Periodontal Ligament, Alveolar
Process and Cementum
DH110
ORAL HISTOLOGY AND EMBRYOLOGY
Lesson 7
Tammy Fisher RDH BS
ROLL CALL
What is your favorite
food and restaurant?
Let’s Get Started
Lesson 7 Objectives
Don’t forget the Smile Train donations!
Homework #3 graded and returned
Homework #5 part #2 returned for discussion
No homework due next week!
Journal Article
What makes a good journal? Trade vs. Scholarly vs. Popular
Ulrichsweb
The Purdue Owl http://owl.english.purdue.edu/owl/
APA formatting (American Psychological Association 6th edition)
Times New Roman 12
Who, When, What , and Where
References
American Dental Association Council on Scientific Affairs (2006). The use of dental radiographs:
update and recommendations. Journal of the American Dental Association, 137(9), 13041312.
Centers for Disease Control and Prevention (2003). Guidelines for infection control in dental
health-care settings-2003. Retrieved from,
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5217a1.htm
Christensen, G. J. (2004). Why switch to digital radiography? Journal of the American Dental
Association, 135(10), 1437-1439.
Dentistry IQ (2010, September). Nomad: handheld x-ray receives accolades. Retrieved
from,
http://www.dentistryiq.com/index/display/articledisplay/4283591955/articles/dentisryiq/
industry/2010/09/nomad-gets_innovation.html
Health Physics Society (2010). Radiation exposure from medical exams and procedures.
Retrieved from,
http://hps.org/documents/Medical_Exposures_Fact_Sheet.pdf
Standley, E. & Emmerling, H. (2011). Dental radiography: technology, infection control and
exposure guidelines. RDH, 31(1), 69-73.
Texas Department of State Health Services Radiation Safety Licensing Branch (2010). Guide for
the preparation of operating and safety procedures for dental facilities. Retrieved from,
http://www.dshs.state.tx.us/Layouts/ContentPage.aspx?PageID=35849&id=4541&terms=proc
edures+for+dental+facilities
Wilkins, E.M. (2009). Clinical practice of the dental hygienist (10th ed.). Philadelphia, PA:
Lippincott, Williams and Wilkins.
Quiz 3
Review Chapters 9-10
Dental Pulp and Cementum
Periodontium
Alveolar Bone Proper
Cementum
Periodontal Ligament
Gingiva
Periodontal Ligament
 Primary function is to support the teeth
 A fibrous connective tissue that attaches to
the alveolar bone proper and the cementum
 Covers the cementum of the root and
connects to the gingiva
 Decreases in size with age
 Highly cellular with vascular, neural, bone
and cemental cells
Organization of the PDL
 Gingival group = Gingival fibers
A. Transeptal
B. Attached gingival
C. Free gingival
D. Circumferential
Organization of the PDL
Dentoalveolar fiber group
A. Apical
B. Oblique
C. Horizontal
D. Alveolar Crest
E. Interradicular
Flash Cards
Interstitial
space
 An area between
each group of
fibers that contains
a network of blood
vessels, nerves, and
lymphatics that
maintains the
vitality of the PDL.
Oxytalan
Fibers
 A type of connective
tissue fibers
chemically different
from collagen fibers
and found in the PDL
and gingiva. They are
elasticlike and support
the vessels and fibers
of the PDL.
Fundus or The part of
an
organ
that
Fundic
is farthest
from its
opening
Trabeculae
Small tissue
elements in
the form of a
small beam,
strut, or rod
Lamellae
 Thin plate-like
structures , often
very close to one
another with
open space
between. A thin
leaf or plate, gilllike.
Lacunae
The very small
cavities in
bone that are
filled with
bone cells.
Aciniform
Fine pain
receptors in the
PDL. They
function as a
protective
measure during
mastication.
Cells of the PDL
Fibroblasts
Osteoblasts
Cementoblasts
Macrophages
Osteoclasts
Epithelial Rests
Intercellular Tissue
Functions of the PDL
Supportive
Maintenance
Sensory
Nutritive
Aging of the Ligament
Cell number and activity decrease due to diet and
loss of function
Scalloping occurs in cementum and alveolar bone
Fibers attach to the peaks of scallops rather than
entire surface of bone
Good health and good oral hygiene can lead to a
healthier periodontium
Hard Tissues of the
Periodontium
Alveolar Process
Alveolar Bone Proper (Lamina
Dura)
•
Supporting Bone
 Cementum
•
Flash Cards
Fenestration
The area of
alveolar bone
loss where an
apical root
penetrates the
bone.
Dehiscence
Alveolar
bone loss in
the coronal
root.
 Perforating
Fibers/Sharpey’s
Fibers
 Penetrating
connective tissue
fibers by which the
tooth is attached to
the adjacent alveolar
bone. These bundles
of collagen fibers
penetrate both the
cementum and the
alveolar bone.
Bundle Bone
Lamina Dura
Alveolar
Bone Proper
 A thin layer of hard
compact bone
lining the tooth
sockets. Appears
more dense
radiographically
than the adjacent
supportive bone.
Supporting Bone
Supporting Compact Bone
•
Similar to Haversian Bone found in the body
Supporting Cancellous Bone
• The supporting bone of the maxilla is filled with
marrow tissue. Bone marrow makes up 4.5% of the body
Cemental Support
•Functions as support by attaching to perforating (or
Sharpey’s)fibers
•Smaller and more numerous than the bundles of
alveolar bone proper
•Cementum is more resistant to resorb than bone
•Cementum does not have a blood supply or nerves
•Cementum WILL resorb in cases of stress caused by
traumatic occlusion or orthodontic treatment
Tooth Movement
•Physiologic Movement
•Orthodontic Movement
Leeway
Space
 The difference in the
space in the arch
required for the two
primary molars and the
successional permanent
premolars replacing
them. The leeway space
in the maxilla is 1.3 mm
and in the mandible is
3.1 mm.
Incisor
Liability
Factor
The
replacement of
the smaller
primary incisors
with larger
permanent
ones.
http://www.checkdent.com/en/videos
/mesial-drift-120.html
Mesial
Drift
General
movement of a
tooth or teeth
anteriorly
toward the
midline of the
jaw.
GREAT BOOKS
NEXT WEEK
No homework!
No quiz!
Read Chapters 13 and 14.
Work on Homework #5.
Start studying for the final.