SPONTANEOUS EXFOLIATION OF TEETH FOLLOWING SEVERE ELEMENTAL MERCURY-POISONING - CASE-REPORT AND HISTOLOGICAL INVESTIGATION FOR MECHANISM

Background. Although the spontaneous exfoliation of teeth and breakdow n of oral tissues from severe mercury intoxication have been noted for over a century, there are no published reports investigating the mech anisms of these phenomena. Severe mercury poisoning is rare in modern times, but it does occur. We present a case report and a histopatholog ic investigation into the mechanism of the associated tooth loss. Meth ods. An exfoliated tooth and periodontal and gingival tissues were obt ained from a 1-month-old patient who had been severely intoxicated wit h elemental mercury over a period of months and hospitalized for sever e neurologic and renal effects; The tissues were examined both by rout ine hematoxylin and eosin stain and by autometallography specific for mercury. For comparison, control tissue from an age-matched subject wa s examined with the autometallography technique. Results. Under light microscopy, the gingival tissue showed evidence of moderate to severe acute and chronic inflammation. The tooth pulp tissue showed evidence of moderate vascular dilatation and congestion, and it was infiltrated by many neutrophils. The autometallographic sections showed intense a ccumulations of mercury in the soft tissues of the mercury-exposed sub ject, but not in the tissues of the control subject. The deposits were primarily found in fibroblasts, which are essential to maintaining th e integrity of the oral tissues. Conclusions. Histopathologic and auto metallographic examination of the affected tissue indicates that the p rimary mechanism of the spontaneous sloughing of tissue and loss of te eth may be the cytotoxic effects of the, accumulation of mercury in fi broblasts. Studies of additional cases would be valuable to confirm th is hypothesis.