DENT 5315/DH 2215 March 4, 2008

Here comesthe Quiz!

Yes!

KEY

Temporomandibular Joint

Dr. Sandra Myers

Director, NIDCR’s TIRR TMJ Implant Repository

NationalInstitute of Dental and Craniofacial Research'sTMJ Implant Registry and Repository

Splints

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Patient slides deleted to protect patient identity.

Temporomandibular Joint (TMJ)

I. Classification of Joints

II. Temporomandibular Joint

I. Classification of Joints

3 Types of Joints:

A. Fibrous

B. Cartilaginous

C. Synovial

I. Classification of Joints

II. Temporomandibular Joint (TMJ)

A. Type of Joint

B. Development

C. Anatomy & Histology

D. Biomechanics

E. Innervation

F. Blood Supply

II. Temporomandibular Joint (TMJ)

A. Type of Joint

“synovial sliding-ginglymoid joint”

Ginglymoid means: Pertaining to, or resembling, a ginglymus, or hinge joint; ginglyform.

II. Temporomandibular Joint (TMJ)

B. Development

Association of Meckel’s cartilage with mandible

Condylar cartilage appears 12th week

II. Temporomandibular Joint (TMJ)

C. Anatomy & Histology

Condylar Head

Bovine Condyle

Condylar Head

A - Fibrous layer

B - Reserve zone

C - Proliferative zone

D - Hypertrophic zone

E - Calcifying zone

F - Bone

Capsule

Functions:

Seals joint space

Passive stability

Synovial lining

Proprioceptive nerve endings

Note synovial membrane over villi (arrow):

Articular Disk

“Acres of Collagen”

Aneural & Avascular

Posterior Ligament

Synovial Membrane

Synovial Fluid:

Liquid environment

Lubrication

Nutrition?

Muscles

Muscles of Mastication

Difference between unipennate, bipennate & multipennate:

Muscles with central tendon

Muscle fiber bundles attached to one side, two sides or around multiple central tendons

D. Biomechanics

Complex combinations of muscle activity

Disk enables complex movements

D. Innervation

Movements of synovial joint initiated & effected by muscle coordination.

Achieved in part through sensory innervation.

Hilton’s Law:The muscles acting on a joint have the same nerve supply as the joint.

Therefore: Branches of the mandibular division of the fifth cranial nerve supply the

TMJ (auriculotemporal, deep temporal, and masseteric)

D. Innervation

4 Types of nerve endings:

1. Ruffini’s corpuscles (limited to capsule)

2. Pacini’s corpuscles (limited to capsule)

3. Golgi tendon organs (confined to ligament)

4. Free nerve endings (most abundant)

Pacinian Corpuscle

http://www.kumc.edu/instruction/medicine/anatomy/histoweb/nervous/nervous.htm

“Onion-like encapusulated pressure receptors

Surrounding concentric lamellae respond to distortion, generate action potential in unmyelinated fiber in core

Bar = 100 microns

Ruffini’s & Golgi Corpuscle

Function: Ruffini’s = Posture (proprioception), dynamic and static balance

Golgi tendon organ = Static mechanoreception, protection (ligament)

Free nerve endings = Pain (nociception) protection (joint)

www.anatomyatlases.org/ MicroscopicAnatomy/Section06/Section06.shtml

Ruffini’s Corpuscle