The oral cavity and oropharynx are described in detail. The oral cavity extends from the lips to the oropharyngeal isthmus and includes structures like the cheeks, gums, hard palate, oral tongue, and floor of mouth. The oropharynx is behind the soft palate and serves as a passageway for food and air. It includes the base of tongue, palatine tonsils, soft palate, and pharyngeal wall. Both areas have detailed descriptions of anatomy, blood supply, nerve supply, lymphatic drainage and functions.

1. Oral Cavity And Oropharynx
Capt. Kyaw Swar Min
PG -1 (ORL-HNS)
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3.  The mouth can be subdivided into the vestibule (external to the teeth) and the
oral cavity proper (internal to the teeth).
 The mouth extends from the lips and cheeks externally to the anterior pillars of
the fauces (palatoglossal arches) internally, where it continues into the
oropharynx.
 The roof of the mouth is the palate and separates the oral and nasal cavities.
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4.  The floor of the mouth is formed by the mylohyoid muscles and is
occupied mainly by the tongue.
 The lateral walls of the mouth are defined by the cheeks and retromolar
regions.
 Opening into the mouth are three pairs of major salivary glands (parotid,
submandibular and sublingual) and numerous minor salivary glands
(labial, buccal, palatal, lingual).
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7. Oral cavity
• The oral cavity extends from
the lips to the oropharyngeal
isthmus, i.e. up to the level
of anterior pillar of tonsils.
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9. 1.lips- They form anterior boundary
of the oral vestibule .
-covered externally by skin and
internally by mucous membrane
(labial mucosa)
- have a muscular skeleton, the
orbicularis oris muscle.
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10. • In the upper lip, the vermilion
protrudes externally in the
midline to form the tubercle,
above which is situated a
grooved region termed the
philtrum.
• -The lower lip shows a
slight depression corresponding
to the tubercle.
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11. 2. Buccal or Cheek mucosa
- The cheeks are covered externally by
skin and internally by mucous
membrane (buccal mucosa) and have
a muscular skeleton, the buccinator.
-Internally, the pink mucosa of the
cheek adheres firmly to the buccinator
muscle.
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12. 3. Gums (gingivae)
-They surround the teeth and cover the upper and
lower alveolar ridges.
4. Retromolar trigone
-It is a triangular area of mucosa covering anterior
surface of the ascending ramus of
mandible.
-Its base is posterior to the last molar while its apex
is adjacent to the tuberosity of maxilla.
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13. 5. Hard palate
-It forms roof of the oral cavity.
-The skeleton of the hard palate is
formed by the palatine processes of
the maxillae and the horizontal plates
of the palatine bones.
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14. 6. Oral tongue
-Only anterior two-thirds of tongue are
included in the oral cavity.
-Posterior one-third or base of tongue is
situated behind the circumvallate papillae
and forms part of the oropharynx.
-Oral tongue is divided into tip, lateral
borders, dorsum and the undersurface.
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15. 7. Floor of the mouth
-This comprises a small horse shoe-
shaped region beneath the tongue .
-Near the base of the tongue in the
midline, a fold of tissue called the
lingual frenum is seen to extend onto
the inferior surface of the tongue.
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16. -The sublingual papilla is a
conspicuous centrally positioned
protuberance at the base of the
tongue.
-The submandibular salivary ducts
open into the mouth at this papilla.
-On either side of the sublingual
papilla are the sublingual folds,
beneath which lie the
submandibular ducts and
sublingual salivary glands.
-The muscle forming the floor of
the mouth is the mylohyoid muscle
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17. -The aperture of communication
between the mouth and pharynx, the
oropharyngeal isthmus, is situated
between the soft palate above and the
dorsum of the tongue below, bounded
on both sides by the palatoglossal
arches.
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18. -Each palatoglossal arch runs
downwards, laterally and forwards and
contains the palatoglossus muscle with
its covering mucous membrane.
-The approximation of the arches, to shut
off the mouth from the oropharynx, is
essential to deglutition.
