Tooth Anatomy and Numbering Systems PDF

Introduction second lecture Dr. Omyma Meabed Tooth anatomy Macro-anatomy Micro-anatomy Enamel Crown Dentin Root Pulp Cervical line cementum  crown Crown part of the tooth covered by enamel end by...

Introduction second lecture Dr. Omyma Meabed Tooth anatomy Macro-anatomy Micro-anatomy Enamel Crown Dentin Root Pulp Cervical line cementum  crown Crown part of the tooth covered by enamel end by incisal edge in anterior teeth or cusp tip in canine and posterior teeth Anatomical crown Clinical crown Part of tooth visible in Part of tooth oral cavity and not covered by enamel covered by gingiva fixed all over life except cases of attrition  Each tooth has a crown and root portion. The crown is covered with enamel the root portion is covered with cementum. The crown and root join at the cementoenamel junction (CEJ). Junction between crown and root called the cervical line  Tooth Microanatomy hard soft enamel The cementum pulp dentin tissue furnishes the blood and nerve supply to the tooth  Enamel: the hardest structure in the body 96% calcium white in color, cover the crown of the tooth Dentin: the main bulk of the tooth less calcified than enamel, yellowish in color, present in crown and root. Cementum: is the root coverage yellow in color meet enamel at CEJ PULP: Is the soft tooth structure, contain blood vessels and nerves consist of: ▪ coronal pulp: pulp chamber which begin by pulp horns and ends by orifices, present in crown ▪ Radicular pulp: Root canals: begin by orifices end by apical foramen, present in roots Junctions in the tooth Dentino-enamel junction Cemento-enamel junction Dention-cemental junction (tomes granular layer) (Pdl) periodontal ligament Is The ligament which attaches the tooth to alveolar bone ❖Periodontium: consist of Hard structure: alveolar bone, cementum Soft structure: gingiva, pdl Numbering systems There are several systems in use in the world, but only a few are considered here. Palmer system. the ADA “universal” numbering system American numbering system. FDI two-digit system universal system of notation for the primary dentition (American system) The universal system of notation for the primary dentition uses uppercase letters for each of the primary teeth: For the maxillary teeth, beginning with the right second molar, letters A through J, and for the mandibular teeth, letters K through T, beginning with the left mandibular second molar. The universal system notation for the entire primary dentition is as follows: Right A B C D E FGHIJ Left TSRQP ONMLK universal notation system for the permanent dentition In the universal notation system for the permanent dentition, the maxillary teeth are numbered from 1 through 16, beginning with the right third molar. Beginning with the mandibular left third molar, the teeth are numbered 17 through 32. Thus, the right maxillary first molar is designated as 3, the maxillary left central incisor as 9, and the right mandibular first molar as 30. The following universal notation designates the entire permanent dentition. 12345678 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 NOTE in universal system(American system) American system the number preceded by hash tag in permanent As # 32 is the lower third molar In deciduous small ( #d) #d 1 is the deciduous upper right second molar may be nombers from 1 to 20 or letters from a tO T Palmer notation system In this system the arches are divided into quadrants with the entire dentition being notated as follows: EDCBA ABCDE EDCBA ABCDE Thus, for a single tooth such as the maxillary right central incisor the designation is A. For the mandibular left central incisor, the notation is given as A. Palmer notation for the permanent dentition The Zsigmondy/Palmer notation for the permanent dentition is a four-quadrant symbolic system in which, beginning with the central incisors, the teeth are numbered 1 through 8 (or more) in each arch. For example, the right maxillary first molar is designated as 6 ,and the left mandibular central incisor as 1 The Palmer notation for the entire permanent dentition is as follows: 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 87654321 12345678 A two-digit system proposed by Fédération Dentaire Internationale (FDI) The FDI system of tooth notation is as follows. For the primary teeth: Upper Right 55 54 53 52 51 61 62 63 64 65 Upper Left 85 84 83 82 81 71 72 73 74 75 Lower Left Lower Right Numeral 5 indicates the maxillary right side, and 6 indicates the maxillary left side. The second number of the two-digit number is the tooth number for each side. The number 8 indicates the mandibular