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Periodontium (Anatomy of periodontium) Part I. DR.HOUNIDA IDRIS. Definition. The periodontium ( peri= around , odontos= tooth) is the functional system of tissues that surrounds the teeth and attaches them to the jaw bone. These tissues include: Gingiva. Periodontal ligaments (PDL).
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Periodontium (Anatomy of periodontium) Part I DR.HOUNIDA IDRIS
Definition • The periodontium ( peri= around , odontos= tooth) is the functional system of tissues that surrounds the teeth and attaches them to the jaw bone .
These tissues include: • Gingiva. • Periodontal ligaments (PDL). • Cementum. • Alveolar bone.
GINGIVA • Definition:that part of tissue that covers the cervical portions of the teeth and the alveolar processes of the jaws. • It is composed of thin outer layer of epithelium and underlying core of connective tissue. • The keratinized epithelium immediately surrounds a tooth
Functions: • The gingiva provides a tissue seal around the cervical portions of the tooth and alveolar processes of the jaws. • resist the mechanical stimuli of hard food particles impinging on it during mastication,
Anatomic Areas: the gingiva is divided into four anatomic areas: • Free gingiva. • Gingival sulcus. • Interdental gingiva (dental papilla). • Attached gingiva. Each area of gingiva differ in thickness and histology according to its function
Bounders of the gingiva: • The coronal boundary or the upper edge of the gingiva is the gingival margin. • The apical boundary or the lower edge of the gingiva is the alveolar mucosa which can be distinguished easily from the gingiva by its dark red color and smooth , shiny surface.
Demarcation of the gingiva: • Free gingiva groove: is a shallow linear depression that separates the free gingiva and attached gingiva .( this line can be visible clinically). • Mucogingival junction: its clinically visible boundary where the attached gingiva meets the alveolar mucosa.
FREE GINGIVAL • also called unattached gingiva or marginal gingiva. • Definition: it is the unattached portion of the gingiva that surrounds the tooth in the region of CMJ ( cemtoenamel junction)
Characteristics: • Not directly attached to the tooth. • Can be stretched away from the tooth surface with a periodontal probe . • The free gingiva also forms the soft tissue wall of the gingival sulcus.
Contour of the gingival margin: • It meets the tooth in a thin round edge called the gingival margin. • The gingival margin follows the contours of the teeth creating a scalloped ( wavy) outline around them.
Gingival sulcus: • It is a shallow fissure between marginal gingival and the enamel or cementum. • Clinical normal gingival sulcus depth = 2-3 mm measured with periodontal probe.
ATTACHED GINGIVA • Definition: is that part of the gingiva that is tightly connect to the cementum on the cervical third of the root and the periostum (connective tissue cover the alveolar bone.) • Distance between mucogingival junction and bottom of sulcus.
Function: • It allows the gingival tissue to withstand the mechanical forces created during activities such as mastication,speeaking and tooth brushing. • It prevents the free gingiva from being pulled away from the tooth when tension is applied to the alveolar mucosa.
Clinical features of gingiva: • color. • Size. • Contour. • Shape. • Consistency. • Surface texture. • Position.
color: in healthy gingiva pale or coral pink. Can be pigmented which occurs more in dark skinned people . Range from light brown to black.
Size: it’s the sum total of the bulk of cellular elements and their vascular supply . Its common appearance of gingival disease.
Contour: depends on shape of teeth and alignment in the arch.
Shape: shape of the interdental papilla is related with the contour of the proximal tooth. the height of the papilla varies with the location of the proximal contact.
Texture: in healthy Gingiva its similar to an orange peel known as stippling ; it presents in 40% of adults. Stippling is caused by the presence of the connective fibers that attach the gingival tissue to the cementum and bone.
Interdental gingiva (dental papilla) • Definition: is the portion of the gingiva that fills the interdental embrasure between two adjacent teeth apical to the contact.
Parts: • Facial papilla. • Lingual papilla ( papilla= singular noun , papillae = plural noun) • the lateral borders and the tip of an interdental papilla are formed by the free gingiva from the adjacent teeth.. • the center portion is formed by the attached gingiva.
3- the Col is vallylike depression in the portion of interdental gingiva that lies directly apical to the contact area.
Function: • Prevention food from becoming packed between the teeth during mastication.
Gingival Crevicular Fluid • Also called the gingival sulcular fluid . • Definition:is a fluid that seeps from the underlying connective tissue into the sulcular space. • little fluid or no fluid in healthy gingival sulcus. • Fluid flow increases in the presence of dental plaque and resulting in gingival inflammation.
The amount of gingival cervicular fluid can be measured by filter strip to index gingival inflammation.