Abstract
Eruption was prevented in the continuously growing lower right incisor of 9 male and 10 female Wistar rats by the surgical procedure of either complete or partial root transection, thereby allowing for a separation of the process of tooth eruption from that of basal cell proliferation. The experimental tooth was cut down to the gingival margin immediately following operation to eliminate masticatory stress. Animals were killed 120 days after operation, following which the jaws were dissected out, radiographed and then sectioned. Following cessation of eruption, the outline of the basal portion of the “root” showed one of the following arrangements: (1) in 10 jaws it was in the form of a smooth curve similar to that of controls, (2) in 3 jaws it was more sharply curved than the controls so that the pulp opening faced directly upwards, (3) in the remaining 6 jaws it was completely recurved so that the pulp opening was directed anteriorly. Histological examination revealed the presence of continued enamel and dentine formation in this basal region with the latter tissue completely obliterating the normal pulp cavity except for a small cone-shaped area at the base. These results clearly demonstrate that the proliferative basal region of the rat incisor is capable of generating a force when eruption is prevented, sufficient to cause a significant change in root morphology. In one complete root transection specimen, the proximal segment continued to erupt forwards and penetrated the side of the socket and then the cheek to reach the exterior.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call