Bone

Question 1

What is the percentage of the inorganic and organic composition of alveolar bone?

Answer 1

67% inorganic
33% organic
(Mineral is deposited in an organic matrix)

Question 2

What consists of the inorganic part of the alveolar bone, contributing to 2/3 of its weight?

Answer 2

Hydroxyapatite crystals

Question 3

What is the function of hydroxyapatite crystals in the alveolar bone?

Answer 3

Hardness and weight

Question 4

What forms the bulk of the organic part of the alveolar bone?

Answer 4

Collagen

Question 5

What is responsible for the alveolar bone’s resilience and toughness?

Answer 5

Dentin

Bone proteins

Question 6

What composes the organic composition of dentin, cementum, and alveolar bone?

Answer 6

Collagen
Dentin, bone sialoprotein
Dentin matrix protein 1
Osteopontin, osteocalcin, osteonectin

Question 7

What are the two types of bone?

Answer 7

Compact/Dense

Spongy/Cancellous/Trabecular bone

Question 8

Enumerate the two surface linings of the bone that are highly vascular and cellular connective tissues.

Answer 8

Periosteum (outer surface lining)

Endosteum (inner)

Question 9

True or false: Both periosteum and endosteum have osteoblasts and osteoclasts.

Answer 9

True

Question 10

Which surface lining has more osteoblasts, thus more active in bone formation?

Answer 10

Periosteum

Question 11

Enumerate the different cells found in the alveolar bone and their origins.

Answer 11

Osteoblasts - ectomesenchymal
Osteocytes - ectomesenchymal
Osteoclasts - hematopoietic

Question 12

Which of the three types of cells in the alveolar bone is actually found in the alveolar bone?

Answer 12

Osteocytes.

Osteoblasts and osteoclasts are found in the periodontal ligament.

Question 13

What is the relationship of osteoblasts and osteocytes?

Answer 13

Osteoblasts become osteocytes

Question 14

These cells are trapped in the matrix during bone formation

Answer 14

Osteocytes

Question 15

Why do osteocytes maintain contact with osteoblasts, periosteum, and other osteocytes?

Answer 15

This is the perfect position to monitor changes in the environment of bone, thus being able to induce adaptive changes in bone to maintain its vitality

Question 16

What is an osteoclast?

Answer 16

Large multinucleated cells on the surface of the bone UNDERGOING RESORPTION

Question 17

Pinpoint the histologic location of osteoblasts and osteocytes

Answer 17

X

Note that osteoblast is found in periodontal ligament, and osteocytes, sa alveolar bone

Question 18

What is the structure encircled in black?

Answer 18

Osteoclasts

note that it looks like an aggregation of cells sa outer part ng PDL

Question 19

Describe the intercellular substance of alveolar bone.

Answer 19

It is calcified and cells are embedded here.

The layers of calcification are called LAMELLAE

Question 20

What are the three microscopic layers (lamellae) of the intercellular substance of the alveolar bone?
Identify them in this picture.
X

Answer 20

Circumferential
Interstitial
Concentric

Question 21

What structure forms the basic metabolic unit of bone?

Answer 21

Osteon or haversian system

Question 22

How do each adjacent haversian canal communicate with each other?

Answer 22

Volkmann’s canal

Question 23

Which lamellae is also called osteon or haversian system?

Answer 23

Concentric lamellae

Question 24

What are the three types of bone formation? Differentiate them from each other.

Answer 24

Intramembranous - Embryonic connective tissue or ectomesenchyme is directly ossified to bone
Endochondral - cartilage to bone
Sutural - between sutures, only in the skull, accommodates growth of organs (i.e. brain, eyes)

Question 25

What are the four main parts or processes of the maxilla?

Answer 25

Zygomatic process of maxilla Frontal process of maxilla Palatine process or palate Alveolar process

Question 26

What type of bone formation happens to form the maxilla?

Answer 26

Mostly intramembranous ossification, a small portion through endochondral

Question 27

What part of the maxilla develops through endochondral ossification?

Answer 27

Zygomatic process (from malar cartilage or zygomatic cartilage)

Question 28

What are the parts of the mandible?

Answer 28

Body of the mandible Ramus - coronoid - condylar

Question 29

What nerve can be found in the body of the mandible, innervating the mandibular teeth?

Answer 29

Inferior alveolar nerve

Question 30

What structure protects the mandibular foramen?

Answer 30

Lingula

Question 31

Which branchial arch did the Meckel's cartilage arise from?

Answer 31

First branchial arch

Question 32

When does the formation of mandible occur? When does it ossify?

Answer 32

Form: 6th week in utero Ossify: 7th week in utero

Question 33

What happens simultaneously with the formation of the mandible?

Answer 33

Fusion of processes (left and right maxillary processes, median nasal processes (upper lip))

Question 34

Where would the mandible form in relation to the Meckel's cartilage?

Answer 34

Anterior and lateral to Meckel's cartilage

Question 35

What does the Meckel's cartilage form?

Answer 35

Malleus and incus of the inner ear | Sphenomandibular ligament of TMJ

Question 36

Where can one find the mandible's primary center of ossification?

Answer 36

Near the mental foramen

Question 37

What are the secondary centers of ossification in the mandible? (They undergo endochondral ossification.)

Answer 37

Condylar cartilage Coronoid cartilage Symphyseal cartilage

Question 38

Generally what structures in the mandible undergo intramembranous ossification and endochondral ossification?

Answer 38

Intramembranous: body and ramus Endochondral: bulk of ramus

Question 39

What direction should the infraorbital foramen ossify to form the frontal process?

Answer 39

Superiorly

Question 40

What is the primary center of ossification of the maxilla?

Answer 40

Infraorbital foramen

Question 41

What direction should the infraorbital foramen ossify to form the incisal region?

Answer 41

Anteriorly