Anatomy of Teeth and Periodontium PDF

Anatomy of teeth and periodontal tissues Dr. Sándor Balázs Comperative anatomy Most vertebrates have teeth Simplest teeth are conical single lobe (reptiles)→ homodont Temporomandibular movements are related tooth morphology→ No lateral movement No mastication 3 lobed te...

Anatomy of teeth and periodontal tissues Dr. Sándor Balázs Comperative anatomy Most vertebrates have teeth Simplest teeth are conical single lobe (reptiles)→ homodont Temporomandibular movements are related tooth morphology→ No lateral movement No mastication 3 lobed teeth in mammals →heterdont dentition Only mammals have multi-rooted teeth The dog is heterodont, but there is no latral movement Bear front dentition is similar to the dog’s, the molar morphology makes them capable of lateral mandibular jaw movement The most complex teeth have 4-5 lobes Primate dentition Anthropoid ape dentition is similair to human dentition. Canines are longer Only ungulates are capable of greater lateral jaw movement  Pulpcavity Between enamel can be and devided dentin(DEJ) into two parts: mantle dentin (15-20 µm), different Pulp chamber composition than cirumpulpal Root canal(s) dentin Anatomy Between ofthethe odontoblasts apex and the mineralized Apical constriction dentin→ unmineralized Foramen apicale predentin (15-50 µm) Apical delta (apical 3 mm) Dentin Accessory is produced foramina during the whole life Tomes-fibers (odontoblast processes) are different from Tomes processes (processes of the ameloblasts during enamel development (see later)  Roots Single rooted teeth: Incisors Canines Upper second premolar Lower firs and second premolar Double rooted teeth: Usually upper first premolar (one buccal and one lingual) Lower molars (one mesial, one distal) Three rooted teeth: upper molars (mesiobuccal, distobuccal, lingual) Root numbers might vary individually , the number of root canals does not alway reflect the number of roots Anatomy of the periodontium The periodontium Main functions: Tissues supporting the teeth with resilient connection, gomphosis Protection against the oral microflora Proprioceptive sensory function Consists of the: Gingiva facing the tooth Periodontal ligament (PDL) Cementum Alvelolar bone Gingiva is a part of the oral mucosa Consists of three zones: Masticatory mucosa (gingiva, hard palate) (25%) Specialized mucosa covering the tongue (15%) Lining mucosa (60%) Oral mucoperiosteum /mucoperiostal flap Cliniclal parts of the gingiva Marginal gingiva Sulcus Attached gingiva (gingiva propria) Interdental gingiva The epithelial junction (dentogingival junction) Seal between the oral cavity and the underlying tissues The bottom of the gingival sulcus 10-30 layer thick stratified squamous nonkeratinizing epithelium Consist of two groups of cells: Basal (cubiod ploriferating cells) Suprabasal Cementum Covers the anatomical root Acellular cementum: the cementoblasts stay on the surface Afibrillar Extrinsic fiber Cellular cementum: they incorporate into the matrix (lacunae). After mineralization they are called cementocytes Intrinsic fiber Development of cementum Cementoblasts differentiate from the dental follicle Epithelial cell rests (Malassez), may persist after the total development→ controls the maintenance and regeneration of the PDL Cementoenamel junction Sharpey’s fibers Mainly in the acellular extrinsic fiber cementum→ resilient attachment of the tooth Periodontal ligament Soft, specialized connective tissue between the root and the alveolar bone Ensures resilient connection with type I collagen fibers (Sharpey’s fibers) Rich in cells They distribute the masticatory forces, shock absorption Proprioceptive function ? Sharpey’s fibers Arranged into bundles: Transseptal Interradicular Apical Oblique Horizontal Alveolar crest Alveolar bone Basic histological structure is the same as of any bone Three layers may be distinguished: Cortical compact bone Alveolar bone proper (lamina dura) Trabecular bone Thank you for your attention!