The rate of incisor dentine calcification and of mandibular growth in the molar region of the ovariectomized rat.

In 14 ovariectomized and 15 control rats, killed at intervals over a 117-day period, the height of the mandible in the molar region was determined radiographically. Mandibular height was significantly related to time after operation in both groups, but their rate of mandibular growth was not significantly different. In a separate study, the rate of dentine formation in the right mandibular incisor of 9 ovariectomized and 10 control rats was calculated from the distance between two fluorescent labels injected at known time intervals. The rate of dentine apposition was measured at 117 and 201 days after ovariectomy. In both groups, the distance between the fluorescent labels was significantly correlated with the time interval between the injections. There was no significant difference between the rate of dentine calcification in either group. Transient changes in dentine apposition may have occurred post-ovariectomy which would be undetected at either 117 or 201 days after operation. There was thus no evidence for an effect of ovariectomy on either the rate of mandibular growth or dentine apposition.