This case report aimed to characterize dento-osseous anomalies in Familial Adenomatous Polyposis (FAP) in a Brazilian patient. Furthermore, FAP was investigate for possible causative. This case report showed the importance of dento-osseous knowledge related to FAP. Early dento-osseous anomalies diagnosis revealed the need to followup FAP family members from childhood and was essential for subsequent clinical or genetic FAP diagnosis. The authors think that this work is important as it provides highlights about the role of the dentist in the early diagnosis of FAP, a disease that predisposes colorectal cancer.