Dental Anatomy Lecture 2 PDF

Lecture 2 12 Dec. Al-Noor University College /Dentistry Numbering Systems 1st Year...

Lecture 2 12 Dec. Al-Noor University College /Dentistry Numbering Systems 1st Year Dental Anatomy By: Assist. Lect. Alaa Hussein Ali 2023-2024  Tooth numbering systems Introduction: Documenting patient treatment with accurate dental records is an important step in any dental practice, that’s why notation systems are used world wide. Otherwise, for each tooth being charted, one must record the dentition, arch, side and type For example, describing a permanent maxillary right second molar requires five Alaa H. Ali words, but it can be simplified by using Numbering (notation) systems 2  Tooth numbering systems There are 3 numbering systems used for teeth notation: Palmer tooth notation system. The international numbering system Universal numbering system Alaa H. Ali 3  Palmer tooth notation system This symbolic system is most frequently used among orthodontists and other practitioners in United Kingdom. It divides the upper and lower arch into four quadrants. It utilizes simple brackets to represent the four quadrants of dentitions as if you are facing the patient: Alaa H. Ali 4  Universal numbering system Central incisor Lateral incisor Canine First molar Second molar Alaa H. Ali 5  Palmer tooth notation system Upper right Upper left ┘ Represents upper right quadrant └ Represents upper left quadrant ┐ Represents lower right quadrant ┌ Represents lower left quadrant Alaa H. Ali lower right lower left 6  Palmer tooth notation system In deciduous teeth the uppercase alphabetic letters represents the primary teeth in each quadrant starting from the central incisor. The palmer notation system for entire primary dentition is : E D C B A A B C D E Alaa H. Ali E D C B A A B C D E 7  Palmer tooth notation system Thus for the primary maxillary right central incisor the designation is A and for the primary mandibular left central incisor is A Q: using palmer notation system , identify the symbol that represents the tooth in black circle C Alaa H. Ali 8  Palmer tooth notation system The permanent dentition are numbered from 1-8 in each quadrant from midline starting from central incisor. The palmer notation system for entire permanent dentition is : 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Alaa H. Ali 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9  Palmer tooth notation system Thus for the permanent maxillary right central incisor the designation is 1 and for the permanent mandibular left central incisor is 1 Q: using palmer notation system , identify the symbol that represents the tooth in black circle 5 Alaa H. Ali 10  Universal numbering system This system was adopted by the American Dental Association n 1975. Basically, the Universal Numbering System uses numbers 1 through 32 for the 32 teeth in the permanent dentition, the maxillary teeth are numbered from 1 to 16 beginning with the maxillary right third molar, while the mandibular teeth are numbered from 17 to 32 starting from mandibular left third molar. Thus the permanent maxillary right central incisor is Alaa H. Ali designated as 8, the permanent mandibular left second molar is notated as 18. 11  Universal numbering system 8 9 7 10 6 11 Upper right 5 12 Upper left Clockwise 4 13 3 14 2 15 1 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 17 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 31 18 Alaa H. Ali 30 19 lower right 29 20 lower left 28 21 27 22 26 23 25 24 12  Universal numbering system Basically, the Universal Numbering System uses uppercase letters from A to T for the 20 teeth in the primary dentition, the maxillary teeth are numbered from A to J beginning with the maxillary right second molar, while the mandibular teeth are numbered from K to T starting from mandibular left second molar. Thus the letter E represents the primary maxillary right central incisor , the letter K represents the primary mandibular Alaa H. Ali left second molar is notated as. 13  Universal numbering system E F D G C H B I A J A B C D E F G H I J T S R Q P O N M L K T K Alaa H. Ali S L R M Q N P O 14  The international numbering system The world dental federation notation system or Federation Dentaire Internationale (FDI) uses two digits for teeth numbering for both primary and permanent dentition that’s why its also known as two-digit notation system. The first number always denotes the dentition, arch and side. The second number denotes the tooth position (1 to 8 for permanent and 1 to 5 for deciduous teeth starting from midline and then backward). UR 1 2 UL UR 5 6 UL LL 4 3 LR LL 8 7 LR Alaa H. Ali For permanent dentition For deciduous dentition 15  The international numbering system The first number of the two numbers used in this system is designated as follows: 1= Permanent dentition, maxillary, right quadrant 2= Permanent dentition, maxillary, left quadrant 3= Permanent dentition, mandibular, left quadrant 4= Permanent dentition, mandibular, right quadrant 5= Deciduous dentition, maxillary, right quadrant 6= Deciduous dentition, maxillary, left quadrant 7= Deciduous dentition, mandibular, left quadrant Alaa H. Ali 8= Deciduous dentition, mandibular, right quadrant 16  The international numbering system For permanent dentition 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 Alaa H. Ali For example the permanent maxillary right first molar is 16 (pronounced as “one six” not “sixteen”) 17  The international numbering system For deciduous dentition 55 54 53 52 51 61 62 63 64 65 85 84 83 82 81 71 72 73 74 75 Alaa H. Ali For example the deciduous maxillary right first molar is 54 (pronounced as “five four” not “fifty four”) 18  Crown and root Each tooth has crown and root portion. The root crown is covered with enamel and the root is covered with cementum. The crown and root join at junction which is called cementoenamel neck junction (CEJ). This junction also called cervical line, which surrounds the neck (cervix) of the crown tooth. The main bulk of tooth is composed of dentin, which is clear in cross section of the Alaa H. Ali tooth. External parts of the tooth 19  Crown and root Alaa H. Ali Cross section of the tooth 20  Tissues of the tooth the four tissues of the tooth are enamel, cementum, dentin and pulp. The first three are known as hard tissues while the pulp is the soft tissue of the tooth. The pulp is rich in blood and nerve supply. The enamel is the hardest tissue in the body. The Alaa H. Ali junction between the enamel and dentin is called dentinoenamel junction (DEJ). Cross section of the tooth 21  The crown of the tooth may Incisal edge have incisal edge or ridge One cusp as in central and lateral Two cusps incisor, one cusp as in More than canines, two cusps as in two cusps premolars or more than two cusps as in molars. The Alaa H. Ali incisal ridge and cusps form the cutting surfaces of the tooth. 