Week 2 Micro and Macro Flashcards
How wide is the PDL space?
.1 to .25 mm
What is the shape of the PDL space?
Hourglass widest at Apex and cervix
Narrowest in middle
Shape of papilla in anterior and posterior teeth?
Ant- pyramidal
Post- col
Where is the mucogingival junction?
Border of the alveolar mucosa and attached gingiva
Where is the MGJ widest and narrowest?
Facial- wide ant and narrow post
Mand Ling- narrow ant incisors and wide in molars
4 PDL functions?
- Physical and mechanical
- Formation of bone and cementum
- Nutritional- blood and lymph
- Sensory
Cementum purpose?
Covers root surface and gives sharpeys fibers a place to attach
Where is the cementum thickest and thinnest?
Thick at apex, thin at CEJ
Thickens as one ages
4 maxillary arteries?
Anterior superior alveolar aka ASA,
Posterior Superior Alveolar aka PSA,
Infraorbital, and the Greater Palantine Artery
Mandibular artery?
Inferior Alveolar Artery
How do the arteries branch off the alveolar arteries to the teeth?
First to the Dental then that breaks into 3
The intraseptal, PDL, and the Supraperiosteal
What teeth do the jugulodigastric lymph nodes serve?
3rd molars
What part of the mouth do the deep cervical lymph nodes serve?
The palatal gingiva
What teeth do the submental lymph nodes serve?
The lower incisors
Other that the palatal gingiva, wisdom teeth and lower incisors what lymph nodes function for the rest of the mouth?
Submandibular
What nerve innervates the mouth autonomically?
Superior cervical ganglion
What nerve is responsible for our senses of pain, pressure, hot and cold in our mouth?
The trigeminal V
How does the trigeminal branch?
Superior alveolar, lingual and inferior
Plus mental/buccal
Other nerves that innervate the mouth?
Palate- sphenopalatine branches to
the greater palantine and nasopalantine
3 types of gingival epithelium and where is it found in a general sense?
All is found in the free and attached gingiva
Oral epithelium
Sulcular epithelium
Junctional epithelium
Cells types in general gingival epithelium and where do they usually begin life?
Start in the basal cell layer (stratum basal)- all gingiva tissue has this layer
Keratinocytes, Langerhans cells, Merkel cells, melanocytes
4 layers of epithelium?
Top to bottom- Stratum Corneum Stratum granulosum Stratum Spinosum Stratum Basale
What do Keratinocytes do?
Produce tonofilaments, soft tissue renewal.
They change shape as they move up the layers becoming flatter till they reach the top for the particular epithelium type they are aka ortho-keratinized, para or NON….
What do Langerhans cells do?
Macrophages that are are antigen presenting cells
What do Merkel cells do?
Tactile touch nerves
What do melanocytes do?
They make pigment
What cell layers are present in ortho-k tissue?
All 4 but stratum corneum keratinocytes have no nucleus
Top to bottom- Stratum Corneum- no nucleus Stratum granulosum Stratum Spinosum Stratum Basale
What layers does para-k epithelium have?
Only 3 missing the stratum granulosum and the top layer keeps the nucleus Top to bottom- Stratum Corneum w/nuclei Stratum Spinosum Stratum Basale
What layers does the non- keratinized tissue have?
Only 2-
Stratum Spinosum
Stratum basale
What is under all epithelium?
A basil lamina layer that connects it to the connective tissue
What 2 layers make up the basal lamina and what are they made of?
Lamina lucida- 40nm underneath the basal epithelium membrane, Proteoglycan
Lamina Densa- underneath lucida and connects to connective tissue, type IV collagen
Tissue type and location of “oral epithelium”?
Top of gingival margin to the MGJ on outside facing the oral cavity
Ortho-K all 4 layers
Fed and controlled by connective tissue which projects fingers into it with blood, lymph and nerves forming rete ridges
Sucular epithelium type and location?
From top of gingival margin but facing the tooth forming the perio pocket ending at the sulcus
Non keratinized thin and susceptible to infection
Location of and tissue type of the junctional epithelium?
Starts at sulcus attaching gingiva to tooth to just above the CEJ
Non-keratanized
How thick is the junctional epithelium?
Thin when healthy due to less adhesions to allow fluid to pass
.25-1.35 mm
Rank and list the tissues types and their turnover rates?