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19. Blood supply of mouth & oral cavity
Arteries
1) Inferior dental artery- supplies mandible and mandibular teeth.
2) Lingual artery- supplies tongue and floor of mouth
3) Maxillary artery- supplies palate and upper jaw.
Veins
1) Veins from the tongue unite to form lingual vein, which join common facial or
internal jugular vein.
2) The veins corresponding to the branches of maxillary artery open into pterygoid
plexus ,then to posterior facial vein. 19

20. 3) The plexus is connected to cavernous sinus by an emissary vein.
4) Venous drainage from the lips enter anterior facial veins.
Nerve supply of the oral cavity
Sensory
-Roof: by greater palatine and nasopalatine nerves ( branches of maxillary nerve)
-Floor: by lingual nerve ( branch of mandibular nerve)
Motor
-Muscle in the cheek (buccinator) and the lip (orbicularis oris) are supplied by the
branches of the facial nerve.
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21. Lymphatic Drainage of Oral Cavity
1. Lips. Lower- Medial portion of lower lip drains into submental and lateral portion to
submandibular nodes. Upper- Drain into preauricular, infraparotid and submandibular
nodes.
2. Buccal mucosa. Submental and submandibular nodes.
3. Upper and lower alveolar ridges. Buccal aspect of mucosa drains into submental and
submandibular nodes. Lingual aspect of upper alveolus drains into upper deep cervical
and lateral retropharyngeal nodes. Lingual aspect of lower alveolus drains into
submandibular nodes.
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22. 4. Hard palate. Upper deep cervical and lateral retropharyngeal nodes.
Anterior part of palate drains into submandibular nodes.
5. Floor of mouth. Anterior portion of floor of mouth drains into
submandibular nodes. Lymphatics from this area also cross the midline.
Posterior portion drains into upper deep cervical nodes.
6. Tongue. Tip of tongue drains into submental and jugulo-omohyoid nodes;
lateral portion drains into ipsilateral, submandibular and deep cervical nodes.
Central portion and base drain into deep cervical nodes of both sides.
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23. Anatomy of tongue
Tongue- Mass of striated muscles covered with the mucous membrane
Divided into right and left halves by a median septum
Four parts:
1-Oral (anterior ⅔)
2-Pharyngeal (posterior ⅓)
3-Root (base)
4-Tip
Two surfaces:
1-Dorsal
2-Ventral 23

24. Dorsal Surface
• Divided into anterior two third and
posterior one third by a V-shaped
sulcus terminalis.
• The apex of the sulcus faces
backward and is marked by a pit
called the foramen cecum
• Foramen cecum, an embryological
remnant, marks the site of the upper
end of the thyroglossal duct
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25. Dorsal Surface contained
Anterior two third: mucosa is rough,
shows three types of papillae:
1-Filliform
2-Fungiform
3-Vallate
Posterior one third: No papillae but
shows nodular surface because of
underlying lymphatic nodules, the lingual
tonsils
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26. • Ventral Surface Smooth (no papillae)
• In the midline anteriorly, a mucosal fold,
frenulum connects the tongue with the floor
of the mouth
• Lateral to frenulum, deep lingual vein can be
seen through the mucosa
• Lateral to lingual vein, a fold of mucosa
forms the plica fimbriata
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27. Muscles of the Tongue
- The tongue is composed of two types of muscles:
Intrinsic and Extrinsic
Intrinsic Muscles- it confined to tongue ,no bony
attachment ; consist of:
-Longitudinal fibers(superior and inferior)
-Transverse fibers
-Vertical fibers
Function: Alter the shape of the tongue.
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28. • Inferior Longitudinal: moves tip up &
down
• Superior Longitudinal: moves tip up &
down
• Transverse: narrows & lengthens
tongue
• Vertical: flattens & depresses tongue
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29. Extrinsic Muscles
• Connect the tongue to the surrounding structures: the soft palate and
the bones (mandible, hyoid bone, styloid process)
Include:
• Palatoglossus
• Genioglossus
• Hyoglossus
• Styloglossus
• Function: Help in movements of the tongue
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31. • Movements Protrusion: Retraction: Depression:
Elevation:
• Protrusion and deviate the tongue to opposite
-Genioglossus on both sides acting together.
