The periodontium refers to the tissues that both invest and support the teeth, including the alveolar bone, root cementum, periodontal ligament, and gingiva. The periodontium develops from the epithelial root sheath of Hertwig as the formation of enamel is completed and roots begin to develop. Cementoblasts are responsible for depositing the organic matrix that later mineralizes to form cementum. The periodontal ligament develops from the dental follicle after root formation begins, and alveolar bone forms around the periodontal ligament as eruption occurs.

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Anatomy And Development Of
The Structures Of Periodontium
periodontium arises from the Greek word peri meaning around and
odont meaning tooth, thus it can be simply defined as the “tissues
investing and supporting the teeth”
The periodontium is composed of the following tissues namely
 alveolar bone,
 root cementum,
 periodontal ligament (supporting tissues) and
 gingiva (investing tissue).

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various diseases of the periodontium are collectively
termed as periodontal diseases.
Their treatment is referred to as periodontal therapy.
The clinical science that deals with the periodontium in health
and disease is called periodontology.
The branch of dentistry concerned with prevention and treatment
of periodontal disease is termed periodontics or periodontia.

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The oral mucosa consists of three zones:
1. Masticatory mucosa: It includes the gingiva and the
covering of the hard palate.
2. Specialized mucosa: It covers the dorsum of the tongue.
3. Lining mucosa: It is the oral mucous membrane that lines
remainder of the oral cavity

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The gingiva is divided anatomically
into
 Free or marginal,
 attached and
 interdental gingiva.
The border or groove between marginal and attached gingiva is
called as a free gingival groove
The junction between the attached gingiva and alveolar mucosa is
called as mucogingival line or junction
The gingiva is divided anatomically
The border or groove between marginal and attached gingiva is
gingival groove.
The junction between the attached gingiva and alveolar mucosa is
mucogingival line or junction
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The border or groove between marginal and attached gingiva is
The junction between the attached gingiva and alveolar mucosa is

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DEVELOPMENT OF PERIODONTIUM
Development of cementum
and roots of the teeth starts
once the formation of enamel
is completed.
The outer and inner epithelia
together form the epithelial
root sheath of Hertwig

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Once the crown formation is complete the cells of the inner enamel
epithelium loose their ability to form enamel and is called reduced
enamel epithelium
DEVELOPMENT OF CEMENTUM
Cementoblasts: These cells are responsible for the deposition of
the organic matrix of cementum, which consists of proteoglycan
ground substance, intrinsic collagen fibers and is followed by
subsequent mineralization of the organic matrix

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The periodontal ligament forms from the dental follicle soon after
root formation begins.
fibers from the follicle are incorporated in the cementum and they
are called as Sharpey’s fibers
Alveolar bone forms around the periodontal ligament With
continuous bone deposition the periodontal ligament space
gradually becomes narrower. The alveolar process develops during
the eruption of the teeth and cells responsible for bone formation
are osteoblasts

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Development of Junctional Epithelium
When the enamel formation is complete The inner enamel
epithelium after laying down enamel reduces to a few layers of
flat cuboidal cells, which is then called as reduced enamel
epithelium.
It covers the entire enamel surface extending till the
cementoenamel junction. During eruption, the tip of the tooth
approaches the oral mucosa leading to fusion of the reduced
enamel epithelium with the oral epithelium.

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As the crown emerges into
the oral cavity the former
ameloblasts that are in contact
with the enamel get trans
formed into junctional epithelium.
Coronally, the JE is continuous
with the oral epithelium.
As the tooth erupts, the reduced enamel epithelium grows
shorter gradually. A shallow groove, the gingival sulcus may
develop between the gingiva and the tooth surface.
As the crown emerges into
the oral cavity the former
ameloblasts that are in contact
get trans-
junctional epithelium.
is continuous
with the oral epithelium.
As the tooth erupts, the reduced enamel epithelium grows
shorter gradually. A shallow groove, the gingival sulcus may
e gingiva and the tooth surface.
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As the tooth erupts, the reduced enamel epithelium grows
shorter gradually. A shallow groove, the gingival sulcus may

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When the junctional epithelium forms from the ameloblasts it is
called primary epithelial attachment.
Junctional epithelium that forms after surgical therapy takes its
origin from the basal cells of oral epithelium instead of ameloblast
is called secondary epithelial attachment