22 - Topographic characteristics of oral mucosa, structure of gingiva + specialized mucosa Flashcards
Topographic characteristics of oral mucosa
- Lining mucosa
- Masticatory mucosa
- Specialised mucosa
Lining mucosa
Soft, pliable + non-keratinised
Composed of a thin layer of epithelium + underlying lamina propria
Epithelium
- Composed of stratum basale, spinosum + superficial stratum w/flattened cells + small oval nuclei
- Non-K epithelium
- Found on floor of mouth, transitional fold, gingival sulcus + lower surface of tongue
Types of lining mucosa
- Lips
- Soft palate
- Cheek
- Floor of mouth
- Ventral surface of tongue
Lips
Lips
- Inner oral surface lined w/non-k epithelium ⇢ small, round seromucous glands of lamina propria
- beneath lamina propria is submucosa ⇢ fibres of orbicularis oris muscle located
- Vermillion border ⇢ mucosa of lips distinguished by this red border that is junction between oral mucosa + skin of lips
- Becomes modified into Keratinised epithelium
- Its red because epithelium is thin, contains eleidin (transparent) + blood vessels near surface of papillary layer
Floor, Soft palate + Cheeks
Floor of mouth
- Non-k mucous membrane covers floor + appears attached to lamina propria
- Mucosa is firmly attached to floor of mouth
- Minor salivary glands + sublingual glands
Soft palate
- Lining mucosa is highly vascularised + more pink compared to hard palates
- Lamina propria contains many small blood vessels
- Submucosa has muscles + mucous glands
Cheeks
- Same as lips/soft palate
- Submucosa contains fat cells + seromucous glands
- These are a unique feature of the cheeks
Masticatory mucosa
Keratinised ⇢ due to attrition of mastication
Covers gingiva + hard palate + dorsal surface of tongue
Thicker than non-K surface to offer resistance to attrition
Free and attached gingiva
Free gingiva
- Bound on its inner margin by gingival sulcus ⇢ separates its from tooth
- Outer margin ⇢ bound by oral cavity
- In some instances may be covered w/parakeratinised mucosa
Attached gingiva
- Lies adjacent to free gingiva
- Separated from alveolar mucosa by mucogingival junction
Free + attached gingiva both keratinised
Alveolar mucosa is not keratinised
Junctional epithelium + sulcus epithelium
Junctional epithelium
- Provides attachment for gingiva to tooth in the cervical area
- Forms epithelial lined floor of gingival sulcus
Sulcus epithelium
- Impermeable to passage of cells + fluid compared to attached gingiva
Interdental papilla
Gingiva located between teeth
Extends high on interproximal area of crowns on labial + lingual surfaces
Specialised mucosa
The tongue
- muscular organ that give the umami of: sugar, acid, sour, bitter and amino acids
- Made of: Back of tongue, villous upper surface, inferior non-villous surface, anterior ⅔ + root of tongue
Papillae
- Filiform
- Fungiform
- Circumvallate
- Foliate
Filiform + Fungiform papillae
Filiform
- Covers entire front surface of tongue
- Create conditions for retention of food + MOs
- fragmentation of food in pressure on the palate
Fungiform
- Red, raised structures
- Covered with non-k epithelium
- scattered between fungiform papillae + have tooth buds at surface
Circumvallate + foliate papillae
Circumvallate
- Taste buds ⇢ 8-12 major papillae
- Deep groove surrounds each papilla
- Lateral walls have taste buds ⇢ have their own blood supply + innervation
Foliate
- 4-11 parallel ridge, separated by deep grooves at back of tongue
- Taste buds
- Behind circumvallate papilla
- Along the side/edge at back of tongue
Features of child mucosa
- Less keratinised w/great mitotic activity
- Colour is bright red ⇢ thin epithelium + superficial capillary network
- More fragile + better regenerative capabilities
