Oral manifestations of hyperoxaluria.

Primary hyperoxaluria is a rare, inherited autosomal recessive disease caused by defects in the metabolism of glyoxylate. Oral manifestations of hyperoxaluria are rare. However, bone and tooth resorption may be the result of chronic inflammation and the presence of osteoclastic cells surrounding the oxalate crystal deposit. A deposit of calcium oxalate in the periodontium was identified in a patient with end-stage renal disease. Dental radiographs indicated bone loss and external tooth resorption. Radiolucent image in the inferior incisor region was observed and removed. The tissue showed granulomatous inflammation with foreign body reaction and associated crystalline deposits. When viewed in polarized light, these deposits are green and presented a birefringent aspect, which were interpreted as calcium oxalate crystals compatible with oxaluria. Oral manifestations of hyperoxaluria are of particular interest because of the unusual location of the oxalate crystal deposition, resulting in aggressive tooth resorption and alveolar bone loss, which may be misdiagnosed.