1. SUBMANDIBULAR REGION I
Dr. Ahmed Fathalla Ibrahim

2. SUPRAHYOID MUSCLES DIGASTRIC MUSCLE: Origin: by 2 bellies:
Anterior belly: from digastric fossa of mandible
Posterior belly: from mastoid notch
Insertion: both bellies unite in an intermediate tendon held by a fibrous loop into the hyoid bone
Nerve supply:
Anterior belly: nerve to myelohyoid
Posterior belly: facial nerve

3. SUPRAHYOID MUSCLES STYLOHYOID MUSCLE: Origin: styloid process
Insertion: hyoid bone
Nerve supply: facial nerve

4. SUPRAHYOID MUSCLES MYELOHYOID MUSCLE:
Origin: myelohyoid line of mandible
Insertion: the muscles on both sides meet in a median raphe extending from symphysis menti to hyoid bone
Nerve supply: nerve to myelohyoid

5. SUPRAHYOID MUSCLES GENIOHYOID MUSCLE: Origin: inferior genial tubercle
Insertion: hyoid bone
Nerve supply: ventral ramus of C1

6. ACTIONS OF SUPRAHYOID MUSCLES
Fixation of hyoid bone (acting with infrahyoid muscles) during movement of tongue.
Depression of mandible to assist lateral pterygoid in opening of the mouth
Elevation of hyoid bone to elevate the floor of mouth & to improve tongue grip

7. EXTRINSIC MUSCLES OF TONGUE
STYLOGLOSSUS MUSCLE (MOST SUPERFICIAL):
Origin: styloid process
Insertion: whole length of side of tongue
Action: the muscles on both sides draw the tongue upwards & backwards

8. EXTRINSIC MUSCLES OF TONGUE
HYOGLOSSUS MUSCLE:
Origin: hyoid bone
Insertion: posterior half of side of tongue
Action: the muscles on both sides depress the tongue

9. EXTRINSIC MUSCLES OF TONGUE
GENIOGLOSSUS (DEEPEST MUSCLE):
Origin: superior genial tubercle
Insertion: whole length of side of tongue
Action: the muscles on both sides protrude the tongue

10. EXTRINSIC MUSCLES OF TONGUE
PALATOGLOSSUS:
Origin: soft palate
Insertion: back of side of tongue
Action: the muscles on both sides draw the tongue towards soft palate

11. NERVE SUPPLY OF EXTRINSIC MUSCLES OF TONGUE
ALL MUSCLES ARE SUPPLIED BY HYPOGLOSSAL (12TH CRANIAL) NERVE EXCEPT: PALATOGLOSSUS (BY CRANIAL PART OF ACCESSORY NERVE)

12. SUBMANDIBULAR REGION (Ramus of mandible is removed)P.
Styloglossus
Hyoglossus
Sublingual
gland
Myelohyoid
Stylohoid M A N D I B L E
Submandibular
Gland
(Superficial part)
Digastric
Posterior belly
Hyoid bone
Digastric
Anterior belly

13. SUBMANDIBULAR REGION (Superficial part of submandibular gland is removed)
Styloglossus
Sublingual
gland
Hyoglossus
Myeolohyoid M A N D I B L E
Deep part of
submandibular
gland
Digastric
Posterior Belly
Hyoid bone
Digastric
Anterior belly

14. RELATIONS OF HYOGLOSSUS (Myelohyoid & digastric muscles are removed)
Styloglossus
Stylopharyngeus
Lingual
nerve
Sublingual
gland
Deep part of
submandibular
gland
Submandibular
ganglion
Submandibular
duct
Stylohyoid
ligament
Glossopharyngeal
nerve
Hyoglossus
Genioglossus
Hypoglossal
nerve
External
carotid
artery
Lingual
artery
Geniohyoid

15. SUBMANDIBULAR REGION 1 3 2

16. LINGUAL ARTERY
BEGINNING: from anterior aspect of external carotid artery, in the carotid triangle, opposite the tip of greater cornu of hyoid bone
COURSE: has a tortuous course, divided into 3 parts:
FIRST PART: forms a loop crossed by hypoglossal nerve
SECOND PART: runs along upper border of greater cornu of hyoid bone, deep to hyoglossus
THIRD PART: ascends along anterior border of hyoglossus & runs along the under surface of tongue to reach its tip & anastomoses with artery of opposite side

17. BRANCHES OF LINGUAL ARTERY
FROM FIRST PART: Suprahyoid artery: runs along upper border of greater cornu of hyoid bone, superficial to hyoglossus, supplying adjacent muscles
FROM SECOND PART: Two dorsal lingual arteries: supply dorsum of tongue
FROM THIRD PART: Sublingual artery: supplies sublingual gland & mucous membrane of floor of mouth
N.B.: VEINS CORRESPONDING TO BRANCHES OF LINGUAL ARTERY UNITE TO FORM A SINGLE LINGUAL VEIN THAT DRAINS INTO INTERNAL JUGULAR VEIN

18. SUBMANDIBULAR GANGLION
It is a small parasympathetic ganglion lying superficial to hyoglossus & is connected to lingual nerve by 2 roots (anterior & posterior)
Origin of fibers: superior salivary nucleus in pons
Preganglionic fibers:
Runs along chorda tympani branch of facial nerve
Chorda tympani transmits fibers to lingual nerve branch of mandibular nerve
Lingual nerve transmits fibers to ganglion through posterior root

19. SUBMANDIBULAR GANGLION
Postganglionic fibers:
To submandibular gland: fibers are distributed directly to the gland
To sublingual gland:
Fibers pass along anterior root to lingual nerve again
Lingual nerve transmits fibers to sublingual gland

20. RELATIONS OF HYOGLOSSUS
SUPERFICIAL (LATERAL):
2 MUSCLES: myelohyoid, styloglossus
2 NERVES: lingual, hypoglossal
2 GLANDS: superficial & deep parts of submandibular glands
2 SUBMANDIBULAR: duct & ganglion

21. RELATIONS OF HYOGLOSSUS
DEEP (MEDIAL):
1 MUSCLE: genioglossus
1 NERVE: glossopharyngeal
1 VESSEL: Lingual
1 LIGAMENT: stylohyoid