Histology of the Gingiva PDF

Histology of the Gingiva Oral and Dental Science Sarah Balian Intended Learning Outcomes By the end of the session students should be able to: Iden%fy and label the three anatomic areas of the gingival epithlium Describe the anatomy and func%on of the following structures: 1. Oral Epithelium...

Histology of the Gingiva Oral and Dental Science Sarah Balian Intended Learning Outcomes By the end of the session students should be able to: Iden%fy and label the three anatomic areas of the gingival epithlium Describe the anatomy and func%on of the following structures: 1. Oral Epithelium 2. Sulcular epithelium 3. Junc%onal epithelium Describe the func%on of gingival connec%ve %ssue Be aware that other structures are part of the gingiva - periodontal ligament, cementum and alveolar bone Please note this lecture is linked with: Histology of Periodontal Ligament Alveolar bone Cementum  4 Oral Epitheliu m Periodon?um A Alveolar Mucosa B Mucogingival junc?on C ADached gingiva D Free gingival groove E Free gingiva F interdental papillae The Gingival Col Dentogingival Junc?on m Epitheliu Oral Three areas of Epithelium (Dento-gingival junc?on) 1. Junc?onal Epithelium 2. Sulcular Epithelium 3. Oral Epithelium Cell Layers of the Oral Epithelium Illustra%on key: KL kera%nized cell layer GL granular cell layer SL superOcial cell layer PL prickle cell layer BL basal cell layer Oral Epithelium Oral Epithelium The oral epithelium covers the outer surface of the free gingiva and aDached gingiva; it extends from the crest of the gingival margin to the mucogingival junc?on. The oral epithelium is the only part of the periodon%um that is visible to the unaided eye. Oral Epithelium Stra%Oed squamous epithelium The layers are listed below in order from the deepest layer to the most superOcial layer. a. Basal cell layer cube-shaped cells b. Prickle cell layer - spine-like cells with large intercellular spaces. The cells of both the basal and prickle cell layers aTach to each other with desmosomes. c. Granular cell layer UaTened cells and increased intracellular kera%n d. Kera?nized cell layer (stratum corneum): UaTened cells with extensive intracellular kera%n. Why does this sec?on have the most cellular layers? Joins with underlying connec?ve ?ssue in wavy paDern Sulcular Epithelium  Epithelium that faces the tooth surface Sulcular Epithelium without being in contact with the tooth surface Thin Nonkera%nized epithelium Without rete pegs Semi permeable (but less so than JE) allowing Uuid to Uow from the gingival connec%ve %ssue into the sulcus. This Uuid is known as the gingival crevicular Uuid (GCF) In health, the sulcular epithelium joins the connec%ve %ssue at a smooth interface with no epithelial ridges (no wavy junc%on). Junc?onal Epithelium  Stra%Oed squamous Junc?onal Epithelium nonkera%nized epithelium Joins gingiva to tooth surface Length 0.71 – 1.35mm Cell thickness coronally – 15-30 cells Coronal – 15 – 30 cells 4 -5 cells thick at apical zone High cell turnover Apically – 4 – 5 If it is non – kera?nised – what does this means cells in comparison to ?ssue that is kera?nised? Why does a tooth need a junc?onal epithelium and where does it come from? Cellular layers Illustra%on key: KL kera%nized cell layer GL granular cell layer SL superOcial cell layer PL prickle cell layer BL basal cell layer Why does a tooth need a junc?onal epithelium and where does it come from? The body is covered by con%nuous sheet of epithelium Teeth penetrate this sheet by erup%on thus crea%ng an opening The body aTempts to seal the opening by aTaching epithelium Hence the name ‘junc%on’ meaning ‘connec%on’ Microscopic Anatomy of Junc?onal Epithelium Closely packed epithelial cells Connected to neighbouring cells by desmosomes (cell junc?on) Internal Basal Lamina –thin layer of extracellular matrix between epithelial cells and tooth surface External Basal Lamina - thin layer of extracellular matrix between epithelial cells and gingival connec%ve %ssue  ATachment to tooth surface is by hemidesmosomes (cell junc?on) & internal basal lamina 8-10 hemidesmosomes per micron at the coronal end and 2 per micron at apical end What does this mean? ATachment to connec%ve %ssue is by hemidesmosomes & external basal lamina Cell Junc?ons Desmosome Cell junc%on that connects two neighbouring epithelial cells and their cytoskeletons together Hemidesmosome Connects the epithelial cells to the basal lamina Func?ons of Junc?onal Epithelium Host ADachment Barrier defense Gingival Connec?ve Tissue Gingival Connec?ve Tissue The gingival connec%ve %ssue of the free & aTached gingiva provides solidity to the gingiva and aTaches the gingiva to the cementum of the root and the alveolar bone. The gingival connec%ve %ssue is also known as the lamina propria. Func?ons of gingival connec?ve ?ssue Integrity and strength of gingival %ssues – dense network Normal func%on of connec%ve %ssues The transporta?on of water, nutrients, metabolites, oxygen, etc., to and from the individual connec%ve %ssue cells occurs within the matrix Host response – immune response Supragingival \bres of connec?ve ?ssue  Supragingival \bres AG Alveologingival Alveolar crest to gingival connec?ve ?ssue C Circular Ring round coronally above crestal bone DG Dentogingival Cementum fan into gingival connec?ve ?ssue PG Periosteogingival Fan from periosteum IG Intergingival Mesiodistal direc?on along whole dental arch linking teeth together IC Intercircular Encircle several teeth linking teeth together IP Interpapillary Located in the papilla connect oral & ves?bular papilla TG Transgingival Cementum to CEJ and run horizontally linking teeth together TS Transeptal Cementum of one tooth to another tooth over crestal bone What is the depth of the gingival sulcus in health? What shape is the gingival sulus? Other structures Please refer to the upcoming histology sessions on the following: Periodontal Ligament Cementum Alveolar bone Image references The Mouth and Body Connec%on [INFOGRAPHIC] | Delta Dental of New Jersey (deltadentalnj.com) Gingiva: Types, histology and clinical aspects | Kenhub healthy gingiva | aTached gingiva is non movable gingiva as the name indicates the... | Dental assistant study, Dental health, Dental (pinterest.co.uk) hTps://www.jaypeedigital.com/eReader/chapter/9789386261731/ch1 12: Oral Mucosa | Pocket Den%stry Chapter 6 Disturbed Tooth Erup%on | SpringerLink Dale BA. Periodontal epithelium: a newly recognized role in health and disease. Periodontol 2000. 2002;30:70– 78. Will you ever look at gums in the same way again? Recommended Reading Read the following journal ar%cle Structure of periodontal %ssues in health and disease. Nanci A. and Bosshardt DD. Periodontology 2000. (2006) 40:1; p11-12,25- 28 hTp://onlinelibrary.wiley.com/doi/10.1111/j.1600-0757.2005.00141.x/full