The evidence to characterize oral health during adolescence in Costa Rica is limited. This lack of adequate research makes it difficult to develop appropriate health policies for this subgroup of the population. This is particularly important because adolescence is the period during which good health habits must take root in order to foster good physical and cognitive development. This study aims to determine the prevalence of tooth loss, bleeding on probing and malocclusion in Costa Rican male adolescents at the “Colegio Técnico Profesional San Agustín” (St. Augustine’s Technical High School) located in the province of Cartago. Data was collected from 428 male adolescents aged 12-22 years in a cross-sectional study during 2019. Prevalence of tooth loss was calculated as the number of individuals having lost at least one tooth. The average number of teeth lost by individuals was also recorded. The bleeding on probing was an indicator used as a proxy parameter for monitoring periodontal health where the presence of bleeding on probing and calculus was also recorded. Malocclusion was measured using the Dental Aesthetic Index (DAI). The results showed that the prevalence of tooth loss, bleeding on probing and malocclusion was of 19%, 70.0% and 98%, respectively. It was also found that 81% of the participants had all their teeth, 11% had lost 1 tooth, 8% had lost more than one tooth of which 0.5% had lost more than 5 teeth. Considering a general classification of periodontal problems based on bleeding on probing and presence of calculus, the prevalence of periodontal problems increases to 92%. Regarding the DAI, the category identifying a very severe malocclusion was the most prevalent in the sample (88%). It is alarming the high prevalence of tooth loss, bleeding on probing, and malocclusions in a sample of Costa Rican male adolescents, compared to similar studies in other countries. The overarching conclusion of this study is that oral diseases represent an important health problem that urgently need proper public health action.

People’s knowledge, attitudes, and practices related to health are built throughout life, particularly during childhood and adolescence, and they reflect the practices of their family and social circle. The aim of this study was to identify the levels of knowledge, attitudes, and practices related to oral health of first-year university students at the Paraíso Campus of the University of Costa Rica. This was done through a questionnaire of closed questions that would allow oral health educational strategies to be established in the future for this population group. For this purpose, a cross-sectional descriptive study was conducted, where 70 first-year students of the Paraíso Campus participated in the first semester of the year 2019.  For data collection, a survey of 22 closed questions on knowledge, attitudes, and practices about oral health was applied, and a score on oral health knowledge was subsequently performed, based on the answers to the questions. According to the results, the level of knowledge shown about oral health is low, since the average knowledge score (7.02 points) was less than half of the maximum score (17 points). The greatest deficiency in knowledge was evidenced in topics, such as, dental biofilm, gingivitis, use of fluorides, and the role of saliva. In addition, several practices that affect the condition of the oral cavity were identified, such as harmful habits, inadequate nutrition, and poor oral hygiene habits. In this study, a general lack of knowledge was identified regarding basic concepts of oral health in young university students, who are not clear about the role of some protective or risk factors related to the main oral diseases.