1. Clinical morphology of the periodontium Flashcards
- Gingiva
- Periodontal ligament
- Cementum
- Alveolar bone(Alveolar bone proper/bundle bone and alveolar process
Function of periodontium
- Attach teeth to bone
- Maintain integrity of mucosa in oral cavity
Types of mucosa
- Masticatory mucosa
- Specialised mucosa
- Lining mucosa
Masticatory mucosa covers
Gingiva and hard palate
Is keratinised
Specialised mucosa covers
Dorsum of tongue
Lining mucosa covers
- Soft palate
- Inside of lips
- Floor of mouth
- Vestibulum
- Ventral surface of tongue
Gingiva macroscopic anatomy
- Covers alveolar process and surrounds tooth cervices
- Consists of lamina propria-epithelial layer and underlying connective tissue
- Free or attached
- Keratinised-orange peel texture
Microscopic anatomy of gingiva-types of epithelium
- Oral epithelium
- Oral sulcular epithelium
- Junctional epithelium
Epithelium that faces the oral cavity
Oral epithelium
Epithelium that faces the tooth without being in contact
Oral sulcular epithelium
The epithelium that is in contact with the tooth
Junctional epithelium
Connective tissue portions that project into epithelium
Connective tissue papilla
Oral epithelium characteristics
- Keratinised
- Stratified
- Squamous epithelium
Oral epithelium cell layers
- Stratum basale(cuboidal cells)
- Stratum spinosum(thickest layer)
- Stratum granulosum
- Stratum corneum(keratinised)
Cells found in epithelium
- Keratinocytes
- Melanocytes
- Immune cells
- Inflammatory cells
Connective tissue fibres are produced by
Fibroblasts
Types of connective tissue fibres
- Collagen fibres
- Reticulin fibres
- Oxytalan fibres
- Elastic fibres
Collagen fibres are arranged according to
Insertion and course
Types of collagen fibres
- Circular fibres
- Dento-gingival fibres
- Dento-periosteal fibres
- Transeptal fibres
Circular fibres(CF) characteristics
- In free gingiva
- Encircle tooth like ring
Dento-gingival fibres (DGF) characteristics
- Embedded in cementum of supra-alveolar portion of root
- Project from cementum in fan like configuration into free gingival tissue
Dento-periosteal fibres (DPF) Characteristics
- Embedded in same portion of cementum as dento-gingival fibres
- Fibres run more apically over vestibular and lingual bone crest
- Terminate in tissue of attached gingiva
Free gingival groove charactertics
- Border between free and attached gingiva
- Epithelium lacks support by underlying collagen fibre bundles
Transeptal fibres characteristics
- Extend between supra-alveolar cementum of adjacent teeth
- Run across interdental septum
- Embedded in cementum of adjacent teeth
Periodontal ligament characteristics
- Richly vascular and cellular connective tissue
- Surrounds roots of teeth
- Joins cementum w/ alveolar bone(bundle bone)
Periodontal ligament fibres
*Alveolar crest fibers(ACF)
* Horizontal fibres(HF)
* Oblique fibres(OF)
* Apical fibres(AF)
Cementum characteristics
- Specialised mineral tissue
- Covers root surface and small portions of crown
- Contains collagen fibres and organic matrix
- 65% mineral-hydroxyapetite
Types of cementum
- Acellular-extrinsic fibre cementum
- Cellular mixed stratified cementum
- Cellular intrinsic fibre cementum
Acellular extrinsic fibre cementum characteristics
- In coronal and middle part of root
- Main sharpeys fibres
- Connects tooth w/ bundle bone
Cellular mixed stratified cementum characteristics
- In apical third of root and furcations
- Contains extrinsic, intrinsic fibres and cementocytes
Cellular intrinsic fibre cementum
- In resorption lacunae
- Intrinsic fibres and cementocytes
Alveolar bone characteristics
- Supports the teeth
- Formed from dental lamina
- Distributes and absorbs masticatory forces
Alveolar process anatomy
- External plate of cortical bone
- Inner socket wall of thin compact bone=alveolar bone proper/bundle bone
- Cancellous trabecular bone between the two layers
Bone coverage misssing a coronal portion of roots
Dihescence
Bone present coronally and apically of a defect
Fenestration
Socket wall is formed by
Bundle bone
