Download Objectives

Dr. Mohamed Ahmad Taha Mousa
Assistant Professor of Anatomy and Embryology
Objectives
a. Identify different components of the oral cavity
b. Describe the relationships of salivary glands to its
surrounding structures
Mouth
Lips: They are two folds surrounding the oral
orifice.
- It is formed by orbicularis oris muscle
covered by mucous membrane.
Mouth cavity: It extends from the lips to the
pharynx.
- It is divided into the vestibule and the mouth
cavity proper.
A. Vestibule: It lies between:
- Lips and cheeks  Externally.
- Gums and teeth  Internally.
- The cheek is made up by the buccinator
muscle and is lined with mucous membrane.
- The duct of the parotid gland: It opens into
the vestibule of the mouth opposite the upper
2nd molar tooth.
B. Mouth cavity proper: It has roof and floor.
- Roof of mouth: It is formed by the hard
palate in front and the soft palate behind
- Floor of mouth: It is formed by the anterior
2/3 of the tongue.
- The duct of the submandibular gland opens
onto the floor of the mouth on either side of
frenulum of the tongue.
- The sublingual gland projects up into the
floor of the mouth producing the sublingual
fold.
- Numerous ducts of the gland open on the
summit of the fold.
Sensory innervations of the mouth:
Roof: Greater palatine and nasopalatine
nerves from maxillary division of the
trigeminal nerve.
Floor:
A- General sensation by lingual nerve (branch
from mandibular division of the trigeminal N).
B- Taste sensation by the chorda tympani nerve
(branch from the facial N).
Cheek: Buccal nerve (branch from mandibular
division of the trigeminal nerve).
Teeth: Deciduous teeth: There are 20 deciduous
teeth.
Permanent teeth: There are 32 permanent
teeth.
Tongue: It is a mass of striated muscle covered
by mucous membrane.
Mucous membrane of the tongue: It is divided
by a V-shaped sulcus (sulcus terminalis) into
anterior 2/3 (oral part containing papillae) and
posterior 1/3 (pharyngeal part containing
lingual tonsils).
- The apex of the V shaped is the foramen cecum
Muscles of the tongue: It divided into two types
A- Intrinsic muscles: They consists of
longitudinal, transverse and vertical fibers.
B- Extrinsic muscles: It includes genioglossus,
hyoglossus, styloglossus and palatoglossus.
- Nerve supply: All of intrinsic and extrinsic
muscles are supplied by hypoglossal nerve
except palatoglossus muscle is supplied by
pharyngeal plexus.
Blood supply: - Lingual artery, facial artery,
and ascending pharyngeal artery.
- The veins drain into the internal jugular vein.
Lymph drainage: Submental, Submandibular
and deep cervical lymph nodes
Sensory innervations:
- Anterior 2/3: General sensation by lingual
nerve
- Taste sensation by chorda tympani nerve.
- Posterior 1/3: Glossopharyngeal nerve
(general and taste sensation).
The Palate
- It forms the roof of the mouth and the floor of
the nasal cavity.
- It is divided into two parts:
A. Hard palate: It is formed by:
- Palatine processes of the maxillae.
- Horizontal plates of the palatine bones.
B. Soft palate: It is a mobile fold attached to
the posterior border of the hard palate.
- Its free posterior border presents in the
midline a conical projection called the uvula.
- It is composed of muscles, palatine
aponeurosis and covered by mucous
membrane.
Mucous membrane: It covers the upper and
lower surfaces of the soft palate.
Palatine aponeurosis: It is a fibrous sheet
attached to the posterior border of the hard
palate.
Muscles of the soft palate: It includes tensor
veli palatini, levator veli palatini,
palatoglossus, palatopharyngeus and
musculus uvulae.
Nerve supply of the palate:
Sensory: - Greater, lesser palatine and
nasopalatine nerves (from the maxillary
division of the trigeminal nerve).
- Glossopharyngeal nerve also supplies the soft
palate.
