Animal Body Function VIII Teeth PDF

Master’s Degree in Veterinary Medicine Maria João Soares www.egasmoniz.com/pt 8th February 2024  www.egasmoniz.com/pt...

Master’s Degree in Veterinary Medicine Maria João Soares www.egasmoniz.com/pt 8th February 2024  www.egasmoniz.com/pt Summary This presentation is for educational purposes only - Histology of teeth References - Evans, HE, Miller, ME (2013).Miller's Anatomy of the Dog(4th ed.). St. Louis, Missouri: Elsevier. Dyce, KM (2010).Textbook of - veterinary anatomy (4)thed.). St. Louis, Missouri: Elsevier. Thomson, C., Hahn, C. (2012). Master’s Degree in Veterinary Medicine - Mescher, A. (2021). Junqueira’s Basic Histology: Text and Atlas (16th ed.). New York: McGraw-Hill Education - Hans-Georg Liebich. Veterinary histology of domestic mammals and birds (5th Edition). 5m Publishing. 2019. ISBN 9781789180091 - Eurell, J.A., Frappier, B.L. (2006). Dellmann’s Textbook of Veterinary Histology (6th ed.). Blackwell Publishing. ISBN 9780781741484 - Bacha, W.J., Bacha, L.M. (2012). Color atlas of Veterinary Histology (3rd ed.). Wiley-Blackwell. ISBN 9780470958513 Animal Body Function VIII 2023/2024  www.egasmoniz.com/pt - Teeth are highly mineralized structures in the oral cavity that serve to: This presentation is for educational purposes only - Procuring, cutting, crushing of food Eurell, 2006 - Weapons of offense and defence Master’s Degree in Veterinary Medicine - Brachydont Hypsodont Animal Body Function VIII 2023/2024  www.egasmoniz.com/pt Structures: This presentation is for educational purposes only - Anatomic crown - Clinical crown - Root – occupies the alveolar process - Neck - - Dental body (hypsodont) - Dentin Master’s Degree in Veterinary Medicine - Dental/Pulp cavity - Dental pulp - Gum - Enamel Depressions in the bone where the Eurell, 2006 dental root (brachydont) articulate - Cementum - Infundibulum Brachydont Hypsodont - Diastema Animal Body Function VIII 2023/2024  www.egasmoniz.com/pt Structures: This presentation is for educational purposes only - Anatomic crown - Clinical crown - Root – occupies the alveolar process - Neck - - Dental body (hypsodont) - Dentin Master’s Degree in Veterinary Medicine - Dental/Pulp cavity – root canal and apical foramen Place for the passage of vessels and nerves Eurell, 2006 - Peridontal ligament – fibrous structure that attaches Brachydont Hypsodont the root to its alveolus rich water bouge bcp et moins car perd eau durant journée Animal Body Function VIII 2023/2024  www.egasmoniz.com/pt In the brachydont, the crown consists from the exterior to This presentation is for educational purposes only the interior: - Enamel - Dentin - Dental Pulp - In the hypsodont there is no crown but a dental body. Master’s Degree in Veterinary Medicine The structure of the teeth is similar to the others except that they present cementum in all body and present infundibulum. The tissues involved in the attachment apparatus of the teeth Eurell, 2006 (to the bone): - Cementum; - Periodontal ligament Brachydont Hypsodont - Alveolar bone Animal Body Function VIII 2023/2024  – www.egasmoniz.com/pt Dental Pulp This presentation is for educational purposes only - Lies in the pulp cavity; - The original mesenchymal characteristics are retained in the adulthood. - - Composed by loose connective tissue, blood vessels and nerve fibers bundles Master’s Degree in Veterinary Medicine Dentin - Lymphatic vessels are absent - Great amount of ground substance Core: network of type III collagen (reticular fibers) with fibroblasts and reticular cells. Periphery: odontoblasts → produce dentin Junqueira, 2013 Pulp - Surrounded by the dentin Liebich, 2019  – www.egasmoniz.com/pt Dental Pulp - Odontoblasts This presentation is for educational purposes only - Columnar cells, arranged at the periphery of the pulp, separating the pulp from the dentin (form the outer layer of the dental pulp) - - Produce the organic matrix of dentin - Polarized cells – granule on the apical pole and nucleus on the basal pole Master’s Degree in Veterinary Medicine - Guarantees that they deposit the organic matrix exclusively on the dentin side - Odontoblast present cytoplasmic extensions that penetrate the dentin – Dentinal fibers or odontoblastic processes (OP) Odontoblasts continue to produce pre-dentin into the adult life → gradually reducing the size of the pulp cavity Animal Body Function VIIILiebich, 2023/2024 2019  – www.egasmoniz.com/pt Dentin This presentation is for educational purposes only - Calcified tissue (about 70%), harder than bone (not as hard as enamel). - Surrounds the pulp cavity, forming the wall of the pulp cavity - Between the dental