BACKGROUND Dental age is less affected than the bone age by nutritional and hormonal factors. The assessment of dental age in children is of value in clinical and forensic practice. The aims of this study were to compare the Demirjian method and the Willems method in the assessment of dental age in children in Poland and to consider the need to standardize dental age assessment. MATERIAL AND METHODS Polish children of Caucasian ethnicity (n=1,002) who were treated at a single orthodontic center between 1994-2016 included girls (n-540) and boys (n=462) aged between 4-17 years, and 1,002 panoramic radiographs were reviewed. Dental age was assessed using the Demirjian method and the Willems method, the findings of the two methods were compared with the chronological age of the study participants. RESULTS Following statistical analysis, both the Demirjian method and the Willems method overestimated the dental age of the younger study participants, and underestimated the dental age of the older study participants. Both the Demirjian method and the Willems method had similar accuracy in estimating the chronological and dental age in the Polish population. CONCLUSIONS In the assessment of dental age in Polish children from panoramic radiographs, both the Demirjian method and the Willems method were accurate and should still be used as a method of choice. However, it seems reasonable to create international standards for the assessment of dentition maturity for this population to obtain a more acceptable range of error values between the dental age and chronological age.