Healthy Periodontium

Periodontal Morphology – Healthy Periodontium

 The Periodontium  Gingiva  Periodontal

Ligament  Root Cementum  Alveolar Bone

(Alveolar Process)

Alveolar Bone

Root Cementum

Periodontal Ligament

Gingiva

Gingiva Gingiva  Tissue covering the

cervical portions of the teeth and the alveolar processes of the jaws

 Composed of thin outer layer of epithelium and an underlying core of connective tissue

 Provides a tissue seal around the cervical portions of the crowns

Alveolar mucosa Attached gingiva

Interdental gingiva Free gingiva

Clinical Anatomy of the Gingiva

Clinical Anatomy of the Gingiva  Attached gingiva  Free gingiva  Free gingival groove  Gingival margin  Gingival sulcus

(gingival crevice)  Interdental gingiva  Papilla/Papillae  Col  Alveolar mucosa  Mucogingival

junction

Clinical Anatomy of the Gingiva  Free gingiva  Gingival margin  Gingival sulcus (gingival

crevice)  Attached gingiva  Mucogingival junction  Alveolar mucosa

Clinical Anatomy of the Gingiva

 Facial papilla  Lingual papilla

 Interdental gingiva

Clinical Anatomy of the Gingiva  Col  Proximal contact

area

Col

Proximal contact area

Clinical Anatomy of the Gingiva Free Gingiva  Unattached portion of the

gingiva that surrounds the tooth in the region of the cemento-enamel junction (CEJ).

 Located coronal to (above) the CEJ. It surrounds the tooth in a turtleneck or cuff-like manner

 Also known as the unattached gingiva or the marginal gingiva

Clinical Anatomy of the Gingiva Free gingiva characteristics   Fits closely around the tooth

but is not directly attached to it   May be stretched away from

the tooth surface with a periodontal probe

  Forms soft tissue wall of gingival sulcus

  Meets the tooth in a thin rounded edge called the gingival margin

  Gingival margin follows the contours of the teeth, creating a scalloped (wavy) outline around them

Free gingiva

Clinical Anatomy of the Gingiva

Gingival Sulcus-  The space between the

free gingiva and the tooth surface

 V-shaped, shallow space around the tooth

 Junctional epithelium – forms base of sulcus

Clinical Anatomy of the Gingiva Gingival Sulcus-  The depth is 1-3 mm for

a clinically normal gingival sulcus

 The depth is measured using a periodontal probe

Dental floss being used to clean the gingival sulcus and the tooth

Periodontal probe being used to measure depth of the sulcus

This periodontal probe is divided into 3 millimeter colored segments

Clinical Anatomy of the Gingiva

  A = incorrect technique for interproximal probing

  B = correct probing technique   C = incorrect probing technique

Gingival Sulcus-  Probing the sulcus depth

interproximally is best accomplished by angling the probe so its tip is located at the center of the root

Clinical Anatomy of the Gingiva

Junctional Epithelium  Specialized type of

epithelium that attaches to the tooth surface

 Located at the base of the gingival sulcus

Clinical Anatomy of the Gingiva Attached gingiva  Gingiva that is tightly

connected to the cementum on the cervical-third of the root and to the periosteum (connective tissue cover) of the alveolar bone

 Lies between the free gingiva and the alveolar mucosa

Clinical Anatomy of the Gingiva

Attached gingiva functions  Allows the gingival tissue to

withstand mechanical forces  Mastication,  Speaking,  Toothbrushing

 Prevents free gingiva from being pulled away from the tooth when tension is applied to the alveolar mucosa.

Clinical Anatomy of the Gingiva Interdental gingiva  The portion of the gingiva

that fills the area between two adjacent teeth apical to the contact area

Clinical Anatomy of the Gingiva

Papilla  The interdental (or

interproximal) gingiva consists of two interdental papillae  one facial papilla  one lingual papilla

 Papilla (singular)  Papillae (plural)

Clinical Anatomy of the Gingiva

Col  Valley-like depression in

the interdental gingiva  Lies directly apical to the

contact area

 The col is not present if the adjacent teeth are not in contact or if the gingiva has receded

Clinical Anatomy of the Gingiva

  Left = incorrect vertical technique for probing interproximal craters   Right = correct angled position of the probe to reach the depth of an interproximal crater

Clinical Anatomy of the Gingiva Alveolar Mucosa   Movable tissue loosely attached to

underlying bone   Nonkeratinized   Thin, smooth and shiny epithelium   Dark red in color   Underlying vessels may be seen

through the epithelium.

