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The oral cavity:
The lips:

- Are two muscular folds covered by skin, lined by

m.m & formed mainly by muscles including the
constrictors & dilators of the oral fissure

- The upper extends laterally to the nasolabial fold &

the lower extend inferiorly to the mentolabial fold

- The philtrum are two skin ridges end below at the

labial tubercle & above at the nasal septum

- The red margin (vemilion border) is covered by dry

transparent m.m which give the underling red color
of the highly vascular organ

- The upper lip is supplied by the infraorbital n. & the lower by the mental n.,

both are supplied by facial artery

- Labial glands are mucous gland in the submucosa & open by small individual

ducts to the surface of m.m

The cheeks;

- Resemble the lips in structure but their main muscle

is buccinator

- The fatty subcutaneous tissue (buccal pad of fat) is

very loose & transmits the parotid duct

- The buccal glands simulate labial glands

The gingivae;

- Consist of dense fibrous connective tissue firmly

attached to the underlying alveolar process

- Covered by smooth highly vascular m.m
- The gingivae also surround the necks of teeth
- The main blood supply to the upper gum are the

palatine arteries & to the lower is the lingual artery

Head & Neck Dr. Nawfal K. Al-Hadithi

Buccinator

The oral cavity:

• The mouth consists of two parts:

1-  The  vestibule;  is  the  narrow  cavity  in  the
interval  between  the  gums  &  teeth  on  one  side
and the lips & cheeks on the other side.
2-  The  mouth  proper;  is  the  part  of  the  cavity
within the alveolar arches roofed by the palate,
floored by the mylohyoid muscle & contains the
tongue.
The roof of the mouth:
1- The hard palate;

- Forms the anterior 2/3 of the roof, it is

formed  in  its  anterior  2/3  by  the  palatal
process  of  maxilla  &  in  its  posterior  1/3
by  the  horizontal  plate  of  the  palatine
bone.

- The m.m is firmly bounded to the

periosteum (mucoperiosteum) especially
in the anterior part therefore any
injection in this area is severely painful.

- It is supplied by the greater palatine &

terminal parts of nasopalatine vessels &
nerves.

Head & Neck Dr. Nawfal K. Al-Hadithi

Soft palate

2- The soft palate; will be discussed later.
The tongue:
-  The  tongue  is  a  highly  mobile  muscular  organ  important  for  mastication,
swallowing, taste & speech.
-  At  its  root  it  is  fixed  by  its  connection  to  the  palate  (palatoglossus),  pharynx
(superior constrictor) & epiglottis (glosso-epiglottic folds), while its anterior part is
free for movement
- It is partially separated into two symmetrical halves by a median septum of areolar
tissue
- Tongue is composed embryologically of
two  different  parts  which  possess
different structure, appearance & in nerve
supply  &  lymphatic  drainage,  they  are
the oral part (anterior 2/3) & pharyngeal
part (posterior 1/3).
-  The  anterior  2/3  is  separated  from  the
posterior  1/3  by  a  v-shape  sulcus
terminalis  whose  apex  is  directed
posteriorly  at  foramen  caecum  of  the
tongue
- The m.m of the anterior2/3 is fur-like &
adheres  to  the  underlying  muscles,  it  is
also characterized by the presence of the
filiform,  fungiform  &  vallate  papillae,
while m.m of the posterior 1/3 is smooth
&  movable  over  the  muscle  &  shows
multiple  round  elevations  produced  by
the underlying lymphoid follicles (lingual
tonsil).

Head & Neck Dr. Nawfal K. Al-Hadithi

- Frenulum linguae is a m.m fold in the midline connects the
undersurface of the tongue to the floor of the mouth
Muscles of the tongue:

I. Intrinsic muscles;

- These are muscle fibers arranged within the tongue in three

directions, antero-posterior (superior & inferior longitudinal),
horizontal & vertical

- They are attached by their ends to the m.m. & to the midline lingual septum
- Their contraction changes the shape of the tongue, the size of the tongue mass

is static, any change in one dimension affects other dimensions, e.g; flattening
of the tongue (contraction of vertical group) is always associated with increase
side to side length of it an d so on.

