DENTO-ALVEOLAR RESORPTION IN PERIODONTAL DISORDERS 305 



bone destruction in the east Greenland Eskimos may be due to the 

 composition and consistency of their food. The latter ensures a very 

 good functional development of the periodontal tissues. 



An explanation should also be given as to the loss of alveolar 

 bone when very little or no color change and swelling is present 

 in the gingiva. This type of periodontal disorder can be found in 

 all age groups, more often in females than in males. A clinical ex- 

 amination does not in these cases disclose local factors which can 

 account for the loss of alveolar bone (Seidler et ah, 1950). In these 

 patients very often the fixed and the movable gingiva have the same 

 light pink color, with a normal mucous membrane. 



In gingival biopsies a regressive inflammation is found, usually 

 with little or no hyperemia and exudative reactions. In autopsy, 

 material bone formation is very rare even in sections from growing 

 individuals. 



Patients with anemic gingiva frequently have cold hands and feet 

 and diminished salivation. In some of them an increase in the blood 

 cholesterol up to double the normal amount has been found. It has 

 been suggested by Wang-Norderud ( 1951 ) that biopsies should be 

 taken from the palate in the region of the second premolar in cases 

 of anemic gingiva accompanied by advanced destruction of alveolar 

 bone. The biopsies reveal that the lumen of the vessels in the palate 

 usually is reduced owing to thickening of their walls. Loss of elastic 

 fibers and degeneration in the vessels also occur (Fig. 5). Similar 

 changes have been found by Quintarelli ( 1957 ) in the vessels of the 

 jaws in patients with periodontal disorders. In biopsies from the 

 palate of diabetic patients the pathological changes in the vessels 

 can be very pronounced. 



These histological findings indicate that insufiBcient bone produc- 

 tion is the main cause of the loss of alveolar bone when there is a 

 decrease in the blood circulation in the periodontium. 



From the observations mentioned above, the conclusion can be 

 drawn that circulatory disturbances increasing the tissue tonus in 

 the periodontium initiate alveolar bone resorption and that a reduced 

 flow of blood in the periodontium may impede the production of 

 alveolar bone. 



