TMJ & Meckel's Cartilage

Question 1

TERM – the initial appearance(s) of bone tissue in the area where each of the 206 bone organs of the body form

Answer 1

Ossification Centers

Question 2

The ossification centers appear in different 2 environments

1.

2.

Answer 2

1. Within Mesenchyme
2. Within Cartilage Model

Question 3

If the ossification center is…

1. Within mesenchyme –> _________ bone organ development
2. Within a cartilage model –> __________ bone organ development

Answer 3

1. Intramembranous
2. Endochondral

Question 4

True or False?

The number of ossification centers vary from bone to bone

Answer 4

TRUE

Question 5

How many ossification centers in…

1. Mandible?
2. Maxilla?

Answer 5

1. Mandible – 2
2. Maxilla – 4 (2/bone)

Question 6

The Mandible and Maxilla are examples of _________ bone development

Answer 6

Intramembranous

Question 7

The ulna and femur are examples of ______ bone organ development

Answer 7

Endochondral

Question 8

Some bones such as the _________ ______ have both intramembranous and endochondrial ossification centers and are referred to as having “_____ _____ _____”

Answer 8

Temporal Bones

Mixed Ossification Centers

Question 9

TERM – The addition of bone tissue to a bone organ

Answer 9

Growth Sites

Question 10

The following are examples of ______ _______

1. Periosteum
2. Endosteium
3. Haversian/Volkman Canals
4. PDL

Answer 10

Growth Sites

Question 11

No matter what environment bone tissue forms in or on, it always forms within a highly ______connective tisssue which is referred to as intramembranous bone tissue formation (not OSS. Centers!)

Answer 11

Vascular

Question 12

Paired Meckels Cartilages:

1. Temporary skeleton of ______ processes of BA 1
2. Temporary attachment for _______ that will attach to mandible eventually
3. Each cartilage serves as models for the 2 ear ossicles:

____ & _____

4. Each serve as a site for the appearance of 2 ligaments

_____ & _____

5. Serve as temporary ______-_____ plate of the forming mandible halves
6. Serve enclosed ______ _____ at the chin end of the mandible halves

Answer 12

1. Temporary skeleton of mandibular processes of BA 1
2. Temporary attachment for muscles that will attach to mandible eventually
3. Each cartilage serves as models for the 2 ear ossicles:

Malleus & Incus

4. Each serve as a site for the appearance of 2 ligaments

Anterior Mallelar and Sphenomandibular

5. Serve as temporary anterior-lingual plate of the forming mandible halves
6. Serve enclosed growth sites at the chin end of the mandible halves

Question 13

Fate of Meckel’s Cartilage…

From the proximal (inner ear) –> distal (chin)… each cartilage serves as sites for:

Answer 13

1. Endochondral Ossification Centers for 2 ear ossicles
2. Undergo retrogressive changes becoming 2 ligaments
3. Undergo growth, mineralization, and resorption while serving as anterior growth sites and replaced as temporary anterior lingual plates by encroaching bone tissue of the growing mandible halves

Question 14

Meckel’s cartilages serve as both _____ _____ of the ear ossicles and as a ______ ______ of each mandible halve.

Answer 14

Ossification Centers

Growth Site

Question 15

The enclosed anterior parts of Meckel’s cartilages serve as

1.

2.

Answer 15

1. Temporary Lingual Plate of mandible halves
2. Growth Site of Developing mandible halves

Question 16

The mandible is ____ of ____ total skull bones

Answer 16

1

22

Question 17

The mandible develops as 2 bilateral halves tha exist throughout the ________ period. Union occurs at the end of the ______ ______ _____

Answer 17

Interuterine

First Postnatal Year

Question 18

1. At what week does the mandible begin to develop?

–> bilateral ossification centers specifically

2. What growth environment?

Answer 18

1. 6th

Same as tooth development!

2. Menenchymal (intramembranous)

Question 19

The ossification centers of the mandible first appear in the area of the future _______ _______

Answer 19

future mental foramina

(Where IA branches to mental and incisive nerves)

Question 20

Anterior Growth of Mandible:

1. Incorporates the ____ parts of Meckel’s cartilage
2. Becomes temporary ______ ______ & growth site of each mandible half

Answer 20

1. distal
2. lingual plate

Question 21

Posterior Growth of Mandible:

1. Bone is in the form of a ‘U’ featuring ____ & ____ plates
2. Posterior end of the _______ plate incorperates an independednt piece of hyaline cartilage that becomes ______ _______ and also another growth site for each mandible half

Answer 21

1. facial and lingual
2. Facial, condylar cartilage

Question 22

True or False?

The condylar cartilage does NOT arise from Meckel’s cartilage

Answer 22

True

Question 23

The mandible grows

• posteriorly towards :
• anteriorly towards :

Answer 23

• TMJ
• midline of the chin

Question 24

Fate of Meckel’s Cartilage

1. Proximal

2. Middle

3. Distal

Answer 24

1. Malleus & Incus ossicles, anterior mallelar ligament
2. Sphenomandibular ligament
3. temporary anterior lingual plate & growth sites of the mandible halves

Question 25

TERM -- Joint that permits **little or no** mobility (fibrous & suture joints)

Answer 25

Synarthrosis ex: maxillary bones

Question 26

TERM -- Joint that permits **slight** mobility (cartilagenous joints)

Answer 26

Amphiarthrosis ex: pubis symphysis

Question 27

TERM -- Joint that permits a variety of movements (synovial joint)

Answer 27

Diarthrosis ex: temporomandibular joint

Question 28

TERM -- Joint that refers to its dual compartment structure and function: Ginglymo and Arthrodial

Answer 28

Ginglyomoarthrodial Joint

Question 29

TERM -- Joint that binds a tooth to a bone socket

Answer 29

Gomphosis

Question 30

A freely moveable joint will usually consist of 3 components 1. 2. 3. **EXCEPT FOR THE TMJ**

Answer 30

1. One joint Cavity 2. Incomplete Articular Disc 3. Cartilage Articular Surfaces

Question 31

What two bones form the TMJ?

Answer 31

1. Temporal bone (squamous portion) 2. Mandible (condyloid process)

Question 32

The components of the freely moveable **TMJ** are:

Answer 32

1. Complete Articular Disc 2. **Two** joint cavities 3. Soft Connective Tissue Articulating Surfaces

Question 33

Another name for rudiments of TMJ (cells, tissuues, organs formed)

Answer 33

Blastema

Question 34

When does the TMJ cavitation occur?

Answer 34

3rd month in utero

Question 35

The articular disk is present at ____ week in utero

Answer 35

6th

Question 36

What type of growth occurs between the articular connective tissue surface and the condylar cartilage?

Answer 36

Appositional

Question 37

The condylar cartilage remains until about the age of \_\_\_\_\_, then it is replaced by _______ bone tissue.

Answer 37

25 Compact bone tissue

Question 38

The TMJ blastema is where what 4 things form 1. 2. 3. 4.

Answer 38

1. Condylar Cartilage 2. Articular Disc 3. Two Joint Cavities 4. Soft Tissue Articular Surfaces

Question 39

True or False? The osseous union of the mandible halves occur at the 8th week

Answer 39

FALSE Occurs at the end of teh 1st year