Morphology and morphometrical study of hamster middle ear bones

Document Type : Full paper (Original article)


Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran


The objective of the current study was to determine the anatomical features of the auditory ossicles in
hamster. Twenty temporal bones from 10 adult hamsters, weighing 275-300 g were used. After dissecting
them, the features of the ossicles were assessed with an ocular micrometer and photographed by a
stereomicroscope. Finally, all data were evaluated and analysed using the Sigma Statt software. The auditory
ossicles were three bones: the malleus, the incus, and the stapes. The lenticular bone was a distinct bone,
articulated with the tip of the long crus of incus. The malleus had an average length of 2.87 mm. In addition
to head and handle (manubrium), the malleus had two distinct processes; lateral and muscular. The rostral
process was unclear and appeared not developed. The incus had a total length of 1.18 mm. It had long and
short crura, the long crus better developed than the short one. The lenticular bone was a round bone that
articulated with the long crus of the incus. The stapes had a total length of 0.77 mm. It had a large stapedial base with anterior and posterior crura. The posterior crus was larger than the anterior one. The hole in stapes (obturator foramen) was very large and triangular in shape.