right side, and the number 7 indicates the mandibular left side. The second number of the two-digit system is the tooth number. Thus, for example the number 51 refers to the maxillary right central incisor  FDI For the permanent teeth: Upper Right Upper Left 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Lower Right Lower Left 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”)  TOOTH SURFACES The crowns of the incisors and canines have four surfaces and a ridge, and the crowns of the premolars and molars have five surfaces. The surfaces are named according to their positions and uses. In the incisors and canines, the surfaces toward the lips are called labial surfaces; in the premolars and molars, those facing the cheek are the buccal surfaces. When labial and buccal surfaces are spoken of collectively, they are called facial surfaces. All surfaces facing toward the tongue are called lingual surfaces. The surfaces of the premolars and molars that come in contact (occlusion) with those in the opposite jaw during the act of closure are called occlusal surfaces. These are called incisal surfaces with respect to incisors and canines.  The surfaces of the teeth facing toward adjoining teeth in the same dental arch are called proximal surfaces. The proximal surfaces may be called either mesial or distal. These terms have special reference to the position of the surface relative to the median line of the face. This line is drawn vertically through the center of the face, passing between the central incisors at their point of contact with each other in both the maxilla and the mandible. Those proximal surfaces that, following the curve of the arch, are faced toward the median line are called mesial surfaces, and those most distant from the median line are called distal surfaces.  Four teeth have mesial surfaces that contact each other: the maxillary and mandibular central incisors. In all other instances, the mesial surface of one tooth contacts the distal surface of its neighbor, except for the distal surfaces of third molars of permanent teeth and distal surfaces of second molars in deciduous teeth, which have no teeth distal to them. The area of the mesial or distal surface of a tooth that touches its neighbor in the arch is called the contact area. Division into thirds When the surfaces of the crown and root portions are divided into thirds, these thirds are named according to their location. Looking at the tooth from the labial or buccal aspect, the crown and root may be divided into thirds from the incisal or occlusal surface of the crown to the apex of the root.The crown is divided into an incisal or occlusal third, a middle third, and a cervical third. The root is divided into a cervical third, a middle third, and an apical third  The crown may be divided into thirds in three directions: inciso- or occlusocervically, mesiodistally, or labio- or buccolingually. Mesiodistally, it is divided into the mesial, middle, and distal thirds. Labio- or buccolingually it is divided into labial or buccal, middle, and lingual thirds. Each of the five surfaces of a crown may be so divided. There will be one middle third and two other thirds, which are named according to their location, for example, cervical, occlusal, mesial, lingual.  Line angels and point angels A line angle is formed by the junction of two surfaces and derives its name from the combination of the two surfaces that join. For instance, on an anterior tooth, the junction of the mesial and labial surfaces is called the mesiolabial line angle. The line angles of the anterior teeth are as follows: mesiolabial distolingual Distolabial labioincisal mesiolingual linguoincisal  Because the mesial and distal incisal angles of anterior teeth are rounded, mesioincisal line angles and distoincisal line angles are usually considered nonexistent. They are spoken of as mesial and distal incisal angles only. The line angles of the posterior teeth (are as follows: mesiobuccal distolingual bucco-occlusal distobuccal mesio-occlusal linguo-occlusal mesiolingual disto-occlusal  point angles A point angle is formed by the junction of three surfaces. The point angle also derives its name from the combination of the names of the surfaces forming it. For example, the junction of the mesial, buccal, and occlusal surfaces of a molar is called the mesiobucco- occlusal point angle. The point angles of the anterior teeth are : mesiolabioincisal mesiolinguoincisal distolabioincisal distolinguoincisal  The point angles of the posterior teeth are: mesiobucco-occlusal mesiolinguo-occlusal distobucco-occlusal distolinguo-occlusal Thank you