• Retraction:
-Styloglossus and hyoglossus on both sides acting together
• Depression:
-Hyoglossus and genioglossus on both sides acting together
• Elevation:
-Styloglossus and palatoglossus on both sides acting together
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32. Sensory Nerve Supply Anterior ⅔
• General sensations: Lingual nerve
• Special sensations : chorda tympani
Posterior ⅓:
• General & special sensations: glossopharyngeal nerve
Base:
• General & special sensations: internal laryngeal nerve
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33. Motor Nerve Supply
• Intrinsic muscles: Hypoglossal nerve
• Extrinsic muscles:
All supplied by the hypoglossal nerve, except the palatoglossus
The palatoglossus supplied by the pharyngeal plexus
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34. Blood Supply
Arteries:
Lingual artery
Tonsillar branch of facial artery
Ascending pharyngeal artery
Veins
Lingual vein, ultimately drains into the internal jugular vein
Dorsal lingual vein
Lingual vein
Deep lingual vein
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35. Phxarynx
• Pharynx is a conical fibromuscular tube forming upper part of the air and food
passages.
• It is 12 - 14 cm long, extending from base of the skull (basiocciput and
basisphenoid)to the lower border of cricoid cartilage where it becomes continuous
with the oesophagus.
• The width of pharynx is 3.5 cm at its base and this narrows to 1.5 cm at
pharyngo-oesophageal junction.
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38. Structure of Pharyngeal Wall
• From within outwards it consists of four layers:
a. Mucous membrane
b. Pharyngeal aponeurosis (pharyngobasilar fascia)
c. Muscular coat
d. Buccopharyngeal fascia
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39. Anatomy of oropharynx
• The four subsites contained within the oropharynx are the base of the tongue, the
palatine tonsils and tonsillar pillars, the soft palate, and the pharyngeal wall.
• The oropharynx is behind the soft palate of the mouth and is below the
nasopharynx. It serves as a passageway for food moving from the mouth to the
esophagus and for air moving to and from the nasal cavity.
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40. • The oropharynx is defined anatomically
by certain boundaries as well. It is bound
superiorly by the plain of hard palate and
inferiorly by the plain of hyoid bone.
• The oropharynx consists of the
pharyngeal wall between the
nasopharynx and the pharyngoepiglottic
fold, the soft palate, the tonsillar region,
and the tongue base.
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41. • The anterior margin of the oropharynx
is formed by a plane that joins the
posterior border of the soft palate, the
anterior tonsillar pillars, and the
circumvallate papillae.
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42. • The superior border of the oropharynx is
located at the soft palate and the ridge of
pharyngeal musculature (Passavant's ridge)
that opposes the soft palate when the soft
palate is elevated.
• The oropharynx is bordered inferiorly by
the vallecula.
• The posterior border of the oropharynx is
formed by the posterior pharyngeal wall.
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43. • The lateral margin consists of the tonsillar
regions. The tonsillar region consists of the
anterior tonsillar pillar (i.e., palatoglossus
muscle), posterior tonsillar pillar (i.e.,
palatopharyngeus muscle), and the lymphoid
tissue–containing fossa situated between these
two pillars, called the palatine (faucial) tonsil.
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44. Lymphatic Drainage
• Lymphatics from the oropharynx drain into upper jugular chain particularly the
jugulodigastric (tonsillar) node.
• The soft palate, lateral and posterior pharyngeal walls and the base of tongue also
drain into retropharyngeal and parapharyngeal nodes and from there to the
jugulodigastric and posterior cervical group.
• The base of tongue may drain bilaterally.
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45. Functions of Oropharynx
1. As a conduit for passage of air and food .
2. Helps in the pharyngeal phase of deglutition.
3. Forms part of vocal tract for certain speech sounds.
4. Helps in appreciation of the taste. Taste buds are present in the base of tongue ,
soft palate, anterior pillars and posterior pharyngeal wall.
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46. Thank you
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