The Permanent Tooth Germ as a Biological Trigger of Physiological Root Resorption in Primary Teeth

Abstract

Physiological resorption of primary tooth roots is an essential developmental phenomenon that enables the transition from deciduous to permanent dentition. Although this process has traditionally been associated with eruptive pressure from the permanent successor, contemporary evidence indicates a substantially more complex biological mechanism involving cellular signaling, molecular mediators, and genetically programmed tissue remodeling. The present review analyzes the initiating role of the permanent tooth germ in primary root resorption and discusses its interaction with odontoclast activation, periodontal ligament remodeling, and cytokine-mediated pathways. Particular attention is paid to the regulatory function of the dental follicle and the RANK/RANKL/OPG signaling system. Existing experimental and clinical data suggest that the permanent tooth germ acts not merely as a mechanical structure but as an active biological regulator capable of orchestrating localized resorptive events. Nevertheless, the occurrence of resorption in the absence of permanent successors indicates that intrinsic developmental programming also contributes significantly to the process. Understanding these mechanisms has direct relevance for pediatric dentistry, orthodontics, and regenerative approaches aimed at controlling pathological root resorption.