Dental Anatomy Lecture 1 PDF

Dental Anatomy Lecture 1 ‫ محمد حامد الجابري‬.‫د‬ Introduction Dental anatomy is defined as the study of the development, morphology, function, and identity of each of the teeth in the human dent...

Dental Anatomy Lecture 1 ‫ محمد حامد الجابري‬.‫د‬ Introduction Dental anatomy is defined as the study of the development, morphology, function, and identity of each of the teeth in the human dentitions, as well as the way in which the teeth relate in shape, form, structure, color, and function to the other teeth in the same dental arch and to the teeth in the opposing arch. Thus, the study of dental anatomy, physiology, and occlusion provides one of the basic components of the skills needed to practice all phases of dentistry. Nomenclature Dental = anything related to teeth Human is a heterodent, which means that he has different-shaped teeth. Human is a diphyodont, which means that he has two sets of teeth; deciduous teeth (primary teeth) and permanent teeth. The Deciduous Teeth At birth, there are no teeth present in the mouth, but many teeth in a various stages of the development are found in the jaws. After birth: (post-natal period), the eruption of deciduous teeth starts at six months and lasts until two and a half years. Figure 1: The Deciduous teeth 1  The deciduous teeth stay until the permanent teeth erupt at about 6 years of when the transition to the permanent dentition begins. The deciduous teeth are 20 in number. They are at each jaw half as the fallowing (figure 1): One central incisor One lateral incisor One canine Two molars The Permanent Teeth The transition to permanent dentition begins with the emergence and eruption of the first permanent molars at the age of six years, followed by shedding of the deciduous teeth and emergence and eruption of the remaining permanent teeth. This process requires about 20 years to be completed. The number of permanent teeth, including third molars when present, is 32. They are at each jaw half as the fallowing: One central incisor One lateral incisor One canine Two premolars (first and second premolar) Three molars (first, second and third molar) Figure 2: the permanent teeth 2  Anterior and Posterior Teeth Teeth are grouped into: 1. Anterior teeth which include the incisors and the canines. 2. Posterior teeth which include the premolars and molars. The Jaw The jaw is the bone which carries the teeth. There are two jaws: 1. The upper jaw, which is fixed, and is called "The Maxilla" 2. The lower jaw, which is movable, and is called "The Mandible". Tooth Numbering Systems 1- Universal numbering system In the universal notation system for the permanent dentition Maxillary 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Right Left 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Mandibular Examples: #2: permanent maxillary right second molar. #9: permanent maxillary left central incisor. #20: permanent mandibular left second premolar. 3 The universal system for the Deciduous dentition Maxillary teeth A B C D E F G H I J Right Left T S R Q P O N M L K Mandibular teeth Examples: #C: Deciduous maxillary Right canine. #J: Deciduous maxillary left second molar. # P: Deciduous mandibular right central incisor. 4 1- Palmer system A- the permanent dentition Maxillary 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Right Left 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Mandibular 1 Permanent maxillary right central incisor 4 Permanent maxillary left first premolar 6 Permanent mandibular right first molar 5  b. Deciduous teeth Maxillary teeth E D C B A A B C D E Right Left E D C B A A B C D E Mandibular teeth B Deciduous maxillary right lateral incisor E Deciduous mandibular left second molar C Deciduous maxillary left canine The universal system is acceptable to computer language, whereas the Palmer notation is generally incompatible with computers and word processing systems. Each tooth in the universal system is designated with a unique number, which leads to less confusion than with the Palmer notation. 6  FDI system : A two-digit system proposed by Fédération Dentaire Internationale (international dental federation) (FDI) for both the deciduous and permanent teeth. Thus, as in the two-digit FDI system for the primary dentition, the first digit indicates the quadrant: 1 to 4 for the permanent dentition, and 5 to 8 for the primary dentition. The second digit indicates the tooth within a quadrant: 1 to 8 for the permanent teeth, and 1 to 5 for the primary teeth. For example, the permanent upper right central incisor is 11 (pronounced “one one,” not “eleven”). FDI system for permanent teeth Maxillary 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 Right Left 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Mandibular Examples: 23:(two-three) permanent maxillary left canine. 46: (four-six) permanent mandibular right first molar. 38: (three- eight) permanent mandibular left third molar 7  FDI system for deciduous teeth Maxillary teeth 55 54 53 52 51 61 62 63 64 65 Right Left 85 84 83 82 81 71 72 73 74 75 Mandibular teeth Example 52: ( five-two) Deciduous maxillary right lateral incisor 85: (eight-five) Deciduous mandibular right second molar 8