Dental Anatomy Introduction Lecture PDF

INTRODUCTION Dental Anatomy Includes: 1- Structures of the oral cavity. 2- Overview of the dentitions. 3- The relationship of the teeth to each other. Facial and oral cavity landmarks 1-Lips Roof of 2-Gingiva the m...

INTRODUCTION Dental Anatomy Includes: 1- Structures of the oral cavity. 2- Overview of the dentitions. 3- The relationship of the teeth to each other. Facial and oral cavity landmarks 1-Lips Roof of 2-Gingiva the mouth 3-Cheek 4-Tongue 5-Floor of the mouth 6-Roof of the mouth 7-Teeth  1- Lips There are two Lips Upper Lip & Lower Lip. The Corner of the mouth where the two lips meet is called Commissure. Two Grooves are distinguished around lips. *Nasolabial groove *Labiomental groove.  2- Gingiva It is the soft tissue that surrounds the cervical part of the teeth.  3- Cheeks The lining of the inside of the cheeks is shiny with a white line called linea alba buccalis running posteriorly on each side at the level where the upper and lower teeth come together. Linea alba buccalis The parotid papilla: It is a round elevation of tissue observed on the cheek between first and second molar at just above the occlusal plane. It covers the opening of the parotid duct. Parotid papilla  4- Tongue The tongue is a broad flat organ composed of muscles and glands. It rests in the floor of the mouth. It is the principle organ of taste and is most important in speech, mastication and swallowing.  5- Floor of the mouth It is shiny and some large blood vessels may be seen near the surface. Beneath the tongue, there are two bilateral bulges caused by the presence of large salivary glands.  6- Roof of the mouth Its anterior part is called hard palate. Its posterior part is called soft palate which ends by a small fleshy structure named uvula.  7- Teeth Teeth are arranged in upper and lower dental arches. The upper arch is called Maxilla The teeth in this arch are called upper or maxillary teeth The lower arch is called the Mandible The teeth in this arch are called lower or mandibular teeth. Midline divides each arch into two equal right and left halves. There are 4 Quadrants in the oral cavity. Upper right, upper left, lower right & lower left This is a quadrant There are Four types of teeth: 1-Incisors: There are two incisors, central and lateral incisors. 2- Canines: There is one canine in each quadrant. Incisors and canines are considered Anterior Teeth.  3-Premolars: There are two in each quadrant. First and second premolars. 4-Molars: There are three in each quadrant. First, second and third molars. Premolars and molars are considered Posterior teeth.  The teeth in the arch can be grouped as follows: 1- Anterior teeth (Incisors and canines). 2- Posterior teeth (premolars and molars). Anterior teeth Posterior teeth  Function Of Teeth 1- Mastication  Functions Of Teeth 1- Mastication: It is the most important function of the teeth. The teeth are designed to perform this function. Incisors Canines Premolars Molars At least two Multiple projections projections Chisel like Wedge like Cutting and (cusps). (cusps) Cutting or Tearing and tearing Grinding incising grinding 2- Appearance (Esthetics) Nice smile Bad smile 2- Appearance: - Well arranged clean teeth with proper alignment give nice appearance to the face. - Teeth give support to the facial expressions. 3- Speech: Teeth are important for clear pronunciation and for production of sound. 4- Growth of jaws: The teeth play a role in the growth of the jaws in some periods of life. Types of Dentitions Humans have two dentitions: 1-The primary dentition 2-The permanent dentition The mixed dentition In each dentition we have to mention 1-Teeth types 2-Dentition periods 3-Dental formula 1-The primary dentition:(deciduous- predecessor ) 20 teeth. 10 maxillary and 10 mandibular. 5 teeth are present in each quadrant: 2 incisors. 1 canine. 2 molars. The dental formula is: 2 1 2 I --- C ---- M ---- = 10 2 1 2 2-The permanent dentition: (secondary, adult or succedaneous ) 32 teeth, 16 maxillary and 16 mandibular. 8 teeth in each quadrant are present: 2 incisors. 1 canine. 2 premolars. 3 molars. The dental formula is : 2 1 2 3 I ---- C ---- PM --- M ---- = 16 2 1 2 3  Note The permanent molars are not preceded with deciduous teeth so they may be termed as non- succedaneous teeth.  Dentition periods 1-The primary dentition period: 6m to 6y (Pre-decessor, deciduous) 2 incisors, 1 canine and 2 molars. 2-The mixed dentition period: 6y to 12 y Ugly duckling stage: Different color & size Edentulous areas Inflammed gingiva  3-The permanent dentition period: after 12 y (secondary, adult or succedaneous ) 2 incisors, 1 canine, 2 premolars and 3 molars.  Tooth Anatomy Macro-anatomy of the tooth Micro-anatomy of the tooth  Macro-anatomy Each tooth has three anatomical parts: I. Crown II. Neck: cervical line Meeting between crown & root / cemento-enamel junction IIΙ. Root (s)  Anatomical and clinical crown. Anatomical Clinical Crown Crown  Anatomical and clinical crown Clinical crown: is the part of a tooth that is visible in the oral cavity above the gum line. Anatomical crown: is the part of the tooth that is covered by enamel. Clinical crown is Both are equal Clinical crown is shorter longer  Clinlical crown may include all of the anatomical crown and part of the root. Part of the anatomical crown may be covered by gingiva.  Anatomical and clinical root. Clinical root Anatomical root  Anatomical and clinical root Clinical root: is the part of a tooth that is hidden below the gum line. Anatomical root: is the part of the tooth that is covered by cementum. Clinical root is shorter (the Clinical root is longer hidden part is shorter than as it includes part of Both are equal that part of the tooth covered by cementum) the crown Anatomical root is longer than clinical root According to the number of roots, teeth are classified into: 1- Single rooted teeth Incisors, canines, premolars except upper first premolar 2- Double rooted teeth Upper first premolar and lower molars 3- Triple rooted teeth Upper molars The undivided portion of the root is called root trunk  Socket Root trunk Bifurcation Crypt  Other terms ❑Socket: Bony space in alveolar bone containing roots of erupted tooth. ❑Crypt: Bony space in alveolar bone containing developing unerupted tooth.  Micro-anatomy Three calcified tissues: Enamel, Dentin and Cementum and only one soft tissue:Pulp. The Pulp cavity consists of Pulp chamber and pulp canal (s)  Enamel Dentin Cementum  Enamel It is the hardest tissue of the human body. It covers the crown of the tooth. It can’t be renewed. Fluoride & saliva can help with remineralization.  Dentin It is a cream-colored (yellowish) hard material. It makes up the bulk of the tooth. Softer than enamel. Covered by enamel on crown & by cementum on roots.  Dentin Produced throughout life. Sensitive.  Cementum Thin calcified tissue. It covers the root of the tooth. Softer than enamel & dentin. Meets enamel at neck of tooth. Anchors tooth to alveolar bone along with periodontal ligaments (PDL).  Pulp A soft tissue rich in blood vessels & nerves. Responsible for nourishing the tooth. Sensitive to thermal stimulation (hot or cold). Pulp horn Pulp chamber Root canal Apical foramen  Periodontium ▪ It is the investing & supporting attachment system of teeth. ▪ It consists of 2 soft tissues & 2 hard tissues. Thank you