- Junctional epithelium- 4-6 days
- Sulcular epithelium 5-8 days
- Oral epithelium 10 days
How many basal layers does junctional epithelium have?
2-
One internal that attaches to the tooth and one external that attaches to the connective tissue
Cell originate on internal and base of the junctional epithelium and migrate toward the tooth and up to the sulcus where they are shed
Lots of inflammatory cells to fight infection
What is connective tissue made of?
60% collagen fibers type I most and IV
Other fibers elastic fibrin and reticular
8% cells mainly fibroblasts that make and degrade collagen
5% ground substance between fibers and cells, blood and nerves run here
What’s kinds of cells can make collagen!
Fibroblasts, chondroblasts, osteoblasts, odontoblasts
Type I is most common
Describe the organization of gingival fiber in connective tissue?
CDAP T^2 I^3
- Circular run around the tooth
- Dentogingival run from tooth cementum below the junctional epithelium out to oral epithelium
- Alveolargingival run from top bone up to oral gingiva
- Periostogingival from bone horizontal to oral gingiva
- Transseptal across septum between the teeth
- Interpapillary- facial to lingual across the papilla
- Intercircular from corner of one tooth to another
- Intergingival- lengthwise along gingiva
- Transginval- around tooth and across to gingiva
What is the PDL made of?
80% collagen Type I and type IiI
Some loose connective tissue, vessels, nerves, fibroblast cells and others
What types of cells are found in the PDL?
- Fibroblasts- make and degrade collagen
- Cementoblasts- form cementum
- Osteoblasts- form bone
- Epithelial rests of Malassez- left from remnants of the Hertwig root sheath
- Defense cells
- Nerves and blood vessels
Name the 6 main fibers of the PDL and how they attach?
OATHAI
- Oblique fibers- (most) from bone diagonal down to tooth- handle the brunt of the vertical forces
- Alveolar crest fibers- go from top of bone upwards to tooth- prevent extrusion and resist lateral movements
- Transseptal- tooth to tooth no bone across bone in between teeth
- Horizontal
- Apical fibers
- Interradicular- in the furcation on molars
What does cementum do?
Attaches PDL to tooth root-Sharpeys fibers from PDL insert into it
Is there vascularization in cementum?
No only gets deposited
Does cementum contain live cells?
Only in the apical 2/3 to 1/2 and not many and only in outer layer
Why this part is thicker because it can keep depositing. This parts is deposited after the tooth erupts
It is also less calcified
When is cementum deposited?
Cervical 1/3 to 1/2 is acellular and formed before eruption- more calcified and more sharpeys fibers
Apical 2/3-1/2 formed after tooth erupts
How is cementum deposited?
In lamellae aka layers/incremental lines
What is cementum made of?
Inorganic mainly hydroxyapatite- 45-50%
Organic-
Collagen-type I 90%
Type II 5%
Proteoglycans, glycoproteins, phosphoproteins
What is the thin layer of connective tissue that cover the inner surface of bone compartments?
Endosteum
What is the Endosteum?
Single layer of osteoblasts and little connective tissue lining inner compartments
What covers the outer surface of bone?
Periosteum
What does the periosteum do?
It is an inner layer of osteoblasts surrounded by osteoprogenitor cells
With an outer layer of blood vessels, nerves, fibroblasts and collagen fibers that penetrate the bone binding it to the bone
What makes up the outer layer of bone?
An external plate of cortical bone is formed by haversian bone and compacted bone lamellae.
What lines the inner sockets?
The inner socket wall of thin, compact bone called the alveolar bone proper is seen as the lamina dura in radiographs. Histologically, it contains a series of openings (i.e., the cribriform plate ) through which neurovascular bundles link the periodontal ligament with the central component of the alveolar
What is the center honeycomb like bone called?
Cancellous trabeculae between these two compact layers act as supporting alveolar
Name 3 major features of bone?
Vasculized, mineralized, and innervated
Constantly remodeling
60% inorganic
What is bone made of?
2/3 inorganic- calcium and phosphate as hydroxyapatite crystals
1/3 collagen type I (90%) and other proteins osteocalcin, osteonectin, bone morphogenetic protein, phosphoproteins, proteoglycans, osteoponin, bone sialoprotein, cell adhesion protein
Live cells- osteoblasts (forming), osteocytes, osteoclasts (resorbing)
What can bisphosphonate do to bone?
Cause osteonecrosis of the jaw
