Tetanus in an adult dog originating from a tooth root abscess

A three-and-a-half-year-old entire male Staffordshire Bull Terrier was presented with a cough and difficulty in swallowing. Two days later the dog was re-presented and a diagnosis of tetanus was made. An abscessed canine tooth was extracted and submitted for culture. Clostridium tetani was cultured from the pulp chamber of the tooth. The dog was treated with tetanus antitoxin, antibiotics and supportive care and made a complete recovery.

Determining the age of adult wild dogs (Canis lupus dingo, C-l. domesticus and their hybrids). I. Pulp cavity: tooth width ratios

In order to determine the age of adult wild dogs, we compared two methods ( that of Thomson and Rose (TR method) and that of Knowlton and Whittemore (KW method)) of measuring and calculating pulp cavity : tooth width ratios on upper and lower canine teeth from 68 mixed-sex, known-age wild dogs of 9 months to 13 years of age reared at two localities. Although significant relationships ( P = 0.0001) were found between age and pulp cavity ratios by both methods, the TR ratio calculation and measurement showed heteroscedasity in error variance whereas the KW ratios had a more stable error variance and were normally distributed. The KW method also found significant differences between pulp cavity ratios between teeth of the upper and lower jaws ( P < 0.0001) and sex ( P = 0.01) but not geographic origin ( P = 0.1). Regressions and formulae for fitted curves are presented separately for male and female wild dogs. Males show greater variability in pulp cavity decrements with age than do females, suggesting a physiological difference between the sexes. We conclude that the KW method of using pulp cavity as a proportion of tooth width, measured 15 mm from the root tip and averaged over both upper canines, is the more accurate method of estimating the age of adult wild dogs.

Orthodontic tooth movement in the prednisolone-treated rat

Adverse effects of corticosteroids on bone metabolism raise concerns as to whether steroid treatment may influence orthodontic movement. This study examined the effect of prednisolone on orthodontic movement using an established rat model. The corticosteroid treated group (N = 6) was administered prednisolone (1 mg/kg) daily, for a 12-day induction period; the control group (N = 6) received equivalent volumes of saline. On day 12, an orthodontic appliance was placed which exerted 30 g of mesial force to the maxillary first molar. Animals were sacrificed on day 24 and tooth movement was measured. Sagittal sections of the molars were stained with haematoxylin and eosin, and for tartrate-resistant acid phosphatase (TRAP) activity. While there were no significant differences in the magnitude of tooth movement between the 2 groups, steroid-treated rats displayed significantly less root resorption on the compression side and fewer TRAP-positive cells within the PDL space on the same side. This suggests steroid treatment suppressed elastic activity.