Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dental Anatomy > Upper & Lower jaws Development > Flashcards

Upper & Lower jaws Development Flashcards

1
Q

Bones from endochondral ossification are ……

A

Bones of the base of the skull

  1. Ethmoid
  2. Inf. concha
  3. Body, lesser wing, base of greater wing, lateral pterygoid plate of the sphenoid; petrosal of temporal bone
  4. Basilar, lateral, and squamous part of occipital
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bones from intramembranous ossification are ….

A
  1. frontal, parietal bones
  2. squamous & tympanic parts of temporal
  3. part of greater wing, and medial pterygoid plate of sphenoid
  4. upper part of squamous portion of occipital
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

All bones of upper face develop by ……

A

intramembranous ossification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The mandible develops by …..

A 
intramembranous ossification (lateral to Meckel's cartilage)
* The condyle develops from endochondral ossification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The Maxilla is derived from two bones …. &…..

A

maxilla proper & premaxilla

* Maxilla grows downward & forward by appositional growth at the sutures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The mandible is first seen in …….

A

the sixth week of life as two bones

  • At one year, the bones fuse at the symphysis
  • The mandible grows downward & forward due to appositional growth at posterior border of the ramus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

First sign of tooth development is at ……

A

six weeks of embryonic life

* The embryo is 11 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

An epithelial thickening, forming a band at the outline of future arches is …….

A

dental lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Bulb like thickening in the dental lamina indicates ……..

A

the future tooth buds

* They are 20 in number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The tooth bud consists of …….

A
  1. Enamel organ (from ectoderm)
  2. Dental papilla (from mesenchyme. Forms pulp & dentin)
  3. Dental sac (from mesoderm. Forms cementum & PDL)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cap stage follows ………

It is characterized by ……….

A

Bud stage

  • There is expansion of the whole tooth bud
    1. Enamel organ: outer cuboidal cells & inner columnar cells (on the concavity). Separated by stellate reticulum
    2. Enamel knot: in the center of the enamel organ
    3. Dental papilla and dental sac: more proliferation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The Bell stage is characterized by ……..

A
  1. Inner enamel epi. becomes ameloblasts
  2. Stratum intermedium: develops between inner enamel epi. & stellate reticulum
  3. Stellate reticulum: more expansion
  4. Dental lamina: forms of new tooth buds for permanent teeth (not for molars though)
  5. Outer enamel epi: cells flatten
  6. Dental papilla: becomes odontoblasts
  7. Dental sac: shows circular arrangement of fibers. resembling a capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vestibular lamina is ………

A

epithelial thickening labial to the dental lamina

It forms the vestibule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ameloblasts will release a factor that will affect ……

A

the dental papilla, and start the transformation into odontoblasts, and formation of predentin
* Odontoblasts will release a reciprocal factor that affects ameloblasts to form enamelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Root formation starts when …..

A

enamel and dentin formation reach the CEJ

* Enamel organ plays an important role in root formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hertwig root sheath is ……

A

the part of the enamel organ, where the inner & outer layers are fused, with no stellate reticulum or stratum intermedium
* It initiates root formation (molding the shape of the root)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

After Hertwig’s sheath initiates root dentin formation, it ……..

A

degenerates, leaving the Epithelial rest of Malassez (which is found in the PDL)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cementoblasts form after ………. come into contact with ……

A

the primitive cells of the PDL
root dentin
* This is after Hertwig’s root sheath is broken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cementoblasts lays down ……

A

cementoid

* calcifies later into cementum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The term “cellular cementum” refers to ……

A

cementoblasts in the apical third of the root, which are trapped into their own secretion
* Acellular cementum is found in the occlusal two thirds of root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Enamel prisms and the interprismatic substance are composed of ……

A

96% inorganic (hydroxyapatite)
1% organic
3% water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Dentin is much more bone-like than enamel. T/F??

A

True

  • Dentin is harder than compact bone, but softer than enamel
  • The most bone like dental tissue is cementum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Enamel rods are arranged in …….

A

a perpendicular fashion on every point of the enamel surface in the crown

  • It starts with a wavy course, close to dentin
  • Every rode runs the entire thickness of enamel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Hunter-Schreger bands appear when ……

A

there is a change in the arrangement of the enamel prisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

A cross section of enamel shows concentric lines of brown color with …….. & colorless with ………
These are …….

A

transmitted light
reflected light
Lines of Retizus (run obliquely in longitudinal section)
* They are growth rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Enamel spindles are ……..

A

extension of the dentin into the enamel (short tubules)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Perikymata are ……

A

transverse, wavy grooves on the enamel, extension of Lines of Retizus

  • Parallel to each other and to the CEJ
  • Disappears with aging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Tomes processes are ……..

A

the projection of the ameloblasts into the enamel

* Ameloblasts long axis is not parallel to the long axis of the rods they produce

29
Q

Enamel lamellae are ……….

A

hypomineralized structures. extend from enamel surface to DEJ or deeper
* No clinical significance

30
Q

Enamel tufts are ……

A

hypocalcified enamel rods extending from the DEJ into the enamel
* Resembles cracks

31
Q

Enamel tufts differ from enamel lamellae by …

A
  1. they are non linear (branched - optical illusion)
  2. extend from DEJ outwards
    * Both are caused by disturbance in enamel formation
32
Q

Dentin is composed of ……

A

70% inorganic

30% organic & water

33
Q

Dentinal tubules start at ……

A

right angles to the pulp, then follow and S shape wavy path

34
Q

Tomes fibers refers to ……

A

odontoblastic process extending into the dentinal tubules

35
Q

Peritubular dentin is …..

