Exordium; evolution,classification and functions of teeth Lanzhou University School of Stomatology

exordium oral anatomy and physiology 1. definition: 2.This chapter covers the oral anatomy and physiology of the teeth, the histology of their tissues and supporting structures, and concentrates on the external features of the teeth.

exordium oral anatomy and physiology conclude dental anatomy, temporomandibular joint anatomy, masseter anatomy etc. Dental anatomy

exordium The viewpoints to learn dental anatomy 1.Describe the external features of the teeth. 2. Know the numbering system, the standard. 3.Teeth differ in size, shape, and other characteristics from one person to another.

Evolution of teeth Concept According to the tooth adhesion to maxillary and mandibulary acrodont pleurodont thecodont

Evolution of teeth According to how many sets of tooth animal have polyphyodont: fish diphyodont: for example Mammals monophyodont: such as hamster

Evolution of teeth According to the shape of tooth animals have homodont: heterodont: incisor, canine, premolar, molar

Evolution of teeth Tooth morphology and characteristics of animals fish ： amphibians ： reptiles ： avifauna mammalia

Evolution of teeth Tooth characteristics number ： shape ： dentition : scatter ： adhesion ：

Evolution of teeth Evolutionary theories of tooth morphology ♠ Concrescence theory ♠ Tritubercular theory

Structure of teeth Contour of teeth : A tooth is divided into two parts: the crown and one or more roots The Crown The crown is divided into the anatomic and clinical crown. The anatomical crown is that portion of the tooth encased in enamel.

Structure of teeth The root The root of a tooth is embedded in alveolar bone and is covered by cementurn. The tip of each root is called apex. On the apex of each root, there is a small opening that allows for the passage of blood vessels and nerves into the tooth. This opening is called the apical foramen

Structure of teeth The Cervix The cervix or cervical line is a slight indentation that encircles the tooth and marks the junction of the crown with the root.

Tooth tissues Enamel Dentin Cementum pulp

Structure of teeth

Classification of teeth 1. classification based on contour and function of teeth incisors, canines, premolars, molars

2. classification based on duration of teeth in mouth deciduous teeth permanent teeth

Physiologic functions of teeth Physiologic function of teeth mastication Pronunciation and speech keep facial coordinate and beautiful