Distance of tissue that isolates alveolar bone from oral cavity
Healthy biological width
1 - 2 mm (1 mm of junctional epithelium and 1 mm of connective tissue proper)
Biological width is located
Between the base of the DGJ and the crest of the alveolar bone
Junctional epithelium (Epithelial attachment)
Formed after ameloblasts have created mature enamel and secreted a basal lamina. Definitive junctional epithelium is formed by remaining epithelial cells since ameloblasts are lost after eruption.
Definitive junctional epithelium is formed once
Erupting tooth reaches functional occlusion
Junction between tooth and gingiva
Importance of DGJ
1. Helps hold tooth in place 2. Part of Periodontium 3. Barrier to PDL space
The DGJ forms from
Reduced enamel epithelium
Oral epithelial tissue makes
Two parts of DGJ
1. Sulcular epithelium 2. Junctional epithelium
DGJ is never seen
Clinically, because next to tooth
Two borders of sulcus space
1. Non-keratinized sulcular epithelium 2. Tooth
When is the first junctional epithelium established?
When the tooth first erupts into the oral cavity
Definitive junctional epithelium is established
When tooth reaches functional occlusion
What are the two basal laminas?
1. External Basal Lamina 2. Internal Basal Lamina
Which basal lamina is located next to the tooth?
Internal basal lamina
What type of oral mucosa is DGJ?
Lining mucosa (Non-keratinized)
What do the pegs and papilla look like in DGJ?
There are NO pegs or papilla in DGJ
What kind of junction is found between enamel and the superficial layer of juntional epithelium?
Internal Basal lamina lies between
The Junctional epithelium and the tooth
Reasons why junctional epithelium may recede
1. Age 2. Disease 3. Trauma 4. Malocclusion 5. Frenum attached too far coronally which pulls tissue
Which direction does junctional epithelium recede?