2 - Connective Tissue, PDL, and Bone Flashcards
What can you tell me about the buccal plate thickness?
Cook 2011 - Based on CBCT data, the labia plate thickness in this phenotype patients (based on probe visibility) is 1/2 that of the thick/average phenotype
Ghassemian 2012 - Based on CBCT data, overall mean thickness of central incisors is 1.05mm. Greatest thickness is over lateral incisors
Huynh- Ba 2010 - Based on clinical data, 87% of anterior teeth with buccal plate <1mm
Temple 2017 - Based on CBCT data, the thickness in the mandible increases from anterior to posterior. The thinnest sites were MAN 1PM and MAX 1M mesial root
What is the relationship between the alveolar crest and CEJ?
Ritchey and Orban
In health, the alveolar interdental crests are parallel to the CEJ.
Flat IP = narrow interdental crest
Convex IP = wide interdental crest
Describe cortical and lamellar bone in the MAX/MAN
Lindhe 2013
Mandible with a thick cortical cap (1.8mm) and greater amounts of lamellar bone (60-70%)
Maxilla with a 0.8mm cortical cap and more bone marrow
What are some quick facts about collagen
Amino acid sequence = Gly-X-Y. 10% are Gly-Pro-HydroxyPro
Alpha chain assembled into procollagen triple helix on RER. Transported to Golgi where it is processed by cleaving ends to form Tropocollagen and then secreted in vesicle. Arranged in sheets to make fibrils and then fibers
1 - most abundant
4 - Basement membrane
7 - Anchoring fibrils
Where are fenestrations and dehiscences most common?
Elliot and Bowers
US skulls
MAX 3X fenestrations (MAX 1M)
MAN 2X dehiscence (PM)
What are Epithelial Rests of Malassez?
HERS touches the tooth and induces the dental papilla cells to differentiate into odontoblasts
Mantle dentin is laid down. HERS breaks down and becomes the only epithelial cells present in the PDL as the ERM
What is the prevalence of palatal exostoses and tori?
Nery - 40% skulls European
Larato - 30% Mexican skulls
Sonnier - 56% tubercles, 81% bilateral. 11mm from GPF
Sonnier - 20% tori. Females
What is the prevalence of mandibular tori?
Sonnier - 27% skulls. 74% bilateral
What is the prevalence of buccal exostosis and lipping?
Horning - African American skull study
Exostosis 7% teeth, 77% patients
Lipping 17% of teeth, 73% patients
NO CORRELATION w/ occlusal attrition and widened PDL. Goes against buttressing bone theory
Discuss the crestal lamina dura
Greenstein
• The composition is the same as the bone surrounding it and does not have a higher mineral content • The presence or absence of crestal lamina dura was not related to the presence or absence of inflammation/BOP/PD/LOA There is much higher agreement on the absence of LD (89%) compared to the presence of LD (24%)
What is the most common bony defect in periodontitis patients?
Manson
Interdental crater, which makes up 1/3 of all defects and 2/3 of all mandibular defects
The maxilla has a greater diversity of defects than the mandible
Which wall is higher in craters? Lingual or buccal?
Tal - Lingual 84%
Were are periodontal defects most common? What type of defect?
Vrotsos
Posterior > anterior. More craters posterior b/c greater B/L width
Posterior mandible > posterior maxilla
Crater 59%
3-wall 17%
How does interproximal distance of roots affect intrabony pockets?
Tal
<2.6mm - horizontal
2.6-3.1mm - 1 vertical
>3.1mm - 2 vertical
What is the range of Waerhaug’s sphere of influence?
0.5-2.7mm
Average 1.6mm
What are the two fibroblast lineages? How are they different?
Mariotti
PDL and gingival FB
Gingival covers a wound faster, greater non-collagen synthesis and DNA
PDL fibroblasts greater collagen synthesis.
Important for GTR. Exclude gingival FB.
What is the width of the PDL? How was it studied? Differences between groups?
Coolidge 1937
Human cadaver block sections
Thickness 0.15-0.2mm
Young - more cellular and wider
Older - decreased collagen turnover
What affects the PDL space radiographically?
Van der Linden
INCREASED - increased root radius, exposure time, and dark X-RAY
DECREASED - Increased kVP, horizontal angulation
What are fibroblast origins in the PDL?
McCulloch
Tooth side : ectomesenchyme of dental papilla/follicle
Bone side: Perivascular mesenchyme
What tissue types are between roots, depending on the width?
Heins & Weider
<0.3 - PDL
0.3-0.5 - PDL + cortical
>0.5 - Cancellous + cortical
Who had a counterargument to Greenstein regarding crestal lamina dura?
Rams 2018
In a 2 year retrospective follow-up of treated ChP patients, a crestal lamina dura in angular or horizontal defects was associated w/ clinical periodontal stability up to 24 months.
Rams was retrospective and treated periodontitis patients.
Is the maxillary tuberosity a good site to harvest autogenous bone?
Gapski
NO. Sparse cancellous bone. 24% vital bone. Surface bone thin and lamellar
Are facial overlay grafts effective?
Poulias
YES - with ridge preservation + Bio-Oss facial overlay graft, lose only 0.3mm width and maintain a flat to convex contour of bone
How much of a ridge is lost without ridge preservation?
Van der Weijden
- 87mm width
- 67mm buccal
- 03mm lingual
Schropp
50% ridge width, 2/3 in first 3 months (molars and premolars)
Describe the human histologic sequence of healing extraction sockets?
Amler
0: Clot 2-3: Fibrin organization 4: Epithelialization 7: Replace clot w/ granulation tissue. Osteoid at base of socket 12: Downgrowth of epithelium into socket 20: Replace granulation tissue w/ CT. Osteoid calcifies 21: Bone development begins 24-35: Fusion of epithelium 40: 2/3 socket filled
Cardaropoli did DOGS
Describe the different cell types during healing
Trombelli
First 8 weeks: Vascular
Osteoblasts peak at 6-8 weeks and remain constant
Macrophages 2-4 weeks
Minimal osteoclasts
