Periodontium: Tooth Supporting Structures

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Questions and Answers

What term is used to refer to the functional system of tissues that surrounds and attaches teeth to the jawbone?

Periodontium (correct)

Gingival sulcus

Cementoenamel junction

Alveolar process

Which part of the periodontium is responsible for covering the cervical portions of teeth?

Gingival sulcus

Interdental gingiva

Free gingiva (correct)

Attached gingiva

What structure includes the demarcations like the free gingival groove and mucogingival junction?

Gingival margin

Alveolar mucosa

Attached gingiva

Gingiva (correct)

What does the attached gingiva primarily protect?

Underlying tooth-supporting structures Signup and view all the answers

What anatomical area of the gingiva is characterized by its scalloped curvature?

Attached gingiva Signup and view all the answers

Which of the following is NOT one of the four anatomical areas of the gingiva?

Collar gingiva Signup and view all the answers

What is the role of the junctional epithelium in the structure of the gingiva?

It attaches the free gingiva to the tooth Signup and view all the answers

How is the position of the gingival margin influenced as one ages?

It may be age dependent Signup and view all the answers

What is the primary composition of the periodontal ligament?

Dense fibrous connective tissue Signup and view all the answers

Which statement correctly describes a function of the periodontal ligament?

It connects the tooth to the alveolar process Signup and view all the answers

How does cementum compare to dentin and enamel?

It is softer than dentin and enamel Signup and view all the answers

What percentage of cementum is organic material?

45% Signup and view all the answers

What characteristic of cementum makes orthodontic treatment possible?

It is more resistant to resorption than bone Signup and view all the answers

Which of the following statements is true about the periodontal ligament’s blood vessels?

They provide oxygen and nutrients to cementum Signup and view all the answers

What can cementum do in response to pressure?

It remodels alveolar bone Signup and view all the answers

Which type of cementum primarily undergoes continuous resorption and repair throughout the life of a tooth?

Cellular cementum Signup and view all the answers

What is the primary function of the attached gingiva?

It allows gingival tissue to endure mechanical forces. Signup and view all the answers

Which structure fills the space between two adjacent teeth?

Interdental gingiva Signup and view all the answers

What is the depth of a clinically healthy gingival sulcus?

1 to 3 mm Signup and view all the answers

What is the name given to the depression connecting the facial and lingual papillae?

Gingival col Signup and view all the answers

What does the gingival crevicular fluid do in a healthy sulcus?

Seeps from underlying connective tissue Signup and view all the answers

Which of the following statements about the col is true?

It is absent if adjacent teeth are not in contact. Signup and view all the answers

What characterizes the gingival sulcus?

It is a V-shaped shallow space encircling the tooth. Signup and view all the answers

Which term refers to the most coronal portion of the junctional epithelium?

Base of the sulcus Signup and view all the answers

What is the main feature of the free gingival margin?

It has a scalloped contour that follows the CEJ. Signup and view all the answers

What characteristic mainly distinguishes attached gingiva from free gingiva?

Attached gingiva is tightly bound to the cementum and periosteum. Signup and view all the answers

In which region is the width of attached gingiva typically the narrowest?

Premolar regions Signup and view all the answers

Which statement regarding the color of attached gingiva when healthy is correct?

It is pale or light coral pink. Signup and view all the answers

What was previously believed regarding keratinized gingiva and periodontal health?

A minimum of 2-mm width was necessary for periodontal health. Signup and view all the answers

What is one characteristic of healthy attached gingiva texture?

It typically exhibits stippling. Signup and view all the answers

What is the role of junctional epithelium in relation to free gingiva?

It anchors the free gingiva to the tooth surface. Signup and view all the answers

Which factor can cause physiologic pigmentation of the attached gingiva?

Melanin production. Signup and view all the answers

What is the primary function of cementum in relation to periodontal ligament fibers?

To give attachment to PDL collagen fibers Signup and view all the answers

What occurs to alveolar bone when teeth are extracted?

It resorbs and diminishes in mass Signup and view all the answers

What is the composition percentage of inorganic material in alveolar bone?

60% Signup and view all the answers

What is the role of the alveolar bone proper?

To form bony sockets for tooth support Signup and view all the answers

Which type of bone appears on a radiograph and is visible?

Cancellous bone Signup and view all the answers

What is the cortical bone's function in relation to the alveolar bone?

To form the outer wall of the mandible and maxilla Signup and view all the answers

What effect does attrition have on the tooth, and how is it compensated for?

It wears down enamel, and cementum compensates for length Signup and view all the answers

Which of the following is true about Sharpey’s fibers?

They anchor periodontal ligament fibers to cementum Signup and view all the answers

Study Notes

Periodontium: The Tooth Supporting Structures

The periodontium is a functional system of tissues surrounding teeth and attaching them to the jawbone.
It's also called the supporting tissues of teeth and the attachment apparatus.
The periodontium is a key anatomical structure for oral health.

