Lecture 4 Alveolar Bone and PDL Flashcards
What is the normal thickness of the PDL?
.1 mm
What are the most abundant cells of the PDL?
Fibroblasts that produce collagenous fibers.
What is the PDL equivalent to where it attaches to the alveolar bone?
Periosteum
T/F PDL fibroblasts differentiate into osteoblasts to form new bone that fills the socket during healing.
True
What are Sharpey’s Fibers?
Are bundles of Type I collagen fibers that strongly bridge the cementum, PDL and alveolar bone
What is bundle bone?
The alveolar bone directly lining a tooth alveolus
T/F Sharpey’s Fiber bundles insert directly into the bundle bone.
True
T/F The PDL is richly innvervated but avascular.
FALSE. It is innervated and vascular
T/F Dental implants placed in compact bone initially rely upon the stability offered by spongy bone to avoid early movement which impedes on inhibits osseointegration of the rest of the device in the spongy bone.
False. Dental implants placed in SPONGY bone initially rely upon the stability offered by COMPACT bone to avoid early movement which impedes on inhibits osseointegration of the rest of the device in the spongy bone.
Which type of ligament is composed of collagen fibers that run between adjacent teeth over the alveolar crest?
transseptal ligament
What is the interdental gingiva that is located between the lingual and buccal interdental papillae called?
gingival col
What are the four types of free nerve endings found in various regions of the PDL?
- Tree-like branch endings
- Dendritic fiber endings
- Coiled endings
- Spindle-type endings
What is the name of the many interconnections within the rich blood supply of the PDL?
Anastomoses
Which gingival ligament fiber bundle has the most numerous fibers, extending from cervical cementum to the lamina propria of the free and attached gingivae?
dentogingival group
Which gingival ligament fiber bundle radiates from the bone of the alveolar crest and extend into the lamina propria of the free and attached gingivae?
alveologingival group
Which gingival ligament fiber bundle forms a band around the neck of the tooth interlacing with other groups of fibers in the free gingiva and helping to bind the free gingiva to the tooth?
circular group
Which gingival ligament fiber bundle runs apically from the cementum over the periosteum of the outer cortical plates of the alveolar process, these fibers insert into the alveolar process or the vestibular muscle and floor of the mouth?
dentoperiosteal group
Which gingival ligament fiber bundle runs interdentally from the cementum just apical to the base of the junctional epithelium of one tooth over the alveolar crest and insert into a comparable region of the cementum of the adjacent tooth?
transseptal fiber system
Which type of fibers in the transseptal fiber system have been implicated as a major cause of postretention relapse of orthodontically positioned teeth?
supracrestal fibers
Which two branches of the of the Trigeminal (V) nerve innervate the PDL?
The maxillary (V2) and mandibular (V3)
T/F Stimulation of the PDL sensory nerves causes jaw opening?
True
What kind of free nerve endings are found along the whole length of the tooth root?
Highly branched nerve endings
What are the four types of free nerve endings found in various regions of the PDL?
- Tree-like branch endings
- Dendritic fiber endings
- Coiled endings
- Spindle-type endings
What is the name of the many interconnections within the rich blood supply of the PDL?
Anastomoses
What are the 5 principal fiber groups of the PDL?
alveolar crest, horizontal, oblique, apical, interradicular
What are the 3 types of collagen fiber groups of PDL?
Types I, II, and VII
Which principal fiber group runs right angles to the long axis of the tooth from cementum to bone just below the alveolar crest?
horizontal group
Which principal fiber group is the most numerous in the PDL and runs from the cementum in an oblique direction to insert into bone coronally around the root?
oblique group
Which principal fiber group radiates from the cementum around the apex of the root to the bone, forming the base of the socket?
apical group
Which principal fiber group is found only between the roots of multi-rooted teeth and runs from the cementum into the interradicular crest of the alveolar bone?
interradicular group
What are the 3 types of collagen fiber groups of PDL?
Types I, II, and VII
Which collagen fiber is the most abundant in PDL?
Type I collagen
What are Oxytalan fibers?
Bundles of elastic fibers distributed in the PDL that run vertically from the apical root cementum to nerves and blood vessels in the cervical region of the PDL.
What are the Oxytalan fibers thought to regulate in response to variations in tension on the tooth?
Vascular flow
What is the difference in physical appearance between Oxytalan fibers and collagen fibers?
Oxytalan fibers are unbanded, while collagen fibers are banded
What does “alveola” mean, and how does it relate to teeth?
means “pockets”
refers to the holes where teeth go
Why is the Lamina Dura radiographically dense?
It is the compact region of the alveolar bone (opposed to the inner spongy region)
What fibers bridge the PDL to the cementum and alveolar bone?
Sharpey’s fibers
