Epithelial tissue

1. Junctional Epithelium / Epithelial AttachmentJunctional Epithelium / Epithelial Attachment
 What and where it is
 Where it comes from
 What it does
 Why it does it

2. What and Where is the Junctional EpitheliumWhat and Where is the Junctional Epithelium
 Epithelial attachment and clinical attachment level
 Collar-like band of nonkeratinised stratified squamous
epithelium
 Extends from cementoenamel junction - bottom of gingival
sulcus
 Coronally: 15-30 cells thick. Apically: narrows to 1-3 cells
 Length: 0.25 – 1.35mm & has rate of turnover

3. A- gingiva
B- sulcular
epithelium
C- junctional
epithelium
D- lamina propria
(connective tissue)
E- alveolar
process
F- PDL ES- enamel space
JE – junctional epithelium
CT- connective tissue

4. Where does it come from ?Where does it come from ?
 Initially derived from Reduced Enamel Epithelium
 REE replaced once tooth erupts – REE covering crown
lost rapidly replaced by squamous epithelial cells
 Transformed REE & oral epithelium form dentogingival
junction and junctional epithelium
 Final conversion of REE to JE may not occur until 3-4
years post eruption

5. Important FeaturesImportant Features
 Cells of JE immediately adjacent to tooth attach to tooth
by hemidesmosomes & basal lamina
 Combination is known as the epithelial attachment
 Basal lamina in contact with tooth: Internal Basal lamina
 On opposite surface – JE in contact with lamina propria of
gingiva & attached by hemidesmosomes and basal lamina
 Basal lamina in contact with lamina propria: External
Basal Lamina

6. Junctional epithelium is unique as itJunctional epithelium is unique as it
possess 2 basement membranes – thepossess 2 basement membranes – the
internal and external basal laminainternal and external basal lamina
Enamel
Lamina
propria
Internal Basal Lamina External Basal Lamina
Hemidesmosomes

7. CTJE
Enamel space Internal basal lamina
External basal lamina

8. Enamel CuticleEnamel Cuticle
 Not visible in demineralised sections
 Non-mineralised structure between JE and
underlying hard tissue
 Cuticle also seen between JE and underlying
cementum

9. Length of Junctional EpitheliumLength of Junctional Epithelium
 Length varies according to stage of eruption
 Tooth first erupts – most of enamel covered by JE
 Tooth reaches occlusal plane – ¼ enamel surface covered
 Eventually JE lies close to CE junction
 Older patients with root exposure (passive eruption or
disease) JE proliferates apically - firm attachment with
cementum

10. Other Fantastic Facts You Really Wanted toOther Fantastic Facts You Really Wanted to
Know About the Junctional Epithelium!!!!Know About the Junctional Epithelium!!!!
 Lamina propria of gingiva – good vaculature and source
of nutrient to JE and source of GCF
 JE is permeable & tissue fluid and cells pass into GCF
 Turnover of JE is rapid. Epithelial cells migrate
coronally & shed into oral cavity via gingival crevice
 Rate of turnover dependent on demands placed on
tissue. Directly related to degree of inflammation

11. What it does and why it does itWhat it does and why it does it
 Has attachment role and protective role
 Permeability allows GCF and defence cells to pass
across to protect underlying tissues from disease
processes (periodonal disease)
 Helps maintain integrity of tooth / periodontium
structure.

12. Role of JE – Clincial significanceRole of JE – Clincial significance
 GCF contains g globulins and ploymorphonucleocytes
(PNMs) giving it immunological / phagocytic properties to
combat disease processes
 Such molecules pass readily across JE to underlying
tissues
 JE (& GCF) good indicator for severity of periodontal
disease – may contain neutrophils & other inflammatory
cells indicating disease – & state of health of periodontium
 Research into this ongoing in Bham – understanding
progression of disease & development of diagnostic
marker of severity of disease

14. Reason why I have not been around for the past 2 weeks!!