Perio Fibers Flashcards
● Functions
o Supportive - anchors tooth to bone
▪ Sharpey’s Fibers - inserts bone and cementum
▪ Contains collagen I, III, and IV
o Formative - helps maintain biological activity of bone and cementum
▪ Think occlusion and bone loss, these PDL take the force
o Nutritive - supplies nutrients and removes waste products via blood and lymph vessels
o Sensory - tactile pressure, pain, sensitivity
● PDL widening
o Width depends on age, stage of eruption, function of tooth, and angle of film
o Seen in radiographs
▪ “The widening of the PDL”, see the tooth on the left compared to the right
▪ You’ll want to look at occlusion or might be of perio origin
o Fiber groups of PDL
▪ The principal fiber bundles consist of individual fibers forming a continuous connection between tooth and bone, developed sequentially
● PDL Fibers
o Alveolar crest
▪ Cementum 🡪 crest of alveolar bone
▪ Prevents extrusion and lateral movements
o Horizontal
▪ Cementum 🡪 alveolar bone @ 90°
▪ Opposes lateral forces
o Oblique
▪ Cementum 🡪 alveolar bone coronal direction
▪ LARGEST group
▪ Resist vertical masticatory forces
o Apical
▪ Cementum 🡪 apical alveolar bone
▪ Resist tipping
o Interradicular
▪ Cementum 🡪 furcation bone
▪ Resist luxation and tipping
Alveolar Bone/Alveolar Process ● Role:
o Supports the teeth
o Vascularized, Lymphatics, Nerves (not in bone, but in the periosteum)
o Attachment of PDL fibers (Sharpey’s fibers)
Alveolar Bone/Alveolar Process ● Components
o External plate
o Inner socket wall: alveolar bone proper
▪ Bundle bone: attachment of PDL fibers into the bone
o Cancellous trabeculae
Alveolar Bone/Alveolar Process: Shape
o Anterior: Scalloped
o Posterior: Flattened scallop
o Depends on interdental distance, tooth contours, root contours
● Distance from CEJ in health
o 1-1.5mm in health
o 1.5-2mm in adult (taking into account the supracrestal tissue attachment concept)
● Dehiscences & Fenestrations
o Dehiscence: lack of bone on facial or lingual of the tooth but with interproximal bone
o Fenestration: lack of bone on the facial or lingual of the tooth resembling a “window”
● Bone that forms and supports the alveoli/tooth socket
o Alveolar bone is NOT the mandible or maxilla
● Consists of alveolar bone proper and supporting bone
● Consists of alveolar bone proper and supporting bone
● Contour of the alveolar bone follows contour of
of the CEJ and arrangements of dentition
● Shape is parallel to the CEJ of adjacent teeth, about 1.5-2mm apical to the CEJ
● Shape is parallel to the CEJ of adjacent teeth, about 1.5-2mm apical to the CEJ
● Cortical plates are thicker in the mandible than the maxilla
o Cortical bone is beneath the alveolar bone
o Alveolar bone is cancellous
o Cortical (compact) bone is dense – underlies the alveolar bone
● If you lose a tooth the alveolar bone will be lost unless some sort of force is put in its place
● If you lose a tooth the alveolar bone will be lost unless some sort of force is put in its place
