13: Oral Cavity

CHAPTER 13

ORAL CAVITY

Overview and Topographic Anatomy

External Anatomy

Boundaries of the Oral Cavity

Teeth

Vascular Supply of the Oral Cavity

Nerve Supply of the Oral Cavity

Salivary Glands

Clinical Correlates

Imaging

Questions

Overview and Topographic Anatomy

GENERAL INFORMATION

Oral cavity: the space located between the lips and cheeks on the external surface to the palatoglossal fold on the internal surface

The oral cavity is important in mastication, tasting, and talking

The area of the oral cavity can be divided into:

Vestibule—the area between the teeth and lips or cheek

Oral cavity proper—the area located internal to the teeth

Posteriorly, the oral cavity is continuous with the oropharynx

The hard palate and the soft palate are important boundaries within the oral cavity

The tongue is a major structure located on the oral cavity floor

All of the major salivary glands—parotid, submandibular, and sublingual—drain into the oral cavity

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External Anatomy

EXTERNAL FEATURES

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VASCULAR SUPPLY OF THE LIPS AND CHEEK

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NERVE SUPPLY

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Boundaries of the Oral Cavity

GENERAL INFORMATION

Boundary

Structure

Superior

The roof is the hard palate

Posterosuperior

Soft palate

Lateral

Cheeks

Inferior

The floor is located along the lingual border of the mandible forming a horseshoe-shaped region

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SUPERIOR BORDER: HARD PALATE

The superior border (or roof) of the oral cavity is the hard palate, comprising the anterior 2/3 of the entire palate

Separates the oral cavity from the nasal cavity

Composed of:

Palatal process of the maxilla

Horizontal process of the palatine

In the anterior midline, an incisive foramen is located on the right and left sides that transmits the terminal branches of the nasopalatine nerve and sphenopalatine vessels

In the posterolateral region of the hard palate, the greater and lesser palatine foramina are located on the right and left sides; these openings transmit the greater and lesser palatine nn. and vessels

The bones of the hard palate are covered by a thick mucous membrane

The mucous membrane has a small elevation in the anterior midline called the incisive papilla that overlies the incisive foramen

Moving posteriorly from the incisive papilla, the mucous membrane has a thick midline palatal raphe

Lateral transverse ridges called transverse rugae (plicae) are located along the mucous membrane of the hard palate

Deep to the mucous membrane of the hard palate are numerous mucus-secreting glands called palatal glands

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POSTEROSUPERIOR BORDER: SOFT PALATE

The posterosuperior border of the oral cavity is the soft palate

The soft palate is the continuation of the palate posteriorly and makes up approximately 1/3 of the entire palate

The soft palate separates the oral cavity from the nasopharynx

An abundance of mucus-secreting palatal glands, which are continuous with the hard palate, are located in the soft palate

The soft palate has 3 margins:

Anteriorly, it is continuous with the hard palate at the vibrating line

Posterolaterally, it forms the superior portion of the palatoglossal and palatopharyngeal folds

Posteriorly, the uvula hangs in the center of the posterior free margin

The thick palatine aponeurosis forms the foundation of the soft palate

The soft palate is composed of 5 muscles:

Musculus uvulae

Tensor veli palatini

Levator veli palatini

Palatopharyngeus

Palatoglossus (sometimes considered in the grouping of tongue muscles)

The soft palate helps close off the nasopharynx during deglutition by forming a seal at the fold of Passavant

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LATERAL BORDER: CHEEK

The lateral border of the oral cavity extends anteriorly from the labial commissure, posteriorly to the ramus of the mandible

Superior limit of the cheek is the maxillary vestibule; inferior limit is the mandibular vestibule

Mucous membrane of the cheek is stratified squamous epithelium

Fordyce’s spots are ectopic sebaceous glands that may be observed on the inner surface of the cheek

Parotid papilla is located in the cheek opposite the maxillary 2nd molar

Pterygomandibular raphe is located in the posterior portion and serves as a landmark for the pterygomandibular space

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INFERIOR BORDER: FLOOR OF THE ORAL CAVITY

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Teeth

GENERAL INFORMATION

Teeth are hard structures attached to the jaws and involved primarily in eating

2 arches contain the teeth:

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Jan 5, 2015 | Posted by in General Dentistry | Comments Off on 13: Oral Cavity
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