Eruption sequestrum: an inflamed odontogenic hamartoma.

Eruption sequestrum (ES) is a single or even multiple, small whitish calcified masses found within the soft tissue of the opercula overlying the crown of erupting permanent molars of children. We herein report a well-documented case of ES, offering a review of published cases in the English literature. An otherwise healthy 6-year-old girl was seen for routine dental examination. A fragment of hard whitish tissue was observed in the gingiva overlying the erupting lower first permanent molar, which showed radiographic appearance of a faint round radiopacity above and separated from the occlusal surface of the related tooth. The patient was submitted to an excisional biopsy, and gross examination showed a hardened whitish fragment surrounded by gingival mucosa. Microscopic examination revealed odontogenic epithelium in association with chronic inflammatory infiltrate and small blood vessels in the connective tissue. Small concentric basophilic calcifications, round osteodentin, and pulp-like structures were also observed. The microscopic evaluation of additional cases of ES may improve the understanding of this uncommon inflamed odontogenic hamartoma.