Iya_Epidemiology & Pathogenesis of Periodontitis

Question 1

How common is periodontitis?

Answer 1

Eke ‘15
»50% in the US population (older than 30 years)

Question 2

What’s the modified gingival index?

Answer 2

Lobene ‘86:
0: Normal
1: Mild inflammation, slight change in color & texture in any portion of the gingival unit
2: Mild inflammation of the entire gingival unit
3: Moderate inflammation of the gingival unit
4: Severe inflammation of the gingival unit

Question 3

Describe the CPITN probe

Answer 3

A 0.5 mm ball, then markings at 3.5, 5.5

Question 4

Describe the CPITN scale

Answer 4

Ainamo ‘82
Code 0: no pockets, BOP, calculus, or overhangs in the sextant - TN0
Code 1: BOP, but no pockets, calculus, or overhangs - TN 1
Code 2: Pockets ≤3mm and there is supra and SubG calculus & overhangs - TN 2
Code 3: Pockets are 4-5 mm - TN 2
Code 4: Pockets are ≥6mm - TN 3

The TN are “treatment needs” and were convenient codes
TN 0 : no tx needed
TN 1: Need improved OH
TN 2: Need scaling, overhang removal, improved OH
TN 3: Advanced treatment

Question 5

What are the Ramfjord teeth?

Answer 5

3, 8, 12, 19, 24, 28

(Looks at 1 molar, incisor, premolar on the upper and lower arches)

Question 6

What are the CIPTN teeth?

Answer 6

2, 3, 8, 14, 15, 18, 19, 24, 30, 31

Question 7

Describe the classic experimental gingivitis study

Answer 7

Loe ‘65
12 healthy subjects with healthy gums stopped brushing. Rapidly, debris accumulated on the teeth and marginal gingivitis developed in all 12 of them (from 10-21 days).
The **gingivitis reversed **within 1 week of resuming oral hygiene.

Question 8

What is the timeline for gingivitis turning into periodontitis?

Answer 8

Page & Schroeder ‘76
Days of plaque accumulation : description
Day 0: Pristine gingiva (histologic perfection): doesn’t exist
Day 2-4: Clinically healthy tissues. Some increased vasodilation and leukocytes
Day 4-7: Early gingivitis. Increased lymphoid cells (monocytes, macrophages, lymphocytes, neutrophils) are collecting below the JE. Rete pegs form on the JE due to the inflammation. Collagen loss reaches 60-70% near the JE.
Day 14-21: Chronic gingivitis. Plasma cells accumulate, but no bone loss yet. JE starts to grow apically. Some ulceration and loss of collagen fibers and matrix occurs.
Day 21+ : Periodontitis. Lesions extend to the bone and PDL. Bone loss occurs. Lots of plasma cells. JE moves apically (CAL loss).

Question 9

Describe the Seymor ‘83 study “HE WANTED TO SEE MORE”

Answer 9

Gingivitis biopsied from dental students
Stopped brushing & flossing for 3 weeks; biopsied the MB gingival of 1st molars at 0, 4, 8, 21 days. Similar findings as Page & Schoeder ‘76, but Seymor found that instead of plasma cells dominating at 14-21 days, it was the T-lymphocytes .

Question 10

Describe the 2 Loe studies on periodontitis progression

Answer 10

Loe ‘78: Steady and continuous progression over time. Compared the Norwegians to the Sri Lankans. Norwegians had slow progression and the Sri lankans had much more progression over time.
- 6-7 yrs. FU, parameters: Plaque, calculus, GI, CAL, caries and fillings
Loe ‘86: different rates of progression:
No progression (0.05 - 0.09 mm/year) - 11% of Sri Lankans
Moderate: (0.05 - 0.5 mm /year) - 81% of Sri Lankans
Rapid): (0.1 - 1mm/year) - 8% of Sri lankans
initial exam was on 1970
Final exam was on 1985

These findings were basically confirmed by Ramseier ‘17 (the followup to Loe ‘86) and Goodson ‘82 (small study of 22 people).

Question 11

How does tooth loss correlate with periodontal maintenance?

Answer 11

Remember the Becker studies (‘79 and ‘84
Becker ‘79: Untreated periodontitis = 0.36 teeth/year lost
Becker ‘84: Treated periodontitis but no maintenance = 0.22 teeth/year lost
Becker ‘84: Treated periodontitis and maintenance= 0.11 teeth/year lost