Oral Mucosa II Flashcards
What’s special about the lip in regards to epithelium/mucosa present?
- Consists of skin, specialised mucosa transition zone (vermillion border) and labial oral mucosa (inner side)
Are striated muscles present in the lip?
- YES
- Striated muscles of facial expression in the lip core
Are Minor Salivary glands in the Submucosa?
- YES
- Beneath the Oral Mucosa
What are the characteristics of the Lip skin?
- Keratinised epidermis
- CT dermis
- Hair follicles
- Sebaceous glands
- Sweat
What are the characteristics of the Vermilion Zone?
- Lacks skin appendages
- Occasional sebaceous glands (corner of the mouth)
- No mucous glands (needs constant moistening)
- Keratinised epithelium
What’s the junction between the Vermilion zone and Oral Mucosa called?
- Intermediate zone
- Parakeratinised
What are the characteristics of the Labial Mucosa?
- Covered in thick, non-keratinised epithelium
- Lamina Propria is wide but the Papillae are short and irregular
- Submucosa with minor salivary glands
- Dense CT fibres bind the mucosa to the Orbicularis Oris muscle
The Cheek: What are its characteristics?
- Non-keratinised epithelium
- Lamina Propria is dense with short and irregular papillae
- Submucosa with many minor salivary glands (biccinator muscles my lay beneath)
- Sebaceous glands sometimes present - become more obvious after puberty
What’s the Linea Akba Buccalis?
- Keratinised line in the buccal mucosa along the occlusal plane
- Low grade irritation
What are Ectopic Sebaceous glands?
- Fordyce’s granules
- Out of place glands
- Don’t cause problems
Whats the Gingiva?
- Portion of the Oral Mucosa that surrounds and is attached to the teeth
What are the 2 main regions of Gingiva?
- Attached Gingiva
- Directly bound to the alveolar bone and the tooth
Coronal to the Attached is…
- Free Gingiva
- Narrow rim of mucosa, not bound to any underlying hard tissue
What is the boundary between the attached and free gingiva called?
Free Gingival Groove
-Shallow groove
What’s the Gingival Sulcus?
- The unattached region between the free gingiva and the tooth
What’s Junctional Epithelium?
- Area apical to the Gingiva Sulcus
- Where the gingiva is bound to the underlying tooth
How is the attached gingiva demarcated from the alveolar mucosa?
- Mucogingival junction
The Attached Gingiva: What are some of its characteristics?
- External surface is masticatory mucosa
- Keratinised
- 75% of the surface maybe parakeratinised
- Papillation varies
- Stippled surface (arise form intersecting epithelial ridges
- No submucosa
The Free Gingiva: What are some of its characteristics?
- Can be demarcated from the attached gingiva by the free gingival groove
What’s the gap between the Enamel and Free Gingiva called?
- Gingival Sulcus
- 0.5-2mm in depth
- Lined by Sulcular Epithelium - folded interface with the lamina propria
The Junctional Epithelium: What are some of its characteristics?
- Epithelial collar that surrounds the tooth and extends from the CEMENTO-ENAMEL JUNCTION to the bottom of the GINGIVAL SULCUS
- High rate of turnover
- Exfoliates coronally
What’s special about Junctional Epithelium?
- It has 2 Basal Lamina
- Adjacent to the Enamel = attach via hemidesmosomes and a basal lamina produced by the cells) = Epithelial attachment
- Adjacent to the Lamina Propria = same method
What are the 2 layers of the Junctional Epithelium?
- Stratum Basale
2. Stratum Spinosum
How does the length of the Junctional Epithelium vary over time?
- At tooth eruption, most enamel is covered
- 1/4 of enamel is covered by the time the tooth reaches occlusion
- Gum recession causes the apical migration of the Cemento-enamel junction
What’s Cervicular Fluid?
- Fluid found within the sulcus - results from the permeability of the junctional epithelium
- Important in the defence mechanism
- Passes continuously from the subepithelial tissue into the gingival sulcus
- Composition is an indicator of the health state of underlying periodontium
What’s Interdental Papilla?
- Part of gingiva between adjacent teeth
- Shape arrangement depends on shape and contact between teeth
- Pointed between anterior teeth
- Fills the contour around the contact point
What’s the Col?
- Continuous with the junctional epithelium
- Non-keratinised
- Proximal surfaces (Distal and Mesial)
Gingival Lamina Propria: What’s its composition?
- Contains dense bundles of collagen whose function is to support the free gingiva
- Binds attached gingiva to the alveolar bone and tooth
- Link teeth to one another
- Contain less contractile proteins, ground substance, Type III collagen
- Collagen bundles are called PRINCIPLE FIBRES
What are the 10 Principle Fibres? (1)
- Dentogingival Fibres
- Run from just above the alveolar crest on the root to the gingiva
What are the 10 Principle Fibres? (2)
- Longitudinal Fibres
- Extend throughout the entire arch
What are the 10 Principle Fibres? (3)
- Circular Fibres
- Encircle each tooth within the marginal and interdental gingiva
- Some attach to the cementum/alveolar bone
What are the 10 Principle Fibres? (4)
- Alveologingival Fibres
- Run from the Alveolar crest, coronally into the overlying lamina propria of the gingiva
What are the 10 Principle Fibres? (5)
- Dentoperiosteal Fibres
- Only in Labial/Buccal/Lingual gingiva
- Arise from Cementum and pass over Alveolar Crest to insert into the Periosteum
What are the 10 Principle Fibres? (6)
- Transseptal Fibres
- Pass horizontally from the root of one tooth, over the alveolar crest to be inserted into the root of the adjacent tooth
- Provide anatomical basis for linking teeth in the dentition
- Implicated in mesial drift (movement of teeth in Orthodontics and after tooth removal)
What are the 10 Principle Fibres? (7)
- Semicircular Fibres
- Arise from cementum near the CEJ, cross the free marginal gingiva and insert into a similar position on the opposite tooth
What are the 10 Principle Fibres? (8)
- Transgingival Fibres
- Reinforce the circular and semicircular fibres
- Arise from the cervical cementum and extend into the marginal gingiva of the adjacent tooth, merging with the circular fibres
What are the 10 Principle Fibres? (9)
- Interdental Fibres
- Pass through the coronal portion of the interdental gingiva in a buccolingual direction
- Connect Buccal and Lingual gingiva
What are the 10 Principle Fibres? (10)
- Vertical Fibres
- Arise from attached gingiva or alveolar mucosa and pass coronally towards the marginal gingiva and interdental papilla
Alveolar Mucosa: What are its characteristics?
- Demarcated from the keratinsied attached gingiva via the MUCOGINGIVAL JUNCTION
- Non-keratinised
- Loose submucosa and elastin - slightly mobile
- Rich blood supply near the surface = red appearance
- Contains minor salivary glands
