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Australian Journal of Zoology Australian Journal of Zoology Society
Evolutionary, molecular and comparative zoology
RESEARCH ARTICLE

Loss of tooth-supporting bone in the koala (Phascolarctos cinereus) with age

Elizabeth F. Lee A , Srinivas Varanasi A , Lyndall M. Pettett B , Philip S. Bird B and Anne L. Symons A C
+ Author Affiliations
- Author Affiliations

A School of Dentistry, The University of Queensland, Brisbane, Qld 4000, Australia.

B School of Veterinary Sciences, The University of Queensland, Gatton, Qld 4343, Australia.

C Corresponding author. Email: a.symons@uq.edu.au

Australian Journal of Zoology 59(1) 49-53 https://doi.org/10.1071/ZO10047
Submitted: 2 July 2010  Accepted: 31 May 2011   Published: 8 July 2011

Abstract

This study investigated changes in alveolar bone height in free-ranging koalas of different age groups. Twenty-seven free-ranging Queensland koalas (15 female, 12 male), admitted to the Moggill Koala Hospital, Brisbane, were used in this study. Koalas were divided into three groups (young, adult, old) on the basis of tooth wear, each group containing nine animals. Defleshed jaws were examined for the presence of alveolar bone defects. The distance from the cemento-enamel junction and the interproximal crestal alveolar bone height was measured on the buccal aspects of the second and third molars. Jaws were photographed and radiographed. Bone defects (dehiscences and fenestrations) were observed in both jaws and were predominantly located on the buccal aspect of the alveolar process. The loss of height of crestal alveolar bone, relative to the cemento-enamel junction, increased with age, with 25 koalas showing moderate to severe bone loss and only two koalas having none/mild loss levels at all measurement sites. Female koalas had higher frequency of ‘none/mild’ cases of bone loss than did males. There was no variation in levels of alveolar bone loss between the upper and lower jaws or the corresponding right and left arches.

Additional keywords: alveolar bone loss, dental, jaws, koala.


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