Motor: - All muscles are supplied by cranial
part of the accessory nerve via the pharyngeal
plexus except tensor veli palatini supplied by
mandibular nerve.
Blood supply of the palate:
- Greater palatine branch of the maxillary
artery.
- Ascending palatine branch of the facial artery.
- Ascending pharyngeal artery
Lymph drainage: Deep cervical lymph nodes.
Parotid gland
Definition: It is the largest salivary gland and
it is composed mostly of serous acini.
Site: It lies in a deep hollow below the external
auditory meatus, behind the ramus of the
mandible and in front of sternocleidomastoid
muscle.
Parts of the glands: The facial nerve divides
the gland into superficial and deep lobes.
Parotid duct: - It emerges from the anterior
border of the gland and passes over the lateral
surface of masseter.
- It opens in the vestibule of the mouth
opposite the upper 2nd molar tooth.
Relation of parotid gland: It is pyramidal form.
- The concave superior surface (base): It is
related to external auditory meatus,
temporomandibular joint and auriculotemporal
nerve.
- Apex: It overlaps the posterior belly of
digastric
- Superficial surface: It is covered by skin and
superficial fascia containing great auricular
nerve and superficial parotid lymph nodes).
- Anteromedial surface: It is related to masseter
muscle, posterior border of the ramus of the
mandible and medial pterygoid muscle.
- Posteromedial surface: It is related to:
- Mastoid process, sternocleidomastoid and
posterior belly of the digastric.
- Styloid process and its associated muscles.
- Carotid sheath containing (internal carotid
artery, vagus nerve and internal jugular vein)
and it is separated from the gland by the styloid
Structures within the parotid gland:
1. External carotid artery: It is the deepest
structures in the gland and it divides into
maxillary and superficial temporal artery.
2. Retromandibular vein: It is formed by
union of the maxillary and superficial
temporal veins.
- It is superficial to the external carotid artery.
3. Facial nerve: It is the most superficial.
Nerve supply:- Parasympathetic secretomotor
supply from the glossopharyngeal nerve 
tympanic branch  lesser petrosal nerve
relay in otic ganglion  
auriculotemporal
nerve
- Sensory supply: By auriculotemporal nerve.
Blood supply: It is supplied by the external
carotid artery.
- Veins drain into the external jugular vein.
Submandibular salivary gland
Structure: It is consists of a mixture of serous
and mucous acini.
Site: - It is situated in the digastric triangle.
Relation : -Inferior surface: It is covered by
skin, superficial fascia containing (platysma,
facial vein and cervical branch of the facial
nerve) and deep fascia.
- Lateral surface: It is related to submandibular
fossa on the body of the mandible.
- Facial artery grooves its posterosuperior part
then it lies between the lateral surface of the
gland and mandible.
- Medial surface: It is related to:
- Mylohyoid muscle, mylohyoid nerve and
vessels
- Hyoglossus, lingual nerve, submandibular
ganglion and hypoglossal nerve.
- Styloglossus, stylohyoid ligament and
Submandibular duct: It emerges from the
anterior end of the deep part of the gland then it
opens into the mouth at both sides of the
frenulum of the tongue.
Arterial supply: It is supplied by facial and
lingual arteries.
Lymphatic drainage: It drain into the deep
cervical lymph nodes
Nerve supply: - Parasympathetic secretomotor
supply is from the facial nerve via the chorda
tympani and the submandibular ganglion. The
postganglionic fibers pass directly to the gland
- General sensation by lingual nerve.
Sublingual gland
Structure: It has both serous and mucous acini,
with the latter predominating.
Site: It lies under the mucous membrane
(sublingual fold) of the floor of the mouth,
close to the frenulum of the tongue.
Sublingual ducts (8 to 20 in number): It
opens into the mouth on the summit of the
sublingual fold.
Arterial supply: It is supplied by facial and
lingual arteries.
Nerve supply: - Parasympathetic
secretomotor supply is from the facial nerve
via the chorda tympani  relay in the
submandibular ganglion  Postganglionic
fibers pass directly to the gland.
Thank you