Healthy Periodontium

A healthy periodontium features a gingival sulcus that is 1-3mm deep.
The gingival margin approximates the curvatures of the cementoenamel junction (CEJ).
The position of the gingival margin can vary based on age.

Structures of the Periodontium and Their Functions

Gingiva: Seals around the tooth's neck, covers jaw alveolar processes, and holds tissue against the tooth during mastication.
Periodontal Ligament: Suspends and maintains the tooth in its socket; anchors periodontal ligament fibers to secure the tooth. Protects the root dentin.
Cementum: A thin, hard mineralized tissue covering the tooth root, softer than dentin or enamel. It's 55% organic (collagen matrix proteins) and 45% inorganic (calcium, hydroxyapatite, trace elements). Resists resorption better than bone.
Alveolar Bone: Supports and surrounds the roots of teeth. It's a mineralized connective tissue composed of 60% inorganic, 25% organic, and 15% water.

The Gingiva

The gingiva is part of the mucosa that surrounds the cervical portions of teeth and covers alveolar processes.
It has different anatomical areas like free gingiva, gingival sulcus, interdental gingiva, and attached gingiva.
The gingiva protects underlying structures from the oral environment.
The gingiva's boundaries consist of the gingival margin and alveolar mucosa.
It's demarcated by the free gingival groove and mucogingival junction.

Free Gingiva

This is the unattached portion of the gingiva that surrounds the tooth at the cementoenamel junction (CEJ).
It's also known as unattached or marginal gingiva.
Free gingiva forms a soft tissue wall of the gingival sulcus.
The free gingiva follows the scalloped, curved contours of the underlying CEJ.

Attached Gingiva

This gingiva is continuous with free gingiva.
It is tightly attached to the underlying cementum on the cervical thrid of the root and periosteum of alveolar bone.
Incisors and molars have the widest attached gingiva. The thinnest is found in premolar regions.

Width of the Attached Gingiva

The width of attached gingiva is widest in the incisor and molar regions and narrowest in premolar regions.

Color of the Attached Gingiva

Healthy attached gingiva is pale or light coral pink.
Pigmentation is a physiological trait that often happens from increased melanin production.

Texture of the Attached Gingiva

Healthy attached and interdental gingiva may exhibit stippling, but it's not always present, and absent in many periodontally healthy adults.

Function of the Attached Gingiva

This part of gingiva withstands the forces during chewing, speaking, and toothbrushing.
It prevents free gingiva from pulling apically from the tooth when tension is placed on the alveolar mucosa.

Interdental Gingiva

This part of the gingiva fills the embrasures between adjacent teeth, apical to the contact area.
It has facial and lingual papillae.
A depression appears apically to the contact area of adjacent teeth.
This area prevents food from packing between teeth while chewing.

Gingival Sulcus

This is a V-shaped shallow space between the free gingiva and the tooth surface, encircling the tooth neck.
It's up to 3 mm deep in clinically healthy individuals, measured by a periodontal probe.
The base of the sulcus interacts with the most coronal portion of the junctional epithelium.

Gingival Crevicular Fluid

Also known as gingival sulcular fluid.
It seeps from underlying connective tissue and is very minimal in healthy individuals.
Levels increase with gingival stimulation, and even more when inflamed. It can be measured using a filter strip.

Periodontal Ligament (PDL)

Network of soft connective tissue that attaches the root of a tooth to the bony walls of its socket.
The PDL is primarily composed of dense fibrous connective tissue whose fibers connect root cementum and alveolar bone.
It connects the tooth to the alveolar process and supports the tooth within the socket.
PDL absorbs mechanical loads on the tooth.
It maintains the tooth and contains nerve endings relaying sensory information, blood vessels providing oxygen and nutrients, as well as structures that aid periodontal regeneration.

Cementum

A thin layer of hard, mineralized tissue that covers the tooth root surface
It overlies the dentin.
It's softer than dentin or enamel and consists of 55% organic material (collagen matrix proteins) and 45% inorganic material (calcium, hydroxyapatite, trace elements).
Two types exist: cellular and acellular.

Alveolar Bone

The jawbone that surrounds and supports the teeth' roots. It's a mineralized connective tissue.
The width depends on the region of the mouth, widest at incisors and molars, and least thick at premolars.
Presence of teeth relates to this bone's existence.
It resorbs when teeth are extracted. It's absent if teeth do not erupt.

Layers of the Alveolar Process

The alveolar process consists of alveolar bone proper, cortical bone, and cancellous bone.
Alveolar bone proper is a thin layer lining the socket that contains the alveolus, foramina, and Sharpey's fibers.
Cortical bone (cortical plate) is a dense outer layer.
Cancellous bone (spongy bone) fills the inner portion of the alveolar process.

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Description

Explore the essential details about the periodontium, the supporting structures that anchor your teeth to the jawbone. This quiz covers its functions, healthy characteristics, and the anatomy involved in maintaining oral health. Test your knowledge on the gingiva, periodontal ligament, and cementum!