maxilla and/or mandible. Variables: Surname-based ethnicity; age; sex; presence/absence of torus and/or exostosis; exostosis shape/location/position; and environmental factors. Three ethnicities were identified based on Maya surnames: Maya indicated by two Maya surnames (e.g. YaEk); Mestizo by one Maya and one non-Maya surname (e.g. YaLópez); and Non-Maya by no Maya surnames (e.g. López Figueroa). Data collected on demographic, environmental, ethnic and clinical factors. Logistical regression used to analyze data.Results: Maya subjects were the majority (62%) of the sample, and this ethnicity was related to presence of exostosis (χ 2 =9.8189, P=0.0436, g.l=2). Twenty subjects excluded due to simultaneous presence of palate and mandibular exostosis. Females (n=57) most frequently exhibited it among the Maya, while males (n=30) exhibited more among the Mestizos. Of the 59 palate exostosis the most common form (55%) was planar in all three ethnicities. Of the 100 mandibular exostosis, whorl was the most common shape among the Non-Maya, and lobular among the Maya and Mestizos.Conclusions: Torus/exostosis prevalence was higher among the Maya than in the Mestizo and Non-Maya. The results support greater frequency of torus/exostosis among mongoloid ethnicities such as the Maya in comparison to other ethnicities.