The document summarizes the muscles around the mouth. It begins with an introduction to the orbicularis oris muscle, which acts as a sphincter, and the 10 paired muscles that converge around the mouth to act as dilators. Each of the 10 muscles is then described in its own section, including origin, insertion, innervation, and action. The document concludes with brief sections on clinical considerations and bibliography.

1. MUSCLES AROUND
THE MOUTH
KARTIKEY SINGH
ROLL NO-40
MBBS BATCH 2017-18

2. CONTENTS
 INTRODUCTION
 ORBICULARIS ORIS
 10 MUSCLES AROUND MOUTH
 CLINICAL
 BIBLIOGRAPHY

3. INTRODUCTION
• The muscles around the mouth are responsible for
the movement of lips and cheek. They include:
1. Orbicularis oris -acts as sphincter.
2. Ten muscles- converging around the mouth act as
dilators.

4. ORBICULARIS ORIS
• It is a complex muscle which surrounds oral orifice
and forms the greater part of lips.
• Some of its fibres originate near the midline from
maxilla superiorly mandible inferiorly.
Nerve supply - supplied by buccal branch of facial
nerve.
Action - pouting, pursing, twisting etc.

5. TEN PAIRED MUSCLES COVERING
AROUND THE MOUTH
1. LEVATOR LABII SUPERIORIS ALEQUE NASI
2. LEVATOR LABII SUPERIORIS
3. LEVATOR ANGULI ORIS
4. ZYGOMATIC MINOR
5. ZYGOMATIC MAJOR
6. RISORIUS
7. DEPRESSOR LABII INFERIORIS
8. DEPRESSOR ANGULI ORIS
9. BUCCINATOR
10. MENTALIS

6. Levator labii superioris alaequae nasi
Origin – Upper part of the frontal
process of maxilla
Insertion – Greater ala cartilage of nose
and skin over it , some fibers into
lateral part of upper lip.
Action – Raises and everts the upper lip,
increases the curvature of top of
nasolabial furrow , dilates the nostrils.

7. Levator labii superioris
Origin – Maxilla above the
infraorbital foramen.
Insertion – Upper lip
Action – Elevates and everts the
upper lip, modifies the nasolabial
furrow.

8. Levator anguli oris
Origin – From the maxilla below infra
orbital foramen.
Insertion – Into and below the angle of
mouth.
Action- It raises the angle of mouth.

9. Zygomatic major
Origin – Zygomatic bone just in
front of zygomaticotemporal
suture.
Insertion – At the angle of the
mouth.
Action – Draws the angle of the
mouth upwards and laterally as
in laughing.

10. LAUGH

11. Zygomatic
minor
Origin – Zygomatic bone
Insertion – Muscular substances
of upper lip.
Action – Elevates the upper lip,
exposing the max teeth ,
deepening and elevating
nasolabial furrow, curl the
upper lip in smiling, contempt.

12. Risorius (grinning muscle)
Origin – Fascia covering the parotid fascia a
continuation of posterior fibers of platysma.
Insertion - Angle of mouth.
Action – Pulls the corner of the mouth laterally.
- Grinning and laughing.

13. GRINNING

14. Depressor labii inferioris
Origin – Oblique line of the mandible.
Insertion – Into the skin and
mucosa of lower lip.
Action – Draws the lower
lip downwards and little
laterally and assist in
eversion of lower lip.

15. Depressor angular oris
Origin – Posterior
part of the oblique
line of mandible.
Insertion – At the angle of the
Mouth.
Action – Draws the angle of
mouth downwards and laterally
in opening mouth, expressing
sadness.

16. sadness

17. Mentalis
Origin – Incisive fossa of mandible .
Insertion – Skin of the chin.

18. Buccinator (whistling muscle)
Origin
 Upper fibers from outer surface of
alveolar process of maxilla and
mandible-opposite three molar teeth.
 Fibrous band extend from
pterygoid hamulus to
maxillary tuberosity.
 Pterygomandibular raphe which
extends from the pterygoid hamulus to
the mandible behind third molar teeth.

19. Buccinator (whistling muscle)
Insertion
 Upper fibre's into upper lip ,
 Lower fibers into lower lip ,
 Upper of middle fibers cross the angle of
mouth to run into lower lip and lower of
these fibres; similarly run into upper lip

20. Innervation – Buccal branch of facial nerve.
• Action – Compresses the cheek against the
teeth and gums during mastication, and assist
the tongue in directing food b/w the teeth.

21. CLINICAL
• Paralysis of orbicularis oris
• Paralysis of buccinator muscle
• Modiolus -dense, compact, mobile, Fibromuscular
mass situated about 1.25cm lateral to the angle of
mouth.
o Pulsations of facial artery can be felt just lateral to
modiolus .

22. BIBLIOGRAPHY
 Textbook of Anatomy by VISHRAM SINGH
 Gray's Anatomy, 41th edition
 Grants Atlas of Anatomy, 14th edition.
 Textbook of anatomy by AK Dutta

23. A man's face is his
autobiography
-Oscar
THANK
YOU