Abstract
When a continuous pressure is maintained upon the bone in the alveolar process of the maxilla the resulting trauma is characterized by several histo-pathological changes.
The manner of applying pressure is by means of bands cemented upon the crowns of the teeth. To these spring wire has been previously soldered so that when the appliance is in place the tension may be increased, decreased or changed in direction merely by bending the spring wire. Such appliances have been in place on teeth of monkeys (Macacus rhesus) from one day to 8 months and the results have been so striking that this preliminary report seems appropriate.
When the crowns of teeth are separated distally their roots are forced nearer each other. This pressure produces areas of absorption in the alveolar process as well as on the periphery of the roots. Combined with this absorption is a great amount of fibroblastic activity. These changes commence apparently early in the experiment as shown by the examination of the tissues from an animal on which the appliances had been in place only 24 hours.
In one case, where the greatest possible tension was applied in the effort to produce absorption, the alveolar process between the teeth was fractured.
The force used in producing this result as measured by Jolly balances was found to be one and three-quarters (1 3/4) pounds.
Approximating teeth were subjected to elongation tension and its opposite a depression tension. This double pull stretched the supporting tissues to a great degree and the effect was one in which the bone at the alveolar crest, the overlying connective tissue and mucosa have been pulled or dragged out of their proper position and have followed the movement of the attached tooth.
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