pulp and the enamel or the cementum (in the root of the brachydont) - - Occlusal surface in the hypsodonts – dentin can be exposed between the enamel crests Master’s Degree in Veterinary Medicine Konig, 2020 Liebich, 2019  – www.egasmoniz.com/pt Dentin - Calcified tissue (about 70%), harder than bone This presentation is for educational purposes only (not as hard as enamel). - First → Pre-dentin: ground substance (glycoprotein and glycosaminoglycans) and type I collagen (produced by the odontoblast [O]). - - Through the odontoblast processes (OP) the odontoblast secrete granules containing calcium and phosphate → mineralization of the pre-dentin. Master’s Degree in Veterinary Medicine Mesher, 2018  – www.egasmoniz.com/pt Dentin - Calcified tissue (about 70%), harder than bone This presentation is for educational purposes only (not as hard as enamel). - First → Pre-dentin: ground substance (glycoprotein and glycosaminoglycans) and type I collagen (produced by the odontoblast [O]). - - Through the odontoblast processes (OP) the odontoblast secrete granules containing calcium and phosphate → mineralization of the pre-dentin. Master’s Degree in Veterinary Medicine Dentin → approximately 70% inorganic substances (hydroxyapatite crystals) and 30% organic matter (collagen and ground substance) Odontoblast processes become enclosed in mineralized tubules → dentinal tubules Dentinal tubules → present the OP and free nerve endings Mesher, 2018 Free nerve endings – important to tooth sensitivity (cold, heat, acidic pH) → the stimuli are usually perceived as painful  – www.egasmoniz.com/pt Enamel - The hardest tissue in the body This presentation is for educational purposes only - Forms the outer layer of the crown → Brachydont teeth Brachydont Hypsodont - Placed between the dentin and the cementum → Hypsodont teeth Acellular layer → the layer is produced by the ameloblasts - This layer do not present capacity to regenerate and usually present a white colour Master’s Degree in Veterinary Medicine Enamel matrix: - Organic part (1%): non-collagenous proteins, glycoproteins and glycosaminoglycans - Inorganic part (99%): Calcium and phosphates → hydroxyapatite crystals Animal Body Function VIII 2023/2024  Mesher, 2018 – www.egasmoniz.com/pt This presentation is for educational purposes only Enamel (E) - The hardest tissue in the body. Produced by ameloblasts. Ameloblasts (A) → cells of ectodermal origin (unlike the other cells of the - tooth, which are originate in the mesoderm or neural crest) - Ameloblast process (Tomes processes): Apical extension of the Master’s Degree in Veterinary Medicine ameloblasts, that contain numerous secretory granules with the proteins of the enamel matrix Ameloblasts differentiate from the inner enamel epithelium of the enamel organ Enamel organ – specialized epithelium in the tooth bud - In the adult (hypsodont) – a small population of columnar cells remains at the base to continue enamel production  Brachydont Hypsodont – www.egasmoniz.com/pt Cementum (5) This presentation is for educational purposes only - Cover the entire tooth (hypsodont) or just the root (brachydont); - Belongs to the attachment apparatus of the teeth - - Resembles the composition of bone tissue, although it does not have blood vessels or Haver’s systems Master’s Degree in Veterinary Medicine Bacha, 2012 fabrique Cementoblasts – present at the junction of the cementum and the periodontal ligament (produce the fibrous matrix of the cementum). Once the cementoblasts are surrounded by matrix, become détruit Cementocytes – almost not communicate with each other; Nutrition comes from the periodontal ligament. Occupy lacunae and canaliculi (like osteocytes) Dog The cementum is composed by cementocytes and mineralised organic matrix  Brachydont Hypsodont – www.egasmoniz.com/pt Peridontal ligament (17) This presentation is for educational purposes only - Fibrous connective tissue that bind the cementum to the alveolar bone (4), through the cementoalveolar fibers or the Sharpey’s fibers. - Sharpey’s fibers (13) – formed by collagen, they penetrate the cement of the tooth and the bone of the alveolus, limiting Master’s Degree in Veterinary Medicine tooth movements. Bacha, 2012 Peridontal ligament is highly cellular, has a rich supply of blood vessels and nerves. - Gives sensory and present nutritive functions - Supports the tooth - Allows the movement of the tooth within the alveolus Dog Dog Legend: 1- Bone tissue; 5- Cemetum; 9- Dentin; 13- Sharpey’s fibers; 17- Precementum Master’s Degree in Veterinary Medicine - www.egasmoniz.com/pt This presentation is for educational purposes only ? ! [email protected]