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 secretion.
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 :
Palatine aponeurosis (tendon of tensor villi palatine)
Levator villi palatine and palatophyryngeus (lies superior to the palatine 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
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