3. DH 150 LO3:Structures of the Oral Cavity

How are tooth surfaces divided vertically on the lingual or buccal (labial) aspect?

Mesial third, Middle third, Distal third.

How are proximal surfaces divided vertically?

Facial third, Middle third, Lingual third.

How is the crown divided horizontally?

Occlusal or incisal third, Middle third, Cervical third.

How is the root divided horizontally?

Cervical third, Middle third, Apical third.

What is the junction of two surfaces called?

A Line angle.

How many line angles do anterior teeth have?

Six.

Name the six line angles for anterior teeth.

Distolabial, Mesiolabial, Distolingual, Mesiolingual, Linguoincisal, and Labioincisal.

How many line angles do posterior teeth have?

Eight.

Name the eight line angles for posterior teeth.

Distobuccal, Mesiobuccal, Distolingual, Mesiolingual, Distoocclusal, Mesioocclusal, Buccoocclusal, and Linguoocclusal.

What is the point where three surfaces meet called?

A Point angle.

Name the four point angles for posterior teeth.

Mesiobuccoocclusal, Mesiolinguoocclusal, Distobuccoocclusal, and Distolinguoocclusal.

What is the space that exists between the lips or cheeks and the teeth?

The Vestibule.

What area is surrounded by the teeth or alveolar ridges back to the palatine tonsils, including the region from the floor of the mouth upward to the hard and soft palates?

The Oral Cavity Proper.

What is the transitional zone of reddish tissue between the skin and lips?

The Vermilion Border.

What is the indentation at the midline of the upper lip where a cleft lip might be formed at the lateral junction?

The Philtrum.

What small elevation of tissue located opposite the maxillary second molar contains the opening of the parotid gland (Stensen’s Duct)?

The Parotid papilla.

What structures border the vestibule posteriorly?

The Ramus of the mandible and the Zygomaticoalveolar crest (Cheekbone).

What is the point at which the mucosa of the lips or cheeks turns to go toward the gingiva?

The Mucobuccal Fold or Mucolabial Fold.

Describe Alveolar Mucosa.

It is loosely attached and movable, red, thin mucosa with the presence of blood, lying against the alveolar bone.

Why does alveolar mucosa appear redder than gingiva?

It is relatively thin tissue, allowing blood vessels underneath to be visible.

What tissue becomes lightly attached to the bone and is pink and thicker?

Gingiva.

What is the area where mucobuccal folds end and gingiva begins?

The Mucogingival Junction.

What is a fold of connective tissue in the vestibule that attaches the alveolar mucosa and contains no muscle tissue?

The Labial frenum.

What is any space in between teeth in the same arch called?

A Diastema.

What is a probable reason for a diastema between maxillary central incisors?

A firm, taut, labial frenum can affect the position of the erupting teeth.

What clinical manifestation moves into the vestibular space when the mouth is opened, complicating x-rays and impressions?

The Coronoid process.

What are Fordyce Granules?

Misplaced sebaceous glands.

How do Fordyce Granules appear?

As small yellowish granular structures embedded in the mucosa area.

What are small bony growths found on the buccal alveolar bone, more often on the mandible?

Exostoses.

What are the transverse ridges of epithelial and connective tissue found on the anterior portion of the hard palate?

Rugae.

What is the singular bulge of tissue located at the midline, immediately between (and lingual to) the central incisors?

The Incisive Papilla.

What structure beneath the incisive papilla carries nasopalatine nerves and blood vessels?

The Incisive Foramen.

Where are the Greater Palatine Foramina located?

Lingual to the second and third molars.

What clinical term refers to excess bony growth that occurs in the midline of the hard palate?

Torus Palatinus.

What is the anatomic division of the hard and soft palates at the midline of the mouth?

The Posterior Nasal Spine.

What are the two small depressions located on each side of the posterior nasal spine?

Fovea Palatinae.

What is the downward projecting muscle located at the midline of the soft palate?

The Uvula.

What are the anterior pillars formed by?

The palatoglossal muscles (Palatoglossal Arch).

What are the posterior pillars formed by?

The palatopharyngeal muscles (Palatopharyngeal Arch).

What lies between the anterior and posterior pillars?

The palatine tonsils.

What is the space between the left and right tonsils and their anterior and posterior pillars?

The Fauces.

What is the small elevation of tissue located posterior to the mandibular third molar?

The Retromolar pad.

What fold of tissue attaches the underside (ventral) of the tongue to the floor of the mouth?

The Lingual Frenum.

What condition results from the lingual frenum being attached too close to the tip of the tongue, limiting movement?

Ankyloglossia.

What small elevation on either side of the lingual frenum contains the opening ducts of the submandibular and sublingual salivary glands?

The Sublingual Caruncle.

What muscle supports the floor of the mouth and raises the tongue when contracted?

The Mylohyoid muscle.

What are bony growths on the lingual cortical plate of bone opposite the mandibular canines?

Mandibular Tori.

What is the stratified squamous epithelial lining of the oral cavity called?

Oral mucous membrane.

Name the three types of oral mucous membrane.

Specialized, Masticatory, and Lining mucosa.

Where is Masticatory mucosa found?

On the gingiva and hard palate.

What type of stratified squamous epithelium has a surface layer of dead cells without nuclei?

Keratinized.

What type of stratified squamous epithelium has some dead cells without nuclei and some dying cells on its surface?

Parakeratinized.

What is another name for the inside of the cheek?

The buccal mucosa.

Mandibular tori present what clinical implication when taking dental radiographs?

The film or sensor needs to be placed behind the tori to avoid patient pain and ensure they can bite together