Eruption sequestrum: x-ray microanalysis and microscopic findings.

A 12 year-old girl with eruption sequestrum of the mandibular left second molars is reported. Intraoral findings revealed that a small hard tissue fragment white in color and with bone-like hardness on the occlusal surface of the mandibular second molar which was erupting. Histopathologically, the fragments consisted of necrotized cortical bone. Chronic inflammatory alterations were also observed in the gingiva in the area of contact with the osseous tissue. X-ray microanalyzer findings revealed the percentages of calcium and phosphorous (by weight) as 78.41% and 21.59%, respectively, for a calcium to phosphorous ratio of 3.63, which was higher than that seen in normal osseous tissue.