Background: Mixed dentition analysis is essential for diagnosis and treatment planning in children. The Tanaka Johnston method remains widely used but is traditionally applied on plaster models, which are time-consuming and require storage. Digital models exist but are expensive and less accessible in developing countries. DSLR photogrammetry may offer a cost-effective alternative.

Aim: To compare the accuracy, efficiency and practicality of Tanaka Johnston mixed dentition analysis using traditional plaster models and DSLR photogrammetric method.

Methods: Thirty-five children aged 8–14 years with Class I molar and canine relationships were included. Alginate impressions were made and plaster casts were measured using a digital Vernier caliper. Intraoral occlusal photographs were taken with a DSLR (Canon EOS 1500D) using an occlusal mirror. Images were processed with software for calibrated tooth measurements. The Tanaka Johnston equation was applied to both methods. Paired t-tests and Pearson correlation were used for statistical comparison.

Results: No statistically significant differences were found between the two methods (p > 0.05). Mean discrepancies ranged from 0.1–0.3 mm considered clinically insignificant. Correlation was high (r = 0.97).

Conclusion: DSLR photogrammetry is accurate, efficient and practical for mixed dentition analysis. It provides a low-cost, accessible alternative to plaster models and advanced digital scanners, especially in developing countries.