The changes in a permanent central incisor of a patient suffering from hypophosphatasia, were investigated light microscopically and compared with those of two of his primary teeth. In addition his other central incisor was studied with transmission and scanning EM. The changes in permanent teeth were similar to those of the primary dentition, including loss of cementum and the presence of deep resorption areas in dentin. Afibrillar cementum was detected with EM, and was attached to dentin surface. The presence of a thick layer of bacterial plaque was a prominent feature in all the teeth examined. A large number of bacteria was also found in resorption bays. It is suggested that bacteria may play an important role in the destruction of soft and hard tissues leading to loss of teeth in hypophosphatasia.

El-Labban NG, Lee KW. Vaseular degeneration in adenomatoid odontogenie tumour: an ultrastructural study. J Oral Pathol 1988: 17: 298-305. Abstract -The blood vessels in 3 cases of adenomatoid odontogenie tumour (AOT) were investigated ultrastructurally. An estimated 70-90% of the blood vessels found in the stroma showed degenerative changes which affected both the endothelial lining and the perivascular connective tissue. These vessels showed multiplication of basal lamina and were also encircled by concentric lamellae consisting either of collagen or fine filaments measuring 5-15 nm in diameter. Degradation of the layered eollagen into fine filaments similar to those forming the concentric layers was observed. The present results suggest that the fine filaments of the concentric lamellae probably result from degradation of the layered collagen surrounding these vessels.

A 22-yr-old man with aplastic anaemia was treated with high dose methylprednisolone. A month later he developed severe epistaxis which was not controlled by regular platelet transfusions. A balloon catheter inserted into the left nostril caused necrosis of the left ala nasi accompanied by gross facial oedema. He received treatment with horse ALG for aplastic anaemia but developed gross facial oedema and anaesthesia of incisor and canine teeth on the right side. Radiographs initially showed thickening of the maxillary antral mucosa and later erosion of the maxilla over the anaesthetic region. A biopsy specimen of this region contained hyphae of zygomycetes. He was treated with amphotericin B and a second course of antilymphocyte globulin followed by oxymetholone. He has made a satisfactory clinical and haematological recovery.