TMJ Temporomandibular joint

1. TMJ
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

2. Glenoid Fossa
Articular Eminence
Condyle
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

3. ●
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Types of Joints
Movements of TMJ
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

4. Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

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Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

6. Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

7. Temporomandibular ligament
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Temporomandibular ligament is t
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1- Spheno-mandibular ligament .
2- Stylo-mandibular ligament.
3- Muscles of mastication.
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

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Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

9. Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

10. Mandibular Condyle.

11. Histology of Mandibular Condyle
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Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

12. Chondrocyte cells covering the condyle during
active growth period until 20 years of age
Fibrous layer
Condrocyte cells

13. Glenoid Fossa & Articular Eminence
Glenoid Fossa is Composed of: Thin layer of compact bone.
Articular eminence is Composed of: Spongy bone covered by, Compact bone.
Fibrous tissue covering both glenoid fossa and articular eminence.
Fibrous tissue is thin at the fossa and thick at the eminence.
Fibrous layer composed of:
1- Inner layer facing the bone contain fibers run at right angle to the bone.
2- Outer layer facing the disc contain fibers run parallel to the bone.
3- Intervening layer contain fibers with complex arrangement.
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

14. Articular Disc
Definition:
The Articular Disc is an oval intra-articular Fibro-cartilage plate, adapted to the bony
surface of the joint.
Structure:
1-Tight collagen fibers.
2- Some elastic fibers.
3- Fibroblasts .
4- Some chondrocytes.
*Shape:
● Oval in shape.
=Upper surface is concavo-convex:
*Anteriorly, concave to fit the articular eminence.
*Posteriorly, convex to fit the articular fossa.
=Lower surface is concave:
Lower surface concave to fit the condyle ** so**
It is termed Biconcave Disc.
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

15. Convex
Concave
Concave

16. Histology of Articular Disc
The articular disc is divided into three bands.
1- Anterior band:
Anterior band split into 2 lamellae:
i- Upper lamella attached to articular eminence.
ii- Lower lamella attached to the anterior part of the condylar.
2- Intermediate band:
Thinnest central part that is non vascular non innervated and not contain cells.
3- Posterior band:
Posterior band split into 2 lamellae:
i- Upper lamella:
●Attached superiorly to both capsule and temporal bone.
●Highly vascular, innervated.
●Consists of loose connective tissue and elastic fibers to allow for free anterior movement of the disc.
ii- Lower lamella:
● Attached inferiorly to the posterior part of the condylar neck.
● Consists of collagen fibers with no elastic fibers to limit the progressive anterior movement preventing
dislocation.
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.

17. Anterior band
Middle band
Posterior band
Upper lamella
Upper lamella
Lower lamellaLower lamella

18. Joint Spaces
The Articular Disc divide the joint spaces into two spaces:
1- Temporodiscal space: Space found between the disc and articular fossa.
2- Condylodiscal space: Space found between the disc and the condyle.

19. ✴Blood Supply:
1. Superficial temporal.
2. Deep auricular.
3. Anterior tympanic.
4. Ascending pharyngeal.
All branches are derived from the external carotid artery.
Nerve Supply:
● Branches of the mandibular division of the trigeminal nerve .
Auriculotemporal nerve.

20. I- Age changes of bone compartments:
1.The bone trabeculi become thickened.
2.The size of bone marrow decreased.
3.The red bone marrow become fatty bone marrow.
II- Age changes of the disc:
1.The disc become less elastic that limit the movement of TMJ.
2.The disc become more cartilaginous.
Dr. Sherif Hassan: associate professor oral biology Azhar Univ. and Uqudent Ksa.