Material and Method: Oral biopsy records from pediatric patients between the ages of 0 and 15 years in the files of Faculty of Dentistry, Mahidol University, and the files of Faculty of Dentistry, Khon Kaen University were reviewed. The patients were divided into three age groups, including 0 to 5, 6 to 10, and 11 to 15 years. Excluding the diagnosis of normal tissues, the oral and maxillofacial lesions were classified into nine categories.

Results: Of 13,050 biopsied oral and maxillofacial lesions, 1,389 cases (10.6%) came from pediatric patients. The largest number of lesions was odontogenic cysts and tumors, followed by inflammatory and reactive lesions, and salivary gland pathology. The top ten most prevalent lesions contributed 73% of all oral biopsies. The most common lesion was dentigerous cyst, followed by mucocele and pyogenic granuloma.

Conclusion: The vast majority of oral diseases in children were benign and related to either developmental or tissue reaction, while malignant lesions were found in a very small proportion of all oral biopsies.

Keywords: Pediatric, Oral lesions, Prevalence, Thai