Odontogenic Tumors in Sweden, Norway, Finland, and Denmark: A Multicenter Study

Updated and comprehensive epidemiological data on odontogenic tumors are not available for the Nordic countries. The aim of the study was to retrospectively examine the prevalence and clinical and radiological characteristics of primary odontogenic tumors over a 10-year period in Sweden, Norway, Finland, and Denmark.

Primary odontogenic tumors diagnosed by oral pathologists from 2010 to 2020 at nine different diagnostic laboratories in Sweden, Norway, Finland, and Denmark were identified. Using histopathology referrals and their corresponding histopathological reports, age and sex, anatomic site, clinical and radiological findings, tentative diagnosis, histopathological diagnosis, and recurrence of the tumors were recorded. Range, mean, and median for continuous variables and frequency tabulation for discrete variables were used.

In total, 1139 primary odontogenic tumors (598 in males and 540 in females) were identified during the study period, giving an annual incidence rate of 4.2/million. The mean age of all patients was 29 years. Ninety-nine percent of the tumors were benign, and the mandible was the predominant location. Odontoma, ameloblastoma, and odontogenic fibroma were the three most common tumors. The mixed epithelial and mesenchymal benign odontogenic tumors were more common at a younger age compared with the epithelial tumors and the mesenchymal tumors (mean age 22, 44, and 35 years, respectively). Information on variables other than sex, age, and tumor site was missing in most referrals.

The annual incidence of 4.2 cases per million indicates that odontogenic tumors are uncommon in Nordic countries. Better practices to improve the quantity and quality of clinical information in the pathology referrals are needed.