Oral cavity

Oral cavity

The oral cavity is divided into three parts
Vestibule
Oral fissure
Oral cavity proper

VESTIBULE:

 space between oral cavity proper and cheeks
 
It communicates with oral fissure
The parotid duct opens in the vestibular region beside the second maxillary molar
 
The entire vestibule is lined by mucous membrane
 
Several glands open in the vestibule
 
The oral vestibule connects with the gums through the frenula of the lips
 
Clinical feature: in the case of parotid calculi the dye is injected through the parotid duct in the vestibule 

CHEEKS:

Is fleshy flap of covering on both sides of the oral cavity

The surface between the oral fissure and the cheek is called a nasolabial sulcus

 

1. Skin

2. Superficial fascia

3. Fatty pads of the cheek( infraorbital fat pads, lateral orbital fatty pads and nasolabial fat pads)

4. Parotid duct

Deep to the masseter and slightly superficial to the buccinator buccal pad of fat is present, it drains the parotid gland secreation.

it is innervated by the facial and trigeminal nerve 

ORAL CAVITY PROPER:

  

anterior contents:

• Frenulum
• Sublingual papilla (with sublingual salivary duct opening)
• Sublingual mucous fold

Posterior relations: 

• tongue
• oropharyngeal isthmus

GUMS: 

2 parts
                1. free gum
                2.attached part which continues with periodontal

membrane

HARD PALATE:
 
Bones: 

 anterior one third - maxilla
Posterior one third - horizontal wall of the palatine.
 
Surfaces:

 anterior surface - continues with alveolar arch
Posterior surface-soft palate
Superior surface - floor of the nasal cavity
Inferior surface  - the roof of the oral cavity 

VESSELS OF HARD PALATE:

Arteries - a great palatine branch of the maxillary artery
Vein - pterygoid plexus of veins
Nerves - great palatine and lesser palatine branch of the maxillary nerve
Lymph - upper deep cervical nodes

SOFT PALATE

RELATIONS OF SOFT PALATE :

Anterior relation - marked by median raphe
Posterior surface - nasal cavity floor
Superior surface - hard palate
Inferior border - uvula and palatoglossal arch 

CONTENTS OF SOFT PALATINE  OF SOFT PALATE :

Palantine aponeurosis (tendon of tensor villi palantine)

Levator villi palantine and palatophyryngeus (lies superior to the palantine aponeurosis)

NERVE SUPPLY :

MOTOR NERVE :

 all five muscles except tensor villi palatine are supplied by the pharyngeal plexus.

Tensor villi palatine is supplied by the mandibular nerve

SENSORY NERVE:

The middle and posterior lesser palatine nerve

Glossopharyngeal nerve

 

GUSTATORY NERVE:

Comes from the nucleus of tractus solitarius

Supplies through lesser palatine nerve

 

SECRETOMOTOR PATHWAY:

From superior salivatory  nucleus 

MUSCLES OF SOFT PALATE 

PASSAVANT RIDGE :

The mucosal ridge formed by the superior constrictor and palatopharyngeal muscle

Covers the pharyngeal  isthmus between the nasopharynx and oropharynx

It is a U shaped loop of mucosae

Aka palatopharyngeal sphincter

Functions of soft palate :

Separates oro and nasopharynx

Forms passavent ridge

Control of voice using pharyngeal isthmus