Dental anomalies can produce alterations in dental shape, number, size, and structure, affecting function and aesthetics. The objective of this study is to determine the frequency and location of teeth number anomalies in healthy Costa Rican children between 6 and 12 years old. An observational and retrospective study was carried out with 157 panoramic radiographs of the patients of the pediatric dentistry and orthodontics clinic of the University of Costa Rica between the years 2015-2017. Hyperdontias and hypodontias were the anomalies observed.  Data were analyzed using a Fisher exact test with a significance level of 5% . The results showed that the overall frequency  of dental anomalies  was 8.3%, 4.5% were hyperdontias and 3.8% hypodontias. Double or multiple hyperdontia and hypodontia were also found. The difference between sex was not significant (p= 0.145). Supernumeraries were more frequent in maxilla and hypodontias in mandible. Mesiodens was the most frequently found supernumerary teeth. Mandibular second premolars were the most commonly missing teeth.

Keywords: Tooth abnormalities/diagnostic imaging, Tooth abnormalities/epidemiology, Tooth supernumerary, Hypodontia