dc.contributor.advisor | Dixon, Padraic M. | en |
dc.contributor.advisor | Kempson, Sue A. | en |
dc.contributor.author | du Toit, Nicole | en |
dc.date.accessioned | 2010-11-22T12:42:20Z | |
dc.date.available | 2010-11-22T12:42:20Z | |
dc.date.issued | 2009 | |
dc.identifier.uri | http://hdl.handle.net/1842/4385 | |
dc.description.abstract | Eighty normal cheek teeth and 26 normal incisors extracted from 14 donkeys (median age 19
years) at post mortem were anatomically examined including grossly and by computerised axial
tomography (CAT) imaging. Decalcified histology was performed on 54 sections from 18 teeth
(8 donkeys), undeclacified histology on 16 sections from 7 donkeys and scanning electron
microscopy on 10 sections from 10 teeth (3 donkeys). The dental formulae and tooth number
was found to be the same as in horses with a higher prevalence (17 %) of canine teeth in female
donkeys. A decrease in tooth length, pulp horn length and pulp horn width with age was
illustrated, as was an increase in occlusal secondary dentine depth with age, although not all
these age changes were statistically significant. Normal histological and ultrastructural features
of donkey teeth were identified and found to be similar to equine findings. Enamel was found to
be thicker buccally in both maxillary and mandibular cheek teeth. Quantitative measurements of
transverse dentine thickness around pulp cavities, dentinal tubule diameters and densities, and
enamel prism diameters were made. Left lower incisors (301) were extracted from 7 donkeys
and 6 horses for micro-hardness determination of enamel, primary and secondary dentine using a
Knoop Hardness indenter. No significant difference between donkey and horse incisor
microhardness was demonstrated. Examination of 19 donkey skulls at post mortem examination
showed donkeys to have a higher degree of anisognathia (27%) compared to horses (23%).
Post mortem dental examination of 349 donkeys (median age 31) demonstrated a high
prevalence of dental disease (93%) and in particular cheek teeth diastemata (85%). Furthermore,
age was associated with increasing prevalence of dental disease and diastemata. Diastemata were
also associated with the presence of other dental disorders and with colic-related death in
affected donkeys. Quantitative measurements of 45 diastemata from 16 donkeys showed no
difference in the medial and lateral width of diastemata but periodontal pockets were deeper
laterally. The definition of valve and open diastemata were confirmed. Pulp exposure, dental
caries and periodontal disease were examined in detail (54 skulls) at post mortem. A total of 19
teeth were extracted for further detailed examination as performed in normal anatomy.
Clinical dental examinations were performed on 357 donkeys in the U.K. that were selected for
age distribution, and the prevalence of dental disease in different age groups was found to
increase from 28% in the youngest group (age 0-10 years) to 98% in the oldest group (age > 35
years). An increased prevalence of most dental disorders with age was demonstrated as was an
association between dental disease and weight loss, poor body condition score, supplemental
feeding and previous episodes of colic. Clinical dental examination of 203 working donkeys in
Mexico showed similar types of dental disorders as found in the U.K. study, with dental disease
present in 62%, of which 18% required urgent dental treatment. There was a significant
association between age groups and dental disease, and age groups and body condition score, but
there was no association between dental disease and body condition score. However, body
condition score was not associated with supplemental feeding or faecal egg counts either. | en |
dc.contributor.sponsor | The Donkey Sanctuary | en |
dc.language.iso | en | |
dc.publisher | The University of Edinburgh | en |
dc.relation.hasversion | du Toit, N., Kempson, S.A., Dixon, P.M. (2008) Donkey dental anatomy. Part 1: Gross and computed axial tomography examinations. The Veterinary Journal 176, 338 -344. | en |
dc.relation.hasversion | du Toit, N., Kempson, S.A., Dixon, P.M. (2008) Donkey dental anatomy. Part 1: Histological and scanning electron microscopy examinations. The Veterinary Journal 176, 345 -353. | en |
dc.relation.hasversion | du Toit, N., Bezensek, B., Dixon, P.M. (2008) Comparison of the microhardness of enamel, primary and regular secondary dentine of the incisors of donkeys and horses. The Veterinary Record 162, 272 - 275 | en |
dc.relation.hasversion | du Toit, N., Gallagher, J., Burden, F.A, Dixon, P.M. (2008) Post mortem survey of 349 donkeys from an aged population (2005-2006). Part 1: Prevalence of specific dental disorders. Equine Veterinary Journal 40 (3), 204 – 208. | en |
dc.relation.hasversion | du Toit, N., Gallagher, J., Burden, F.A, Dixon, P.M. (2008) Post mortem survey of 349 donkeys from an aged population (2005-2006). Part 2: Epidemiological studies. Equine Veterinary Journal 40 (3), 209 - 213. | en |
dc.relation.hasversion | du Toit, N., Burden, F.A., Dixon, P.M. (2008) Detailed investigation of dental caries and pulpar exposure in donkey cheek teeth using CAT, histology and SEM, The Veterinary Journal, 178 (3), 387 - 395. | en |
dc.subject | donkey teeth | en |
dc.subject | histology | en |
dc.subject | ultrastructure | en |
dc.subject | clinical examination | en |
dc.title | Anatomical, pathological and clinical study of donkey teeth | en |
dc.type | Thesis or Dissertation | en |
dc.type.qualificationlevel | Doctoral | en |
dc.type.qualificationname | PhD Doctor of Philosophy | en |