Atypical root resorption (ARR) is the condition of a superficial and circumferential resorption process along the lateral and/or apical root surface of a primary maxillary incisor. This case series demonstrates longitudinal observations of six patients with atypical root resorption following root-fractured primary incisors. The characteristics of atypical root resorption were different from pathologic root resorption. Keywords: dental trauma, primary tooth, root resorption, tooth injury