  Alveloar mucosa also covers the vestibule and floor of the mouth and becomes the buccal and labial mucosa

Clinical Anatomy of the Gingiva

Mucogingival junction  The clinically visible

boundary where the pink attached gingiva meets the red, shiny alveolar mucosa

Microscopic Anatomy of the Gingiva  Gingival Epithelium

 Oral epithelium (OE)  Sulcular epithelium (SE)  Junctional epithelium

(JE)  Gingival connective tissue

Microscopic Anatomy of the Gingiva

 Gingival Epithelium  Oral epithelium – faces

oral cavity on outer surface of the free gingiva and attached gingiva

 Sulcular epithelium – lines the gingival sulcus

  Junctional epithelium – provides contact between the gingiva and the tooth. Often referred to as the epithelial attachment

Sulcular epithelium

Junctional epithelium Oral

epithelium

Microscopic Anatomy of the Gingiva

 Gingival connective tissue – underlies the epithelium and provides support through an organization of collagen fibers

OE = oral epithelium

SE = sulcular epithelium

JE = junctional epithelium

CEJ = cementoenamel junction

Periodontal Ligament Periodontal Ligament (PDL)  Layer of soft connective

tissue  Covers the root of the tooth  Attaches the root to the

bone of the tooth socket  Composed mainly of fiber

bundles  Fibers attach on one side to

the root cementum  Fibers attach on the other

side to the alveolar bone of the tooth socket.

Periodontal Ligament Functions of the Periodontal Ligament   Support - suspends and maintains the

tooth in its socket   Sensory - provides sensory feeling to

the tooth; pressure and pain sensations   Nutritive - provides nutrients to the

cementum and bone   Formative - builds and maintains

cementum and the alveolar bone of the tooth socket

  Resorptive - can remodel the alveolar bone in response to pressure

  Example: pressure applied during orthodontic treatment (braces)

Root Cementum Root Cementum  Thin layer of hard,

mineralized connective tissue

 Covers tooth from the cementoenamel junction to, and around, apical foramen

 Overlies and is attached to the dentin of the root

 Periodontal ligament attaches to the cementum

Root Cementum Root Cementum  Light yellow in color  With normal gingival

position, it is not visible but can be seen when gingival recession is present

Gingival recession is present on the facial surface due to trauma from overly vigorous toothbrushing

Alveolar Bone Alveolar Bone (also called alveolar process)

 The bony portion of the maxilla or mandible that extends occlusal to the basal bone and surrounds and supports the roots of the teeth  The existence of the alveolar

bone is dependent on the presence of teeth

 When teeth are extracted, in time, the alveolar bone resorbs so only basal bone remains

 If teeth do not erupt, the alveolar bone does not

Alveolar process

Alveolar Bone

Function of Alveolar Bone  Forms the bony sockets

that provide support and protection for the roots of the teeth

Alveolar Bone

Alveolar Bone Anatomical Areas of the Alveolar Bone:  Alveolar crest  Interproximal bone  Interradicular bone (bone

between the roots of the same tooth)

Anatomical Areas of the Alveolar Bone

Alveolar Crest  Most coronal portion of the

alveolar process  Located 1-2 mm apical to

the CEJs of the teeth (in health)

 Viewed from the facial aspect, alveolar crest meets the teeth in a scalloped (wavy) line that follows the contours of the CEJs

Anatomical Areas of the Alveolar Bone

Interproximal Bone  The area of bone that lies

between the proximal surfaces of two adjacent teeth

 Also known as interdental septum

Anatomical Areas of the Alveolar Bone

Crestal Contour of Interproximal Bone

 The contour of the crest of the interproximal bone is a good indicator of periodontal health

 In posterior sextants, the contour of the interproximal crest is parallel to an imaginary line drawn between the CEJs of the adjacent teeth

Anatomical Areas of the Alveolar Bone

Horizontal Crest Contour  Crest has horizontal

contour when the CEJs of the adjacent teeth are at the same level

Angular Crest Contour  Crest has vertical

contour when one of the adjacent teeth is tilted or erupted to different heights

Radiograph showing angular crest due to tilted mandibular second molar

Radiograph showing horizontal contour of the interproximal bone in the maxilla due to good tooth alignment

Anatomical Areas of the Alveolar Bone jaw

Interradicular Bone (multirooted teeth only)

 Bone between the roots of a multirooted tooth

Components of the Alveolar Bone jaw

 Cortical bone  Supporting bone  Alveolar bone proper  Alveolus  Periosteum

Components of the Alveolar Bone Cortical bone  Forms the hard, outside

wall of the mandible and maxilla on the facial and lingual aspects

 Buccal cortical bone  Thin in the incisor,

canine, and premolar regions

 Thicker in the molar regions

Components of the Alveolar Bone Defects of cortical bone  Fenestration

 Window-like defect in the cortical bone

 Results in an isolated area of the root that is not covered by bone

 Dehiscence  Cleft-like defect in the

cortical bone  Includes bone margin

Components of the Alveolar Bone

Supporting Bone  Lattice-like bone  Fills interior portion of the

alveolar process  Between the cortical

bone and the alveolar bone proper

 Also known as spongy bone, cancellous bone

Components of the Alveolar Bone

Alveolar bone proper  Thin layer of bone that lines

each alveolus  In radiographs, the alveolar

bone proper is identified as the lamina dura

 Contains numerous holes that allow the blood vessels from the cancellous bone to connect with the vessels of the periodontal ligament space

Components of the Alveolar Bone

Alveolus  The alveolus is the bony

socket in the alveolar bone

 It is the cavity in the alveolar bone that houses the root(s) of a tooth

 Alveolus (singular)  Alveoli (plural)

Components of the Alveolar Bone

Periosteum  The thin layer of

connective tissue that covers bone and is overlaid by the soft tissue (gingiva or alveolar mucosa)