L. F. Belanger, T. Semba, S. Tolnai, D. H. Copp, L. Krook, C. Gries 



The result should be a progressive loss of bone manifested by an enlargement of the 

 osteonic canal and a gradual loss of bone substance. 



Alpharadiographs of demineralized sections of normal bone have revealed that 

 the areas where osteolysis is occurring are characterized by the presence of enlarged 



Fig. 5 



and oftentimes confluent lacunae surrounded by low-density matrix (Belanger et al., 

 1963 b). Newly-formed portions of the tissue, at the border of osteonic canals consist 

 of denser matrix containing small lacunae (Belanger et al., 1963 b). The lower- 

 density matrix of the osteolytic sites stains more intensely with the periodic acid- 

 Schiff and exhibits toluidine blue and azur metachromasia, indicative of a concentra- 

 tion of mucopolysaccharides in these areas (Belanger et al., 1963 b). 



In the present series, the periodontal bone (lamina dura) was still fairly compact 

 after 4 weeks (Fig. 3). The canals were small but there was already a considerable 

 Intensification of osteolysis. 



After 7 weeks (Fig. 4), the areas of osteolysis were more extensive and character- 

 ized by lower density of matrix corresponding to more widespread p.a.-Schiff 

 staining. 



After 12 weeks (Fig. 5), the canalicular arrangement of the lamina dura had in 

 great part disappeared and the newly-formed bone was of the trabecular type. The 

 central portion of the trabeculae showed the characteristic manifestations of osteo- 

 lysis. At this stage consequently, bone formationhad regressed to a more primitive 

 form, but this younger type of bone could still be considered as normal bone. At this 

 stage also, some less dedifferentiated areas, showed the disappearance of the p.a.- 

 Schiff positive areas characteristic of osteolytic resorption. Numerous, irregular 

 cementing lines separated the areas of new growth. The newly-formed bone con- 

 tained only osteocytes of small size and many lacunae were empty. 



After 30 weeks, the trabeculae were thin and either uniformly dense of fibrillar 

 (Fig. 6). The tissue surrounding this abnormal bone was also de differentiated and 

 inhabited mostly by mesenchymal cells. 



