Objectives: In this review, the dual legal framework governing the radiographic practicum in Korean dental hygiene education is analyzed, a quantitative safety range is derived for intersubject practice, and policy directions are proposed. Methods: A critical narrative review was performed by integrating an analysis of Korean statutes, the International Commission on Radiological Protection (ICRP) dosimetric framework, the 2024 Korea Disease Control and Prevention Agency (KDCA) diagnostic reference level guidelines, and international comparisons. Results: Student radiography of human subjects is restricted, not by an explicit statute, but by an administrative interpretation combining the Medical Service Technologists Act and the Nuclear Safety Act. The 2024 Enforcement Rule Appendix 1 widens this regulatory gap by phasing in a mandatory clinical practicum, while practical restrictions on student radiography remain unchanged. Using published dose-area product-to-effective-dose conversion coefficients with the 2024 KDCA diagnostic reference levels, the estimated effective dose for one adult mandibular molar periapical exposure was 3–6 μSv; within an operational reference level of 100 μSv/year (10% of the public limit), approximately 20 exposures per student per year fall within a quantitatively reviewable range. Mannequin and virtual reality simulators retain inherent limitations that intersubject practice may complement. Conclusions: Within the conservative operational benchmark proposed here, quantitative guidelines permitting controlled intersubject practice may support the minimum clinical competency of new dental hygienists, informing future discussion on statutory amendments and curricular integration.