Gingivitis around the deciduous teeth of sheep

Two-hundred and eight sheep from two farms were killed mostly in age-matched groups of 6 between the ages of 6 and 141 weeks. Sheep from one farm (W) had excessive tooth wear whilst sheep from the other (G) had little. The four deciduous incisor teeth and the third premolar from one side of the mandible of each sheep were examined by light microscopy. The inflammatory reaction in the gingiva around the sulcus and sulcular epithelial proliferation were subjectively assessed. Sheep from both farms initially showed a neutrophilic reaction. From approximately 25 to 100 weeks of age, sheep from farm G had a more extensive reaction than those from farm W involving neutrophils and mononuclear cells. The latter showed a more frequent tendency to spread on farm G than on farm W. The length of the sulcus was also more often greater on farm G. In contrast, the proliferation of the sulcular epithelium in both width and length was not greater on farm G. It is suggested that the severity of the gingivitis was arrested at a less severe stage on farm W than on farm G and that the pathogenesis of sulcular epithelial proliferation may different from that of gingival inflammation.