This paper proposes an efficient dental radiograph registration algorithm using Phase-Only Correlation (POC). The use of phase components in 2D (twodimensional) discrete Fourier transforms of dental radiograph images makes it possible to achieve highly robust image registration and recognition. The proposed algorithm finds correspondence points between two images using the sub-pixel correspondence search using POC and corrects nonlinear distortion based on the Thin-Plate Spline (TPS) model. Experimental evaluation using a dental radiograph database indicates that the proposed algorithm exhibits efficient recognition performance even for distorted radiographs.