Lecture 1 _ (2_2_2016) Introduction to dental anatomy .ppt.pptx

Introduction to Dental Anatomy

1. Introduction to Dental Anatomy Dental Anatomy Dr. Firas Alsoleihat, BDS, PhD Department of Conservative Dentistry

2. Introduction Human dentition is diphyodont 2 sets of dentitions Primary/deciduous 20 teeth in total Incisors/canines/molars Smaller size Secondary/permanent 32 teeth in total Incisors/canines/premolars/molars Bigger size

3. Deciduous & permanent dentitions Why do we have to have 2 sets of teeth?

4. Why 2 sets of dentitions? The jaws have to accommodate the increased number of permanent teeth and their bigger size

5. Dental formula I for incisors C for Canines PM for premolars M for molars Deciduous teeth are indicated by the letter D before the initial

6. Human dental formula Deciduous teeth DI 2/2 DC 1/1 DM 2/2 = 10 Permanent teeth I 2/2 C 1/1 PM 2/2 M 3/3 = 16 The numbers following the letter refer to the number of teeth of each type in the upper then the lower dentition for one side only

7. Quadrants Tooth-bearing region of the jaw can be divided into 4 quadrants Right maxillary (1 or 5) Left maxillary (2 or 6) Left mandibular (3 or 7) Right mandibular (4 or 8) Quadrants in permanent dentition have the numbers 1 - 4 and in deciduous have the numbers 5 - 8

8. Quadrants 1 or 5 2 or 6 4 or 8 3 or 7

9. Teeth order Each tooth in a quadrant takes a letter (A – E for deciduous) or a number (1 – 8 for permanent) indicating its order when counting from the midline 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 E D C B A E D C B A A B C D E A B C D E

10. Dental nomenclature By words Set Deciduous or permanent Jaw Maxillary or mandibular Class Incisor/canine/premolar/molar Order within a class Central or lateral First/second/third Side Right or left By numbers, letters and/or symbols Palmer notation system Universal numbering system FDI numbering system

11. Palmer/Zsigmondy notation system American Dental Association in 1947 Tooth is represented by a number 1 – 8 (permanent) or a letter A – E (deciduous) Two lines; indicates which quadrant the tooth belongs to a horizontal representing the occlusal plane and a vertical representing the midline Examples: Maxillary right central incisor Mandibular left second deciduous molar 1 E E D C B A E D C B A A B C D E A B C D E 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

12. Universal numbering system Palmer – difficulty in keyboard typing ADA adopted the universal system in 1968 Uppercase letters for deciduous teeth Consecutive from A to T Following a clockwise order from maxillary right second molar to mandibular right second molar Numbers for permanent teeth Consecutive from 1 to 32 Following a clockwise order from maxillary right third molar to mandibular right third molar A B C D E T S R Q P O N M L K F G H I J 1 2 3 4 5 6 7 8 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 9 10 11 12 13 14 15 16

13. FDI numbering system Proposed by FDI & adopted by WHO Each tooth is allocated a two-digit number; the left designates the quadrant and the right designates the tooth order Examples Mandibular right permanent canine 43 Maxillary left deciduous lateral incisor 62 55 54 53 52 51 85 84 83 82 81 71 72 73 74 75 61 62 63 64 65 18 17 16 15 14 13 12 11 48 47 46 45 44 43 42 41 21 22 23 24 25 26 27 28 31 32 33 34 35 36 37 38

14. Types of dentitions: Diphyodont. Most mammals--humans included--typically develope and erupt into their jaws two generations of teeth. The term literally means "two generations of teeth." Monophyodont. Some mammals--such as the manatee, seals, and walruses have only a single generation of teeth.

15. Polyphyodont. Most reptiles and fishes develope a lifetime of generations of successional teeth--Such teeth have a brief functional life and are anatomically simple in design. Homodont. In many vertebrates, all of the teeth in the jaw are alike. They differ from each other only in size. The alligator is an example of homodontism.

16. Heterodont. Most mammals, humans included, develope distinctive classes of teeth that are regionally specialized. We will discuss classes of teeth in the next unit. Anodontia is the developmental absence of teeth. Among mammals, the whalebone whale and the anteater are toothless; their ancestors had teeth. In humans, anodontia is a pathological condition. Partial anodontia is one or a few teeth missing.