JVD 2020 #3 Morphology of the Cementoenamel Junction in Permanent Teeth of Dogs: A Scanning Electron Microscopic Study; Hernandez Flashcards Preview

JVD 2019-2021 > JVD 2020 #3 Morphology of the Cementoenamel Junction in Permanent Teeth of Dogs: A Scanning Electron Microscopic Study; Hernandez > Flashcards

Flashcards in JVD 2020 #3 Morphology of the Cementoenamel Junction in Permanent Teeth of Dogs: A Scanning Electron Microscopic Study; Hernandez Deck (18)
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1
Q

What are Choquet cases of cementoenamel junction morphologies

A

Types of human CEJ morphology (4 types)

2
Q

What is type 1 CEJ morphology

A

The cementum overlaps the enamel

3
Q

What is type 2 CEJ morphology

A

The enamel overlaps the cementum

4
Q

What is type 3 CEJ morphology

A

Cementum and enamel are edge-to-edge

5
Q

What is type 4 CEJ morphology

A

Gap between the enamel and cementum with exposed dentin

6
Q

What was the most prevalent type of CEJ morphology in dogs?

A

Type 3, either alone or in combination, 90.7% of samples

7
Q

What was the 2nd most prevalent type of CEJ morphology in dogs?

A

Type 4, gap with exposed dentin. Present in 31.58% of samples

8
Q

How many teeth samples showed only one type

A

65.13%

9
Q

How many teeth samples showed a combination of types?

A

34.87%

10
Q

The CEJ of dogs evaluated showed a high degree of variability in:

A

different types of teeth
within a same tooth
within the dentition of a single individual
and among individuals

11
Q

Which type of CEJ morphology?

A

Type 1- Cementum overlapping the enamel

12
Q

Which type of CEJ morphology?

A

Type 2- Enamel overlapping cementum

13
Q

Which type of CEJ morphology?

A

Type 3- Edge-to-edge relationship between the cementum and enamel

The most common type in dogs (alone or in combo) 90.79% of samples

14
Q

Which type of CEJ morphology?

A

Type 4- Gap between the enamel and cementum with exposed dentin.

Second most common type in dogs- 31.58% (alone or in combo)

15
Q

What causes an irregular limit of cervical enamel in its marginal edge and an irregular onset of the formation and deposition of cementum?

A

Non-uniform fragmentation of Hertwig’s epithelial root sheath.

16
Q

What is Hertwig’s epithelial root sheath?

A

The enamel organ gives rise to Hertwig’s epithelial root sheath which is 2 epithelial layers: inner and outer epithelium. After enamel formation, the sheath irregularly fragments in time and space promoting deposition of cementum onto the newly formed dentin. After fragmentation, it participates in cementogeneis and formation of the periodontal ligament, giving rise to epithelial rests of Malassez.

17
Q

CEJ type 2 (enamel covering cementum) should not be embryologically possible, why?

A

Because development of the enamel ceases before that of the cementum. Those seen in the study were only in small segments or some kind of enamel strips on the cementum. These regions may be explained by existence of a hyperactive Hertwig’s sheath as it happens in formation of enamel pearls.

18
Q

In DeLaurier et.al. Analysis of the characteristics and mineralization status of feline teeth using scanning elecron microscopy. J Anat. 2006 , what type of CEJ was most common in cats and how does this relate to pathology?

A

Type 4 CEJ (gap between E &C) was most common followed by type 3 (edge-to-edge).

Suggested a possible relationship between the presence of exposed dentin and development of resorptive lesions.

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