22  The crown portion is never covered with bone after its fully erupted inside oral cavity but its partly covered at the cervical in young adult with soft tissue called gingiva or gingival tissue or gum. Alaa H. Ali 23  Crown and root Anatomical crown is that portion of the tooth that is covered by enamel. Clinical crown is that portion of the tooth that is visible in the mouth. In healthy person, the anatomical crown is longer than the clinical crown. Alaa H. Ali 24  Crown and root The anterior teeth consist of incisors and canines. The posterior teeth consist of premolars and molars Single root: in all anterior teeth, mandibular premolars and maxillary second premolar. Two roots with bifurcation: in mandibular molars and maxillary first premolar. Three roots with trifurcation: in maxillary molars Alaa H. Ali Single-rooted Multi-rooted 25  The root portion of the tooth is firmly fixed in the bony process of jaw bone so that each tooth is held in its position relative to others in dental arch. The portion of the jaw that serves as support for the tooth is called alveolar process. The bone of Alaa H. Ali tooth socket is called alveolus (plural, alveoli) 26  Pulp cavity The cross section of the tooth displays the pulp chamber and pulp canal, which normally contain the pulp tissue. The pulp chamber is in the crown and pulp canal is in the root. The spaces are continuous with each other and are spoken Alaa H. Ali collectively as the pulp cavity 27  Pulp cavity The coronal pulp consists of Pulp chamber Pulp horn The radicular pulp consists of Pulp canal Apical foramen Alaa H. Ali 28  Surfaces and ridges the crowns of incisors and canines contain 4 surfaces and 1. Facial surface a ridge. The crowns of premolars and molars have 5 2. Lingual or surfaces. The surfaces are named according to their palatal surface position and use. 3. Mesial 4. Distal 5. Occlusal or incisal (functioning) Alaa H. Ali Incisors and canine Premolar and molar 29  Facial surface The facial surface of the tooth is toward the face. In incisors and canines, the facial surfaces that are toward the lip are called the labial surfaces. In premolars and molars, the surfaces that are facing the cheek is called the buccal surfaces. The buccal and labial surfaces when are spoken collectively called the facial surfaces. Alaa H. Ali Labial surfaces buccal surfaces 30  Lingual surface Lingual surfaces are the surfaces of maxillary and mandibular teeth nearest to the tongue. In maxillary teeth, the lingual surface can be called palatal surface due to its proximity to palate Alaa H. Ali In mandible In maxilla 31  Functioning surfaces (biting and chewing) The surfaces of premolars and molars that come in contact (occlusion) with those of opposing jaw during act of closure are called occlusal surfaces. In anterior teeth they are called incisal surfaces (incisors and Alaa H. Ali canines) 32  Proximal surfaces The proximal surfaces are the sides of tooth next to an adjacent tooth. Depending on whether the proximal tooth surface faces toward the arch midline between the central incisors or away from the midline Alaa H. Ali 33  Proximal surfaces Mesial surface: Facing towards the midline Distal surface: facing away from the midline Alaa H. Ali 34  Proximal surfaces Four teeth have mesial surfaces that are in contact with each other: maxillary and mandibular central incisor. In all other teeth the mesial surface of one tooth is in contact with the distal surface of the adjacent tooth except for the distal surface of permanent third molar and primary second molar that have no tooth distal to them. Alaa H. Ali 35  Proximal surfaces The area of mesial and distal surface of the tooth that touches the adjacent in the arch is called contact area Alaa H. Ali Contact area 36  Line angle point angles Line angle is formed by the junction of two surfaces and its name is derived from both surfaces. Point angle is formed by the junction of three surfaces and its name is derived from these three surfaces Alaa H. Ali 37  Line angles of anterior teeth Alaa H. Ali 6 line angles 38  Line angles of posterior teeth Mesio-occlusal line angle Mesio-buccal line angle Mesio-lingual line angle Disto-occlusal line angle 8 line angles Disto-buccal line angle Disto-lingual line angle Alaa H. Ali Bucco-occlusal line angle Linguo-occlusal line angle 39  4 Point angles of anterior and posterior teeth 4 point angles for anterior teeth Distolinguo incisal point angle Distolabio incisal point angle Mesiolinguo incisal point angle Mesiolabio incisal point angle 4 point angles for posterior teeth Distolinguo occlusal point angle Distobucco occlusal point angle Alaa H. Ali Mesiolinguo occlusal point angle Mesiobucco occlusal point angle 40  Division into thirds For purposes of description, the crown and roots are divided into thirds and these thirds are named according to their location. When looking at the crown and root from labial or buccal surface we can see that the crown and root are divided from the incisal or occlusal surface of the crown to the apex of the root. The crown is divided into occlusal or incisal third, middle third and cervical third. The root is divided into cervical third, middle third and apical third. Alaa H. Ali 41  Division into thirds The crown may be divided in three directions: Inciso- or occlusocervically Mesiodistally into (mesial third, middle third, distal third) Labio- or buccolingually (labial or buccal third, middle third, lingual third) Alaa H. Ali 2  References Woelfel’s Dental Anatomy It’s Revelance to Dentistry (theoretical) Wheeler’s Atlas of Tooth Form (practical) Alaa H. Ali Thank you