Hyoid bone by asif

Hyoid bone - Anatomy & Clinical importance

1. Hyoid bone
Muhammed Asif BMLT., M.Sc- medical anatomy
Lecturer, Dept of Anatomy, YMC.

3. Importance ....
•In a suspected case of murder, fracture
of the hyoid bone strongly indicates
throttling and strangulation .

4. Importance ......
•Tip of greater cornu is palpated in the relaxed neck
near the anterior border of sternocleidomastoid
muscle, midway between the laryngeal prominence
& mastoid process.

•It forms the landmark for the ligation of lingual
artery during surgery of the neck .

12. Notes

13. •It is a u shaped bone.
•Situated in the anterior midline of the neck
between the chin and the thyroid cartilage.
At rest it lies at the level of the 3
rd
cervical
vertebra behind and the base of the mandible in
front.
Hyoid bone

14. Hyoid bone
•It is kept in suspended position by muscles and
ligaments

•It provides attachment to the floor of the mouth &
to the tongue above, to the larynx below and the
epiglottis and the pharynx behind.

15. Hyoid bone consists of 5 parts
A body
A pair of greater cornu (or horns)
A pair of lesser cornu (or horns)

16. The body
•It has anterior and posterior surfaces, and upper and
lower borders.
•The anterior surface is convex and is faces forwards and
upwards.
•It is crossed by transverse line in upper part &
vertical median ridge divides the body into two halves.

17. The body
•The posterior surface in concave and is directed
backwards and downwards.
•Each lateral end is continuous posteriorly with the greater
horn or cornua.
In early life the lateral part of the body is connected to
greater cornu by cartilage.
After middle life this connection become united by bone

18. The greater cornua
•Greater cornua are flattened.
•Each cornua tapers posteriorly, ends in a tubercle.
•It has two surfaces Upper and lower
•Two borders medial and lateral and a tubercle.

19. The lesser cornua
•These are small conical projection of bone which
project upwards from the junction of the body
and greater cornua.
•The lesser cornua are connected to the body by
fibrous tissue .
•The stylohyoid ligament is attached to the tip of
lesser cornu.

20. Attachments
•Suprahyoid and infrahyoid muscles
•Thyrohyoid membrane

21. Ossification
•Formed by Cartilagenous ossification
•Ossifies by 6 centers
•1 primary center each for greater cornua just
before birth
•2 secondary center for the body soon after birth
•1 secondary center each for lesser cornua at
puberty

22. Development
•2
nd
pharyngeal arch
•Superior part of body
•Lesser cornu
•3
rd
pharyngeal arch
•Lower part of the body
•Greater cornu