Asymptomatic, nonexpansile radiopacity of the jaw associated with external root resorption: a diagnostic dilemma.

Incidental radiopacities of the jaws are commonly identified on routine intraoral and extraoral radiographs. Dentists should be able to develop a differential diagnosis of these lesions. This article presents 2 cases in which mandibular radiopacities associated with external root resorption were identified incidentally and discusses the differential diagnosis of these lesions. Both patients were referred by their general practitioners to dental specialists for further evaluation of homogenous osteosclerotic foci surrounding and resorbing the roots of the permanent mandibular right first molar. The lesions were asymptomatic, caused no cortical expansion, and were static over time. The clinical and radiographic features were consistent with a diagnosis of idiopathic osteosclerosis (IO). External root resorption is present in 10%-12% of cases of IO and often involves the permanent mandibular first molars.