Effects of aging on the endodontic system, reserve crown, and roots of equine mandibular cheek teeth.

OBJECTIVE: To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth. DESIGN: Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations. SAMPLE POPULATION: 48 right hemi-mandibles from horses 2 to 9 years old. PROCEDURE: Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types. RESULTS: Permanent mandibular cheek teeth of the horse, at the time of eruption, consisted of an exposed crown and a reserve crown with a widely dilated apex. The endodontic system consisted of 5 or 6 pulp horns that connected to an expansive pulp in the reserve crown, which was confluent with the primordial pulp bulb surrounding the tooth's apex. At the time of eruption, mandibular cheek teeth did not have a distinct pulp chamber, roots, or evidence of root formation. However, within 2 years after eruption, mesial and distal roots and a pulp chamber were present. A distinct pulp chamber, communicating with the pulp horns and both root pulp canals, was identifiable for 4 to 5 years from the time of root formation. The endodontic system of cheek teeth, 6 to 8 years after eruption, consisted of 2 unattached compartments, made up of a root canal, pulp chamber, and 2 or 3 pulp horns. CLINICAL RELEVANCE: The age-related morphologic changes in equine mandibular cheek teeth have important implications for application of endodontic therapy in horses.

The in vitro effects of EDTA-tris, EDTA-tris-lysozyme, and antimicrobial agents on equine genital isolants of Pseudomonas aeruginosa.

Five isolants of Pseudomonas aeruginosa collected from clinical cases of equine genital infection and one standard strain of P. aeruginosa were exposed to various concentrations of ethylene-diaminetetraacetic acid (EDTA) and tris (hydroxymethyl) aminomethane (tris buffer pH 8) and EDTA-tris lysozyme. Colony forming units of the isolants and minimal inhibitory concentrations for 11 antimicrobial agents were determined with each isolant before and after exposure to the EDTA solutions. Decreased cellular viability was found with all six isolants after exposure to the EDTA-tris solutions. Reversal of antimicrobial resistance was variable and unpredictable. These effects were not enhanced by the addition of lysozyme. The results suggest that EDTA-tris could be a useful adjunct in treating equine genital infections caused by Pseudomonas aeruginosa.

MMPI traits of incestuous fathers.

Compared MMPI scores of a group of 10 documented incestuous fathers and stepfathers to those of a matched control group of nonincestuous fathers. Analyses of variance and covariance reflected more pathological scores for incest fathers than control fathers on the psychopathic deviate scale, the psychasthenia scale and the schizophrenia scale of the MMPI. Results were discussed in terms of a character disordered personality type among incestuous fathers.

Nonverbal assessment of interpersonal affect.

Two nonverbal methods for assessing degree of interpersonal attraction were explored. Twenty children ranging from 11 to 13 years of age were asked to select two liked and two disliked classmates of the same sex. On four different trials, subjects selected one geometric block to represent themselves and one to represent a pre-selected classmate, then placed the figures on a ruled board. Distance between objects was measured and found to be significantly related to degree of peer liking. In addition, subjects were asked to draw each of the four peers. The human figure drawings were rated for total pictorial detail which was found to vary strongly across magnitude of liking for female subjects, and for parts integration which was found to vary with degree of peer liking for both sexes. The degree of rated positive affective tone of drawings was also found to increase with liking. Implications for the use of these two interpersonal assessment techniques in clinical practice were discussed.