A STUDY OF THE HEALING PROCESS FOLLOWING OPERATIVE INTERFERENCE WITH THE CONTINUITY OF THE RAT MAXILLA

¹ Ohio State University, Columbus, Ohio

The animals used in this study were 6 male albino rats. The zygomatic process was chosen as the operative site because it could be easily demonstrable radiographically. A dental burr was employed to cut a slot approximately halfway through the zygomatic process extending anteriorly from the free edge of its posterior border. Radiographs were taken before and after surgery and following sacrifice. The animals were sacrificed at intervals of 6 and 9 weeks and 3, 4, 5, and 6 months. The heads were fixed in 10 per cent formalin, decalcified in Custer's solution, imbedded in celloidin, sectioned serially in a frontal plane and stained with hematoxylin and eosin.

It can be concluded from the radiographic and histologic evidence that in this study of operative interference with the continuity of the rat maxilla, in which the factors of infection, mobilization, and apposition of the edges were eliminated, the healing process results in bony union. There is no evidence of a cartilaginous callus stage in the process of healing. The sites of new bone formation which repair the defect are: (1) the periosteum, (2) the endosteum, (3) the connective tissue callus. The end results in the presence of infection are bony union in spite of osteomyelitis.