II) Extrinsic muscles;
There are three muscles which are related to the
tongue,  they  connect  the  tongue  to  three
different  bones  &  their  contraction  alters  the
p o s i t i o n  &  d i r e c t i o n  o f  t h e  t o n g u e .
Palatoglossus, thogh it is a palatal muscle it will
be discussed here for its important action.
Hyoglossus:
Origin; upper border of greater horn & body of
hyoid
Insertion;  fibers  ascend  anteosuperiorly  to  be
inserted in the posterior part of the lateral border
of the tongue intermingling with other muscles.
Action; retracts the tongue & depresses its sides.
It also elevates the hyoid bone.
Genioglossus:

Head & Neck Dr. Nawfal K. Al-Hadithi

Origin; inferior genial tubercle
Insertion;  fibers  go  back  to  enter  the  substance  of
the  tongue  contributing  to  its  mass,  the  superior
fibers are inserted into the tip of the tongue, middle
fibers  into  the  dorsum  &  the  lowest  fibers  are
inserted inferiorly.
Action; -protracts the tongue
                    -the superior fibers brings the tip of the
tongue in contact with the floor of the mouth
                         -the dorsal fibers cause cupping of the
tongue
Styloglossus;
Origin; lower part of styloid process anteriorly
Insertion;  fibers  descend  anteroinferiorly  &
medialward to be inserted into the posterior part of
hyoglossus, the fibers entr the tongue & pass forward along its side
Action; retracts the tongue & deviates it laterally

Palatoglossus:
Origin;-oral surface of the palatine aponeurosis
Insertion; fibers arch down under the m.m of the mouth
raising the anterior pillar of the fauces (palatoglossal
arch) to be inserted into the side of the tongue.
Action; It is the opponent of LVP:
-sphincter of the fauces
-depresses the soft palate
-raises the tongue

Head & Neck Dr. Nawfal K. Al-Hadithi

Hyoglossus

Genioglossus

Inferior genial tubercle

Stylohyoid ligament

Nerve supply of lingual muscles:
All muscles of the tongue are supplied by the
hypoglossal nerve except palatoglossus which is
supplied (as a palatal muscle) by the pharyngeal plexus.
Sensory nerve supply of the tongue:

• Anterior 2/3;

-lingual n.; common sensation
-chorda tympani; taste sensation
Chorda tympani is an autonomic nerve derived
from nervus intermedius (VII?), it joins the Vc
just  below  the  base  of  the  skull  in  the  ITF  &
runs  in  its  lingual  branch  to  supply
parasympathetic  power  to  the  submandibular
ganglion & give taste fibers to the anterior 2/3
of the tongue

• Posterior 1/3;

glossopharyngeal nerve supplies it with both
types of senses

Arterial supply of the tongue:
Lingual artery:

This branch of ECA provides the tongue with
all its blood, at its origin (level with the tip of
grater horn of hyoid) it is crossed externally
by the XII nerve & posterior belly of
digastric & stylohyoid muscles. It passes
forward to lie deep to hyoglossus between it
& the septum of the tongue 5 mm deep to the
inferior surface of the tongue, it gives:

a. Dorsal lingual branches to the tongue

mass.

b. Sublingual branches to the sublingual

gland & floor of the mouth

Veins of the tongue:

Head & Neck Dr. Nawfal K. Al-Hadithi

Lingual n.

1- Deep lingual veins; two in number, accompany the lingual artery & receive similar
tributaries, they empty in the IJV

2- Veni comitans nervi hypoglossi; accompany the XII, bring blood from the tip, they
are larger than the deep veins & empty in the facial vein.

The floor of the mouth:

- The floor of the mouth is mylohyoid

Head & Neck Dr. Nawfal K. Al-Hadithi

Origin; mylohyoid line of the mandible
Insertion;

- The fibers descend downward & backward, those of anterior 2/3 interdigitate

with the opposite one in a midline raphe which extends from the symphysis
menti to the hyoid bone

- The posterior fibers reach

the  hyoid  bone  leaving  a
posterior  free  border  for  the
muscle  which  connects  the
o r a l  m o u t h  t o  t h e
submandibular triangle

Nerve  supply;  mylohyoid  nerve,
branch  of  the  inferior  alveolar
nerve
Action;

A. An essential swallowing

muscle,  by  wavy  elevation
of  the  tongue  from  anterior
to posterior direction against
the  palate  it  compresses  the
bolus backward

B. Moves the tongue changing

its position & direction

C. Elevates the hyoid & eventually the larynx

Structures in the floor of the mouth:

- A coronal section through the mid-mouth reveals a slit like cavity in the floor

of the mouth between mylohyoid laterally & the side of the tongue
(hyoglossus) medially.

- This cavity is covered with m.m of the floor of the mouth & contain important

structures in relation to the lateral surface of hyoglossus, these are:

*Lingual nerve above (hooks around the submandibular duct)
*Submandibular duct in the middle

Head & Neck Dr. Nawfal K. Al-Hadithi

*XII nerve is the lowest

- Structures deep to hyoglossus are:

*Deep lingual artery page 95
*Stylohyoid ligament page 93
*IX nerve

The soft palate:

- Is a triangular fold of m.m containing

aponeurosis of tensor palati, muscle fiber,
mucous glands, vessels & nerves

- It hangs from the posterior border of the hard

palate where its anterior surface will face
forward to the oral cavity & its posterior
surface faces backward

- The tip of the triangle contains a rounded mass

of muscle fibers (musculus uvulae) with
mucous glands it is called the uvula

- The main function of the soft palate is to act as

policeman between the airway & foodway
regulating swallowing in relation to berathing.

