Oral Mucosa

Oral Mucos Structure

Stratified squamous epithelium

Lamina propria

Submucosa

Periosteum

Lamina propria

CT directly beneath the epithelium

• Rete pegs are invaginations of the epithelium into the CT to increase contact surface

Submucosa

Contains fat cells and mixed glands

Periosteum

Bone or muscle providing underlying support

Oral Mucosa Cells

Keratinocytes

Nonkeratinocytes

Inflammatory cells

Nonkeratinocytes

Minority of epithelial cells

Melanocytes

Langerhans cells

Merkel cells

Keratinocytes

Main epithelial cells

Inflammatory Cells

May appear during inflammation

Lymphocytes and leukocytes

Mast cells

Often seen in gingival and CT

Relevant beneath the junctional epithelium

Melanocytes

Produce melanin and transfer pigment to keratinocytes

Langerhans Cells

Antigen-presenting immune cells

Merkel Cells

Touch/pressure receptors

Lymphocytes and Leukocytes

Increase during inflammation

Mast Cells

Resident CT cells - participate in the inflammatory response

Oral Mucosa Neuovascular

Oral epithelium is avascular

Blood vessels in the lamina propria nourish the epithelium

Mucosa contains sensory receptors for touch, pain, and temperature

Lips and tongue are among the most sensitive oral sites

Types of Oral Mucoasa

Lining - nonkeratinized - soft and flexible

Masticatory - keratinized - masticatory stress

Specialized - papillae and taste function

Lining Mucosa

Non-keratinized - soft and flexible

Lips

Cheeks

Floor of the mouth

Soft palate

Ventral tongue

Masticatory Mucosa

Keratinized - resists stress

Gingiva

Hard palate

Specialized Mucosa

Dorsum of the tongue

Papillae and taste function

Lining Mucosa Layers

Stratum basale

Stratum intermedium (spinosum)

Stratum superficiale

Beneath is lamina propria

Lips Submucosa

Contains minor salivary glands and orbicularis oris muscle

Vermillion Border

Marks the transition between oral mucosa and skin

• Appears red because the epithelium si thin and underlying vessels show through

Fordyce Granules

Ectopic sebaceous glands and are a common finding

Cheeks

Nonkeratinized stratified squamous epithelium with underlying lamina propria & submucosa

Submucosa contains fat cells and mixed glands (seromucous) located within and between the muscle fibers

Floor of the Mouth

Covered by thin nonkeratinized epithelium

Loosely attached to the underlying CT

Contains minor salivary glands and is closely related to the sublingual gland

Thin and highly vascular - important for rapid drug absorption

Soft Palate

Covered by nonkeratinized stratified squamous epithelium

Highly vascular

Submucosa contains mucous glands and is closely associated with the soft palate muscles

Superior/nasal surface is lined by respiratory eptihelium

Masticatory Mucosa Layers

Stratum basale

Stratum spinosum

Stratum granulosum

Stratum corneum

More resistant to friction

Masticatory Mucosa Structure

Basal cells rest on the basal lamina

Hemidesmosomes help attach basal cells to the basal lamina

Attachment helps stabilize the epithelium against underlying CT

Hemidesmosomes

Help attach basal cells to the basal lamina

Basal cels rest on basal lamina

Stippling

Refers to an orange peel appearance of the gingiva

Results from the CT invaginations into the gingival epithelium

Presence or absence is NOT a reliable indicator for health or disease

Attached Gingiva

Keratinized, firm, resilient tissue tightly bound to the underlying periosteum of alveolar bone

• Non-movable

Extends from the mucogingival junction (MGJ) to the free gingival margin (FGM)

Mobility of Oral Mucosa

Movable

Mobility of Attached Gingiva

Non-movable

Color of Attached Gingiva

More pale

Color of Oral Mucosa

Darker in color

Mucogingival Junction (MGJ)

The border that separates attached gingiva from the oral mucosa

Present on maxillary buccal, mandibular buccal, and lingual aspects

It is absent on the maxillary lingual aspect (palate) - due to no oral mucosa

Unattached (Marginal or Free) Gingiva

Terminal (most coronal) border of the gingiva that surrounds the teeth

Extends from gingival margin to the free gingival groove

Present on both buccal and lingual aspects of maxilla and mandible

Scalloped outline and obtains it in conjunction with eruption of the teeth

Gingival Sulcus (Crevice)

Shallow fissure (space) between the marginal gingiva and the enamel of the cementum

Permits the entrance of a periodontal probe - an important diagnostic parameter

Width can vary in different individuals and can be affected by medical history and meds

After eruption - 1.5 - 2 mm coronal to the CEJ

Interdental Gingiva/Papilla

Fills the interdental space beneath the contact area

Anterior Interdental Gingiva

Usually pyramidal

Posterior Interdental Gingiva

Flatter, with a col between the facial and lingual papilla

Interdental Gingiva Morphology Depends On

Tooth contact relationships

The width of the approximal tooth surfaces

CEJ contour

Is absent in edentulous areas

Junctional Epithelium

Attaches the gingiva to the tooth near the cervical region

Forms the base of the gingival sulcus

Nonkeratinized and structurally different from oral gingival epithelium

Has rapid turnover

Loss of this attachment is an early event of periodontal disease

Hard Palate

Covered by keratinized stratified squamous epithelium

Midline is the median palatine raphe

Anterior palate has rugae

Anterior lateral contains adipose tissue - consideration during gingival graft harvesting

Posterior lateral is a glandular zone and important vital structure - considering in gingival graft harvesting

Midline Hard Palate

Palatine raphe

Anterior Hard Palate

Has rugae

Anterior Lateral Hard Palate

Contains adipose tissue - consideration during gingival graft harvesting

Posterior Lateral Hard Palate

Glandular zone and important vital structure - considering in gingival graft harvesting

Specialized Mucosa

Anterior 2/3 of the dorsal tongue

Filiform Papillae

Most numerous

Keratinized, mechanical, no taste buds

Fungiform Papillae

Mushroom shaped

Scatted among filiform

Taste buds present

Foliate Papillae

Folds on the posterolateral tongue

Taste buds present

Circumvallate Papillae

Largest

Arranged in a V-shaped row

Taste buds on the side walls

Taste Buds

Found mainly in fungiform, foliate, and circumvallate papillae

Also present in the soft palate, epiglottis, and pharynx

Undergo rapid turnover

Sensory organs for taste

Oral Mucosa Aging

Becomes thinner and less resilient

Surface Aging

May appear smoother

Salivary Function Aging

May decline

Contributes to dryness (xerostomia)

Changes with Aging

Oral mucosa becomes thinner and less resilient

Surface may appear smoother

Salivary function may decline, contributing to dryness (xerostomia)

Repair and healing are slower

Gingival recession becomes more common with age