Dental Anatomy Lecture -2 PDF

‫جامعة البيان– قسم طب االسنان‬ ‫المرحلة االولى‬ Dental Anatomy Dr.Ali Ahmed Lecture -2- MSC. conserv...

‫جامعة البيان– قسم طب االسنان‬ ‫المرحلة االولى‬ Dental Anatomy Dr.Ali Ahmed Lecture -2- MSC. conservative Numbering Systems 1. Universal notation system: A. Permanent Teeth: 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: #11: Permanent Maxillary Left Canine. #29: Permanent Mandibular Right Second Premolar. #8: Permanent Maxillary Right Central Incisor. 1 B. Deciduous Teeth: Maxillary Right A B C D E F G H I J Left T S R Q P O N M L K Mandibular Examples: #B: Deciduous Maxillary Right First Molar #O: Deciduous Mandibular Left Central Incisor #D: Deciduous Maxillary Right Lateral Incisor 2. Palmer notation system: A. Permanent Teeth: 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 2 Examples: 6 Permanent Maxillary Right First Molar 3 Permanent Mandibular Left Canine 8 Permanent Maxillary Left Third Molar B. Deciduous Teeth: Maxillary Right E D C B A A B C D E Left E D C B A A B C D E Mandibular Examples: B Deciduous Mandibular Left Lateral Incisor E Deciduous Maxillary Right Second Molar C Deciduous Mandibular Right Canine 3 Crown and Root Each tooth has a crown and root. The crown is covered with enamel. The root is covered with cementum and they join at the cemento-enamel junction (CEJ) or cervical line. The enamel, cementum and dentin are the hard tissues of the tooth. The major bulk of the tooth is dentin. Dental pulp: is the soft tissue of the tooth and present in the pulp chamber and pulp canal. Pulp chamber: is the part of dental pulp in the crown. Pulp canal: is the part of dental pulp in the root. The pulp chamber is continuous with the pulp canal and collectively called as the "pulp cavity". 4  Anatomical crown: is the portion of the tooth which is covered by enamel. Clinical crown: is the portion of the tooth which is visible in the mouth. In healthy person, the anatomical crown is larger than the clinical crown. The number of roots: 1. Single root: in all anterior teeth, mandibular premolars and maxillary second premolar. 2. Two roots with bifurcation: in mandibular molars and maxillary first premolar. 3. Three roots with trifurcation: in maxillary molars. Surfaces and Ridges The crowns of incisors and canines have 4 surfaces and a ridge and the crowns of the premolars and molars have 5 surfaces. The surfaces are: 1. Labial surface: is the surface which is towards the lip in incisors and canines (= in anterior teeth). 2. Buccal surface: is the surface which is towards the cheek in premolars and molars (= in posterior teeth). The labial and buccal surfaces could be termed as the "Facial" surfaces. 5  3. Lingual surface: is the surface which is facing the tongue (all teeth). 4. Occlusal surface: is the surface of the posterior teeth coming in contact with the teeth in the opposite jaw during closing the mouth. In anterior teeth, this surface is called " Incisal ridge ". 5. Proximal surface: is the surface of the tooth facing towards adjacent teeth in the same dental arch. a. Mesial surface: is the surface which is facing towards the median line. b. Distal surface: is the surface which is facing away from the median line. All teeth have their mesial surfaces touching the distal surfaces of the adjacent tooth except the maxillary and mandibular central incisors (both permanent and deciduous). The area of the mesial and distal surface that touch its neighbor in the arch is called the "contact area". 6 Division of the crown into thirds: For description, the crown and the root are divided into thirds according to the position of the surface. Line angle: it is formed by the junction of two surfaces and gets its name from these surfaces. Example: mesio-labial line angle. 7  Point angle: it is formed by the junction of 3 surfaces and gets its name from these surfaces. Example: mesio-linguo-incisal point angle. D M M I I E S D S T D I A L A Apical L E L Middle Cervical Cervical Cervical Middle Incisal Apical 8