- Muscles of the soft palate are; tensor veli palatini, levator veli palatini,

palatoglossus, palatopharyngeus & musculus uvulae

Tensor veli palatini:

- One should think of this muscle as two triangles, a muscular one lies in the ITF

& an aponeurotic one in the oral cavity

- These two triangles are united to each other by a tendon which get access to

the mouth through the fibro-osseous canal produced by attachment of the
pterygomaxillary ligament between the pterygoid hamulus & maxillary
tuberosity

Head & Neck Dr. Nawfal K. Al-Hadithi

Origin:
The  muscular  triangle  in  the  ITF
arises by two of its limbs;
-  from  the  roof  of  ITF  (from  the
spine of sphenoid to the scaphoid
fossa)
-from  the  posterior  border  of
medial  pterygoid  plate  passing
over  the  cartilagenous  part  of  the
auditory tube
The  third  border  of  the  muscle  is
free

The  muscle  will  lie  in  the  fossa
between  the  medial  pterygoid  plate  &
muscle  to  taper  as  it  approaches  the
maxillary  tuberosity  into  a  slender
tendon
Insertion:
The  slender  tendon  after  entering  the
fibro-osseous  canal  expands  into
aponeurotic triangle with three borders:
-One  is  attached  to  the  posterior
border of the hard

palate

- The other will fuse with the opposite fellow
- The third will hang freely inside the

oropharynx suspending the uvula

Action:

Head & Neck Dr. Nawfal K. Al-Hadithi

Uvula

Contraction  of  TVP  causes  tension  of
the  soft  palate  (aponeurosis  of  the
muscle)  which  becomes  straight  &
lower  down  to  be  elevated  by  the
levator  muscle  to  fit  the  Passavant
ridge  in  the  junction  between  the  oro-
& nasopharynx separating the two.
Levator veli palatini:
Origin:  From  the  petrous  apex  &
cartilagenous part of the auditory tube
Insertion:  the  pencil-like  muscle
descends  deep  to  the  m.m  of  the
nasopharynx  elevating  a  ridge  near  the
tube orifice to be inserted into the dorsal
surface of the palatine aponeurosis
Action:  elevate  the  tense  palatine
aponeurosis  closing  the  naso  from
oropharynx
Both  TVP  &  LVP  contraction  opens  the
auditory tube since part of their origin is
taken  from  it  &  since  their  contraction
occurs  mainly  during  swallowing  this
process  will  open  the  auditory  tube
equalizing  pressure  on  both  sides  of  the
eardrum

Palatoglossus:”discussed”
Palatopharyngeus:
Origin:
- Nasal side of palatine aponeurosis
- Posterior part of the hard palate
Insertion:  fibers  arch  down  behind
palatoglossal fibers to raise the posterior
pillar  of  the  fauces  (palatopharyngeal
fold)  &  inserted  in  the  posterior  border
of the thyroid cartilage
Action: - depresses the soft palate
              - elevates the larynx in the early
stage of deglutition
Nerve supply of palatal muscles:
All  palatal  muscles  are  supplied  by  the

Head & Neck Dr. Nawfal K. Al-Hadithi

LVP

TVP

pharyngeal  branch  of  X  nerve  in  the  pharyngeal
plexus  except  TVP  which  is  supplied  by  nerve  to
medial pterygoid from the main trunk of Vc.
Arteries of the palate:
1- Greater palatine; hard palate
2- Long sphenopalatine; hard palate
3- Lesser palatine; soft palate
4- Ascending palatine br. of facial a.; soft palate
5- Palatine br. of ascending pharyngeal; soft palate
Veins of the palate:
Similar to arteries; pterygoid venous plexus
Nerves of the palate:
1- Greater palatine n.
2- Nasopalatine n.
3- Lesser palatine n.
4-  Pharyngeal  branch  of
PPG --> pterygo palatine ganglion
5- IX nerve.

100

Head & Neck Dr. Nawfal K. Al-Hadithi

Rt. & lt. Greater

palatine arteries

Lesser

palatine

arteries

Long
Sphenopalatine
aretry

Ascending

pharyngeal artery

Ascending palatine

artery

ﻭﻻ ﻛﻞ ﻛﻞ ﺍﻟﺨﺎﻟﻌﻴﻦ ﺍﺭﺍﺫﻝٌﻖﻳﺪﺻ ﺎﻬﺑﻮﺛ ﺔﻗﺍﺪﺼﻟﺍ ﺲﺒﻟ ﻦﻣ ﻞﻛ ﺎﻣﻭ

101

Head & Neck Dr. Nawfal K. Al-Hadithi

Nasopalatine nerve

Greater palatine nerves

Lesser palatine nerves

Pharyngeal branch of PPG