A

dentin surrounding the odontoblast process

* Stain darkly, highly mineralized

36
Q

Intertubular dentin is …..

A

forms the main bulk of dentin. Less mineralized than peritubular
* More collagenous fibers in ground substance

37
Q

Imbrication lines or ………, are …….

A

Von Ebner lines, are lines run at right angle to the dentinal tubules in cross section. Sign of incremental apposition
* resembles lines of Retizus in enamel

38
Q

Contour line of Owen is …..

A

an exaggeration of the Von Ebner incremental lines

  • due to disturbance in mineralization process
  • If due to trauma, it is called neonatal lines
39
Q

Predentin is non mineralized. T/F??

A

true

40
Q

The first sign of predentin mineralization is formation of ……
Failure of fusion of the globules in the dentin will form ……

A 
Korff fibers (fan like arrangement of collagen fibers), which forms globules that fuse later, forming a regular dentin
* interglobular dentin (poorly mineralized dentin between the globules)
41
Q

Interglobular dentin subjacent to cementum is called ……

A

Tomes granular layer

* Note that: Dentin is considered a vital tissue

42
Q

Secondary dentin is characterized by ……

A
  1. separated from early dentin by dark line

2. less tubules, but more wavy

43
Q

In response to injury, odontoblasts may …… or ……….

A
  1. degenerate, and replaced by undifferentiated cells from the pulp, which form hard reparative dentin
  2. continue to produce dentin to protect the pulp
44
Q

The reparative dentin have ……

A

less tubules, which are twisted

45
Q

Scelrotic dentin is ……..

A

seen in elderly people, where calcium salts may obliterate the dentinal tubules
* It is transparent dentin

46
Q

Cementum is composed of …….

A

65% inorganic

35% organic & water

47
Q

Cementocytes in the root apical third have …….

A

processes that branch & anastomose in canaliculi

48
Q

If damage occurs to the cementum, ……

A

PDL cells differentiate into cemetoblasts, which form secondary cementum
* Secondary cementum resembles cellular cementum, and reabsorbs more easily (but less than bone)

49
Q

Secondary & cellular cementum are similar to bone by …….

A

contain cells in lacunae, have canaliculi, & can be reabsorbed (though not under normal condition)
* Note that: cementum doesn’t have a Haversian system like bone

50
Q

Cementum can compensate for tooth structure loss. T/F??

A

true

51
Q

Hypercementosis occurs in ……

A

chronic inflammation in the periapical area

* May also occur due to hypofunction of a tooth

52
Q

The primary function of the pulp is ……

A 
the production of dentin
Also:
1. Nutrition
2. Sensory: GVE (pain only) and sympathetic (for the blood vessels)
3. Defensive
53
Q

Describe the embryonic pulp tissue.

A

argyrophilic, and lacks vessels & collagen fibers
* Adult pulp has cells, fibroblasts, and intercellular substance (argyrophilic fibers, collagen fibers & ground substance). There is no elastic fibers. Histiocytes are present

54
Q

Pulp vessels communicate with the PDL vessels via ……..

A

accessory canals

* Lymph vessels also found in the pulp

55
Q

What are the types of nerve fibers in the pulp?

A
  1. Myelinated: mediate pain

2. Unmyelinated; sympathetic

56
Q

What is the pulp stones? and what are the types?

A

Pulp stones (denticles) are normal finding in the adult pulp

  1. True: has real dentin structure with tubules
  2. False: calcified mass
    * Denticles could be free (surrounded by pulp), attached, or embeded
57
Q

TMJ is …….

A

a sliding hinge joint (diarthrosis) between articular eminence of the temporal and the condyle of the mandible.
* An articular disc is interimposed between the two bones

58
Q

The articular surface of the eminence is ……..

The condyle is ……..

A

concave in its posterior portion & convex anteriorly

* arc shaped with its axis placed medially & posteriorly

59
Q

The articulating surface of TMJ is covered by ……

A

fibrous CT (not hyaline cartilage like the rest of the body)

60
Q

TMJ blood supply is from

A

superficial temporal branch of the external carotid artery

61
Q

The condyle is …….

A

cancellous bone covered by thin layer of compact bone. Filled with bone marrow or fat (in older age)
* Same for the articular eminence

62
Q

The glenoid fossa is composed of …….

A

a thin layer of compact bone. May get perforated by the condyles in severe trauma

63
Q

Articular disc center is made of ………

A

very dense connective tissue, with no blood vessels. Resemble an erythrocyte
* The posterior border of the disc is connected to the capsule by loose CT

64
Q

Articular capsule is ……

A

a fibrous sac, lined by synovial membrane. attached to the circumference of the mandibular fossa (superiorly), the eminence (anteriorly), & the condylar neck inferiorly

  • Laterally strengthened by the temporomandibular ligament
  • Capsule has numerous blood vessels
65
Q

The temporomandibular ligament is …….

A

composed of two short fibrous ligaments
1. one from the zygomatic arch
2. one from the eminence
both attach to the lateral of the condylar neck

66
Q

Some fibers of the lateral pterygoid muscle attach to ……..

A

anterior border of the disc

67
Q

The synovial membrane of the capsule is originated from ……

A

mesothelium. Secrete hyaluronic acid synovial fluid

* Lines the upper and lower space of TMJ

68
Q

All muscles of the tongue are innervated by hypoglossal nerve except ……

A

palatoglossus, innervated by CN X from the pharyngeal plexus

Dental Anatomy (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions