Abstract
The present study was designed to clarify structural changes appeared in maxillary alveolar bone and its neighboring bones after tooth extraction.
Ten adult dogs whose all the upper premolars and molars on one side were extracted at the same time were kept for 57-181 days. During the first half of experimental period, dogs were injected with tetracycline continuously and, during latter half, with calcein. The large ground sections showing the frontal section of the maxillary bone and its neighboring bones were microradiographed and, then, were subjected to fluorescence microscopy. From a montage of fluorescence micrograms, a color tracing of labelling sites was made on plastic sheet.
Within 2 weeks after tooth extraction, intense remodelling becomes observable in the new bone in extraction socket, spongy bone of alveolar supporting bone and compact bone at the periphery of alveo-lar bone, so that spongy bone becomes very much porous, compact bone facing to oral and orbital cavi-ties moves to lower level, and the volume of entire alveolar bone decreases markedly.
Even 57 days after tooth extraction, structural chages can be observed in neighboring bones. In zygomatic bone, the density of trabecule distribution in the bone marrow becomes gradually lower and, buccal compact bone begins to decrease, its width. In the perpendicular plate of palatine bone and frontal bone, decrease of their width due to intense resorption progressed at their outer surface becomes observable, whereas no particular change is observed in the horizontal plate of palatine bone even 181 days after tooth extraction.
Above mentioned changes appear more prominently in young animals than in old ones.
