Oral Histology - Oral Mucosa

the oral cavity is lined by what?

stratified squamous epithelium

what are the three variations of the oral mucosa?

• lining mucosa (unattached mucosa or nonkeratinized mucosa)

• masticatory mucosa (attached mucosa or keratinized mucosa)

• specialized mucosa

what mucosa covers floor of mouth, cheeks, lips and soft palate and does not function in mastication?

lining mucosa (unattached mucosa/nonkeratinized)

what mucosa covers the hard palate, alveolar ridges, and gingiva and comes in primary contact with food during mastication?

masticatory mucosa (attached mucosa/keratinized mucosa)

what type of mucosa covers the surface of the tongue and is composed largely of keratinized papillae?

specialized mucosa

what is lamina propria?

connective tissue layer immediately below the epithelium composed of the papillary layer and deeper reticular layer

in papillary layer, connective tissue extends into what?

rete ridges of epithelium (pockets)

reticular layer contains what?

more vessels and nerves supported by connective tissue

what is found beneath the lamina propria?

submucosa

lining mucosa is composed of what?

a thin layer of epithelium and an underlying lamina propria

in lining mucosa, what describes the composition of the epithelium?

• cuboidal basal layer of cells (stratum basale)

• spinous layer (stratum spinosum)

• above spinous layer is more superficial epithelium

the inner oral surface of the lips is lined by nonkeratinized epithelium and associated with what?

small, round seromucous glands

nonkeratinzed mucosa of the lips is distinguished by what?

a red border known as the vermillion border

skin of lip transitions to what?

keratinized epithelium

what structures are seen in skin of lip?

hair follicles and associated sebaceous glands, arrector pili muscles, and sweat glands

where can ectopic sebaceous glands (not associated with hair follicles) be seen?

on the buccal mucosa

what describes fordyce granules?

ectopic sebaceous glands that can be seen on the buccal mucosa that are not associated with hair follicles

lining mucosa of the soft palate is what?

highly vascularized and thus more pink

the submucosa of the soft palate contains what?

muscles of soft palate and mucous glands

what are the features of the mucosa of the inner cheeks that differentiates them from the mucosa of the lip and soft palate?

• fat cells

• mixed seromucinous glands

the submucosa of the tongue has what?

musle fibers

the submucosa of the tongue continues with what?

the deep muscles of the tongue along with connective tissue fibers

the mucosa on the floor of the mouth is what?

attached more loosely to the lamina propria than in ventral tongue

ventral tongue has what?

epithelium that is more firmly attached

what is present in the floor of the mouth?

• minor salivary glands

• right and left sublingual glands

the addition of the keratinized surface to the masticatory mucosa offers what?

resistance to attrition

what describes keratin?

tough, nonliving material that is resistant to friction and bacterial invasion

the granular layer (stratum granulosm) and keratin layer (stratum corneum) are prominent where?

in the masticatory mucosa

what describes papakeratin?

nuclei retained in keratin

what describes orthokeratin?

nuclei absent in keratin

what describes odontogenic keratocyst?

• recurrence rate: ~25

• associated with parakeratin

what describes orthokeratinized odontogenic cyst?

• recurrence rate: <2%

• associated with orthokeratin

in the oral mucosa, the gingiva surrounds and extends where?

the cervical areas of the teeth and extends apically to the mucogingival junction

what develops as a coalescence of the oral epithelium and reduced enamel epithelium when the tooth emerges into the oral cavity?

ginigiva

what aer the three zones of the gingiva?

• free/marginal zone

• attached gingiva

• interdental zone/groove

what describes the free gingival groove?

the indistinct groove that separates the free and attached gingiva

what describes the free/marginal zone of gingiva?

encloses the tooth and defines the gingival sulcus

what describes the attached gingiva?

portion of the epithelium attached to the neck of the tooth

what describes interdental zone/groove?

area between two adjacent teeth beneath their contact point

what separates the tooth from the free gingiva?

gingival sulcus

attached gingiva lies adjacent to the free gingiva and is separated from the alveolar mucosa by what?

the mucogingival junction

free and attached gingiva are what?

keratinized

alveolar mucosa is what?

nonkeratinized

attached gingiva is stippled due to what?

attachments sites to underlying alveolar bone

epithelium of gingiva does what?

naturally sheds or exfoliates over time (prevents bacteria from attaching to gingiva and is a form of innate immunity)

the gingival sulcus is what?

the space between a tooth and the surrounding gingiva

the gingival sulcus is apically bound by what?

junctional epithelium

junctional epithelium connects to what?

root surface

what describes the dentogingival epithelium?

junction between the tooth surface and the gingival tissues

the dentogingival epithelium is composed of what?

sulcular/crevicular epithelium & junctional epithelium

what describes sulcular/crevicular epithelium?

lines the gingival sulcus or the area between the free gingiva and the tooth; filled with crevicular fluid

junctional epithelium begins where?

at the base of the sulcus and is a deeper extension of the sulcular epithelium

junctional epithelium is firmly attached to the tooth via what?

hemidesmosomes

roof of mouth is covered with what?

keratinized stratified squamous epithelium

what is the midline of the hard palate known as?

midline raphe

what is seen anteriorly on the hard palate?

incisive papilla

what are found on each side of the midline raphe?

ridges of tissue called rugae

traction bands exist in the lamina propria of the rugae and do what?

anchor palatal mucosa to underlying bone

mucous glands predominate what area?

hard palate

recurrent intraoral herpes (caused by HSV-I, usually) occur almost exclusively where?

keratnized mucosa

aphthous ulcers (idiopathic) occur almost exclusively on what?

nonkeratinized mucosa

the dorsum of the anterior 2/3 of the tongue is covered by what?

specialized mucosa

what are the four types of epithelial papillae?

• filiform

• fungiform

• circumvallate papillae

• foliate papillae

what is the only tongue papillae that does not have taste buds?

filiform

what is the function of filiform papillae? 

facilitate mastication and movement of food on the surface of the tongue (does not have taste buds)

the covering epithelium is thin and nonkeratinized on what kind of papillae?

fungiform

where are circumvallate papillae found?

along the V-shaped sulcus between the body and the base of tongue

what is seen opening into the grooves surrounding the circumvallate papillae?

Von Ebner glands (ducts of the underlying serous glands)

when present, foliate papillae do have what?

taste buds

with age, what happens to the oral epithelium?

it become thinner and more fragile

because of gradual atrophy of the minor salivary glands and less activity of the major glands, what happens with age?

oral mucosa is less moist

with aging, cellular activity and fibrosis increase causing what?

• ability to repair to be reduced

• length of the healing time is increase

apical migration of gingiva occurs with periodontal disease but also happens when?

routinely with aging mucosa